JBR 2015-2 by office

WETTEREN 1

P 702083

Volume 98 Page 63-103 March-April

Bimonthly

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2015

DIAGNOSTIC AND INTERVENTIONAL IMAGING, RELATED IMAGING SCIENCES, AND CONTINUING EDUCATION

PUBLISHED BY THE BELGIAN SOCIETY OF RADIOLOGY (BSR)

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Contrast for life The Belgian radiology journal wishes to thank Guerbet for their continuous support

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Editor-in-Chief: J. Pringot Consulting Co-Editor: Ph. Grenier (Paris) Managing Editor: P. Seynaeve Webmaster: P. Vanhoenacker

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Editorial Board: F. Avni, L. Breysem, N. Buls, B. Coulier, B. Daenen, E. Danse, H. Degryse, P. Demaerel, B. Ghaye, J. Gielen, P. Habibollahi, N. Hottat, M. Laureys, F. Lecouvet, M. Lemmerling, B. Lubicz, J.F. Monville, T. Mulkens, A. Nchimi, J.F. Nisolle, B. Op de Beeck, R. Oyen, S. Pans, V.P. Parashar (USA), P. Parizel, P. Peene, H. Rigauts, N. Sadeghi, P. Simoni, S. Sintzoff Jr, A. Snoeckx, J. Struyven, H. Thierens, P. Van Dyck, F. Vanhoenacker, Ph. Van Hover, J. Verschakelen, K. Verstraete.

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Treasurer: P. Vanhoenacker BVAS/ABSYM-Representative: O. Ghekiere Board Members: P. Aerts, B. De Foer, J.-F. De Wispelaere, M. Grieten, H. Jaspers, J.-P. Joris, R. Oyen, P. Seynaeve, G. Souverijns, D. Tack, B. Vande Berg, G. Vandenbosch, Ch. Van de Velde

Scientific Committee Members: R. Achten, D. Bielen, B. De Foer, Y. Lefebvre, M. Lemort, J. Pringot, R. Salgado, D. Tack, J. Ver schakelen

President: R. Oyen Secretaries: J. de Mey, B. Vande Berg

Sections of the Belgian Radiological Society (BSR): Abdominal and digestive imaging Bone and joints Breast imaging Cardiac imaging Cardiovascular and interventional radiology Chest radiology Head and neck radiology Neuroradiology Pediatric radiology

B. Op de Beeck, E. Danse J.F. Nisolle, M. Shahabpour M. Mortier, S. Murgo N. Mollet, A. Nchimi S. Heye, D. Henroteaux B. Ghaye, W. De Wever J. Widelec, R. Hermans M. Lemmerling, L. Tshibanda B. Desprechins, L. Breysem

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JBR-BTR  98/2  2015 Journal Belge de  Belgisch Tijdschrift voor  RADIOLOGIE

Founded in 1907 A bimonthly journal devoted to diagnostic and interventional imaging, related imaging sciences, and continuing education published by the Belgian Society of Radiology Contents Can diffusion weighted MRI differentiate between inflammatory-infectious and malignant pleural effusions? O. Karatag, T. Alar, S. Kosar, G. Ocakoglu, Y. Yildiz, E. Gedik, U. Gonlugur, H. Ozdemir . . . . . . . . . . . . . . . . . . . 63 Assessment of normal values of fractional anisotropy and mean diffusivity of mobile lumbar spine roots by diffuson tensor MRI: comparison between 1.5 and 3T. J. Lincot, J.P. Laissy, A. Hess, V. Balbi, E. Schouman-Claeys, A. Cotton, B. Dallaudière. . . . . . . . . . . . . . . . . . . . 68 Lunotriquetral coalition, a normal variant that may rarely cause ulnar sided wrist pain M. Mespreuves, F. Vanhoenacker, K. Verstraete. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 A rare malignant hepatic tumor of childhood: transitional liver cell tumor revisited O. H. Nursun, O. Berna, S. Tutku, T. Beril, H. Mithat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Erdheim Chester disease presented isolated breast and axillary involvement I. Basara, E. Yavuz, P. Balci, E. B. Tuna, I. Sari . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Cysts in a Brunner’s gland hamartoma: a clue to diagnosis Y-K. Fan, Y-P. Liu, Y-L. Lin, W-K. Su. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Bronchial lipoma : an unusual cause of pleural empyema S. Lanotte, P. Mailleux, R. Frognier, O. Van Cutsem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 IMAGES IN CLINICAL RADIOLOGY ‘Backfill’ of the sacroiliac joint space in spondlyloarthritis F. Laloo, N. Herregods, H. Cypers, K. Verstraete, L. Jans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Rare presentation of Langerhans cell histiocytosis A. Gieraerts, P. Vandaele, R. Schildermans, L. Daveloose, K. Ramboer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 A glomus tumor P. Kulczycka, B. Dallaudière, O. Barbier, B. Vande Berg, A. Larbi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Dirty shadowing in emphysematous pyelonephritis A. Eeckhoudt, F.M. Vanhoenacker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 MDCT findings of polymicrobial descending necrotizing mediastinitis C. Karanikas, P. Lampropoulou, D. Karakiklas, C.S. Baltas, A. Demertzis, C. Drosos. . . . . . . . . . . . . . . . . . . . . . . 95 Tentorium hypoplasia with partial occipital lobe herniation E. Thomaere, S. Schepers, B. Termote, R. Vanwyck, G. Souverijns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 320-row-detector CT angiography findings of a case with myocardial bridging in the three main coronary arteries. S. Akay, U. Bozlar, Dermikol Sait, M. Tasar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 The single right coronary artery. E. Christiaanse, D. Verdries, K. Tanaka, S. Carlier, J. de Mey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Symptomatic coracoclavicular joint S. Lanotte, S. Van Den Broeck. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 LETTER TO THE EDITOR A case of symptomatic mesenteric panniculitis presenting with unusual positive FDG PET/CT nodular components: an atypical imaging strategy with histopathologic correlation. B. Coulier, I. Bueres, F.C Deprez, F. Richelle, R. Rubay, I. Gielen, C. Fervaille . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Charter Young Radiologists section (YRS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

u The terms used for indexation of subjects were developed by the Radiological Society of North America (RSNA) over a period of years. Their use here is by permission of the RSNA. The terms may not be used in any other index, print or electronic, except by specific permission of RSNA. uu Indexed in Index Medicus and in Zentralblatt Radiologie. Evaluated for Medline User, EMBASE and CANCERNET. Abstracted in Excerpta Medica Journals.

JBR–BTR, 2015, 98: 63-67.

CAN DIFFUSION WEIGHTED MAGNETIC RESONANCE IMAGING BETWEEN INFLAMMATORY-INFECTIOUS AND DIFFERENTIATE MALIGNANT PLEURAL EFFUSIONS? O. Karatag1, T. Alar2, S. Kosar 1, G. Ocakoglu4, Y. Yildiz1, E. Gedik2, U. Gonlugur3, H. Ozdemir1 Aim: To assess exudative pleural effusions with diffusion-weighted magnetic resonance imaging (DW-MRI) in order to determine non-invasive differentiation criteria for inflammatory-infectious and malignant effusions. Materials and methods: Thirty-two patients with pleural effusions underwent DW-MRI with 4 different b values (10, 500, 750 and 1000 s/mm2). ADC maps were generated automatically. Signal intensity and ADC values were measured. Following MRI, pleural fluid of 10-15 ml was obtained and analyzed. AUC values were compared for different diffusion levels of ADC and SI measurements. The relationship between ADC values and pleural effusion LDH and total protein levels was examined. Results: The cut-off values obtained from signal intensity and ADC measurements to differentiate exudates with malignant pathology were not found to be statistically significant. In the inflammatory-infectious group, a significant negative correlation was observed between ADC values and pleural fluid LDH measurements in all b values. In the malignant group, a significant positive correlation was observed between ADC values and pleural fluid total protein measurements in b values of 500 and 1000. Conclusion: Infectious/inflammatory and malignant effusions overlap strongly and cannot therefore be differentiated using DW MRI. Key-words: Lung, effusion – Lung, MR – Magnetic resonance (MR), diffusion study.

Pleural effusions are usually diagnosed on the basis of clinical, radiological and pathological findings. The main types of pleural effusions are defined as transudate and exudate according to their biochemical features, mostly separated by Light’s criteria (measurement of lactate dehydrogenase (LDH) and protein concentrations in both pleural fluid and serum) (1). However, transudate and exudate classification of pleural effusions with Light’s criteria can occasionally fail, especially in cases that have undergone diuresis (2, 3). If the pleural effusion is definitely identified as a transudate, no further diagnostic procedures are needed (1, 4). If it is found to be an exudate, additional diagnostic procedures such as pleural fluid cytopathology, Gram staining, culture, etc. are necessary (2, 5). Differentiation of transudate and exudate before thoracentesis therefore becomes mandatory in order to avoid unnecessary interventional procedures and their potential complications. Exudative effusions can have benign (bacterial pneumonia, viral infection, pulmonary embolism, etc.) and malignant (lung cancer, breast cancer, lymphoma, etc.) causes. We believe that there is a need for an

lternative non-invasive diagnostic a method for inflammatory-infectious and malignant differentiation of exudative pleural effusions. In this study, we aimed to assess exudative pleural effusions with diffusion-weighted magnetic resonance imaging (DW-MRI) in order to determine differentiation criteria for inflammatory-infectious and malignant processes. Materials and methods This prospective study was approved by the institutional review board and written informed consent was provided by all subjects. A total of 43 patients who presented to Canakkale Onsekiz Mart University Research and Application Hospital between January 2011 and December 2012 with various symptoms and in whom the chest x-ray, ultrasound (US) and computed tomography (CT) examinations revealed pleural effusion were included in the study. The study inclusion and exclusion criteria were as follows: 1. The amount of pleural effusions had to be adequate for accurate measurement of apparent diffu-

From: Department of 1. Radiology, 2. Thoracic Surgery, 3. Chest Diseases, Canakkale Onsekiz Mart University, School of Medicine, 4. Dpt of Biostatistics, Uludag University, Shool of Medicine, Turkey. Address for correspondence: Dr O. Karatag, MD, Canakkale Onsekiz Mart University School of Medicine, 17100 Canakkale, Turkey. E-mail: okaratag17@gmail.com

sion coefficient (ADC) without being affected by the partial volume effect and motion artifact. The thickness of the pleural effusions detected on chest x-ray was evaluated by US. The thickness of the pleural effusions detected on CT examination was measured. Pleural effusions less than 1 cm in thickness were excluded from the study. 2. Cases where pleural effusion aspiration and analysis were planned were included in the study. 3. Cases who were severely dyspneic, and would not be able to lie in the supine position during the entire diffusion-weighted imaging (DWI) examination or had claustrophobia were excluded from the study. All patients were examined with a 1.5 T MRI scanner (GE Signa, HDxt). The maximum gradient power of this system was 30 mT/m and the slew rate was 150 mT/m/msec. T1and T2-weighted conventional images on the axial plane were obtained to evaluate the anatomical detail better and to determine the pleural effusion localization and signal characteristics. Subsequently, 4 series of single-shot spin-echo echo-planar (SS-SE-EPI) diffusionweighted (DW) images (TR 4050 ms, TE 78.2 ms, field of view 38 × 30.4 cm2, matrix size 128 × 160, slice thickness 8 mm, interslice gap 2 mm) were obtained using 4 different b values (10, 500, 750 and 1000 s/mm2) on the axial plane.

JBR–BTR, 2015, 98 (2)

statistical power: 0.80). Statistical significance was set at p < 0.05. MedCalc v.12.7.5.0 were used for statistical analyses. Results

Fig. 1. — A fifty-six year old male diagnosed with para pneumonic effusion. Axial T2W image shows a 53 mm wide left pleural effusion with high signal intensity (A). Three different ROI placement for SI measurement on DW images obtained with a b-value of 10 (B), 500 (C), 750 (D) and 1000 (E) and ADC measurement on corresponding ADC map (F) are shown.

nidirectional diffusion gradients U (readout direction; right-left, R-L) were applied. ADC maps were generated automatically from the DW images obtained. Quantitative analyses were performed on a dedicated workstation (General Electric, Advantage workstation, 4.4 edition). An average of 203 mm2 elliptical or spherical regions of interest (ROI) were placed in 3 different locations of the pleural effusion in order to measure signal intensity values (SI) on DW images and the ADC values on ADC maps (Fig. 1). Both values were averaged separately and the resulting values were considered the final quantitative values. ROI of the same dimensions was used for each b factor. In order not to be affected from possible magnetic susceptibility and motion artifacts, we stayed away from the lung-pleural fluid sections, diaphragmatic areas and the regions where the heart and major vascular structures were present during ROI placement and measurement, placing the ROI’s at the most homogeneous segments possible of the pleural effusions.

Thoracentesis was performed by a thoracic surgeon after MRI. Pleural fluid of 10-15 ml was obtained and analyzed. The pleural fluid was primarily classified as transudate or exudate according to Light’s criteria (6). The pleural fluid sample was then microbiologically and pathologically analyzed. Whether the fluid was of benign or malignant origin was determined. Statistics Data was presented as median (minimum-maximum) values. ROC (receiver operating characteristic) analysis was used for obtaining cutoff values for inflammatory-infectious/malignant differentiation and comparing the AUC (Area under the curve) values for different diffusion levels of ADC and SI measurements. The relationship between ADC values and pleural effusion LDH and total protein levels was examined by performing correlation analysis and Spearman correlation coefficient was computed. The minimum sample size required for each group was determined at least n = 30 (desired

Seven patients could not keep still during MR imaging and the obtained images were of poor quality, so they were excluded from the study. Of the remaining 36 patients, 4 patients who were found to have transudative pleural effusions were also excluded. Finally we included 6 females and 26 males for a total of 32 patients. The median age was 63 (min: 26, max: 88) years. The causes for exudative pleural effusion are given in table I. We evaluated DWI in terms of inflammatory-infectious/malignant differentiation of exudative pleural effusions and found that the SI and ADC values measured with different b values were not appropriate for inflammatory-infectious/malignant differentiation of the exudates. After ROC Analysis, the cut-off values obtained from SI and ADC measurements to differentiate exudates with malignant pathology were not found to be statistically significant. No difference was found between ROC curves obtained with different b values for SI and ADC. There was no significant difference between the AUC in the analyses performed for each b value. The p value was > 0.05 for all analyses in both tables (Table II). When inflammatory-infectious and malignant groups are analysed separately, in the former group, a significant negative correlation was observed between ADC values and pleural fluid LDH measurements in all b values of 10 (r = –0.46, p = 0.021), 500 (r = –0.76, p < 0.001), 750 (r = –0.70, p < 0.001), and 1000 (r = –0.59, p = 0.002) (Fig. 2) and no statistically significant correlation was found between ADC values and pleural fluid total protein measurements. In the malignant group, a significant positive correlation was observed between ADC values and pleural fluid total protein measurements in b values of 500 (r = 0.67, p = 0.012) and 750 (r = 0.73, p = 0.005) (Fig. 3) and no statistically significant correlation was found between ADC values and pleural fluid LDH measurements. The correlation analysis results of ADC values with LDH and total protein levels of pleural effusion in both groups are given in table III.

DIFFUSION WEIGHTED MRI OF PLEURAL EFFUSIONS — KARATAG et al

Table I. — Causes of pleural effusions. Etiology Benign (n = 19) Parapneumonic effusion Empyema Tuberculosis Sarcoidosis Ruptured hydatid cyst Malignant (n = 13) Non-small cell lung carcinoma Small cell lung carcinoma Adenocarcinoma Malignant mesothelioma Deciduoid mesothelioma Breast carcinoma metastasis Non-specific primary Total

12 4 1 1 1 3 2 2 2 1 1 2

n = 32

Fig. 2. — Fifty-five (A, B and C) and seventy-four (D) year old male patients diagnosed with empyema. The former patient who has higher pleural effusion LDH level (2388 U/L), demonstrates lower ADC measurement (0.002757) compared with the latter patient who has a LDH level of 151 U/L and mean ADC measurement of 0.004057.

Table II. — ROC analysis results of SI and ADC values calculated for each b factor for differentiation of inflammatory-infectious / malignant exudative pleural effusions. SI AUC b = 10 0.60 b = 500 0.55 b = 750 0.54 b = 1000 0.54 Comparison of ROC curves between b factor levels DBA b = 10-b = 500 0.06 b = 10-b = 750 0.07 b = 10-b = 1000 0.07 b = 500-b = 750 0.01 b = 500-b = 1000 0.01 b = 750-b = 1000 0

SE 0.11 0.10 0.10 0.10

p-value 0.319 0.625 0.710 0.712

SE 0.10 0.11 0.11 0.05 0.04 0.02

p-value 0.580 0.530 0.534 0.812 0.800 1.00

ADC AUC b = 10 0.65 b = 500 0.55 b = 750 0.55 Comparison of ROC curves between b factor levels DBA b = 10-b = 500 0.10 b = 10-b = 750 0.10 b = 10-b = 1000 0.05 b = 500-b = 750 0.01 b = 500-b = 1000 0.05 b = 750-b = 1000 0.05

SE 0.10 0.11 0.11

p-value 0.131 0.667 0.675

SE 0.13 0.13 0.15 0.07 0.11 0.09

p-value 0.425 0.411 0.729 0.977 0.662 0.577

AUC: Area under ROC curve, DBA: Difference between ROC areas.

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Table III. — The correlation analysis between ADC values and pleural fluid LDH and total protein levels in all b values. ADC value LDH U/L TOTAL PROTEIN

r p r p

b = 10 -0,46 0,021* -0,05 0,817

Benign b = 500 b = 750 -0,76 -0,70 <0,001* <0,001* -0,09 -0,13 0,678 0,532

b = 1000 -0,59 0,002* 0,13 0,551

r p r p

b = 10 -0,02 0,943 0,13 0,674

Malignant b = 500 b = 750 -0,21 -0,25 0,494 0,409 0,67 0,73 0,012* 0,005*

b = 1000 -0,34 0,263 0,28 0,353

*Significant correlation.

Fig. 3. — Fifty-nine (A, B and C) and seventy-nine (D) year-old male patients diagnosed with non-small cell lung carcinoma. The former patient who has higher pleural effusion total protein level (7 gr/dl), demonstrates higher ADC measurement (0.004913) compared with the latter patient who has a total protein level of 2.5 gr/dl and mean ADC measurement of 0.00197.

