Imaging Single Best Answer

imaging Single Best Answer Questions and answers for the Final FRCR (Part A) modules 1–6

Edited by Rajat Chowdhury and Simon Ostlere

imaging Single Best Answer Questions and answers for the Final FRCR (Part A) modules 1–6 Edited by Rajat Chowdhury and Simon Ostlere

Published by

The British Institute of Radiology 48–50 St John Street, London EC1M 4DG, UK www.bir.org.uk Registered Charity No. 215869 Published in the United Kingdom by The British Institute of Radiology Š 2014 The British Institute of Radiology This publication is in copyright. Subject to statutory exemption and the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of the British Institute of Radiology British Library Cataloguing in Publication data A cataloguing record for this publication is available from the British Library ISBN-13 978-0-905749-81-5 ISBN-10 0-905749-81-2 The British Institute of Radiology has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate All opinions expressed in this publication are those of the respective authors and not the publisher. The publisher has taken the utmost care to ensure that the information and data contained in this publication are as accurate as possible at the time of going to press. Nevertheless the publisher cannot accept any responsibility for errors, omissions or misrepresentations howsoever caused. All liability for loss, disappointment or damage caused by reliance on the information contained in this publication or the negligence of the publisher is hereby excluded

Preface Imaging Single Best Answer is a convenient, easy-to-use learning resource aimed at trainee radiologists taking the Royal College of Radiologists’ Final FRCR (Part A) Examination.

This book was conceived and developed through the collaborative efforts and innovations of the BIR Young Professionals and Trainee Committee. Senior authors (and then radiology registrars) Madhuchanda Bhattacharyya, Jeremy Jones, and Amrita Kumar were commissioned with the task. They successfully recruited highly motivated and experienced registrars across the UK to write and contribute questions from their diverse FRCR (Part A) exam experiences. The vast bank of questions was then reviewed and assessed by an expert editorial panel of leading consultant radiologists in their respective fields, which has resulted in a final selection of 450 independently validated questions.

With 75 questions, answers and explanations in the new single best answer format on each of the required modules: Cardiothoracic and Vascular; Musculoskeletal and Trauma; Gastro-intestinal; Genitourinary, Adrenal, Obstetrics & Gynaecology and Breast; Paediatric; and Central Nervous System and Head & Neck; this book covers all of your revision needs.

We hope you find this resource helpful and easy to use, and wish you best of luck with your revision!

Rajat Chowdhury and Simon Ostlere, Editors

iii

Edited by Rajat Chowdhury and Simon Ostlere Senior Authors Madhuchanda Bhattacharyya Jeremy Jones Amrita Kumar

Chapter Editors Helen Bungay Priya Narayanan Simon Padley Fintan Sheerin Aslam Sohaib William Teh Katherine Wessely

Contributors Bahir Almazedi Chinedum Anosike Shaheel Bhuva Amy Eccles Emma Giblin Radhakrishnan Jayan Annette Johnstone Stuart Kerr Harpreet Lyall Kate Mahady

Dhivya Murthy Francesca Ng Madhusudan Paravasthu Simon Prowse Vikas Shah Nawaraj Subedi Shalini Umranikar Ashley Uttley Paul Walker Tom Watson

Contents Cardiothoracic and Vascular

Questions

1

Answers

137

Musculoskeletal and Trauma

Questions

25

Answers

173

Questions

47

Answers

197

Questions

69

Answers

227

Questions

91

Answers

255

Questions

115

Answers

289

Gastro-intestinal Genito-urinary, Adrenal, Obstetrics & Gynaecology and Breast Paediatrics Central Nervous System and Head & Neck

1

Cardiothoracic and Vascular Questions

Imaging Single Best Answer

1

Cardiothoracic and Vascular

1

1

A 25-year-old male presents with a 3-week history of dry cough and chest pain. A plain chest radiograph reveals a well-defined opacity in the right paratracheal region.

CT chest reveals a well-defined soft tissue mass with a peripheral rim calcification that measures 3 cm and has an average Hounsfield unit of 45 and there is no enhancement following contrast. At MRI, the mass returns high signal on both T1 and T2 weighted images. What is the most likely diagnosis?

