EFSUMB Newsletter
European Federation of Societies for Ultrasound in Medicine and Biology
EUROSON 2017 EFSUMB Young Investigator Prize Winners First Prize – Clinical Presentation Matteo Garcovich – Italy Joint First Prize – Technical Presentation Ruud JG van Sloun – The Netherlands Maria Theodorou – UK
Abstract Assessing Baveno VI criteria with a new point-shear wave elastography technique: the BAVElastPQ study Purpose To date no study has explored the potential role of ElastPQ, a novel point-SWE technique, in the assessment of clinically signifiant portal hypertension. The aim of our study was to determine a liver stiffness (LS) cut-off value measured by ElastPQ and/or laboratory parameters that could help identify those patients who can safely avoid screening endoscopy, similarly to the recently proposed Baveno VI criteria which recommends a LS value < 20kPa measured by transient elastography in combination to a platelet count > 150,000/μl.
met the “BAVElastPQ” criteria (that is, LS < 12kPa and platelet count > 150,000/μl). Within this group 11/63 (17 %) had any grade of varices and only 1/73 (1 %) had high-risk varices. The BAVElastPQ criteria gave sensitivity of 0.95, specificity of 0.44, positive predictive value of 0.16 and negative predictive value of 0.98. The AUROC for LS and platelet count was 0.81 and 0.76, respectively.
Conclusion The BAVElastPQ criteria correctly identified 99 % of patients without high-risk varices. By applying such criteria we could have potentially avoided 40 % surveillance endoscopies in our cohort.
Methods
Matteo Garcovich
Matteo Garcovich received his medical degree at the “A. Gemelli” Hospital in Rome. He later became an Internal Medicine Specialist and obtained a PhD at the same University, having spent a year as a clinical research fellow at the Royal Free Hospital (London, UK) during his speciality training. In the last years he (co-) authored 27 publications in ISI journals and has won several Young Investigator awards at the annual conferences of EASL, UEG and SIUMB. His main fields of interest include liver elastography, contrast-enhanced ultrasound and portal hypertension. He speaks Italian, German and English and has, collaterally, an academic degree in Violin.
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Data was collected on 1385 patients who underwent ElastPQ measurement from January 2013 to January 2016 in our Department. Inclusion criteria were a LS value of ≥ 7kPa (to reasonably rule-in all patients with advanced fibrosis and cirrhosis) and an upper gastrointestinal endoscopy within 12 months, with a diagnosis of compensated chronic liver disease. Exclusion criteria were history of decompensated liver disease, evidence of porto-spleno-mesenteric vein thrombosis and non-cirrhotic portal hypertension. Varices were graded as low risk (grade < 2) or high risk (grade ≥ 2).
Ruud J. G. van Sloun
Results The study included 184 patients (114[62 %] HCV, and 160[87 %] Child-Pugh A). Varices were present in 36 % cases, with 10 % prevalence of high-risk varices. According to ROC curve analysis LS measurement and platelet count were evaluated as predictors of high-risk varices. Overall 74/184 (40 %)
Ruud J. G. van Sloun was born in Roermond, The Netherlands, in 1990. He received the B.Sc. and M.Sc. degree (with distinction cum laude) in electrical engineering from the Eindhoven University of Technology, The Netherlands, in 2012 and 2014, respectively, where he is currently pursuing the Ph. D. degree. In 2013 – 2014, he was Ultraschall in Med 2018; 39: 100–104
an intern at Philips Research Eindhoven, specializing in the field of medical ultrasound imaging and nonlinear acoustics. He has authored over 30 publications including 12 papers in international peerreviewed scientific journals. His current research interests include quantitative (contrast enhanced) ultrasound imaging in oncology, machine learning, compressed sensing, signal and image processing, and sensor analytics.