Discussion DWI is an MR imaging method providing tissue analysis based on the diffusion of water molecules inside the tissue (7). Carr and Purcell were the first to report that the MRI signal is affected by the diffusion of water molecules in 1954 (8). DWI was first used to determine acute cerebral ischemia and then in other body regions in recent years thanks to developing technologies (7, 9, 10). A high image quality could not be obtained in areas outside the brain in the first studies conducted with DWI and the ADC quantification was not very successful. These problems have later been overcome by the introductionof stronger gradient fields, parallel imaging techniques

and phased-array coils (9, 10). However, application to thoracic imaging is still difficult since DWI is very sensitive to artifacts (7). Stimulated-echo and SE pulse sequencesthat require a very long acquisition time and are therefore very sensitive to motion artifacts were used in the first DWI applications (11). Today, SS-SE-EPI sequence that is not markedly affected by motion artifacts is used (7). The differentiation of whether the effusion is a transudate or exudate has been mainly attempted in studies on the detection of the nature of the pleural effusion by DWI (1, 2). When DWI was applied with the appropriate b values, the ADC values were found to be significantly lower in exudative pleural effusions than

the transudative ones. The reason was thought to be the high proteinaceous and cellular content of pleural fluid in exudative effusions leading to a decrease in ADC values. DWI was performed with b = 0 s/mm2 and b = 1000 s/mm2 values and the mean ADC values were calculated as 3.42 ± 0.76 × 10-3 mm2/s and 3.18 ± 1.82 × 10-3 mm2/s in transudative and exudative effusions by Baysal et al. (1). DWI was performed with b = 0 s/mm2, b = 500 s/mm2 and b = 1000 s/mm2 values and the ADC cut-off value was found to be 3.6 × 10-3 mm2/s for the transudative/exudative pleural effusion differentiation with DWI by Inan et al. (2). We aimed to perform the inflammatory-infectious/malignant differentiation of exudative pleural effusion with DWI in our study. Our main objective was therefore different from the two previous studies. The SI and ADC measurements we conducted by using 4 different b values (b = 10, 500, 750 and 1000) did not lead to statistically significant results for inflammatory-infectious/malignant differentiation in exudates. In the inflammatory-infectious group, a significant negative correlation was observed between ADC values and pleural fluid LDH measurements in all b values. This result was in accordance with Baysal et al’s study supporting the higher the viscosity of the pleural fluid, the smaller is the diffusion (1). On the other hand, in the malignant group, a significant positive correlation was observed between ADC values and pleural fluid total protein measurements in b values of 500 and 1000. This result can be explained by decrease in serum protein levels relative to pleural fluid (hypoalbuminemia). Due to this relative decrease of proteins, an increase in diffusion of water molecules may develop leading to increase in ADC values (1). In another study, Coolen et al. investigated combination of DWI and dynamic contrast enhanced MRI

DIFFUSION WEIGHTED MRI OF PLEURAL EFFUSIONS — KARATAG et al

(DCE-MRI) for differentiation of benign and malignant lesions of pleura. They made the ADC measurements of the pleural lesions taking care to exclude necrotic areas and considering the most solid parts for ROI placement. Similar to Baysal et al’s and Inan et al’s study, they calculated ADC values of malignant pleural diseases significantly lower than benign lesions (1.40 × 10-3 mm2/s ± 0.33 and 2.49 × 10-3 mm2/s ± 0.81, respectively). They stated that this result was most likely because of hypercellularity and hypervascularity of malignant lesions causing diffusion restriction. They concluded that DWI can differentiate malignant pleural diseases from benign lesions with high accuracy especially with the combination of DCE-MRI. They also concluded that by using a purely ADC-based diagnosis, false-negative diagnoses may occur mostly due to necrotic and inflammatory area within the tumor (12). In our study, we aimed to assess only the pleural effusions with DWI and we disregarded the solid parts of the malignant pleural lesions in order to make a truer comparison between the ADC values of inflammatory-infectious and malignant effusions. Because we were not be able to assess the cellularity of the effusions due to technical limitations, we could not give support to Coolen et al. (12) regarding their assumption about the higher the cellularity of the lesion, the smaller is the diffusion. The main limitation in our study was the inadequate number of cases. We believe that much larger number of patients should be included in the study to perform inflam matory-infectious/malignant differ entiation of the exudative qualified effusions with DWI first and then to perform subgrouping within the malignant processes afterwards, and that perhaps more statistically significant results can be obtained with a large case series. Another limitation was our application of unidirectional diffusion gradient in DWI. The patients in our study had marked pleural effusions and therefore many suffered respiratory distress, especially in the supine position. We tried to keep the examination short by applying a unidirectional diffusion gra-

dient in order to avoid respiratory distress and to ensure that patients could stay motionless during the examination so that we could obtain better image quality. However, at least three orthogonal directions should be used in DWI imaging. Molecular diffusion is a tridirectional process and diffusion can be anisotropic as in the cerebral white matter (13). We believe that data obtainedby applying tridirectional diffusion gradient will provide statistically healthier results. Another limitation was that the DW images we obtained with the EPI sequence had low signal-to-noise ratio especially when a high b value was used and this caused image distortion. In addition, the EPI sequence can also cause anatomic distortion with its susceptibility effect (14). We did not perform pulse-triggered DWI in our study. Mürtz et al used the SS-SE-EPI sequence with ECG triggering in their study to avoid the negative effect of cardiac pulsation and emphasized that the accuracy of ADC measurements was reduced in DWI without pulse-triggering (15). We believe that the ADC values obtained by DWI usingthe pulse-triggering technique will provide more accurate results. Conclusion DWI did not provide sufficiently accurate results in inflammatory-infectious/malignant differentiation of the exudative effusions in our study. Prospective studies with larger series are required to support the efficacy of DWI which can be performed within a short time and also can easily be added to routine thoracic MRI examination for transudate/exudate differentiation of pleural fluids and inflammatory-infectious/malignant differentiation of exudates. References 1. Baysal T., Bulut T., Gökirmak M., Kalkan S., Dusak A., Dogan M.: Diffusionweighted MR imaging of pleural fluid: differentiation of transudative vs exudative pleural effusions. Eur Radiol, 2004, 14: 890-896. 2. Inan N., Arslan A., Akansel G., Arslan Z., Eleman L., Demirci A.: Diffusion-weighted MRI in the charac terization of pleural effusions. Diagn Interv Radiol, 2009, 15: 13-18.

3. Romero-Candeira S., Fernández C., C., Sánchez-Paya J., Martín Hernández L.: Influence of diuretics on the concentration of proteins and other components of pleural transudates in patients with heart failure. Am J Med, 2001, 110: 681-686. 4. Romero-Candeira S., Hernández L., Romero-Brufao S., Orts D., Fernández C., Martín C.: Is it mean ingful to use biochemical parameters to discriminate between transudative and exudative pleural effusions? Chest, 2002, 122: 1524-1529. 5. Tarn A.C., Lapworth R.: BTS guidelines for investigation of unil ateral pleural effusion in adults. Thorax, 2004, 59: 358-359. 6. Light R.W.: Management of pleural effusions. J Formos Med Assoc, 2000, 99: 523-531. 7. Luna A., Sánchez-Gonzalez J., Caro P.: Diffusion-weighted imaging of the chest. Magn Reson Imaging Clin N Am, 2011, 19: 69-94. 8. Carr H.Y., Purcell E.M.: Effects of diffusion on free precession in nuclear magnetic resonance. Phys Rev, 1954, 94: 630-638. 9. Guo Y., Cai Y.Q., Cai Z.L., et al.: Differentiation of clinically benign and malignant breast lesions using diffusion-weighted imaging. J Magn Reson Imaging, 2002 , 16: 172-178. 10. Wang J., Takashima S., Takayama F., et al.: Head and neck lesions: characterization with diffusionweighted echo-planar MR imaging. Radiology, 2001, 220: 621-630. 11. Le Bihan D., Breton E., Lallemand D., Grenier P., Cabanis E., Laval-Jeantet M.: MR imaging of intravoxel in coherent motions: application to diffusion and perfusion in neurologic disorders. Radiology, 1986, 161: 401407. 12. Coolen J., De Keyzer F., Nafteux P., et al.: Malignant pleural disease: diagnosis by using diffusion-weighted and dynamic contrast-enhanced MR imaging – initial experience. Radiology, 2012, 263: 884-892. 13. Ozsunar Y., Sorensen A.G.: Diffusionand perfusion-weighted magnetic resonance imaging in human acute ischemic stroke: technical con siderations. Top Magn Reson Imaging, 2000, 11: 259-272. 14. Naganawa S., Kawai H., Fukatsu H., et al.: Diffusion-weighted imaging of the liver: technical challenges and prospects for the future. Magn Reson Med Sci, 2005, 4: 175-186. 15. Mürtz P., Flacke S., Träber F., van den Brink J.S., Gieseke J., Schild H.H.: Abdomen: diffusion-weighted MR imaging with pulse-triggered singleshot sequences. Radiology, 2002, 224: 258-264.

JBR–BTR, 2015, 98: 68-71.

Assessment of normal values of fractional anisotropy and mean diffusivity of mobile lumbar spine nerve roots by diffusion tensor MR imaging: Comparison between 1.5 and 3T J. Lincot1, J.P. Laissy1,2, A. Hess1,2, V. Balbi3,4, E. Schouman-Claeys1,2, A. Cotten3,4, B. Dallaudière1,2,5 Purpose: To assess the normal values of fractional anisotropy (FA) and mean diffusivity (MD) of L4, L5 and S1 nerve roots using diffusion tensor imaging (DTI) in healthy volunteers. Materials and methods: 37 subjects without previous history of lumbalgia or radiculalgia were prospectively examined: 27 at 1.5T and 10 at 3T MRI. The protocol included standard anatomical sequences and a DTI acquisition. Nerve root fibers were semi automatically extracted from DTI tractography. FA and MD values were measured at 4 key portions along each L4, L5 and S1 nerve roots. Results: At 1.5T MRI, FA and MD were 0.221 ± 0.011 and 460.9 ± 35.5 mm2.s-1 respectively; at 3T MRI, FA and MD were 0.216 ± 0.01 and 480.1 ± 36.1 mm2.s-1 respectively, which may be considered as normal values for mobile lumbar spine nerve roots, independently of intersomatic space level (p = 0.06) and nerve root portion (p = 0.08) or magnetic field (p = 0.06). Conclusion: Normal FA and MD values can be measured along lumbar mobile spine nerve roots in healthy subjects. These values were not dependent on intersomatic space level, side or anatomical portion of the nerve root or m agnetic field. Key words: Magnetic resonance (MR), diffusion study – Spine, MR.

Diffusion tensor imaging (DTI) can provide non-invasive, quantitative data to evaluate neural pathways in the central and peripheral nervous systems in vivo (1-5). This technique explores the anisotropic microscopic Brownian motions of water molecules along the preferential direction of fibers (6, 7). In each voxel, the diffusion tensor allows the calculation of eigenvalues, which are used to characterize the anisotropy, as reflected by fractional anisotropy (FA), and the mean diffusivity (MD, average of the 3 eigenvalues) of the middle. The degree of anisotropy and the average diffusion lead to the determination of the main diffusion direction in each voxel of the explored tissue (8), reflective of the orientation of the tissular components, e.g. axonal fibers. DTI has been mostly used in neuroradiology in order to study neural connectivity in white matter. It is a tool to approach microstructural networks, capable to provide a threedimensional visualization tool of nerves and muscles fibers (4). The feasibility of DTI and tracto graphy of human peripheral nerves (9, 10) was recently demonstrated in the carpal and ulnar tunnel syndromes (9-11). In lumbar spine,

few studies reported fiber tracking of the nerve roots. Compression of lumbar nerve root consecutive to disc herniation has been associated to modifications of the diffusion parameters, namely FA and MD (12). DTI fiber tracking may reflect histological changes in the nerve root tissue secondary to the compression, independently of a patent discoradicular conflict seen on MRI. It may then be used as an additional diagnostic tool in clinical routine, particularly in case of discordance between anatomical MRI and clinical symptoms. Indeed, increase in the vascular permeability with disruption of the nerve root barrier, intraneural edema, intra and perineural hyperaemia have been attributed to chronic compression of the nerve roots and may explain modifications of water diffusion along the nerve root (11-13). Moreover, ischemia, demyelination and Wallerian degeneration may reduce anisotropy by increasing the distance between axons fascicles, thus leading to a decrease in the FA value, as well as an increase in that of MD. Thereby, DTI evaluation of lumbar nerve roots may stand as a new imaging approach with more functional assessment of the microstructural changes

From: 1. Service de Radiologie, CHU Bichat – Claude Bernard, Paris, France, 2. Faculté de Médecine Xavier Bichat, Université Paris 7, 3. Service de Radiologie OstéoArticulaire, CHRU Roger Salengro, Lille, France, 4. Faculté de Médecine, Université Lille 2, 5. Inserm U698, CHU Bichat – Claude Bernard, Paris, France. Address for correspondence: Dr J. Lincot, M.D., Dpt of Radiology, Bichat-Claude Bernard University Hospital, 46, rue Henri Huchard, F-75018, Paris, France. E-mail : julienlincot@gmail.com

undergone by compressed nerve roots. However, only few studies (1, 12, 13) established normal values of FA and MD of lumbar nerve roots at 1.5T MRI and none at 3T MRI, according to demographic data (14). More, inter individual variations of normal diffusion parameters may exist, as well as physiological variations according to the level and the portion of the considered nerve root. Because of the growing importance of DTI in lumbar imaging and its clinical implications, we are interested in determing normative diffusion tensor parameters and to assess whether these normative findings differ according to the magnetic field strength. Consequently, the purposes of our study were to confirm the feasibility of the DTI technique in the exploration of nerve roots of the mobile lumbar spine and to define normal values of FA and MD in healthy subjects at 1.5T and to compare them with results at 3T. Material and methods Patients Thirty-seven volunteers without previous clinical history of lumbalgia or lumbar radiculalgia (BD, JL) were included prospectively in our single center study from April 2011 to January 2012. Written inform con sent was obtained from each subject before inclusion. Exclusion criteria were a previous history of spinal trauma, surgery, or neurological disease and contraindication to MRI (pregnancy, metallic

NORMAL FA AND MD VALUES OF LUMBAR SPINE NERVE ROOTS — LINCOT et al

implants, and claustrophobia). We collected clinical data including age and gender whereas ethnic group or sports habits were not considered. MRI The MRI scans were performed on the day of inclusion on GE systems (GE Healthcare, Milwaukee, WI) in random order: on a 1.5T unit in 27 subjects and on 3T unit in the remaining 10 volunteers. We used a 6 elements phased array spine coil with the patient in supine position. The standardized MRI protocol (with non-use of parallel imaging) typically included T1 weighted FSE (for 1.5T: TR, 660ms; TE, 9.5ms; number of averages (NEX), 1; field of view (FOV), 380 × 380 mm; matrix, 512 × 512; slice count, 12; slice thickness, 4 mm; slice gap, 0.4 mm; ac quisitiontime 2 min53 s; for 3T: TR, 973 ms; TE, 8ms; NEX, 1; FOV, 360 × 360 mm; matrix 512 × 512; slice count, 8, slice thickness, 3 mm; slice gap, 0.3 mm; acquisition time 3min23s) and T2 weighted TSE (for 1.5T: TR, 2960 ms; TE, 70ms; NEX, 2; 380 × 380 mm; matrix, 512 × 512; slice count, 12; slice thickness, 4 mm; slice gap, 0.4 mm; acquisition time, 3 min21 s; for 3T: TR, 3781ms, TE, 57.4ms, NEX, 1.5; FOV, 360 × 360 mm; matrix, 512 × 512; slice count, 8; slice thickness, 3 mm; slice gap, 0.3 mm, acquisition time, 3min06) sequences of the lumbar spine both in the sagittal plane and a T2 weighted TSE (for 1.5T: TR, 5680 ms; TE, 123 ms; FOV, 200 × 200 mm; matrix, 512 × 512; NEX, 2; slice count, 30; slice thickness, 3 mm; slice gap, 0; acquisition time, 3 min40 s; for 3T: TR, 3769 ms; TE, 116.7 ms; NEX, 1.5; FOV, 200 × 200 mm; matrix, 512 × 512; slice count, 30; slice thickness, 3 mm; slice gap, 0; acquisition time, 3min18) sequence in the axial plane in the last 2 mobile levels L4-L5 to L5-S1 of the lumbar spine. In addition to these previous sequences, single-shot echo-planar spin-echo DTI sequence was performed in axial plane from L4-L5 to L5-S1 intersomatic spaces with the use of the following parameters: for 1.5T: TR, 8400ms; TE, 85.1 ms; FOV, 200 × 200 mm; matrix, 256 × 256; NEX, 4; slice count, 30; slice thickness, 3 mm; slice gap, 0; b value, 900 s.mm-2; motion probing gradients applied in 25 non-collinear directions; acquisition time, 9 min12 s; for 3T: TR, 4500 ms; TE, 83.5 ms; FOV, 200 × 200 mm; matrix, 256 × 256; NEX, 4; slice count, 30; slice thickness, 3 mm; slice gap,