A Bronchogenic cyst B Pericardial cyst C Haemangioma D Ascending thoracic aortic aneurysm E Neurogenic tumour

2

A 40-year-old obese male had a chest radiograph following a low-impact road traffic accident. This revealed a widened superior mediastinum with a central trachea and a large epicardial fat pad. Lungs were clear and heart size was normal. He describes rightsided pleuritic chest pain, but is haemodynamically stable and clinical examination is normal. A CT chest is performed: which of the following is likely in this patient?

A Diffuse increased attenuation within the mediastinum with a higher CT number than soft tissue B Streaky soft tissue attenuation and calcification within the mediastinal fat with compression and distortion of the superior vena cava C Diffuse low attenuation within the mediastinum with CT number of –110 D Multiple nodular soft tissue deposition within the mediastinal fat E Normal mediastinum and central great vessels

3

A 30-year-old male was treated with combined chemoradiotherapy for mediastinal Hodgkin’s disease and underwent complete remission. A follow-up CT scan depicted a homogeneous soft tissue mass with biconvex margins in the anterior mediastinum.

Which of the following is the best imaging modality to differentiate between rebound thymic hyperplasia and recurrent lymphoma?

A Contrast-enhanced CT B In- and opposed-phase MRI C Fat suppressed T1 weighted MRI D Fludeoxyglucose positron emission tomography/CT E 201Tl scintigraphy

4

A 60-year-old heavy smoker presents to the accident and emergency department with acute onset shortness of breath. A PA chest radiograph shows diffuse interstitial pulmonary oedema and consolidation localized to the right upper lobe. His electrocardiogram is unremarkable but he has an elevated troponin level. What is the most appropriate next investigation?

2

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Cardiothoracic and Vascular

A B C D E

Sputum culture and sensitivity Bronchoscopy with bronchoalveolar lavage, biopsy or both High-resolution CT chest Echocardiogram Repeat chest X-ray after 6Â weeks to ensure resolution

5

A 40-year-old female presents to the rheumatology clinic with pain in the small joints of her hands and feet. Blood tests show a normochromic, normocytic anaemia with a high erythrocyte sedimentation rate and positive rheumatoid factor.

She is diagnosed with rheumatoid arthritis and commenced on oral methotrexate and analgesia. After 6Â months, she represents with a dry cough and breathlessness. A chest radiograph is obtained. Which of the following is the most common radiographic finding in this patient?

A Pleural effusion and thickening B Upper zone volume loss C Pulmonary nodules D Reticulo-nodular opacity involving the lower zones E Pericardial effusion

6

A previously fit and well 30-year-old male born in the UK has a chest radiograph for emigration purposes. This reveals a well-defined, rounded mass, which obscures the right heart border. CT of this area shows it to be of fluid density. What is the most likely diagnosis?

A Pericardial cyst B Bronchogenic cyst C Hydatid cyst D Hiatus hernia E Bochdalek hernia

7

A young Asian male presents to the accident and emergency department with worsening shortness of breath and chest pain. On further questioning, he admits to night sweats and fever. The chest radiograph reveals a globular-shaped heart with bilateral perihilar lymph node enlargement and some left upper zone pulmonary infiltrate. What is the most likely diagnosis?

A Pericardial effusion and tuberculosis B Hodgkin’s lymphoma C Dilated cardiomyopathy D Pulmonary stenosis E Sarcoidosis Imaging Single Best Answer

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1

1

Cardiothoracic and Vascular Answers

Imaging Single Best Answer

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Cardiothoracic and Vascular

1

1

Answer: A

All of the options are causes of a mediastinal mass. While the majority of bronchogenic cysts occur in subcarinal region of the middle mediastinum, they can sometimes occur in the right paratracheal region or in the posterior mediastinum. The diagnosis is often confirmed by CT, which shows a thin walled cyst containing fluid of either low attenuation or soft tissue attenuation if it contains mucinous material.

High T1 and T2 signal intensities reflect the presence of mucinous contents. They are usually detected incidentally in patients without symptoms. In some, they may produce chest pain, dyspnoea or cough. Rapid increase in size of the mass indicates secondary haemorrhage or infection.

Pericardial cysts typically occur in the right anterior cardiophrenic angle, can produce similar symptoms, but should not have mucinous contents. Haemangiomata are round or oval soft tissue masses that may contain coarse calcification and avidly enhance after intravenous contrast. An ascending aortic aneurysm may exhibit peripheral calcification but signal void due to flowing blood is typical at MRI. Neurogenic tumours are usually seen as incidental soft tissue masses in the posterior mediastinum but return low to intermediate in T1 weighted imaging.