Abstract Prostate cancer localization with contrast-enhanced ultrasound – from technical innovation to clinical implementation Purpose Prostate cancer (PCa) is the second-leading cause of cancer death in men, and the most frequently diagnosed cancer in men aside from skin cancer [1]. PCa diagnosis is typically performed using systematic needle biopsies. Despite being the current golden standard, initial systematic biopsies miss nearly a quarter of the clinically significant cancers, requiring additional biopsy sessions in case of suspicion. To enhance cancer detection rates, targeting of biopsies using multi-parametric magnetic resonance imaging (mpMRI) has been proposed. Accurate imaging of lesions would also enable the use of minimally invasive focal therapies as opposed to radical intervention. Nevertheless, mpMRI is a modality associated with high costs and a complex workflow. Angiogenesis is known to play a central role in the growth of tumours towards a metastatic or a lethal phenotype. It is characterized by the formation of a chaotic network of microvessels feeding the tumour. With the aim of detecting those changes in the vascular architecture that are associated with cancer, we have introduced a wide spectrum of advanced contrast-enhanced ultrasound (CEUS) technologies for quantification of the chaotic nature of tumour vasculature.
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▶ Fig. 1 3 D Contrast-enhanced ultrasound tractography (CEUS-T) and tortuosity quantification on a human prostate with corresponding histology. Colours encode the tract tortuosity by the inflection count metric. CEUS-T displays elevated tortuosity and higher tract-density on the left mid-base side of the prostate. Similarly, histology reveals a significant malignant lesion (Gleason grade: 4 + 5), with a left mid-basal focus.
Methods
Results
In [2], we proposed for the first time the characterization of the microvascular network by local system identification, enabling the estimation of flow velocity and contrast dispersion. Both parameters were shown to be correlated to the presence of malignant tissue. Later [3], this work was extended by estimating the full vascular flow vector field across the organ. The heterogeneity of these flow patterns was higher in cancer. When testing the method on 24 patients referred for radical prostatectomy, its quantification through the local vector field entropy yielded a cancer classification accuracy of 82 %, outperforming the traditional perfusion parameters by almost 10 %.
All these methods have shown their promise in a preliminary validation. To extend beyond technical innovation and make the translation towards clinical impact, we are currently investigating the clinical value of these techniques for CEUS-targeted biopsies in a clinical study [4] at the Academic Medical Centre (University of Amsterdam, Amsterdam, The Netherlands). Although this study is still on-going, initial results on 49 patients suggest advanced CEUS alone to produce tumour detection rates similar to complex, costly, and time-consuming mpMRI-targeted biopsies.
More recently, we developed CEUS-tractography, which combines revolutionary concepts from diffusion tensor tractography MRI for fibre visualization with CEUS blood flow vector imaging to yield 3 D images of contrast agent trajectories using a clinical ultrasound scanner. An example of CEUStractography applied to clinically acquired 3 D CEUS data is provided in ▶ Fig. 1.
References [1] American Cancer Society, “Cancer Facts & Figures 2015”, American Cancer Society, Atlanta, 2015 [2] van Sloun RJG, et al., Medical Image Analysis, 2017; 35: 610 – 619 [3] van Sloun RJG, et al., IEEE transactions on medical imaging, 2017; 36(3): 826 – 837 [4] Postema AW, et al., BMC Urology, 2017
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EFSUMB Newsletter
Abstract Permelastography: Quantitative poroelastic property imaging by combining shear wave and strain Elastography Purpose
Maria Theodorou
Maria Theodorou received her MSc in Biomedical Engineering from Imperial College London in 2010 and after working in the private sector the following two years, she joined the four year doctoral programme of the Institute of Cancer Research, University of London, where she completed her PhD in Medical Physics funded by Cancer Research UK. She is currently a postdoctoral researcher at the Institute of Cancer Research and Royal Marsden Hospital, working in the area of quantitative ultrasound imaging and elastography methods.
Poroelastic theory may be used to explain both cellular and tissue rheology. It describes the movement of fluid away from a region of tissue during sustained compression. The resulting time- and spatially varying deformation of the tissue matrix may be imaged as a change in ultrasound echo strain over time. Strain movies allow the quantitative imaging of the product of the tissue’s aggregate modulus and fluid permeability, Hk, and its Poisson’s ratio, ν. We have successfully developed a novel ultrasound technique to measure tissue fluid permeability, k, independently of H, which we have assessed on tissue-mimicking phantoms.