0; b value, 900 s.mm-2; motion probing gradients applied in 25 non-collinear directions; acquisition time, 7 min53. Data analysis All MRI scans were reviewed in consensus by 2 readers (JL and BD), with respectively 2 and 4 year experience in spine imaging, blinded to clinical data. Image analysis was performed for each subject, immediately after the acquisition for qualitative assessment and secondly for data extraction (24 days later in mean; range, 13-35 days). A coregistration of DTI and axial T2-weighted images was systematically performed to increase the anatomical resolution of DTI images. A “neurography” was obtained using the diffusion volume (b value, 900 s.mm-2) which was visualized as maximum intensity projection, to evaluate neurograms, before tractography color maps, in order not to include obvious artifacts. Indeed, Diffusion-weighted magnetic resonance imaging postprocessed by maximum-intensity projection reportedly demonstrates the nerve roots (15, 16). Image processing was first performed using MedINRIA v1.9.4 software (©Sofia Antipolis, France). The following parameters were defined for automatic fiber tracking across the whole study DTI volume: FA threshold, 0.1; minimum fiber length, 10 mm. No ROI was used to initiate the fiber tracking. L4, L5 and S1 fiber bundles were manually segmented on each side for all subjects. Anatomical fusion between the axial T2 sequence and the DTI reconstructions was performed to allow better visualization of the different anatomic spaces. Once reconstructed, L4, L5 and S1 fiber bundles were manually segmented on each side (Fig. 1). We considered as being significant at least 5 fibers for each nerve root. FA color maps were displayed using the classic three-directional color code: blue for fibers running in the cephalocaudal direction, green for those running in the anteroposterior direction and red for those running right and left (12). Matching between the encoded color maps and the T2weighted images was also manually verified. Processing with FiberViewer v1.2.3 (©University of North Carolina, http://www.ia.unc.edu/dev/) software permitted automatic FA and MD values measurement for each fiber bundle at the root emergence, in the lateral recess, in the fo-

ramen and in the extra foraminal portion, except for L4 nerve roots in which origin part was not in the exploration field on 1.5T (Fig. 2). No ROI was used. FA and MD values were measured in both sides of L4, L5 and S1 nerve roots and compared between them. Statistical analysis We described FA and MD data generated by FiberViewer software as mean, median, minimal, maximal and standard deviation for continuous variables. Association between diffusion parameters and topography of the measure was attested using non-parametric tests (Wilcoxon test). Time data extraction was also described as mean, minimal with standard deviation. FA and MD data were compared and analyzed to clinical data using Medcalc© v11.0 software. Statistical testing was done at the 2-tailed alpha level of 0.05. Results Subjects Thirty-seven subjects were in cluded: – 27 clinically healthy volunteers (17 men, 10 women) on 1.5T MRI – 10 clinically healthy volunteers (5 men, 5 women) on 3T MRI Mean age was 62 years old (range, 43-86; SD, 5.6). Standard MRI and DTI analysis The DTI sequence was interpretable in all cases, with a good depiction of L4, L5 and S1 nerve roots. Fusion between DTI and axial T2 weighted images permitted a good anatomical correlation in all cases. We insured that the entire path of the root was taken into account from its emergence to its extraforaminal portion by MedInria and Fiber Viewer softwares in 22 patients (132 nerve roots). In 26 nerve roots (11.7%) in 13 patients, fiber tracking was discontinuous in isolation on 1.5 T MRI and on 3 nerve roots (1.4%) in 2 patients on 3T MRI, the largest bundle gap measuring 5 mm. At 1.5T, anatomical disruption were right lateral recess L4 (n = 4), right foraminal L4 (n = 1), left lateral recess L4 (n = 2); right spinal canal L5 (n = 2),right foraminal L5 (n = 1), left lateral recess L5 (n = 4); right spinal canal S1 (n = 3), right extra foraminal S1 (n = 3), left foraminal S1

JBR–BTR, 2015, 98 (2)

Fig. 1. — 55 year-old male; image fusion of diffusion tensor tractography and T2-weighted acquisition. A. Unprocessed tracto graphy across the entire acquisition volume showing the lumbosacral roots as polylines within the cropping box; three-directional color code for fiber direction: blue, cephalocaudal; green, anteroposterior; red, transverse. B. Processed tractography showing individualized radicular fiber bundles as polytubes; color code: red, right S1; green, left S1; blue, right L5; cyan; left L5.

(n = 2) and left extra foraminal S1 (n = 4) roots. At 3T, anatomical disruption were right lateral recess L4 (n = 1), left foraminal S1 (n = 2). Fiber tracking can’t be performed after changing parameters (threshold and/or minimum length) whose initial tracking was discontinuous. According to our experience, FA threshold, 0.1; minimum fiber length, 10 mm are optimal parameters for lumbar nerve roots fiber tracking. The mean values of FA and MD for all subjects were respectively: FA, 0.221 ± 0.011; MD, 460.9 ± 35.5 mm2.s-1 at 1.5T MRI; FA, 0.216 ± 0.01; MD, 480.1 ± 36.1 mm2.s-1 at 3T MRI. Mean values of FA and MD in the 37 healthy volunteers were not significantly different according to intersomatic space level (p = 0.06), nerve root portion (p = 0.08) and MRI magnetic strength (p = 0.06). Discussion We aimed to determine normal values of diffusion tensor parameters in lumbar nerve roots of asymptomatic volunteers without prior history of low back surgery or nerve root pain. In this study, FA was MD was 0.221 ± 0.011, 460.9 ± 35.5mm2.s-1 at 1.5T MRI; and FA was 0.216 ± 0.01, MD was

480.1 ± 36.1 mm2.s-1 at 3T MRI, which might be considered as normal values for mobile lumbar spine nerve roots, independently of MRI field. Fiber tracking and measurement of diffusion parameters was successfully obtained in 86.9 % of the subjects, confirming the feasibility of DTI for lumbar nerve roots (12). Indeed, these disruptions couldn’t be corrected because when we modify and particularly when we increase the parameters of automatic fiber tracking across the whole study DTI volume, too much artifacts like para vertebral musculature fibers were identified. Hence, according to our experience, the mentioned parameters seems to be the better compromise and permits reliable measurements, with a negligible gap. Our values of FA on volunteers are consistent with those reported in the literature of 0.218-0.219 (12). Furthermore, FA and MD were measured and compared according to the same post-processing algorithms, software and readout procedure at 1.5 and 3T. However, to our knowledge there are only few reports of normal diffusion parameters values for lumbar nerve roots in the literature and these findings have to be confirmed by further studies. The systematic co registration of axial T2 and DTI se-

quences permitted a good anatomic correlation. Measurements of FA and MD according to anatomical imaging probably contributed to the precision of our measurements (17). Determination of normal values of diffusion parameters in lumbar nerve roots may have further implications in the comprehension and the management of mechanical nerve root pain due to disc herniation. Some interesting reports (1, 12) have already demonstrated modifications of FA and MD values in case of compressed nerve root, emphasizing the importance of defining reliable and reproducible normal values in the healthy population. We acknowledge that our study has several limitations. First, we focused on the last 2 intersomatic space levels since L4, L5 and S1 are the most frequently involved nerve roots in disc herniation or foraminal nerve root entrapment. In fact, exploration of the other intersomatic space levels would have implied an additional DTI sequence on 1.5T with substantial increase in the acquisition time. The exploration of the other intersomatic space levels was limited by the size of the FOV and the number of slices of the DTI sequence, fixed to optimize the spatial resolution and the acquisition time. Another important limitation concerns the small sample size of

NORMAL FA AND MD VALUES OF LUMBAR SPINE NERVE ROOTS — LINCOT et al

Fig. 2. — Same patient as in Fig. 1. A. Right S1 root fiber bundle processed in FiberViewer© software shown within the cropping box with crossing analysis plane. B,C: fractional anisotropy (FA) and mean diffusivity (MD) measurements along this fiber bundle with red squares on the graphs marking the level of the crossing analysis plane.

subjects included in our study, requiring confirmation of the results by further larger studies. Nevertheless, to our best knowledge we reported the largest series of lumbar nerve roots DTI and also the only one on 3T MRI and studied FA and MD measurements on 222 nerves roots. In conclusion, our study shows that FA and MD are not subject to variations according to the magnetic field. References 1. Eguchi Y., Ohtori S., Orita S., et al.: Quantitative evaluation and visualization of lumbar foraminal nerve root entrapment by using diffusion tensor imaging: preliminary results. AJNR Am J Neuroradiol, 2011, 32: 18241829. 2. Andreisek G., White L.M., Kassner A., Sussman M.S.: Evaluation of diffusion tensor imaging and fiber tractography of the median nerve: preliminary

results on intrasubject variability and precision of measurements. AJR Am J Roentgenol, 2010, 194: W6572. 3. Filippi C.G., Andrews T., Gonyea J.V., Linnell G., Cauley K.A.: Magnetic resonance diffusion tensor imaging and tractography of the lower spinal cord: application to diastematomyelia and tethered cord. Eur Radiol, 2010, 20: 2194-2199. 4. Rha D.W., Chang W.H., Kim J., Sim E.G., Park E.S.: Comparing quantitative tractography metrics of motor and sensory pathways in children with periventricular leuko malacia and different levels of gross motor function. Neuroradiology, 2012, 54: 615-621. 5. Budzik J.F., Balbi V., Le Thuc V., Duhamel A., Assaker R., Cotten A.: Diffusion tensor imaging and fibre tracking in cervical spondylotic myelopathy. Eur Radiol, 2011, 21: 426-433. 6. Le Bihan D., Mangin J.F., Poupon C., et al.: Diffusion tensor imaging: concepts and applications. J Magn Reson Imaging, 2001, 13: 534-546.

7. Tensaouti F., Lahlou I., Clarisse P., Lotterie J.A., Berry I.: Quantitative and reproducibility study of four tractography algorithms used in clini cal routine. J Magn Reson Imaging, 2011, 34: 165-172. 8. Le Bihan D., Johansen-Berg H.: Diffusion MRI at 25: exploring brain tissue structure and function. Neuro Image, 2012, 61: 324-341. 9. Breitenseher J., Moritz T., Bodner G., Paul A., Prayer D., Kasprian G.: 3 T MR Tractography of Forearm Nerves and Muscles in Cubital Tunnel Syndrome. RSNA. Chicago, , 2011. 10. Lindberg P., Feydy A., Maier M., Drape J.-L.: Relation between Diffusion Tensor Imaging, Electromyography, and Grip Force Control in Patients with Recurrent Carpal Tunnel Syndrome after Surgical Release. RSNA. Chicago, 2011. 11. Hiltunen J., Suortti T., Arvela S., Seppa M., Joensuu R., Hari R.: Diffusion tensor imaging and tracto graphy of distal peripheral nerves at 3 T. Clin Neurophysiol, 2005, 116: 23152323. 12. Balbi V., Budzik J.F., Duhamel A., Bera-Louville A., Le Thuc V., Cotten A.: Tractography of lumbar nerve roots: initial results. Eur Radiol, 2011, 21: 1153-1159. 13. Eguchi Y., Ohtori S., Yamashita M., et al.: Clinical applications of diffusion magnetic resonance imaging of the lumbar foraminal nerve root entrap ment. Eur Spine J, 2010, 19: 18741882. 14. Budzik J.F., et al.: Assessment of reduced field of view in diffusion tensor imaging of the lumbar nerve roots at 3 T. Eur Radiol, 2013, 23: 1361-1366. 15. Tsuchiya K., et al.: Demonstration of spinal cord and nerve root abnormalities by diffusion neurography. J Comput Assist Tomogr, 2008. 32: 286-290. 16. Yamashita T., Kwee T.C., Takahara T.: Whole-body magnetic resonance neurography. N Engl J Med, 2009. 361: 538-539. 17. Arana E., Royuela A., Kovacs F.M., et al.: Lumbar spine: agreement in the interpretation of 1.5-T MR images by using the Nordic Modic Consensus Group classification form. Radiology, 2010, 254: 809-817.

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Lunotriquetral coalition, a normal variant that may rarely cause ulnar sided wrist pain M. Mespreuve1,2, F. Vanhoenacker1,2,3, K. Verstraete2 Lunotriquetral coalition (LTC), the most frequent and often bilateral type of carpal coalition, is in general considered as asymptomatic. In rare cases – however – fibrocartilaginous LTC may be an uncommon cause of ulnar sided pain in the wrist due to the pseudarthrosis or a post-traumatic disruption of LTC. Two rare cases of symptomatic LTC are presented and the role of MRI is emphasized. MRI shows the pseudarthrosis and may additionally show bone m arrow edema and subcortical cysts. In symptomatic cases surgical lunotriquetral fusion may be considered as treatment option. Key-word: Wrist, abnormalities.

Carpal fusion may occur in two or more adjacent bones in almost any combination (lunotriquetral, capitate-hamate, trapezium-trapezoid, scapho-trapezium, scapho-lunate, capitate-lunate, pisiform-hamate, hamate-triquetrum, triquetral-pisiform and trapezoid-capitate) (Fig. 1). Those on the ulnar side are more commonly involved (1). The bone fusion may involve two or more carpals or even all carpals may appear as a single bony mass. However, most coalitions occur between carpals within the same carpal row (1). Coalitions between carpals from different rows are thought to be quite rare (2) (Fig. 2). Complicated carpal fusions (Fig. 2E and 2F) are likely to be associated with more widespread anomalies. Fusion of carpal bones is hereditary and the trait is transmitted as a dominant factor which is not sex linked (3). The lunotriquetral coalition is caused by a failure of cavitation of the cartilaginous hand bud precursor (during the fourth to eighth week of gestation) or cartilaginous segmentation of a common cartilaginous carpal precursor of the lunate and triquetral bone (4). The resulting malsegmentation between two normally distinct carpals results in a carpal coalition. This coalition may be fibrous (syndesmosis), cartilaginous (synchondrosis), frequently a mixture of both or osseous. As their ossification centers occur between 6 to 15 years the fusion may become visible on plain film. Burnett (5) proposed a very simple classification with only two forms of coalition, osseous and non osseous.

de Villiers Minnaar (6) classified the carpal coalitions into four types, also known as the Minnaar types, on plain film (Table I) (Fig. 3). The latter classification is more frequently used. Minnaar type 1 (about 2%) resembles a pseudarthrosis due to its incomplete fibrocartilaginous coalition. In type 2 (second most frequent, about 22%) there is an incomplete osseous fusion, whereas in type 3 (most frequent, about 75% ) the osseous fusion is complete. If other carpal congenital abnormalities are associated with a complete osseous coalition it is considered as a type 4 (about 1%) (7). Our purpose was to review the plain film findings in our series (n = 9 patients, 12 LTC), compare the data with the literature and define the (potential) role of MRI. The differential diagnosis will be discussed as well. Materials and methods We examined nine patients with a LTC (of whom four had a known bilateral LTC) and analyzed the age, gender, type, clinical manifestation and imaging findings of LTC. A standard MRI protocol was used on a 1,5 Tesla MR with a dedicated wrist coil. A Field of View varying from 100140 mm and a matrix varying from 256 x 180 to 512 x 360 were used. Coronal SE-T1 weighted (TR 470 msec, TE 22 msec, Slice Thickness (ST) 2 mm), Coronal PD-SE T2 weighted (TR 3930 msec, TE 13 and 93 msec, ST 2 mm) and Coronal GRE TR (23,59 msec, TE 8,31 msec, ST 0,5 mm) images were obtained. The number of averages varied from 1 to 3.

From: 1. Department of Radiology, St.-Maarten General Hospital, Mechelen, Belgium, 2. Department of Radiology, University Hospital Ghent, Ghent, Belgium, 3. Department of Radiology, University Hospital Antwerp, Antwerp, Belgium. Address for correspondence: M. Mespreuve, St.-Maarten General Hospital, Leopoldstraat 2, 2800 Mechelen, Belgium. E-mail marc.mespreuve@skynet.be

Fig. 1. — Carpal coalitions (arrows). Plain radiography. Thick arrows show the two most frequent coalitions (lunotriquetral and capitate-hamate).

Results Our series includes 6 females and 3 males, all known with a LTC. Imaging findings and clinical manifestations are summarized in Table II. The age of our patients ranges between 11 and 56 years, with a mean of 30 years. The majority of the LTC were asymptomatic coincidental findings (Fig. 4). Two of them with type 1 LTC – of whom also the second youngest patient – had a symptomatic LTC (Fig. 5, 6). The other two with type 1 LTC were asymptomatic. Most of the LTC were of Minnaar type 3. In three patients LTC was bilateral. One of them (Fig. 7A) had a different Minnaar type on either side, the two other persons had the same type of LTC on both sides (Fig. 7B). On plain radiography one patient findings were in

LUNOTRIQUETRAL COALITION — MESPREUVE et al

Fig. 2. — Isolated and combined coalitions. (A), (B), (C), (E) and (F) Plain radiography, (B) Coronal SE T1-WI and (D) Coronal SE T2-WI. A and B trapezoid-capitate coalition (arrows), C, and D capitate-hamate (long arrows) and trapezoid-capitate (short arrows). E. scapho-trapezium (long arrow) and capitate-hamate (short arrow). F. trapezo-trapezoideum (long arrow), capitate-hamate (short arrow) and LTC (double short arrow).

compliance with Minnaar type 3. Revaluation on MRI redefined this case as type 2 Minnaar (Fig. 8). Two symptomatic patients with a Minnaar type 1 LTC had ulnar sided pain. MRI showed subchondral cysts and a clear bone marrow edema adjacent the LTC (Fig. 5 B-D, 6 B-D). There were no associated soft tissue abnormalities. The surrounding joints were considered normal. These two symptomatic patients were successfully treated, one conservatively with medication and the second was surgically treated (Fig. 9). Discussion Lunotriquetral coalition (LTC) is the most frequent type of carpal coalition, representing 90% of all carpal fusions (8). The general prevalence is about 0,1% in Caucasian population and the congenital variant is commonly bilateral. We found a bilateral appearance in all of the three patients from whom the wrist was examined bilaterally. The congenital fusion of the lunate and the triquetral

Fig. 3. — Minnaar types 1 to 4. Schematic view. Type 1: narrowed LTJ with irregular sclerotic margins (arrow). Type 2: incomplete osseous fusion with (small) mostly distal remnant of the joint space (arrow). Type 3: complete osseous fusion between the lunate and triquetral bone (arrow). Type 4: = Type 3 with other carpal congenital bony abnormalities.

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Table I. — (de Villiers) Minnaar classification (plain film) with MR correlation, histopathology and clinical corrrelation. Coalition

Plain film (de Villiers) Minnaar

MRI

Histopathology

Clinical correlation

Type 1

– narrowed LTJ – irregular sclerotic margins – possibly subcortical cysts

– narrowed LTJ – irregular sclerotic margins – possibly subcortical cysts – possibly bone marrow edema – possibly damage to the surrounding cartilage – possibly concomitant pathology

fibro-cartilaginous

(a) symptomatic

Type 2

– incomplete osseous fusion – (small) mostly distal remnant of the joint space

incomplete osseous

asymptomatic

Type 3

– complete osseous fusion between the lunate and triquetral bone

– complete osseous fusion between the lunate and triquetral bone – dd. type 2 and 3

complete osseous

asymptomatic

Type 4

– complete osseous fusion between the lunate and triquetral bone – other carpal congenital bony abnormalities

– complete osseous fusion between the lunate and triquetral bone – other carpal congenital bony abnormalities – possibly anomalies of the soft tissues

complete osseous

other carpal congenital abnormalities

Table II. — Illustrative cases of LTC.