McAdams HP, Kirejczyk WM, Rosado-de-Christenson ML, et al. Bronchogenic cyst: imaging features with clinical and histopathologic correlation. Radiology 2000; 217: 441–6.

2

Answer: C

The most likely diagnosis in this case is mediastinal lipomatosis, which is commonly seen in an asymptomatic obese subject or in patients on long-term steroid treatment.

The redistribution of body fat in the anterior mediastinum, cardiophrenic angles and paravertebral regions produces smooth widening of superior mediastinum, a large epicardial fat pad and lateral displacement of the paraspinal lines on the chest radiograph.

The widening of the mediastinum can be difficult to differentiate from mediastinal haemorrhage or generalized lymphadenopathy but can be easily confirmed in CT. Answer A describes mediastinal haemorrhage, which can be seen in trauma and haemorrhagic disorders but the trachea is usually displaced. Answer B describes mediastinal fibrosis, which is seen in a wide variety of conditions, for example, previous radiotherapy, tuberculosis and fungal infections. Patients may be asymptomatic or present with signs of superior vena cava obstruction. Answer D is seen with mediastinal lymphadenopathy of any aetiology, which causes a lobulated mediastinal contour.

Homer MJ, Wechsler RJ, Carter BL. Mediastinal lipomatosis. Radiology 1978; 128: 657–61. doi: 10.1148/128.3.657.

3

Answer: B

Rebound thymic hyperplasia is common in patients treated for lymphoma or other malignancies. A reliable non-invasive technique to diagnose it from residual, recurrent or metastatic disease is extremely useful in clinical practice. Chemical shift MRI is a 138

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sensitive imaging modality to detect the presence of microscopic fat, typical of thymic hyperplasia. Chemical shift MRI demonstrates the intravoxal mixture of fat and water by showing homogenously decreased signal in the opposed phase image when compared to the in phase image. Lymphoma recurrence would display no such change in signal.

Contrast-enhanced CT would not be sensitive to delineate the tiny amounts of fat that are present in thymic hyperplasia. Fat suppressed MRI sequences are extremely useful to detect the presence of macroscopic fat in a lesion but it cannot detect the presence of microscopic fat. 201Tl scintigraphy is useful for differentiating normal thymus from hyperplastic thymus, and thymic lymphoma but it has several disadvantages including its low spatial resolution and overlap in diagnostic criteria. Increased thymic 18 F-fludeoxyglucose activity may be striking in rebound hyperplasia causing diagnostic uncertainty.

Nasseri F, Eftekhari F. Clinical and radiologic review of the normal and abnormal thymus: peals and pitfalls. Radiographics 2010; 10: 413–28. doi: 10.1148/rg.302095131.

4

Answer: D

This patient has alveolar pulmonary oedema localized to the right upper lobe due to severe mitral regurgitation that is probably secondary to myocardial ischaemia.

Preferential regurgitant flow of blood into the right upper (or middle) lobe pulmonary vein across the superiorly and posteriorly orientated mitral valve results in localized alveolar pulmonary oedema. In addition, there is generalized interstitial oedema. An echocardiogram will confirm the diagnosis and determine the severity of valvular heart disease as well as determining residual left ventricular function.

Synchronous pulmonary infection is a possibility given the radiographic appearance, but the sudden onset of symptoms without features of septis makes it more unlikely.

Hence, sputum culture is not appropriate. Pulmonary mass lesions can sometimes impede normal lymphatic drainage causing asymmetric and localized pulmonary oedema, but the clinical picture does not favour this and bronchoscopy with biopsy is not a suitable option. High-resolution CT chest in this clinical scenario would not offer any more information as it will simply demonstrate fluid overload. Repeat imaging after treatment is appropriate in cases of pneumonia in elderly people where an obstructive lesion may be the causative factor.

Gurney JW, Goodman LR. Pulmonary edema localized in the right upper lobe accompanying mitral regurgitation. Radiology 1989; 171: 397–9.

5

Answer: A

Thoracic manifestations of rheumatoid arthritis develop as disease progresses and pleural involvement is the most common manifestation of thoracic disease. Pleural thickening is the most common thoracic manifestation. Pleural effusion is seen less often and it is usually unilateral and occurs late in the disease process. It is not possible to accurately differentiate between the two on a plain film alone.