Methods In the new method, which we call permelastography, H is calculated from ν and the tissue’s Young’s modulus, E, where E is obtained from shear wave elastography (SWE). This was tested on a series of agarose phantoms of varying matrix pore size,
controlled by varying agarose concentration. By combining the Hk, ν and E maps, the permeability was extracted and varied systematically and reproducibly with matrix pore size. Intra-phantom variation in k was about 15 % of the mean, and the mean values of k fell within about 28 % of those measured using an independent but destructive method.
Results & Conclusion The non-invasive estimation of the biomechanical properties E, k and ν could be valuable clinically because cancer is associated with altered ability of fluid to move in tissue due to angiogenesis. The experimental setup was adapted into a light, 3 D printed handheld design comprising one ultrasound and one SWE transducer jointly held above a compressor plate, which provides force-feedback to the operator. The prototype has been evaluated clinically to characterize the changes in the poroelastic behavior of the breast of healthy volunteers due to the hormonal response of tissue fluid flow in different phases of the menstrual cycle. Key words: permeability, elastography, breast
EFSUMB President Paul S Sidhu writes We look forward to the New Year and 2018 promises to be a busy year for EFSUMB. During the EUROSON meeting in Ljubljana, Slovenia the Board of Delegates met, with the composition of the various committees of EFSUMB seeing new blood which by now is firmly in place and engaging in the new tasks ahead. A number of long-standing committee members have stepped down, including Gail ter Haar (Safety), Christoph F Dietrich (Executive Board) and Michael Bachman-Nielsen (Publications) amongst others, all having devoted considerable time to the progress of EFSUMB. The President thanks all the previous committee members for their tireless efforts over the years. With new energy on the various committees we can look forward in 2018 to continuing innovation and policy making.
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In the last year we have had much success under the auspices of the past President, Odd Helge Gilja, notably in the publication of two sets of EFSUMB guidelines (Liver elastography and Gastrointestinal) and one statement (Paediatric CEUS), all well received by the ultrasound community worldwide, with immediate impact as demonstrated by citations in the medical literature. In 2018, the update on non-liver CEUS will be published. In addition the steering committee and contributors will meet in February to put the final touches to a new set of guidelines related to non-liver elastography, likely to be completed and ready for publication in 2019. A further number of possible guidelines are under consideration and will be progressed over the coming year. None of these guidelines would be possible without the co-operation
of all experts within the European ultrasound community who contribute their time and expertise so generously. We will continue to endeavour to publish the guidelines in our journal, European Journal of Ultrasound (Ultraschall in der Medizin), which continues to be a well-respected publication with a high impact factor. Needless to say in order to maintain the integrity of the journal all manuscripts undergo a rigid peer-review process, and this includes the guidelines produced by EFSUMB. The safety committee have been tasked by the journal editors to produce a series of continuing education articles (CME) on all aspects of ultrasound safety; expect to see these articles published regularly over the coming few years.
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The next EUROSON meeting will take place this year in Poznan, Poland form the 6 â&#x20AC;&#x201C; 9 September in conjunction with the Polish Society. Preparations are well advanced with a lively program scheduled in the delightful setting of the charming city of Poznan. This year there is an ultra-early registration fee set at a very reasonable cost; look on the website and book now to take advantage of this extremely generous registration fee. We welcome as many as possible of the EFSUMB members to join us for the education and, of course, meeting old and new friends. There will be a busy year of planned EFSUMB Schools in 2018, with courses on MSK, neonatal brain, chest and of course CEUS (London, Munich, Hong Kong and Berne) continuing the commitment of EFSUMB to continuing education. Please review these courses on the website and book early as the courses are very popular. Over the last year, EFSUMB has introduced webinars, so far dealing with aspects of CEUS. Another is planned for the 19th January dealing with Intracavity CEUS, a niche topic but so very useful as a problem solving tool. Registration for these webinars is free and has proved to be popular. We are currently exploring the expansion of this method of education, taking topics from outside CEUS, and would value contributions and ideas from all members. We are actively exploring industry support for these webinars, in order to continue with an expanded program. Going forward, we anticipate a very busy 2018, with all the committees working to produce many new documents, policies and guidelines. The website will continue to expand and include many new educational aspects, with continuing development of mobile information portals. I hope this year will be beneficial to all members of EFSUMB! Professor Paul S. Sidhu President of EFSUMB
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Future Euroson Schools
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