Patient

Age (y)

Sex F/M

Minnaar type L-side

Minnaar type R-side

Surgery

Additional clinical information

Figure(s)

symptomatic

asymptomatic (both sides)

7A, 7B, 8

symptomatic

6, 9

asymptomatic

4A, 4B

asymptomatic

4C, 4D

asymptomatic (both sides)

7C, 7D

asymptomatic

asymptomatic (both sides), complicated carpal fusion

Mean Range

30 11 -56

6F / 3M

7L (2?)

5R (4?)

2 symptomatic / 7 asymptomatic (4 on both sides)

bone is more common in females which was in line with our series (Table II) (female to male ratio is 2:1, as in larger series), in African-Americans (1,6%) and up to 9% in West African natives (6). This coalition is mostly bilateral but – if unilaterally

present – more common on the left side. This is probably the reason why we encountered more LTC on the left side. It is usually considered as an asymptomatic normal variant. LTC can be associated with other hand-

wrist abnormalities. Complicated carpal fusions are likely to be associated with more widespread anomalies. In our series we only found Minnaar type 1 (33%) and 3 (67%) LTC based on plain film.

LUNOTRIQUETRAL COALITION — MESPREUVE et al

Fig. 5. — LTC type 1 (patient 1). A. Plain radiography, B. Coronal SE T1-WI, C. Coronal SE T2-WI and D. Coronal 3D-GRE. A. The LTJ is narrowed with irregular margins (long arrow) and subchondral cysts (short arrow). B, C and D: The LTJ is filled with fibrovascular tissue (long arrows). There is oedema ( B, C,short arrows) surrounding a subchondral cyst (C) (short arrow) and the margins are irregular (D) (short arrow).

Fig. 4. — Asymptomatic variant. Plain radiography. A. and B. A LTC (arrows) type 3 was found during X-ray examination after major trauma (patient 4). C. and D. A LTC (long arrows) type 1 was found during X-ray examination after minor trauma (short arrows) (patient 5).

The type 1 coalition may become symptomatic due to the pseudarthrosis or – as for all structures – in case of fracture. The weaker fibrocartilaginous coalition appears to be more susceptible to stress or trauma. The deficient intra-articular cartilage formation at the lunotriquetral joint results in a clinical and anatomic condition similar to degenerative osteoarthritis (9). The cartilage of the surrounding joints may become damaged as well due to disturbed motion. Our two symptomatic patients had a type 1 Minnaar LTC. Although carpal fusion is mostly an asymptomatic condition, symptoms may appear in specific conditions such as after intense and repeated movements. A possible alteration of the normal biomechanics of the wrist may cause an abnormal stress on the contributing joints and the surrounding soft tissues. In rare cases fibrocartilaginous type 1 LTC may be an uncommon cause of ulnar sided pain in the wrist due to the pseudarthrosis or a posttraumatic disruption of the fibrocartilagineous LTC (10). Two of our pa-

Fig. 6. — Symptomatic patient with LTC type 1 (patient 3). A: Plain radiography and B: Coronal SE T1-WI, C, SE proton density and D, SE T2-WI. Type 1 LTC with subchondral cysts (A) and surrounding edema (B-D) in a patient with ulnar sided wrist pain.

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Fig. 7. — Bilateral LTC in the same patient. Plain radiography. A. Type 3 LTC on the left side and B and type 1 LTC on the right side (patient 2). C and D, LTC type 3 on both sides (patient 6).

tients with type 1 LTC had ulnar sided pain. The other two with type 1 LTC were asymptomatic. Osseous LTC (type 2 and 3) of the lunate bone and the triquetral bone are in general considered as asymptomatic. However a case of painful wrist movement on the side of a complete bony fusion has been reported (8), without clear explanation of the possible pathogenetic mechanism. All of our six patients with type 3 LTC (of whom two bilateral) were asymptomatic. Although fractures of osseous coalitions also have been reported, some suggest that these might have been symptomatic fibrocartilaginous types (10). Plain film findings LTC type 1 resembles a pseudarthrosis with irregular sclerotic margins. There is a narrowed joint space (LTJ) between the lunate bone and triquetral bone, possibly with subcortical cysts. This non-osseous coalition may result in degenerative osteoarthritis due to abnormal joint mechanics and the thin cartilage between the affected carpals (11). In type 2 there is an incomplete osseous fusion with trabeculae traversing the lunotriquetral joint space and a (small), mostly distal (but occasionally also proximally) remnant of the joint space, whereas in type 3 the osseous fusion between the lunate bone and the triquetral bone is complete and forms a so called os lunatotriquetrum. In type 4 other car-

Fig. 8. — Reevaluation on MRI compared to plain radiography (patient 2). A. Plain radiography, B: Coronal SE T1-WI, C: Coronal SE T2-WI and D: coronal 3D-GRE. A. Based on plain film evaluation LTC seems complete, in compliance with Minnaar type 3. B, C and D: on MRI of the same patient, a (small) distal notch can be seen, thus redefining this case as type 2 Minnaar.

Fig. 9. — Surgical treatment of a symptomatic LTC (patient 3). Plain radiography. A corticocancellous wedge from the dorsal side of the distal radius (short arrows) was interposed between the lunate and triquetral bone (long arrows) after resection of the pseudarthrosis.

pal congenital abnormalities are associated with the complete osseous LTC. Remarkably LTC has been associated with a widening of the scapholunate joint space (12), which does not reflect a scapholunate ligament disruption. This differential diagnosis may be particularly important in a

post-traumatic setting. This widening is namely caused by a compensatory thickening of the cartilage on the opposing surfaces of the scaphoid bone and the lunate bone. Examination of the opposite wrist may be useful as LTC is often bilateral (6) (about 60%) but not always of the same type.

LUNOTRIQUETRAL COALITION — MESPREUVE et al

Fig. 11. — Secondary fusion due to surgery for a lunotriquetral ligament lesion. A: Plain radiography and B: Coronal SE T1-WI. There is a carpal “coalition” between the lunate bone and the triquetral bone (long arrows). Notice the bony defect after prelevation of a bone graft in the distal radius (A, short arrow) and the susceptibility artifacts after surgery (B, short arrows).

MRI findings

Fig. 10. — Secondary fusion due to arthritis. A and B: Plain radiography, C: Coronal SE T1-WI and D: Coronal SE T2-WI. There is a carpal “coalition” (here between the scaphoid and the lunate) but also an associated “coalition” with the radius (arrows). The scaphoid bone has lost a part of its volume and the proximal cortical delineation of the lunate bone is irregular. The fusion is secondary to a juvenile arthritis.

MRI in LTC type 1 shows the pseudarthrosis with irregular sclerotic margins a narrowed joint space filled with fibrocartilage between the lunate and triquetral bone, subchondral cysts and may additionally show bone marrow edema on fluid-sensitive sequences adjacent to lunatotriquetral joint in symptomatic cases. After contrast administration the edema and the fibrovascular tissue

Table III. — Carpal coalitions in association with other abnormalities. Differential diagnosis. Disease

Abnormalities

Turner’s syndrome

– dorsal and radial bowing of the radius (Madelung deformity) – short fourth metacarpal with a positive metacarpal sign (positive sign of Kosowicz) – carpal angle less than 117° – fusion of the capitate and hamate bone – extra carpal bones – malformed carpals – broad, short middle phalanx – polydactyly (“six-fingered dwarfism”) – polydactyly – hypoplastic or triphalangeal thumb – partial or complete absence of the radial bone – accessory carpal bones – camptodactyly – ulnar deviation – dwarfism – narrow joint spaces – hitchhiker thumb – symphalangism – radio-ulnar synostosis – deformed scaphoid bone – anomalies of shape and position of carpal bones as comma shaped trapezoid and transverse position of the capitates bone

Ellis-van Creveld syndrome

Holt-Oram syndrome

arthrogryposis diastrophic dysplasia Nievergelt-Pearlman syndrome foetal alcohol syndrome hand-foot-uterus syndrome oto-palatodigital syndrome symphalangism

– partial or total absence of interphalangeal joints

in the synovium and the subcortical cysts will enhance (13), although this does not add any clear diagnostic information. MRI may provide the necessary information about the condition of the surrounding articular cartilage and may also exclude concomitant pathology of the wrist, which is to be evaluated certainly if any operative treatment is considered. In type 2 LTC there is an incomplete proximal osseous fusion and a (small) mostly distal notch filled with hyaline cartilage, whereas in type 3 the osseous fusion is complete. MRI will evaluate the LTJ more in detail. Due to the absence of osseous superposition, MRI allows a more accurate evaluation and classification than plain radiography. Type 3 coalitions will often be reclassified on MRI as a type 2 LTC. However this does not seem to have any clinical importance. In type 4 possibly additional soft tissue anomalies are illustrated as well. Differential diagnosis Carpal coalitions may be associated with other hand-wrist abnormalities (Table III). LTC specifically is most frequently seen in Turner’s syndrome, Ellis-van Creveld syndrome, Holt-Oram syndrome and arthrogryposis. Anamnesis and clinical information should always exclude an acquired fusion secondary to arthritis (Fig. 10), trauma, surgery (Fig. 11), drug intake during pregnancy or a metaplastic conversion of intra-articular structures (fibrous tissue, ligaments or cartilage) (14). Therapy After resection of the pseudarthrosis, lunotriquetral surgical fusion (15) may be performed in symptomatic cases (i.e. type 1) using a

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Herbert screw (16) and/or a corticocancellous wedge from the dorsal side of the distal radius (Fig. 9) or the iliac crest. Normally the symptoms should disappear completely and mostly mobility is also restored, although sometimes there may be a residual a minor loss of range of motion (9). Conclusion Lunotriquetral coalition (LTC) – the most frequent and often bilateral type of carpal coalition – is usually considered asymptomatic. In rare cases however fibrocartilaginous LTC type 1 may be an exceptional cause of ulnar sided pain in the wrist due to the pseudarthrosis or a posttraumatic disruption of the fibrocartilaginous LTC. MRI shows the pseudarthrosis more clearly and offers a more accurate classification than plain films. It directly evaluates the symptomatic variants that may benefit from (surgical) treatment by showing eventually present bone marrow edema and subcortical cysts. Associated bone and soft tissue abnormalities will be illustrated as well. Moreover, it offers a complete preoperative cartography of the surrounding joints. Symptomatic variants may be treated conservatively or by lunotriquetral surgical fusion which may result in pain relief and restored mobility. References 1. Garn S.M., Frisancho R., P oznanski A.K., et al.: Analysis of Triquetral-Lunate fusion. Am J Physical Anthropology, 1971, 34: 431-434. 2. Poznanski A.K., Holt J.F.: The carpals in congenital malformation syndromes. Am J Roentgenol Radium Ther Nucl Med, 1971, 112: 443-459. 3. Henry M.B.: Anomalous fusion of the scaphoid and the greater multangular bone. Archives of Surgery, 1945, 50: 240-241.

4. Cockshott W.P.: Carpal fusions. Am J Roentgenol Radium Ther Nucl Med, 1963, 89: 1260-1271. 5. Burnett S.: Hamate-pisiform coalition: morphology, clinical significance and a simplified classification scheme for carpal coalition. Clin Anat, 2011, 24: 188-196. 6. de Villiers Minnaar A.B.: Congenital fusion of the lunate and triquetral bones in the South African Bantu. J Bone Joint Surg Br, 1952, 34: 4548. 7. De Fazio M., Cousins B., Miversuski R., et al.: Carpal coalition. Hand, 2013, 8: 157-163. 8. Lotter O., Stahl S., Luz O., et al.: Bilateral paradoxically symptomatic lunotriquetral coalition: a case report. Open Access J Plastic Surg, 2010, 6 www.eplasty.com 9. Gross S.C., Watson H.K., Strickland J.W., et al.: Triquetral-lunate arthritis secondary to synostosis. J Hand Surg Am, 1989, 14(1): 95-102. 10. Lotter O., Amr A., Stahl S., et al.: Pseudarthrosis after disruption of an incomplete luno-triquetral coalition: a case report. Ger Med Sci, 2010, 8, doc34 - http://www.egms.de/en/ journals/gms/2010-8/000123.shtml 11. Resnik C.S., Grizzard J.D., Simmons B.P., et al.: Incomplete carpal coalition. Am J Roentgenol, 1986, 147: 301-304. 12. Ganos D.L., Imbriglia J.E.: Symptomatic congenital coalition of the pisiform and hamate. J Hand Surg Am, 1991, 16: 646-650. 13. Metz V.M., Schimmerl S.M., Gilula L.A., et al.: Wide scapholunate joint space in lunotriquetral coalition: a normal variant? Radiology, 1993, 188: 557-559. 14. Stäbler A., Glacer C., Reiser M., et al.: Symptomatic fibrous lunato-triquetral coalition. Eur Radiol, 1999, 9: 1643-1646. 15. Poznanski A.K., Holt, J.F.: The carpals in congenital malformation syndromes. Am J Roentgenol, 1971, 112: 443-459. 16. Van Schoonhoven J., Prommersberger K.J., Schmitt R.: Traumatic disruption of a fibrocartilage lunate-triquetral coalition – a case report and review of the literature. Hand Surg, 2001, 6: 103-108.

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A RARE MALIGNANT HEPATIC TUMOR OF CHILDHOOD: TRANSITIONAL LIVER CELL TUMOR REVISITED H.N. Ozcan, B. Oguz, T. Salim, B. Talim, M. Haliloglu Transitional liver cell tumor is an extremely rare entity and has a poor prognosis. It has similar histopathologic findings with hepatoblastoma and hepatocellular carcinoma. Up to now, only 10 cases have been reported in the literature. We report on an 8-year-old boy with histologically proven transitional liver cell tumor and describe the pertinent radiological findings. Key-word: Liver neoplasms, in infants and children.

Two-thirds of primary liver tumors in the pediatric population are malignant, and malignant primary hepatic tumors account for 1%-2% of all childhood cancers (1). Primary malignant liver tumors in children comprise a heterogeneous group of neoplasms, the majority of them being hepatoblastomas (HBL) and hepatocellular carcinomas (HCC). HBL occurs almost exclusively in patients younger than 5 years old, whereas HCC develops in older children and adolescents (2). On the other hand, transitional liver cell tumor (TLCT) is an aggressive tumor, which is histologically neither typical HBL nor HCC; however, it has several pathological findings in common with those tumors. To the best of our knowledge, there are only 10 pediatric patients reported with TLCT in the literature (3). In this regard, we report an 8-year-old boy with histologically proven TLCT and describe the pertinent radiological findings. Case report An 8-year-old boy presented with a one-month history of right upper abdominal pain. He described a fall episode one-month before the onset of abdominal pain. The medical history was otherwise unremarkable. Physical examination revealed mild hepatomegaly. An abdominal ultrasound (US) showed mild hepatomegaly and heterogeneous mass with solid and cystic components in the right lobe of the liver (10 cm in anterior-posterior and 8 cm in transverse diameter). The right portal vein was encased within the mass and there was also 2 × 1 cm portal lymphadenopathy. Laboratory tests showed anemia, leukocytosis (with

Fig. 1. — Axial T1-weighted image shows hypointense tumor with lobulated margin (arrows) and cystic-necrotic area in the central part of the tumor (arrowhead).

neutrophilia) and elevated erythrocyte sedimentation rate. Liver function tests were normal. Serum α-fetoprotein (AFP) level was significantly elevated 37241.67 IU/mL (N: 0-6.67). Magnetic resonance imaging (MRI) revealed a multilobulatedlarge (9.5 cm in craniocaudal, 10.5 cm in anterior-posterior and 7 cm in transverse diameter), heterogeneous solid mass in the right liver lobe. The tumor involves segments V, VII and VIII (PRETEXT Classification II) (4). The tumor exhibits central necrotic areas with low signal intensity on T1weighted and high signal intensity on T2-weighted images (Fig. 1 and 2). The tumor enhanced slightly, but less than adjacent liver parenchyma after gadolinium administration (Fig. 3) and showed diffusion restriction on diffusion-weighted images.

From: Department of Pediatric Radiology, Hacettepe University Medical School, Ankara, Turkey. Address for correspondence: Dr H. Nursun Özcan, M.D., Fakülteler Mah. Dirim sok 22/3 Cebeci, 06590 Ankara, Turkey. E-mail: drhnozcan@yahoo.com

Encasement of the right h epatic vein could also be seen. The US guided percutaneous biopsy was performed and histological examination revealed a tumor composed of cellular components with features of both HBL and HCC (Fig. 4). The tumor was diagnosed as TLCT. The patient received chemotherapy. On repeat abdominal MRI (3 months later), the size of the tumor was found not to have changed -with further elevated AFP levels (93095.40 IU/ml). Thereafter, a right extended hepatectomy was performed. One week after surgery, AFP level dropped to 11901.30 IU/ml. The patient also received postoperative chemotherapy. Two months after the operation, abdominal US showed a 1 cm hypoechoic mass in the left hepatic lobe parenchyma. There was a 2×2 cm solid mass on the anterior aspect of the left hepatic lobe outside the liver capsule and a 4 × 3.5 cm solid mass in the right lower quadrant near the incision scar in the subcutaneous tissue. Doppler US revealed increased vascularity in both

JBR–BTR, 2015, 98 (2)

Fig. 2. — Axial T2-weighted MR image demonstrates a large hyperintense tumor in the right liver lobe (arrows). Note also the cystic-necrotic area in the central part of the tumor (arrowhead).

Fig. 4. — Hepatocellular carcinoma component with trabecular pattern composed of cells with high nucleus-cytoplasmic ratio (Hematoxylin and Eosin. Original magnification: ×100).

Fig. 5. — Two months after operation post contrast axial CT scan demonstrates a solid lesion in the right abdominal lateral wall (arrows).

lesions. Thorax and abdominal contrast enhanced CT showed multiple pulmonary metastases and multiple hypodense lesions in the left liver lobe, a solid mass in the anterior abdominal wall within the rectus abdominis muscle and another solid lesion in the right abdominal lateral wall (Fig. 5). At the last follow-up, AFP level was 17968.65 IU/ml. Discussion

B Fig. 3. — Axial gadolinium-enhanced T1-weighted MR images show heterogeneous enhancement of the tumor which is hypo intense relative to the normal liver parenchyma (arrows in A and B). There is lack of enhancement of the central necrotic area (arrowheads in A and B).