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1

Cardiothoracic and Vascular

Pericardial effusions and subcutaneous nodules are often seen. Pulmonary nodules are uncommon, usually seen in patients with subcutaneous nodules although they may cavitate and tend to occur in advanced disease.

1

Lower lobe pulmonary fibrosis manifests as reticular and reticulo-nodular opacities and is seen in a small percentage of patients with advanced disease. High-resolution CT usually shows thick irregular interlobular septa in peripheral zones of both lower lobes.

As the disease progresses, honeycombing and volume loss becomes evident. Other radiological manifestations of thoracic disease in rheumatoid arthritis are pericardial effusion and bronchiolitis obliterans. Shoulder joint arthritis and distal clavicular erosions may be seen.

Mayberry JP, Primack SL, Müller NL. Thoracic manifestations of systemic autoimmune diseases: radiographic and high-resolution CT findings. Radiographics 2000; 20: 1623–35.

6

Answer: A

The fact that this patient has the chest radiograph for immigration purposes suggests that he is asymptomatic and that this is an incidental finding.

Pericardial cysts are fluid filled structures with walls composed of parietal pericardium.

They are more common in men, usually right sided and located at the cardiophrenic angle. Patients tend to be asymptomatic.

Bronchogenic cysts are congenital abnormalities that occur during the fourth to sixth week of embryogenesis and arise from the bronchial tree. Seventy percent occur in the mediastinum most commonly located in a subcarinal position. Hydatid cysts do not usually cause symptoms. They are caused by infection with echinoccocus and while the liver is the commonest site of involvement, the lung is the second commonest site to be affected. When hydatid cysts occur in the lung, they tend to be more peripherally located, ovoid in shape, and may demonstrate an air fluid level. Collapsed daughter cysts within may create the appearance of the water lily sign. Hiatus herniae tend to be seen in a retro-cardiac position, and may demonstrate an air-fluid level. Bochdalek herniae are usually left sided and located posteriorly. They may be symptomatic if stomach or small bowel herniates into the thoracic cavity through this diaphragmatic defect.

Jeung MY, Gasser B, Gangi A, et al. Imaging of cystic masses of the mediastinum. Radiographics 2002; 22: S79–93.

7

Answer: A

While tuberculosis may affect any body system, cardiac involvement is rare. When it does occur, the commonest feature is pericardial effusion that results in a globular cardiac silhouette when chronic. While there are numerous causes of pericardial effusion (for example, heart failure, empyema, trauma, malignancy), the other features in the history point to tuberculosis: the patient is Asian and has clinical features of night sweats and fever.

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Imaging Single Best Answer

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Biographies Rajat Chowdhury Rajat Chowdhury is a Consultant Radiologist in Oxford. He graduated from Oxford University, and after obtaining MRCS, joined the Wessex Radiology Training Programme and obtained FRCR. He spent a year training in musculoskeletal radiology at Chelsea and Westminster Hospital, London with further specialist training at the Nuffield Orthopaedic Centre, Oxford. He took up his post in Oxford in 2013.

In 2010, Rajat was appointed to Chair of the Young Professionals and Trainee Committee at the BIR and developed a dynamic and innovative multidisciplinary team with a national network. He was subsequently elected to BIR Council in 2011. He was awarded a NICE Scholarship in 2010, training as an NHS ambassador and was subsequently appointed as the National Representative for Leadership and Management at the Academy of Medical Royal Colleges’ Trainee Doctors Group. Rajat has published several papers and books, including the undergraduate textbook Radiology at a Glance (Wiley– Blackwell) and was awarded an international young academic research scholarship in 2011 by the Radiological Society of North America.

Simon Ostlere Simon Ostlere is a Consultant Radiologist based at the Nuffield Orthopaedic Centre, Oxford. He graduated at St Bartholomew’s Hospital, London in 1978, and after obtaining MRCP joined the radiology training scheme at Leeds Teaching Hospitals. He spent a year training in musculoskeletal radiology at the University of California, Los Angeles before taking up his post in Oxford in 1990.

Simon lectures at national and international educational courses and academic conferences, has authored scientific papers, review articles, abstracts and book chapters related to musculoskeletal radiology as well as having held the posts of Clinical Tutor and Head of Training for the Oxford Radiology Training Scheme and Clinical Director of Scientific Services at the Nuffield Orthopaedic Centre.

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