Primary malignant liver cell tumors in children represent a heterogeneous group, whereby HBL is seen predominantly in children less than 5 years of age, and HCC in older children and adolescents. Additionally, Prokurat and Zimmermann denoted a distinct group of malignant hepatocellular tumor named as TLCT, which

TRANSITIONAL LIVER CELL TUMOR — OZCAN et al

share common histological features with both of the aforementioned two types (5). They occur in older children and adolescents and markedly express beta-catenin, typically with a mixed nuclear and cytoplasmic pattern (5). The usual presentation is that of a large or multifocal and/or unresectable primary mass most commonly seen in the right liver lobe. TCLT displays an expanding growth pattern, sometimes exhibiting a large central necrosis. In cases of TLCT, in contrast to HBL and HCC, the tumor displays a poor response to initial chemotherapy with higher serum AFP levels at diagnosis. In the previous reports, due to the giant size of the tumors, surgery was connected with many technical difficulties and resulted in a high percentage of patients in whom microscopic radicality of surgery was impossible (3). Concerning the differential diagnosis, HCC usually occurs in children aged 10-14 years and 40-60% of the cases have elevated serum AFP levels (6). On post-contrast MR images, HCC typically demonstrates early arterial phase enhancement and may wash out with relative low signal intensity during the portal venous phase. If present, the tumor capsule is usually hypointense on T1- and

T2-weighted images with delayed enhancement. The imaging characteristics of HBL reflect its histologic composition. Histologically, HBL is classified into two types: the epithelial type and the mixed epithelial and mesenchymal type. Epithelial HBLs demonstrate a more homogeneous appearance, while mixed tumors are more heterogeneous in attenuation. At MR imaging, epithelial HBLs are homogeneously slightly hypo intense on T1-weighted images and hyperintense on T2-weighted images relative to adjacent liver parenchyma. Mixed tumors demonstrate more heterogeneous signal intensity characteristics. In our patient, the giant tumor included a central necrosis and serum AFP level was very high expected than HCC or HBL. MR images demonstrated slightly contrast enhancement after gadolinium administration but less than adjacent liver parenchyma. Diffusion restriction was seen on diffusion-weighted images. In conclusion, presenting this rare case of ours, we underscore the importance of multidisciplinary approach for prompt diagnosis of TLCT whereby the onward treatment will be tailored accordingly.

References 1. Chung E.M., Lattin G.E. Jr., Cube R., et al.: From the archives of the AFIP: Pediatric liver masses: radiologicpathologic correlation. Part 2. Malignant tumors. RadioGraphics, 2011, 31: 483-507. 2. Isaacs H. Jr.: Fetal and neonatal hepatic tumours. J Pediatr Surg, 2007, 42: 1797-1803. 3. Prokurat A., Chrupek M., Kaz´mirczuk R., et al.: Primary malignant liver cell tumours in children different treatment strategies. Ann Diagn Pediatr Pathol, 2006, 10: 17-22. 4. Roebuck D.J., Aronson D., Clapuyt P., et al. International Childrhood Liver Tumor Strategy Group.2005 PRETEXT: a revised staging system for primary malignant liver tumours of childhood developed by the SIOPEL group. Pediatr Radiol. 2007, 37: 123132. 5. Prokurat A., Kluge P., Kos´ ciesza A., Danuta P., Kappeler A., Zimmermann A.: Transitional liver cell tumors (TLCT) in older children and adolescents: A novel group of aggressive hepatic tumors expressing betacatenin. Med Pediatr Oncol, 2002, 39: 510-518. 6. Moore S.W., Hesseling P.B., Wessels G., Schneider J.W.: Hepatocellular carcinoma in children. Pediatr Surg Int, 1997, 12: 266-270.

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Erdheim Chester Disease Presented Isolated Breast and Axillary Involvement I. Basara1, E. Yavuz1, P. Balci1, E.B. Tuna2, I. Sari3 Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis of unknown aetiology. The most common sites of involvement are the long bones, skin, orbit, pituitary and retroperitoneal space. Isolated breast involvement is rare in the literature. ECD of the breast has been rarely reported. ECD should be considered in the differential diagnosis of histiocytoid breast lesions, including fat necrosis and histiocytoid invasive mammary carcinoma. In this case report, we present an unusual presentation isolated breast involvement of ECD with radiological and histopathology findings. Key-word: Liopogranulomatosis.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis. The aetiology of this disease is unknown (1, 2). The disease was first described as “lipoid-granulomatous” in two patients by William Chester and Jakob Erdheim in 1930 (2). Histologically, ECD is characterized by infiltration by foamy non-Langerhans cell histiocytes, Touton-type giant cells and mixed lymphoid infiltrates (3). The commonest involvement sites are bone, skin, orbit, pituitary, retroperitoneal space, pericardium, and lung (1, 2). Perivascular region, central nervous system, thyroid, testis, liver, and spleen are the rarer sites of ECD involvement (4). The symptoms of the disease include bone pain, diabetes insipidus, exophthalmos, dyspnoea, and neurologic symptoms. The prognosis of the disease depend on extend and severity of extraskeletal findings. Of 57% patients die secondary to pulmonary or cardiac involvement (2). Isolated breast involvement in ECD has been rarely described. To the best of our knowledge, there are only a few case reports of ECD of the breast. We present a case of ECD presenting as bilateral clinically malignant breast and axillary masses, with imaging findings suggestive of bilateral breast cancer. Case report In September 2013, a 62-year-old woman presented with palpable breast masses in the upper outer quadrant of both breasts and axillar regions. She did not have any trauma and did not report nipple dis-

charge. The patient had been admitted to the hospital with a complaint of nodular lesions on her eyelids 6 years ago. At that time these lesions were evaluated and biopsy was performed. Histopathology result was xanthomatous granuloma. In the meantime she did not have any specific complaints except cervical and lumbar pain. Blood and biochemical examinations, abdominal ultrasonography (US), cervical and lumbar magnetic resonance imaging (MRI) examinations were normal. In radiology department of our institute, the patient was evaluated with mammography. There were irregular opacities on both outer quadrants and axillary regions (Fig. 1A). After that she was examined with US. In US evaluation there were multiple, hypoechoic, macrolobulated solid nodular lesions. Also there were hypoechoic nodular lesions with hyperechogenic area which were thought as central hilum of lymph nodes at her both axillary regions (Fig. 1B). After these evaluations the patient was investigated with MRI examination. On MRI images there were well defined but irregular lesions in her both breasts extending to the axillary regions (Fig. 1C). The lesions were located on the anterior part of pectoral muscle and they were separated from the muscle. After contrast material administration, the lesions were enhanced and in pharmacokinetic evaluations type 2 curves were obtained (Fig. 1D). The lesions had diffusion restrictions in diffusion weighted MRI (Fig. 1E). After these evaluations the patients was referred to biopsy procedure and with 18G needle, tru-cut

From: Department of 1. Radiology, 2. Pathology, 3. Internal Medicine, Dokuz Eylul University School of Medicine, Izmir, Turkey. Address for correspondence: Dr I. Basara, M.D., Department of Radiology, Dokuz Eylul University School of Medicine, 35340, Izmir, Turkey. E-mail: isilbasara@gmail.com

iopsy was applied to the lesions on b her axillary regions. In the histopathology evaluation, the histiocytes had positive staining with antibodies for CD68 and were negative for S-100 protein (Fig. 2). After clinic, radiologic and histopathology evaluations of breasts, additionally systemic radiological and clinic evaluations were applied but there was no sign of ECD involvement in any other part of the body. As a result a diagnosis of isolated breast involvement of ECD was then proposed. Discussion ECD is an extremely rare disease of unknown aetiology, with distinct clinic, pathologic, and radiological findings in the absence of detectable serum lipid abnormalities. The clinical manifestations of ECD are not well defined, but men and women in the 50th through 70th decades of life appear to be affected (2). The clinical presentation is largely determined by the sites of involvement as a result of mass lesions, local pain, or functional compromise. Usually the most commonly reported symptoms are juxtaarticular bone pain of knee and ankle. There is no response to analgesics. Other symptoms include exophthalmos, diabetes insipidus, constitutional symptoms, retroperitoneal or ureteric/renal involvement (2). However less frequently symptoms are neurologic symptoms, body cavity effusions, cutaneous xanthomas and diffuse interstitial lung involvement (2). Isolated breast involvement by ECD is exceedingly rare and has rarely been described in the literature (3, 5, 6). There are only six cases published in the English literature (7). Our case is one of the few cases in the literature. In histological determination, there are mainly xanthomatous nonLangerhans histiocyte cells. The histiocytes in this disease do not

ISOLATED ERDHEIM CHESTER DISEASE OF BREAST — BASARA et al

Fig. 1. — A. On mammographic examination of right and left breasts, there are irregular lesions extending from both upper outer quadrant to axillar sites. B. On ultrasonograhic examination, the images at the upper are breast lesions, and the lesions at the lower part are axillar lesions. The breast lesions are hypoechoic, solid lesions with irregular contours. There are hyperechogen areas at the center of the lesions which were thought as hilum (arrows). C. On MR views, the images at the upper part are, axial fat saturated T2 weighted and the images at the lower part are axial post-enhanced subtracted images. There are irregular, enhanced lesions at the anterior of bilateral pectoral muscles extending to both axillar parts (arrows). D. There are type 2 pharmacokinetic curves obtained from the breast lesions. E. At the upper part there are b-1000 diffusion weighted images and at the lower part apparent diffusion coefficient images. There are marked diffusion restriction at the lesions (Circles and arrows).

xpress CD1a or S-100 protein (but e may display weak and focal positivity by immunohistochemistry for S-100 protein), and lack intra cytoplasmic Birbeck granules ultra-structurally. The cells are typically positive for CD68 and lysozyme (2, 8, 9). The xanthomatous cells are diffusely infiltrative, apparently resulting in collagenous fibrosis of tissues, and are usually associated with sparse lymphocytic infiltrates and Touton-type giant cells. All cells lack atypical cytological features in the lesion (2, 3, 8, 9). The symptoms of the disease such as bone pain, pathologic bone fractures and pancytopenia depend on replacement of the marrow space by xanthomatous histiocytes typically. The course of disease generally reflects the extend and sites of extra skeletal involvement (2, 9).

In our case, the breast lesions were radiological intermediate especially with axillary involvements. After all the radiologic evaluations, the lesions were accepted as BIRADS 4 lesions. In breast lesions, the differential diagnosis on histology includes fat necrosis, panniculitis such as lupus profundus mastitis, other histiocytic lesions including Langerhans cell histiocytosis and Rosai-Dorfman disease, and infection. Other lesions that can mimic histiocytes, particularly the histiocytoid variant of invasive lobular carcinoma, must be excluded (10). In fat necrosis, there should be a trauma history and architectural skin distortion of the breast. Rosai-Dorfman disease is a rare histiocytic proliferation, primarily nodal-based but with extra-nodal involvement, including

the breast (11). It is represented by a histiocytic proliferation with pale acidophilic cytoplasm, mildly atypical round vesicular nuclei and socalled lymphocytophagocytosis. The histiocytes are strongly positive for S100-protein as just the opposite of ECD. The most important differential diagnosis is the histiocytoid variant of invasive lobular carcinoma (12, 13). In this pathology, additionally there can be cutaneous metastasis such as eyelids mimicking xanthelasmas of ECD. Helpful diagnostic features favouring ECD versus histiocytoid carcinoma both in the primary and metastatic depositories are the lack of nuclear atypical in the former as well as absence of the immune reactive for cytokeratin (13). Immune suppressive drugs, prednisolone can be the first option in

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isease. Although, radiological evald uations are helpful in diagnosis, histopathology evaluation should be applied for correct diagnosis. References

C Fig. 2. — A. Core biopsies show extensive infiltration by foamy histiocytes with no nuclear atypical, and a patchy mature lymphoid infiltrate (H&E x20). B. The histiocytes are strongly positive for CD68, and C. negative for S100.

medical treatment. Furuta et al reported tyrosine kinase inhibitors for cases with BRAF V600E mutation (7). However, our patient receipt immune suppressive medical treatment, the lesions regressed and is followed-up period at our department.

In atypical breast lesions, a high grade of suspicion is needed to establish the correct diagnosis. It is important to keep in mind that patients harbouring systemic illness and breast lumps should be carefully investigated to exclude a breast involvement by the generalized

1. Allen T.C., Chevez-Barrios P., Shetlar D.J., Cagle P.T.: Pulmonary and ophthalmic involvement with Erdheim-Chester disease: a case report and review of the literature. Arch Pathol Lab Med, 2004, 128: 1428-1431. 2. Veyssier-Belot C., Cacoub P., Caparros-Lefebvre D., Wechsler J., Brun B., Remy M., et al.: ErdheimChester disease. Clinical and radiologic characteristics of 59 cases. Medi cine (Baltimore). 1996, 75: 157-169. 3. Andrade V.P., Nemer C.C., Prezotti A.N., Goulart W.S.: ErdheimChester disease of the breast associated with Langerhans-cell histiocytosis of the hard palate. Virchows Arch, 2004, 445: 405-409. 4. Sheu SY., Wenzel R.R., Kersting C., Merten R., Otterbach F., Schmid K.W.: Erdheim-Chester disease: case report with multisystemic manifestations including testes, thyroid, and lymph nodes, and a review of literature. J Clin Pathol, 2004, 57: 1225-1228. 5. Ferrozzi F., Bova D., Tognini G., Zuccoli G. Pseudotumoral bilateral involvement of the breast in ErdheimChester disease: CT appearance. J Comput Assist Tomogr, 2000, 24: 281283. 6. Tan A.P., Tan L.K., Choo I.H.: ErdheimChester disease involving breast and muscle: imaging findings. AJR Am J Roentgenol, 1995, 164: 1115-1117. 7. Furuta T., Kiryu S., Yamada H., Hosoi M., Kurokawa M., Morikawa T., Shibahara J., Ohtomo K.: ErdheimChester disease with an 18F-fluorodeoxyglucose-avid breast mass and BRAF V600E mutation. Jpn J Radiol, 2014, 32: 282-287. 8. Lenahan S.E., Helm K.F., Hopper K.D.: Erdheim-Chester disease. J Cutan Med Surg, 2003, 7: 129-132. 9. Loeffler A.G., Memoli V.A.: Myocardial involvement in Erdheim-Chester disease. Arch Pathol Lab Med, 2004, 128: 682-685. 10. Provenzano E., Barter S.J., Wright P.A., Forouhi P., Allibone R., Ellis I.O.: Erdheim-chester disease presenting as bilateral clinically malignant breast masses. Am J Surg Pathol., 2010, 34: 584-588. 11. Ng S.B., Tan L.H., Tan P.H.: Rosai- Dorfman disease of the breast: a mimic of breast malignancy. Patholo gy, 2000, 32: 10-15. 12. Gupta D., Croitoru C.M., Ayala A.G., Sahin A.A., Middleton L.P.: E-cadherin immunohistochemical analysis of histiocytoid carcinoma of the breast. Ann Diagn Pathol, 2002, 6: 141-1417. 13. Tomasini C., Soro E., Pippione M.: Eyelid swelling: think of metastasis of histiocytoid breast carcinoma. Der matology, 2002, 205: 63-66.

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Cysts in a Brunner’s Gland Hamartoma: A Clue to Diagnosis Y.-K. Fan, Y.-P. Liu, Y.-L. Lin, W.-K. Su1 The appearance of cystic Brunner’s gland hamartomas (BGHs) on computed tomography (CT) or magnetic resonance imaging (MRI) has only been reported in a very small number of cases. Imaging diagnosis of cystic BGHs is usually difficult. We present a case of cystic BGH and characterize it in conjunction with previously reported cases. We found that the cysts of BGHs are smaller than those of other cystic duodenal lesions. The presence of cysts in BGHs can limit the differential diagnosis to cystic duodenal lesions, and our observations may assist others in the discrimination of cystic BGHs from other cystic duodenal lesions. Key-words: Brunner’s gland – Hamartoma – Duodenum — Cyst.

Brunner’s gland hamartomas (BGHs) are uncommon duodenal lesions, and account for approximately 5% of all duodenal masses (1). BGHs contain cysts on rare occasions, and only a very small number of cases of cystic BGH with accompanying computed tomography (CT) or magnetic resonance imaging (MRI) documentation have been reported (2-4). Imaging diagnosis of BGHs is usually a challenge, due to their nonspecific appearance. The presence of cysts can limit the differential diagnosis to cystic duodenal lesions. Characterization of the cysts in BGHs may facilitate their differentiation from other cystic duodenal lesions. Herein, we present a case of duodenal cystic BGH and review the cases reported to date, to determine the differences between the cysts of BGHs and those of other cystic duodenal lesions.

Fig. 1. — Endoscopic findings. A submucosal tumor with intact mucosa (asterisk) in the second portion of the duodenum causes luminal narrowing.

Case report A 39-year-old man who had been experiencing postprandial epigastric pain and vomiting for three days visited our emergency department. The results of his physical examination, laboratory tests, and abdominal sonography were unremarkable. An endoscopic examination of the upper gastrointestinal tract revealed a shallow gastric ulcer and a submucosal tumor in the second portion of the duodenum causing marked luminal narrowing (Fig. 1). Contrastenhanced abdominal CT showed a 2.2 × 4.5 cm mass with multifocal, cyst-like low densities occupying the second portion of the duodenum (Fig. 2). An endoscopic biopsy of the duodenal tumor was performed and pathologic examination revealed

that the cells and lobules of the Brunner’s glands were enlarged, but otherwise normal in appearance with no cellular atypia (Fig. 3). On the basis of the histologic findings, a diagnosis of a Brunner’s gland hamartoma was made. During hospitalization, oral intake was withheld and esomeprazole and metoclopramide were administered intravenously. Three days after admission, his abdominal pain and vomiting resolved, and the patient was discharged from the hospital. Surgical excision of the duodenal hamartoma was not performed. The patient has followed up twice in the outpatient department in the 1 month since his discharge, and remains symptomfree.

From: 1. Dpt of Radiology, Mackay Memorial Hospital, Taiwan, R.O.C. Address for correspondence: Dr Y.-K. Fan, Dpt of Radiology, Mackay Memorial Hospital, N° 690, Sec. 2, Guangfu Rd, East Dist., Hsinchu, Taiwan 300, R.O.C. E-mail: fyk5358@gmail.com

Discussion Brunner’s glands are normally located in the duodenal submucosa, and their concentration gradually decreases towards the distal part of the duodenum. These glands produce an alkaline secretion to protect the duodenum from injury by gastric acid and optimize the pH for pancreatic enzymes. The pathogenesis of BGHs is unknown. BGHs are glandular hyperplasias or hamartomas, rather than true neoplasms. Because these lesions do not have features of cellular atypia, the terms Brunner’s gland “hyperplasia” or “hamartoma” are preferable to “adenoma.” The distinction between Brunner’s gland hyperplasia and Brunner’s gland hamartoma is arbitrary. According to the guidelines used at the Armed Forces Institute of Pathology (Washington DC, USA), if the lesion is less than 5 mm in size it is called a hyperplasia, and if it is greater than 5 mm it is called a hamartoma (5).

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Fig. 2. — Axial and coronal contrast-enhanced CT images. A mass (white arrows) in the second portion of duodenum contains multiple small cysts. Duodenal lumen: black and white arrowheads, pancreas: asterisks.

Fig. 3. — Photomicrographs of the BGH (hematoxylin and eosin, original magnification ×80 in A and ×200 in B) shows proliferation of Brunner’s glands and cystic dilatation of a gland (asterisk in B).

BGHs may be symptomatic, and symptomatic lesions are often larger. The most common presentations in symptomatic patients are gastrointestinal hemorrhage (37%) and obstructive symptoms (37%) (6). In a series of 27 patients, 70% of BGHs were located in the duodenal bulb, 26% in the second portion of the duodenum, and 4% in the third portion, and most (89%) were pe dunculated (6). Cysts can only be identified in BGHs via CT or MRI on rare occasions. To our knowledge, only 4 cases demonstrating the CT or MRI appearance of cystic BGHs have been reported in the English-language

literature to date (2-4). These cysts are dilated acini or ducts of B runner’s glands. The CT findings of the previously reported cases and the current case are summarized in Table I. The smaller hamartomas (< 2 cm) contain a solitary cyst, and the larger ones (≥ 4 cm) manifest as a soft tissue mass containing multiple cysts. These cysts are round, ovoid, or elongated in shape. We found that the short axes of all cysts in these BGHs do not exceed the diameter of the abdominal aorta at the same level, in axial images. Diagnosis of BGHs is usually difficult, due to nonspecific imaging findings. However, the presence of cysts is helpful in di-

agnosis because the differential diagnosis is limited to cystic duodenal lesions. Cysts in BGHs differ from those in other cystic duodenal lesions. Duplication cysts and lymphangiomas are thin-walled cystic masses without mural nodules or soft tissue components. These cysts are larger than those in cystic BGHs (7, 8). In contrast with conventional soft tissue and central nervous system schwannomas, cysts are unusual in gastrointestinal schwannomas (9). If present, they are fewer in number and larger than those in BGHs of similar size (4, 10). Cystic change is not uncommon in gastrointestinal stromal tumors (GISTs),

CYSTS IN A BRUNNER’S GLAND HAMARTOMA — FAN et al

Table I. — Summary of the CT findings of cystic BGHs in the current case and the literature. Case

Age/Sex

Size of tumors (cm)a

Number of cysts

Reference

39/M

4.5

Current case

30/M

4.0

≥ 10

49/F

1.8

(3)

66/F

6.0

≥ 5c

(3)

48/M

< 2.0b

(4)

(2)

Largest dimension. The exact size of the BGH is not available in case 5. However, the largest dimension of the hamartoma approximates the diameter of abdominal aorta, and the diameter of abdominal aorta is estimated to be less than 2 cm. c Because limited images are available in these cases, exact number of cysts cannot be determined. a

and is more commonly seen in large tumors. Cysts in GISTs are significantly larger than those in BGHs (11, 12). The duodenum is an uncommon site for pancreatic pseudocyst formation. In the cases reported by McCowin and Federle (13), these pseudocysts were solitary and larger than the cysts of BGHs, and in all patients, CT revealed other evidence of pancreatitis in addition to duodenal pseudocysts. Cystic dystrophy in heterotopic pancreas (CDHP), most commonly located in the second portion of the duodenum, has a similar appearance to cystic BGHs. These cysts are multiple and small, and are very similar to those seen in larger cystic BGHs. However, inflammatory changes such as periduodenal edema, periduodenal effusion, and enlarged lymph nodes are observed in most cases with CDHP (14). Conclusion The size of cysts is the key to diagnosing cystic BGHs. The cysts in BGHs are smaller than the cysts of other cystic duodenal lesions, except CDHP. When a mass containing a small solitary cyst or multiple small cysts is found in the first and second portion of the duodenum, without evidence of periduodenal inflammatory change or pancreatitis, cystic BGH should be considered.

References 1. Botsford T.W., Crowe P., Crocker D.W.: Tumors of the small intestine. A review of experience with 115 cases including a report of a rare case of malignant hemangio-endothelioma. Am J Surg, 1962, 103: 358-365. 2. Park B.J., Kim M.J., Lee J.H., Park S.S., Sung D.J., Cho S.B.: Cystic Brunner’s gland hamartoma in the duodenum: a case report. World J Gastroenterol, 2009, 15: 4980-4983. 3. Hur S., Han J.K., Kim M.A., Bae J.M., Choi B.I.: Brunner’s gland hamartoma: computed tomographic findings with histopathologic correlation in 9 cases. J Comput Assist Tomogr, 2010, 34: 543-547. 4. Lee J., Park C.M., Kim K.A., Lee C.H., Choi J.W., Shin B.K., et al.: Cystic lesions of the gastrointestinal tract: multimodality imaging with pathologic correlations. Korean J Radiol, 2010, 11: 457-468. 5. Patel N.D., Levy A.D., Mehrotra A.K., Sobin L.H.: Brunner’s gland hyper plasia and hamartoma: imaging features with clinicopathologic correlation. AJR Am J Roentgenol, 2006, 187: 715-722. 6. Levine J.A., Burgart L.J., Batts K.P., Wang K.K.: Brunner’s gland hamartomas: clinical presentation and pathological features of 27 cases. Am J Gastroenterol, 1995, 90: 290-294. 7. Macpherson R.I.: Gastrointestinal tract duplications: clinical, pathologic, etiologic, and radiologic considerations. Radiographics, 1993, 13: 10631080.

8. Levy A.D., Cantisani V., Miettinen M.: Abdominal lymphangiomas: imaging features with pathologic correlation. AJR Am J Roentgenol, 2004, 182: 1485-1491. 9. Levy A.D., Quiles A.M., Miettinen M., Sobin L.H.: Gastrointestinal schwan no mas: CT features with clinico pathologic correlation. AJR Am J Roentgenol, 2005, 184: 797-802. 10. Bayraktutan U., Kantarci M., Ozgokce M., Aydinli B., Atamanalp S.S., Sipal S.: Education and Imaging. Gastrointestinal: benign cystic schwannoma localized in the gastroduodenal ligament, a rare case. J Gastroenterol Hepatol, 2012, 27: 985. 11. King D.M.: The radiology of gastro intestinal stromal tumours (GIST). Cancer imaging, 2005, 5: 150-156. 12. Naitoh I., Okayama Y., Hirai M., Kitajima Y., Hayashi K., Okamoto T., et al.: Exophytic pedunculated gastrointestinal stromal tumor with remarkable cystic change. J Gastro enterol, 2003, 38: 1181-1184. 13. McCowin M.J., Federle M.P.: Computed tomography of pancreatic pseudocysts of the duodenum. AJR Am J Roentgenol, 1985, 145: 10031007. 14. Vullierme M.P., Vilgrain V., Flejou J.F., Zins M., O’Toole D., Ruszniewski P., et al.: Cystic dystrophy of the duodenal wall in the heterotopic pancreas: radiopathological correla tions. J Comput Assist Tomogr, 2000, 24: 635-643.

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Bronchial lipoma: an unusual cause of pleural empyema S. Lanotte1, R. Frognier2, O. Van Cutsem2, P. Mailleux1 We report a case of rapidly growing pleural empyema due to endobronchial lipoma. The diagnosis was established by chest computed tomography (CT). Endobronchial lipoma is a rare benign tumor of the tracheobronchial tree which can cause irreversible damage to the distal lung parenchyma if diagnosis and treatment are not carried out in time. Key-word: Lipoma and lipomatosis.

Case report A 63-year-old man treated for bilateral pneumonia for two days was admitted to the emergency department with a temperature of 39°C, tachycardia and left basi-thoracic chest pain. Blood tests showed a Creactive protein (CRP) of 92 mg/L (reference < 5 mg/L) without leukocytosis. Chest radiography at the admission showed bilateral opacities in the bases of the lungs. Patient’s condition worsened despite large spectrum antibiotherapy. A repeated chest radiograph, two days after admission, showed a complete opacification of the left lung. A chest computed tomography (CT) was performed and showed a huge left sided pleural effusion (Fig. 1). The ultrasonography show ed multiloculated pleural fluid. The diagnostic was a rapid development pleural empyema. A left thoraco scopy was performed and the collection was drained. Three months later, a control CTscan was performed and showed that the left pleural empyema had completely resolved but it revealed in the left basal trunk, a nodular lesion, with homogeneous fat density and a bronchus parietal defect (Fig. 2). Bronchoscopy revealed a subtotal obstruction of the basal segmental bronchi of the left lower lobe by a yellowish polypoid lesion protruding into the bronchial lumen (Fig. 3). Histopathological examination of the biopsies confirmed a proliferation of mature fat tissue. There was no evidence of malignancy, and thus, a diagnosis of endobronchial lipoma was established.



From: 1. Department Radiology and Medical Imaging, 2. Department of Pneumology, Clinique Saint-Luc, Bouge (Namur), Belgium. Address for correspondence: Dr S. Lanotte, M.D., Department Radiology and Medical Imaging, Clinique Saint-Luc, Bouge (Namur), Belgium. E-mail: solennelanotte@gmail.com

Fig. 1. — A. Coronal reconstruction CT scan shows a huge left pleural empyema (white star). B. On a control CT performed three months later, meticulous analysis of bronchial tree revealed the presence of an adipose mass occluding the left basal trunk, including a homogeneous fat density area (- 98 HU), with bronchus parietal defect (white arrow).

BRONCHIAL LIPOMA — LANOTTE et al



Fig. 2. — CT scan with contrast injection of iodinated contrast (KV 120, mA 180, DLP 390 mGycm). Axial CT views at the level of left basal trunk show an endobronchial lipoma (- 111 HU) in the left basal trunk (white star) with bronchus parietal defect (black arrowheads) through bronchial wall (white arrows).

The patient was treated with ndobronchial resection by laser and e cryotherapy. The patient underwent bronchoscopic regular follow up to detect a possible recurrence because of the bronchus parietal defect at the level of the lipoma. Discussion Endobronchial lipoma is a benign tumor of the tracheobronchial tree, defined as a mass composed exclu-

sively of mature fat tissue (1) arising from the submucosal fat of large bronchus. Benign neoplasm of the tracheobronchial tree is quite rare, accounting for less than 10% of all airways neoplasms, while endobronchial lipoma is extremely rare. The tumors are more frequent in middle-age men (mean age, 60 years). Smoking and obesity are significant risk factors (2). Lipoma, like other endo-bronchial tumors, produces respiratory symp-

toms due to upper airways obstruction that occur when more than 50%75% of the luminal diameter is occluded. All of the symptoms are nonspecific and include persistent cough, dyspnea, chest pain, hemoptysis and recurrent pneumonia. Endobronchial lipoma is a benign tumor but it can cause irreversible damages to the distal lung parenchyma, unless the diagnosis and treatment are carried out in time (3). Chest radiographs usually show nonspecific changes related to the

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is permanent distal damage or any feature suggesting a possible malignant process (2). Conclusion Endobronchial lipoma is a rare and benign tumor of the lung. D uring the analysis of a chest CT scan, a systematic examination of the endobronchial tree should be performed, especially when imaging shows persistent changes due to upper airway obstruction or rapid development pleural empyema. Early diagnosis and endoscopic resection help to prevent irreversible distal lung damage. References Fig. 3. — Bronchoscopy revealed a smooth, polypoid lesion protruding into the bronchial lumen, obstructing the orifice of the left basal trunk (white arrows), below the Nelson bronchus (black arrows).

bronchial obstruction such as atelectasis or pneumonia. Less frequently, pleural effusion was observed on chest radiography. Our patient presented pneumonia of the left lung with rapid development pleural empyema. Pleural empyema associated to endobronchial lipoma was only recorded in four cases, and this is the fifth English-language reported (3). CT typically shows a homogeneous mass with fat density (-70 UH to -140 UH) and no contrast enhancement (4). Because of his high specificity and sensitivity in fat detection, computed tomography (CT) has a key role in establishing the diagnosis of endobronchial lipoma. However, when a fatty endobronchial mass is

identified on CT, differential diagnosis should include lipoma and fatty hamartoma that also can appear as a fatty mass (5). Pathological analysis of the resected tissue is necessary for accurate diagnosis but the distinction of endobronchial lipomatous hamartoma from lipoma is of minor interest as both are rare benign mesenchymal tumors in clinical practice Definitive diagnosis is made by bronchoscopy and biopsy (6). Bronchoscopic examination typically reveals a yellow polypoid mass with a smooth, regular and soft surface. Bronchoscopic resection is the treatment of choice as it helps preserving lung parenchyma. However, surgical resection is required if there

1. Park C.M., Goo J.M., Lee H.J., Kim M.A., Lee C.H., Kang M.J.: Tumors in the tracheobronchial tree: CT and FDG PET features. Radiographics, 2009, 29: 55-71. 2. Muraoka M., Oka T., Akamine S., et al.: Endobronchial lipoma: review of 64 cases reported in Japan. Chest, 2003, 123: 293-296. Ouadnouni 3. Y., Bouchikh M., Bekarsabein S., et al.: Endobronchial lipoma a rare cause of pleural empyema: a case report. Cases Journal, 2009, 2: 6377. 4. Simmers T.A., Jie C., Sie B.: Endobronchial lipoma posing as carcinoma. Neth J Med, 1997, 51: 143-145. 5. Wilson R.W., Kirejezyk W.: Pathological and radiological correlation of endobronchial neoplasm. Part I. enign tumors. Ann Diagn Pathol, B 1997, 1: 31-46. 6. Rodrigues A.J., Coelho D., Dias Junior S.A., Jacomelli M., Scordamaglio P.R., Fiqueiredo V.R.: Minimally invasive bronchoscopic resection of benign tumors of the bronchi. J Bras Pneumol, 2011, 37: 796800.

JBR–BTR, 2015, 98: 91.

IMAGES IN CLINICAL RADIOLOGY ‘Backfill’ of the sacroiliac joint space in spondyloarthritis F. Laloo1, N. Herregods1, H. Cypers2, K. Verstraete1, L. Jans1 Three patients of the outpatient rheumatology clinic of our hospital with inflammatory type low back pain suggestive for spondyloarthritis were referred for MRI of the sacroiliac joints. MRI showed high T1 signal within the SI joint (arrows) in all three patients, filling the extended erosions of the iliac bone in two patients (Figs. A and B) whereas a more petechial appearance in the sacroiliac joint space was seen in the third patient (Fig. C). The diagnosis of ‘backfill’ of erosions and of the sacroiliac joint space in spondyloarthritis was made. Comment

The prevalence of spondyloarthritis is estimated 1.5%. MRI of the sacroiliac joints is a cornerstone in the diagnosis, classification and follow-up of the disease since it depicts active inflammatory lesions long before radiographic changes become evident. Moreover, MRI may demonstrate late structural changes such as erosions, sclerosis, fat deposition and ankylosis. As new bone formation is a hallmark of spondyloarthritis, ankylosis of the sacroiliac joint is the well-known end-stage of the disease. Ankylosis may occur at sites where new bone formation is present. Early new bone formation may be seen as high T1 signal within erosions or within the sacroiliac joint itself. As this tissue reossifies the eroded bone and fills the joint space, this high T1 signal is called ‘backfill’ and is very specific for the diagnosis of spondyloarthritis. Reference 1. Weber U., et al.: Can erosions be reliably detected in patients with ankylosing spondylitis? A cross- sectional study. Arthritis Res Ther, 2012, 14: R124.

C 1. Department of Radiology, 2. Department of Rheumatology, Ghent University Hospital, Gent, Belgium.

JBR–BTR, 2015, 98: 92.

IMAGES IN CLINICAL RADIOLOGY Rare presentation of Langerhans cell histiocytosis C. Gieraerts1, P. Vandaele1, R. Schildermans2, L. Daveloose3, K. Ramboer1

A 51-year old woman consulted at our hospital with rightsided chest pain. A thoracic radiograph revealed multiple nodules in both lungs. These nodules were not present on a radiograph taken two months earlier during a routine check-up. A computed tomography of the thorax demonstrated multiple nodules varying from 3 to 15 mm (Fig. A). The nodules were spiculated and randomly distributed with predominance for the middle and upper lung zones (Fig. B). The mediastinal and hilar lymph nodes were slightly enlarged. Furthermore, a right sided osteolytic bone lesion was present anterolaterally in the eighth rib (Fig. C). Since the radiological differential diagnosis was very broad, a surgical lung biopsy and partial rib resection was performed. Histologically, the nodules showed infiltration of lymphocytes, eosinophils and Langerhans’ cells. The osteolytic bone lesion showed typical findings of an eosinophilic granuloma. Both lesions were consequently a presentation of the same disease and the diagnosis of Langerhans’ cell histiocystosis (LCH) with pulmonary involvement was made. Immunosuppressive therapy with glucocorticoids was initiated resulting in partial regression of the pulmonary nodules on a follow-up scan. Unfortunately, the patient refused to stop smoking and a recent scan showed disease progression. Comment

Langerhans cell histiocytosis is a rare histiocytic disorder characterized by accumulations of large mononuclear cells forming granulomas B in various organs. The disease can be divided into two groups based on single or multisystem involvement. Multisystemic disease is most common in young children whereas single organ involvement is more common in adults. When the lung is the primarily affected organ, the disease is called pulmonary Langerhans cell histiocytosis (PLCH), previously known as Histiocystosis X or eosinophilic granuloma of the C lung. In the whole spectrum of LCH, PLCH is considered as somewhat atypical since it is associated with cigarette smoking in more than 90 percent of cases. Patients with PLCH usually present with respiratory or constitutional symptoms. Frequently the diagnosis is made incidentally on a routine chest radiograph. Our patient shows multisystemic disease but the pulmonary changes are most notably. Typically, in the first stage of pulmonary disease, multiple small nodules are present with middle and upper lung zone predominance. The nodules are normally around 5 mm in diameter. With disease progression, the nodules start to excavate and form cystic lesions. The advanced form is the most commonly seen by radiologists: multiple pulmonary cysts, usually less than 10 mm in diameter but often confluent, with variable wall thickness and middle and upper lung zone predominance, sometimes associated with some nodules. Multiple nodules lesions in the absence of cysts are only present in the early stage of LCH and are seldom seen in imaging. Multisystemic presentations like in our patient with a concomitant bone lesion are rare in older patients. Next to smoking cessation, glucocorticoid treatment is often effective in the treatment of this disease (1). Reference 1. Mogulkoc N., Veral A., Bishop P.W., Bayindir U., Pickering C.A., Egan J.J.: Pulmonary Langerhans’ cell histiocytosis: radiologic resolution following smoking cessation. Chest, 1999, 115: 1452.

1. Department of Radiology, 2. Department of Pneumology, AZ Sint-Lucas, Bruges, Belgium, 3. Medical student, Ghent University, Ghent, Belgium.

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IMAGES IN CLINICAL RADIOLOGY A glomus tumor P. Kulczycka1, B. Dallaudière1, O. Barbier2, B. Vande Berg1, A. Larbi1

A 54-year-old woman presented with a two-year-history of tenderness and cold sensitivity of the subungueal region of her 3rd left finger. Physical examination revealed a pinkish red spot under the nail. Ultrasonography of the 3rd left finger shows a well-delimited hypoechoic and hypervascularised mass in the subungueal area (Fig. A). X-ray of the 3rd left finger shows well-defined bony erosion with sclerotic margins in the distal phalanx (scalloping) which indicating a chronic growth lesion (Fig. B). The diagnosis proposed was the glomus tumor. A tumor excision was performed and the histologic examination confirmed the glomus tumor diagnosis (Fig. C). The localized pain and point tenderness disappeared after surgical excision. The patient did not experience any recurrence or further complications. Comment Glomus tumor is rare, often-benign neoplasms arising from a neuromyoarterial structure called a glomus body that controls blood pressure and temperature (Masson’s tumor). It can appear in any part of the body, although it mostly appears in the extremities, especially in the hand at the subungueal area. Usually, it is a solitary tumor, but in 10% of all cases there are multiples lesions. Glomus tumors are difficult to diagnose clinically and the diagnosis is frequently delayed. Classic clinical symptoms are aching pain, focal tenderness and cold hypersensitivity. Bony erosion with sclerotic margins can be seen on X-Rays but this finding is rare (Fig. B). An ultrasound examination is a good tool for detecting glomus tumor, showing a well-delimited hypo echoic and hyper vascularised mass (Fig. A). It can however underestimate the size of a glomus tumor. MRI can be used but is not necessary for the diagnosis. It shows a well-delineated mass with a low signal on T1-weighted sequence and high signal intensity on T2-weighted sequence. Glomus tumor enhances early, intense and rapid after intravenous gadolinium administration. The treatment of a glomus tumor should be surgical and the dramatic pain relief after excision is characteristic. These tumors have a high recurrence rate because it is difficult for the surgeon to distinguish it from the adjacent tissues.

Reference 1. Tang C.Y.K., Tiptoe T., Fung B.: Where is the Lesion? Glomus Tumours of the hand. Archives of Plastic Surgery, May 2013.

1. Department of Radiology, 2. Department of Orthopedy and traumatogy, Cliniques Universitaires St-Luc, Brussels, Belgium.

JBR–BTR, 2015, 98: 94.

IMAGES IN CLINICAL RADIOLOGY Dirty shadowing in emphysematous pyelonephritis A. Eeckhoudt1,2, F.M. Vanhoenacker1,2,3

A 62-year-old female presented with progressive pain at the left loin region, chills and fever for 1 week. Laboratory results showed an elevation of CRP and raise of white blood cell count. Creatinine and urea were normal. Midstream urine sample showed an elevation of white blood cells, as well as detection of bacteria. The patient had no prior medical history of diabetes mellitus or urinary obstruction. Glycemia was within normal range. On ultrasound, visualization of the left kidney was largely impaired due to dirty shadowing caused by subcapsular air (Fig. A, arrows). CT scan of the abdomen showed an enlarged left kidney, with multiple subcapsular air bubbles (Fig. B and C, arrows). There was inhomogeneous enhancement of the left kidney with formation of subcapsular fluid collections at the upper and middle pole. Based on the combination of characteristic clinical and imaging findings, the diagnosis of an emphysematous pyelonephritis was made. The patient was treated with intravenous antibiotics and left nephrostomy. Clinical evolution was favorable, although the left kidney showed a shrunken appearance on follow-up studies. Comment

Emphysematous pyelonephritis is an acute necrotizing infection of the r enal parenchyma and its surrounding tissues. Mortality due to emphysematous pyelonephritis is most commonly associated with septic complications. Mortality rate is approximately 20%. In 95% of the cases, there is an underlying undiagnosed diabetic mellitus. Other risk factor are urinary tract obstruction, immunosuppression, polycystic kidneys and end stage renal disease. Our patient had none of these predisposing factors. Escherichia coli is the causative pathogen in most cases (70%). It produces gas via fermentation of glucose and lactate. The clinical presentation of emphysematous pyelonephritis is similar to non-complicated pyelonephritis. Signs and symptoms that may be present are: fever, dysuria, nausea and flank pain. Loin tenderness is frequently noticed on clinical examination. Sometimes crepitus around the renal region or in the scrotum can be felt. Because of its nonspecific clinical presentation, emphysematous pyelonephritis is a radiological diagnosis. Sings of emphysematous pyelonephritis on ultrasonography (US) are an enlarged kidney, with hyperechogenic foci within the parenchyma and dirty shadowing, corresponding to gas. Impaired visualization of the kidney may result in underestimation of the disease. CT is the preferred imaging technique to allow a specific diagnosis and evaluation of the extent of infection. The presence of bubbly and/or linear gas bubbles within the renal parenchyma, combined with renal enlargement and heterogeneous enhancement with C wedge-shaped hypodense areas and abscess formation, are the signature of emphysematous pyelonephritis. It is important to distinguish emphysematous pyelonephritis from emphysematous pyelitis, because emphysematous pyelitis has a far better prognosis, and can be treated with mere antibiotics. Emphysematous pyelitis can be recognized by gas formation that is limited to the renal collecting system. The most successful treatment strategy for emphysematous pyelonephritis is a combination of antibiotics with percutaneous or surgical nephrostomy. In conclusion, emphysematous pyelonephritis is a potentially life threatening condition. It is an imaging diagnosis, with CT as the first choice imaging technique. Reference 1. Ubee S.S., McGlynn L., Fordham M.: Emphysematous pyelonephritis. BJU Int, 2011, 107: 1474-1478. 1. Department of Radiology, AZ Sint-Maarten, Duffel-Mechelen, 2. Department of Radiology, University Hospital Ghent (UZ Gent), 3. Department of Radiology, University Hospital Antwerp (UZA).

JBR–BTR, 2015, 98: 95.

IMAGES IN CLINICAL RADIOLOGY MDCT findings of polymicrobial descending necrotizing mediastinitis C. Karanikas, P. Lampropoulou, D. Karakiklas, C.S. Baltas, A. Demertzis, C. Drosos1

A 43-year-old Caucasian male with an uneventful medical history resented to ER complaining of sore throat and fever of 38.3°C. Clinical p examination revealed unilateral right sided tonsillitis. Over the next 4 days, he developed malaise, shortness of breath, right-sided neck swelling and chest pain and he was admitted. The patient was systematically unwell with clinical manifestations of persistent neck swelling and pain radiating to the right shoulder, fever, slight discoloration of overlying skin, subcutaneous crepitation, mild trismus, odynophagia and decreased oral intake, in the setting of a peritonsillar abscess. Within a few hours after hospitalization, the patient presented upper airway obstruction due to massive edema, resulting in acute respiratory insufficiency that necessitated tracheal intubation and transfer to the ICU, while planning for surgical intervention. MDCT scan of the cervical and thoracic region (Fig. A,B,C) showed a parapharyngeal abcess descending into the mediastinum, spreading towards the diaphragm, with bilateral pleural effusions, along with diffuse necrotizing fasciitis, collection of gas in mediastinal compartments and soft tissue infiltration with loss of normal fat planes. The patient underwent combined extensive neck and thorax drainage in conjunction with limited surgical debridement consisting of cervicotomy. Swabs identified a polymicrobial infection with predominant species of Streptococcus pyogenes, anaerobic Peptostreptococci and Streptococcus viridans. The empirical antibiotic regimen included piperacillin – tazobactam and v ancomycin. After 29 days of intubation and ventilation in ICU, the patient was extubated and transferred to the ward in order to complete the 6-weekcourse of IV antibiotic therapy. By this time the patient presented no r esidual deficits. Comment

Numerous series of patients suffering of mediastinitis have been reported, especially the descending necrotizing type both focal and diffuse, that lead Endo et al to develop a classification system of the extent of the disease on the basis of the CT findings. Type I disease represents mediastinitis confined above the carina, type IIA disease extends to the anterior lower mediastinum and type IIB disease involves both anterior and posterior mediastinum. Patients with type I mediastinitis may not require drainage at all, while type IIA patients require drainage without sternotomy (via the subxiphoid approach) and type IIB patients require drainage with open thoracotomy. MDCT is the study of choice for evaluation of mediastinal emergencies C such as DNM, since it provides sagittal/coronal reconstructions, is readily available, non invasive and easy to perform. There are both primary and secondary CT features of DNM, both of which were present in our case. Primary features include free gas bubbles in the mediastinum and/or localized fluid collections, or even abscess, and secondary CT findings include increased attenuationof mediastinal fat, pleural and/or pericardial fluid, enlargement of lymph nodes and rarely lung parenchymal abnormalities. Reference 1. Weaver E., Nguyen X., Brooks M.A.: Descending necrotizing mediastinitis: two case reports and review of the literature. Eur Respir Rev, 2010, 19: 141-149. 1. Radiology Department, “G. Gennimatas” General Hospital of Athens, Athens, Greece.

JBR–BTR, 2015, 98: 96

IMAGES IN CLINICAL RADIOLOGY Tentorium hypoplasia with partial occipital lobe herniation E. Thomaere1, S. Schepers2, B. Termote2, R. Vanwyck2, G. Souverijns2 A 50-year-old woman was referred by her general practitioner to our hospital with complaints of vertigo and headaches. Magnetic resonance (MR)-imaging, axial (Fig. A) and coronal (Fig. B) T1 weighted, revealed a partial right occipital lobe herniation (inferior precuneus), secondary to a congenital focal hypoplasia of the tentorium, located on the anterosuperior part of the cerebellum, a rare incidental finding. Comment The tentorium cerebelli is the second largest dural reflection. It extends horizontally between the cerebellum and the cerebral hemispheres and thereby divides the cranial cavity into supra tentorial and infratentorial. Agenesis or hypoplasia of the tentorium cerebelli is usually associated with extensive central nervous system malformations, such as Dandy-Walker Syndrome and Arnold- Chiari Malformation. A Isolated hypoplasia has only been described in four cases before in adults. In the first case described by Tanohata a computed tomography (CT) showed a focal hypoplasia of the left tentorium cerebelli with secondary protrusion of the temporal lobe into the superior cerebellar and quadrigeminal cisterns. The symptoms of the patient (galactorrhea) were not related to the imaging findings. The other three cases are described by Abi-Jaoudeh and Chevrette. In the first case CT and MRI investigations showed a hypoplasia of the right tentorial leaf with protrusion of the isthmus of cingulate gyrus and the medial occipitotemporal gyrus into the superior cerebellar cistern. In the second case a CT showed a small hypoplasia of the right tentorial leaf with discrete protrusion of the medial occipitotemporal gyrus and the parahippocampal gyrus into the cerebellar cistern. In the third case an angio-MRI for cerebral aneurysm screening, showed a hypoplasia of the right tentorial leaf with protrusion of the parahippocampal gyrus into the quadrigeminal cistern. In all three cases the symptoms were unrelated to these imaging findings. The most accepted hypothesis about the development of the tentorium is an abnormal fusion of the tentorium by Tanohata. The tentorium develops as the second dural reflection, first the medial parts develop and secondly the lateral parts. Afterwards the medial parts involute and the lateral parts, which consists of the caudo B lateral and the rostrolateral parts, fuse. Abnormal fusion of the lateral parts can possibly lead to this anomaly. Birth traumas or perinatal insults can also be considered as the cause of this anomaly. Most probably symptoms depend on the severity and location of the tentorial defect, but the exact clinical significance is still uncertain. It is important to recognise a tentorial hypoplasia and to know and report that there are no known clinical symptoms associated with this finding. In this case no treatment was needed, because the symptoms were unrelated to the i maging findings. Reference 1. Abi-Jaoudeh N., Chevrette E.: Isolated hypoplasia of the tentorium. J Comput Assist Tomogr, 2006, 30: 131-134.

1. Department of Radiology, UZ Gasthuisberg, Leuven, 2. Department of Radiology, JESSA ziekenhuis, Hasselt, Belgium.

JBR–BTR, 2015, 98: 97.

IMAGES IN CLINICAL RADIOLOGY 320-row-detector CT angiography findings in a case with myocardial bridging in the three main coronary arteries S. Akay1, U. Bozlar2, Demirkol Sait3, M. Tasar2

A 46-year-old man with the complaining of palpitation was admitted to our hospital. Polymorphic ventricular early beats were observed on electro cardiography, The patient was referred to our department for coronary artery computed tomography angiography (CTA) for a probable congenital anomaly. On coronary CTA performed by a 320-Row-Detector scanner; left main coronary artery was short. The myocardial bridging (MB) causes approximately 75% luminal stenosis in a 2.5-cm segment was observed in the middle segment of left anterior descending artery (Fig. A, white arrow). The circumflex artery was continuing as the first obtus margin artery and this branch was separating to four branches in the middle part. All of these branches were coursing subepicardially in the middle and distal part (Fig. B, white arrowheads). The right main coronary artery was separating to two branches in the proximal part, and the thinner one was showing MB in its middle part (Fig. C, black arrow). This branch had a subepicardial course as well, in its distal part along the right atrium (Fig. C, black arrowheads). Eventually, all the cardiologic examinations and imaging findings were reevaluated. Based on those findings, antiarrhythmic drug therapy was prescribed by cardiology department, and the patient was called for regular follow-up. Comment

CTA study was performed by using a 320 row-detector CT scanner (Aquilion One; Toshiba Medical Systems, Ottawara, Japan). Because of the heart rate of the patient was 60 beats per minute, we did not give betablocker drug. Prospective ECG-triggered dose modulation was used. The tube voltage was 120 kV. A biphasic injection of intravenous contrast was C used and the total amount of 70 ml non-ionic contrast agent (Iohexol-350; GE Healthcare, USA) was injected into the antecubital vein at a flow rate of 5.0 ml, followed by a saline flush. In order to synchronise the arrival of the contrast agent and the scan, bolus arrival was detected using automated peak enhancement detection in the ascending aorta using a threshold of 200 HU. An initial data set was reconstructed with a slice thickness of 0.5 mm and a reconstruction interval of 0.25 mm. The images were transferred to an image postprocessing workstation (Vitrea 2.0; Vital Images, Minnetonka, MN). Then axial raw, multiplanar, curved and rotated reformatted images were evaluated along the course of each coronary artery and major side branches, and thin-slab maximum-intensity projection images created at the workstation. The clinical importance of the MB is controversial. Although the bridging is asymptomatic in most of the cases, it can rarely cause myocardial ischemia and related complications. While MB was observed in 0.5-2.5% of the catheter angiography studies, it was reported as ranging rates from 15% to 85% in the autopsy series. MB is seen most commonly in the middle segment of left descending artery. The other main coronary arteries and their branches are affected less frequently. In 320-detector row CT, the entire heart is imaged with temporal uniformity. The temporal resolution of an multi detector CT scanner reflects the ability to freeze cardiac motion, thus producing motion-free images. The 320-detector scanner has a standard temporal resolution of approximately 175 ms which is a very short time compared with the lower detector row CT scanners. Wide-area coverage multidetector CT, such as 320-detector row scanner, has enabled volumetric imaging of the entire heart free of stair-step artifacts at a single time point within one cardiac cycle. MB is not a rare situation in the routine clinical practice. But bridging in all the three main coronary arteries is very uncommon. Multidetector coronary CTA, especially by using a 320-row-detector scanner is an effective and non- invasive imaging modality for understanding the normal coronary anatomy and detecting the congenital anomalies of the coronary arteries. References 1. Möhlenkamp S., Hort W., Ge J., Erbel R.: Update on myocardial bridging. Circulation, 2002, 106: 2616-22. 2. Hsiao E.M., Rybicki F.J., Steigner M.: CT coronary angiography: 256-slice and 320-detector row scanners. Curr Cardiol Rep, 2010, 12: 68-75. 1. Dpt of Radiology, Sirnak Military Hospital, Sirnak, 2. Dpt of Radiology, 3. Dpt of Cardiology, Gulhane Military Medical School, Ankara, Turkey.

JBR–BTR, 2015, 98: 98.

IMAGES IN CLINICAL RADIOLOGY The single right coronary artery E. Christiaanse1, D. Verdries2, K. Tanaka2, S. Carlier3, J. de Mey2

An asymptomatic obese 60-year-old man with an increased cardio vascular risk profile (arterial hypertension and hypercholesterolemia) was checked prior to hip surgery. Resting ECG was normal. Exercise test was not possible. A dipyridamole myocardial perfusion scintigraphy showed inferolateral ischemia and a preserved left ventricular (LV) function. Coronary angiography demonstrated moderate atherosclerosis in the proximal segment of the right coronary artery (RCA) and a moderate stenosis in the distal segment of the posterolateral branch (Fig. A). The left anterior descending artery (LAD) and diagonal branches were visualized simultaneously. No additional coronary ostium could be found. The contrast enhanced cardiac CT was performed and it confirmed the absence of a left coronary ostium and a single RCA with two large right ventricular (RV) branches continuing to the left coronary artery (LCA). The first RV branch continued to the diagonal branch. The second RV branch continued to the LAD. Interestingly, in the anterior interventricular sulcus, the LAD had a bidirectional course proximally and distally, with proximally the emergence of an hypoplastic left circumflex artery (LCX) (Fig. B, C). None of the branches were running between the pulmonary artery and the ascending aorta, corresponding with a R-II A classification according to Lipton/ Yamanaka. Comment

A single RCA is an extremely rare congenital anomaly with an estimated incidence of 0.066% of the population. In a single coronary artery (SCR) B by definition only one coronary artery originates from the aortic trunk and supplies the entire heart. The current classification system was introduced by Lipton et al. and modified by Yamanaka et al. In this classification the origin of the SCA from the right sinus of Valsalva is defined as ‘R’ and from the left sinus of Valsalva as ‘L’. The normal anatomical course of the SCA is defined as ‘I’. The type ‘II’ SCA provides the contralateral coronary artery and crosses the base of the heart to assume its inherent normal position. In the type ‘III’ SCA, after leaving the right coronary sinus of Valsalva LAD and LCX arise separately from proximal part of the artery. A further subdivision can be made according to the anatomical course. In type ‘A’ the main left or right coronary passes anterior to the pulmonary artery, ‘B’ passes between the aorta and pulmonary artery and ‘P’ posterior to the aorta. Yamanaka et al. distinguished a septal type ‘S’ with the course of the SCA through the interventricular septum and a combined type ‘C’. Patients with a SCA are usually asymptomatic and the anomaly found incidentally during angiography. The clinical significance mainly depends C on the course of the SCA in relation to the great arteries with a course between the pulmonary artery and the aorta being at risk to arrhythmias, ischemia and sudden death especially during exercise. According to our knowledge, this is the first anatomical description of right ventricular branches of a single RCA continuing to a diagonal branch, a bidirectional LAD and a hypoplastic LCX. Reference 1. Lipton M.J., Barry W.H., Obrez I., Silverman J.F., Wexler L.: Isolated single coronary artery: diagnosis, angiographic classification, and clinical significance. Radiology, 1979, 130: 39-47.

1. Department of Radiology, ZorgSaam Zeeuws-Vlaanderen, Terneuzen, The Netherlands, 2. Department of Radiology, Universitair Ziekenhuis Brussel, Brussels, Belgium, 3. Department of Cardiology, CHU Ambroise Paré & Faculty of Medicine and Pharmacy, University of Mons, Mons, Belgium.

JBR–BTR, 2015, 98: 99.

IMAGES IN CLINICAL RADIOLOGY Symptomatic coracoclavicular joint S. Lanotte1, S. Van Den Broeck1

A 47-year-old woman was referred to our radiology epartment for right shoulder arthroscanner evaluation d because of anterior shoulder pain. She had previously been practising professional dance. Computed Tomography (CT) (Fig. A) did not show any shoulder pathology but meticulous analysis revealed the presence of a joint between the clavicle and the coracoid process with degenerative changes. In retrospect, the coracoclavicular joint was visible on plain radiographs (Fig. B). A coracoclavicular joint arthrogram (Fig. C) confirmed a diarthrosis with articular cartilage covering both articulation surfaces surrounding by an articular capsule. The patient was treated with local intraarticular injection of steroids under image guidance. Comment

Coracoclavicular joint (CCJ) is a true synovial diarthrosis between the coracoid process of the scapula and the conoid tubercle of the clavicule. This relatively rare anatomical structure is reported by 0.04% to 3.0% of radiological investigations. The presence of such a joint is mostly asymptomatic but may cause shoulder pain. There are so far only 17 other reports of symptomatic CCJ but this incidence is likely underestimated due to underreported and underdiagnosed cases. Patients commonly suffer from diffuse shoulder pain radiating to the arm. This pain can be accompanied by paraesthesia and is aggravated by movement. Plain radiographs are typical of a joint and reveal a bony outgrowth from the undersurface of the clavicle forming an articular surface with a tubercle on the dorsomedial surface of the coracoid process. Arthrograms typically show the two processes forming a real joint surrounded by a capsule and the two bony surfaces being covered by cartilage. In conclusion, CCJ is an unusual cause of shoulder pain which can be recognised on plain radiographs and ought to be considered in the differential diagnosis of unexplained shoulder pains.

Reference 1. Singh V.M., Singh P.K., Trehan R., Thompson S., Pandit R., Patel V.: Symptomatic coracoclavicular joint: incidence, clinical significance and available management options. Int Orthop, 2011, 35: 1821-1826.

1. Department Radiology and Medical Imaging, Clinique Saint-Luc, Bouge (Namur), Belgium.

JBR–BTR, 2015, 98: 100-102.

LETTER TO THE EDITOR A case of Symptomatic Mesenteric Panniculitis Presenting with Unusual Positive FDG PET/CT Nodular Components: An Atypical Imaging Strategy with Histopathologic Correlation. B. Coulier1, I. Bueres2, F.C Deprez3, F. Richelle4, R. Rubay5, I. Gielen6, C. Fervaille7

Dear Editor in Chief, Mesenteric panniculitis (MP) is a benign inflammatory condition of unknown etiology that involves the adipose tissue of the proximal mesentery and has received considerable attention over the last two decades. In a recent couple of papers published in volume 94 (2011) of JBR-BTR we successively tried to explore the typical imaging findings and to prospectively study the prevalence and natural course of MP (1,2). The radiological CT diagnosis of MP is classically based on typical if not pathognomonic features clearly described and documented in the literature (1-6). They comprise the presence of a well-defined “mass effect” on neighboring structures (sign 1) constituted by mesenteric fat tissue of inhomogeneous higher attenuation than adjacent retroperi toneal or mesocolonic fat (sign 2) and containing small soft tissue nodules (sign 3). These nodules are typically surrounded by a hypo attenuated fatty “halo sign” (sign 4) and a hyperattenuating pseudo capsule may also surround the all entity (sign 5). The last two signs (4 and 5) are considered inconstant but extremely specific. We first concluded that the preva lence of mesenteric panniculitis was much higher than previously re ported ranging from 3, 42% to 7, 83% of patients – following the number of CT signs (3 or 5) considered as efficient to achieve the diagnosis – in which an abdominal CT was per formed for various reasons or symp toms (2). This high prevalence could probably explain the spontaneous association with the numerous and probably unrelated clinical situations

found in the literature in many single cases reports. In fact we also con cluded that the vast majority of cases could be considered as idiopathic, benign an asymptomatic (2). More over follow-up CT studies showed a great stability of the CT findings of mesenteric panniculitis in about 85% of cases (2).

One of our most important but still controversial conclusions was that the value of MP in term of pre dictivity of an associated neoplasm was probably not relevant. Indeed except a discretely higher prevalence found in patients presenting with bladder and/or prostatic neoplasms and with

Fig. 1. - Axial images (A-C) illustrate rather typical CT features of mesenteric pannicu litis (MP) comprising mesenteric fat tissue of slightly higher attenuation than adjacent retroperitoneal or mesocolonic fat, a “mass effect” on neighbou ring structures, diffuse small soft tissue nodes and a subtle “halo sign” around several nodes. Nevertheless unusual and sometimes supracentimetric large nodes (black arrows) are also associated in the mesentere itself and in the preaortic retroperitoneal fat. Fortunately a previous abdominal CT performed 30 months earlier is available in our PACS (D-F) already showing MP signs and subtle peripheral nodes. We first conclude that the process has an extremely slow growth reinforcing From: Department of 1. Diagnostic Radiology, 2. Gastroenterology, 4. Nuclear Medecine, the high probability of a begnin process. 5. Visceral Surgery, Clinique St Luc, 5004 Bouge (Namur), Belgium, Department of For safety reasons a PET/CT is proposed 3. Diagnostic and Interventionnal Radiology, 7. Pathology, CHU Mont-Godinne, UCL, (G-I) to reinforce the diagnosis of benign Belgium, 6. Institute of Pathology and Genetics, Gosselies, Belgium. MP. Nevertheless the results appear very Address for correspondence and reprint requests: Bruno Coulier, Department of ambiguous and paradoxically pejorative Diagnostic Radiology, Clinique St Luc, Rue St Luc 8, 5004 Bouge (Namur) Belgium. with a marked hypermetabolism of the E-mail: bcoulier.md@gmail.com largest atypical nodules.

LETTER TO THE EDITOR — COULIER et al

Fig. 2. - On a control CT performed 2 months (A, B) after surgical exploration it clearly appeared (as suspected in the light of the histologic result) that the surgical biopsy whose trace was still perfectly visible (white arrow on A) had been made in the predominantly lipomatous portion of the MP. The most superficial supracentimetric hypermetabolic nodule was still present (B). During complementary abdominal Ultrasound this nodule appears as a hypoechoic, hyperattenuating and almost avascular mass (C). The nodule was successfully biopsied under combined ultrasound and ConeBeam CT guidance (black arrow on D).

lymphoma the general prevalence of mesenteric panniculitis in our study didn’t significantly differ in our two “neoplastic” and “non neoplasic” large cohorts of patients (2). This important conclusion remains am biguously controversial for several authors (7, 8) but nevertheless and recently been comforted by a large matched case-control study (9). Another of our conclusions, which remained more speculative, was that the potential progression of MP to the heavy more debilitating retractile mesenteritis was extremely difficult to predict. It seemed to remain a very rare event that was not encountered in our rather long period of obser vation (1,2). Therefore such a pro gres sion may also be considered as doubtful. A real kinship or a complete independence between the two entities remains thus an open question which cannot be unequi vocally answered. Finally PET/CT as reported by Zissin (10) was also comforted as

being useful to correctly exclude mesenteric tumoral involvement in doubtful or ambiguous cases (2). Nevertheless even with an excel lent experience in CT diagnosis of MP, unusual and ambiguous situa tions may be found in several patients necessitating the deploy ment of more unusual and/or inva sive strategies to obtain an unam biguous certified diagnosis. So we also recently read with interest the paper of Garg (11) who performed CT-guided percutaneous administration of Spot sterile carbon stain to a single F-18 FDG positive mesenteric lymph node to allow identification during subsequent laparoscopic resection in a patient presenting with an atypical PETpositive mesenteric panniculitis. We recently experienced a similar atypical and ambiguous case. A 68 year-old presented to the department of gastroenterology with complaints of fluctuating epigastric abdominal pain. Gastroscopy, upper abdominal

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Ultrasound and laboratory tests were normal. Abdominal CT demon strated typical CT findings of mesen teric panniculitis (MP) (Fig. 1A-C) but some unusual and sometimes supra centimetric large nodules were also associated in the mesentery itself and in the preaortic retroperitoneal fat. A previous abdominal CT per formed 30 months earlier was (Fig. 1D-F). available in our PACS Typical MP was already clearly visible and had been described. The nodules described today were also already present but at this time there were infracentimetric. It was thus first concluded that the process has an extremely slow growth, reinforcing the high probability of a benign process. However for safe ty reasons PET/CT was performed (Fig. 1 G-I) to reinforce the diagnosis of benign MP. Nevertheless the results appeared very ambiguous and para doxically pejorative with a marked hypermetabolism of the largest atypical nodules. Celioscopic mesenteric biopsy was first performed and illustrated typical histopathologic features of MP. Nevertheless we remained con vinced that the histology did not correspond to the nodule that had been supposed to have been biop sied. Indeed the fat content of the histologic specimen was too im portant to correspond to the positive PET-CT dense nodule. In fact the histology was more corresponding to the more classical and usual inflammatory fat that constitutes most of the volume of the mesentery in cases of MP (Fig. 3 A, B). Effectively the nodule was still visible on a control CT performed two months later (Fig. 2B) and the scar of the unsuccessful surgical biopsy was clearly seen near it (Fig. 2A). The nodule was clearly visible during focused abdominal ultrasound (Fig. 2C, D) and pressure on the lesion was painful. Percutaneous biopsy under ultrasound guidance and supported by Conebeam CT revealed a benign histology of dense inflammatory fibrosis (Fig. 3C, D). The patient was finally discharged with symptomatic treatment (anal gesic and anti-inflammatory drugs) This case demonstrates that while most cases of MP have pathog nomonic CT appearances there are atypical presentations where more invasive diagnostic strategies are needed. Our case also offers the opportunity to illustrate different histological patterns of the same benign disease.

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References 1. Coulier B.: Mesenteric panniculitis.

Fig. 3. - Photomicrographs. A (Hematoxylin and Eosin, × 5) & B (Hematoxylin and Eosin, × 20) illustrate the typical histopathology of the predominantly adipous component of the mesenteric panniculitis obtained during celioscopy. The mesenteric adipous tissue (white stars) is dislocated by fibrous bands (black star on a). A minimal inflammatory reaction is present with a lymphoid focus (black arrow). Figure B shows an area of adiponecrosis with macrophagic reaction (white arrow) surrounded by fibrosis (black stars). C, D illustrate the benign histopathology of the hypermetabolic nodule biopsied under ConeBeam CT guidance. Extensive fibrosis (grey star) is intermingled with a predominantly lymphocytic inflammatory reaction. Some plasmo cytes and eosinophiles are also present on figure D.

Until now the precise etiology of MP (the more accurate histological name being “sclerosing mesen teritis”) remains unknown. However, as shown in the reported cases, many histological features such as the presence of lymphocytic infil trates, and to a lesser degree of plasmocytic and eosinophilic reac tions in “active” nodules and but also the development of massive fibrosis which succeeds when the lesions become more quiescent is not unlike the appearance of auto immune diseases. In this autoimmune hypothesis the possibility that MP could repre sent another additional expression of the constantly increasing group of IgG4 related diseases (IgG4-RD) has already been suggested by several authors (12, 13) but rejected by others (14) because of a relatively low rate of IgG4+ plasma cells during immunohistochemistry. Nevertheless today there is no published international consensus on the diagnostic criteria for IgG4RD (15). A raised serum IgG4 level is

not mandatory for the diagnosis but may be of valuable assistance. More over, not every entity with increased IgG4+ plasma cells and a high histo logic IgG4/IgG ratio can be con sidered to belong to the IgG4-RD spectrum. Most authors agree that a definitive diagnosis of IgG4-RD re quires histo logic confirmation in cluding the presence of characteristic histo pathologic features such as dense lymphoplasmacytic infiltra tion, stori form fibrosis, obliterative phlebitis, mild to moderate eosino philia and germinal center formation along with immunohistochemical staining demonstrating an increased number of IgG4+ cells (15). Except the absence of obliterative phlebitis most of these classical histo patho logic were undoubtedly found in the reported case. One thing is certain, future research is still needed to continue to affirm or refute the possibility that mesenteric panniculitis MP (alias sclerosing mesenteritis) be longs to the ever growing group of IgG4-RD.

Part 2: prevalence and natural course: MDCT prospective study. JBR-BTR, 2011, 94: 241-246. 2. Coulier B.: Mesenteric panniculitis. Part 1: MDCT – pictorial review. JBRBTR, 2011, 94: 229-240. 3. Sabaté J.M., Torrubia S., Maideu J., et al.: Sclerosing mesenteritis: imaging findings in 17 patients. AJR, 1999, 172: 625-629. 4. Horton K.M., Lawler L.P., Fishman E.K.: CT findings in sclerosing mesenteritis (panniculitis): spectrum of disease. Radiographics, 2003, 23: 1561-1567. 5. Mata J.M., Inaraja L., Martin J., Olazabal A., Castilla M.T.: CT features of mesenteric panniculitis. Comput Assist Tomogr, 1987, 11: 1021-1023. 6. Okino Y., Kiyosue H., Mori H., et al.: Root of the small-bowel mesentery: correlative anatomy and CT features of pathologic conditions. Radio graphics, 2001, 21: 1475-1490. 7. van Putte-Katier N., van Bommel E.F., Elgersma O.E., Hendriksz T.R.: Mesenteric panniculitis: prevalence, clinicoradiological presentation and 5-year follow-up. Br J Radiol, 2014, 87 (1044): 20140451. 8. Daskalogiannaki M., Voloudaki A., Prassopoulos P., et al.: CT evaluation of mesenteric panniculitis: prevalence and associated diseases. AJR, 2000, 174: 427-431. 9. Gögebakan Ö., Albrecht T., Osterhoff M.A., Reimann A.: Is mesenteric pan niculitis truely a paraneoplastic phe nomenon? A matched pair analysis. Eur J Radiol, 2013, 82: 1853-1859. 10. Zissin R., Metser U., Hain D., EvenSapir E.: Mesenteric panniculitis in oncologic patients: PET-CT findings. Br J Radiol, 2006, 79: 37-43. 11. Garg V., Alvarado N., Raju R.: CTguided percutaneous administration of Spot sterile carbon stain to a single F-18 FDG positive mesenteric lymph node to allow identification during subsequent laparoscopic resection. Abdom Imaging, 2014, 39: 1134-1136 12. Nomura Y., Naito Y., Eriguchi N. et al.: A case of IgG4-related sclerosing mesenteritis. Pathol Res Pract, 2011, 207: 518-521. 13. Chen T.S., Montgomery E.A.: Are tumefactive lesions classified as sclerosing mesenteritis a subset of IgG4-related sclerosing disorders? J Clin Pathol, 2008, 61: 1093-1097. 14. Belghiti H., Cazals-Hatem D., Couvelard A., Guedj N., Bedossa P.: Sclerosing mesenteritis: can it be a IgG4 dysimmune disease? Ann Pathol, 2009, 29: 468-474. 15. Coulier B., Montfort L., Beniuga G., Pierard F., Gielen I.: Small bowel obstruction caused by peritoneal immu no globulin g4-related disease mimicking carcinomatosis: case report. Korean J Radiol, 2014, 15: 66-71.

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ANNOUNCEMENT CHARTER YOUNG RADIOLOGISTS SECTION (YRS)

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The Young Radiologists Section (YRS) is a subdivision of the Belgian Society of Radiology (BSR) dedicated to residents + recently (< 5 years) graduated radiologists, who are member of the BSR.

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Representation by each of the 7 universities (Universiteit Antwerpen, Université Catholique de Louvain, Université de Liège, Universiteit Gent, Université Libre de Bruxelles, Katholieke Universiteit Leuven, Vrije Universiteit Brussel)

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Two Presidents (one Dutch + one French speaking), Two Vice-Presidents (one Dutch + one French speaking) and One Secretary. The two Vice-Presidents and the Secretary are elected every year. The positions of President will be filled in by the two Vice-Presidents of the previous year.

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Key Goals: •

Education: standardized education and examination between the universities

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Communication: communication with external organizations (e.g. ECR)

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Scientific: co-organization of the Annual Symposium of the BSR

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Communication language: English

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By general consensus 4-5 meetings/year in a central location in Belgium with subsequently a report of the meeting by the Secretary. Every member of the YRS is welcome to join the meetings of the Scientific Board of the BSR (most interesting for the members who participate in the (co)organization of the annual symposium of the BSR)

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The Presidents, Vice-Presidents and Secretary will be the communication bridge between the General/Scientific Board of the BSR and the members of the YRS.