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Radiology quiz
self-assessment
Radiology quiz Questions
Case 2 A 20 year old man presented with an asymptomatic swelling on the volar aspect of the right wrist. What are the MRI findings?
Case 1 A 13 year old boy presented with a history of valgus injury to the knee one week ago. What are the main imaging features and the likely diagnosis?
Figure 1
Asha Ramakrishnan FRCR is a Specialist Registrar, Musculoskeletal Centre, Chapel Allerton Hospital, Leeds Teaching Hospitals, Leeds, UK. Philip Robinson FRCR is a Consultant Musculoskeletal Radiologist, Musculoskeletal Centre, Chapel Allerton Hospital, Leeds Teaching Hospitals, Leeds, UK.
oRTHOPAEDICS AND TRAUMA 23:2
Figure 2
122
© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Case 4 A 42 year old male presented with a two month history of swelling of the right knee. He underwent surgery of the right knee six months ago. What are the relevant findings and likely diagnosis?
Case 3 This 24 year old woman gave a three month history of pain along the left proximal thigh. What do the MRI images show? What is the likely diagnosis?
Figure 3
Figure 4
oRTHOPAEDICS AND TRAUMA 23:2
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© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Case 5 This 14 year old boy presented with a history of trauma to the left knee. What is the demonstrated abnormality?
Case 6 This 27 year old man developed clinical signs of brachial plexus injury and Horner’s syndrome following a motor bike accident one month ago. What are the findings on axial and coronal MRI images? What is the likely diagnosis?
Figure 5
Figure 6
oRTHOPAEDICS AND TRAUMA 23:2
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© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Answers
Case 3 On MRI, there is evidence of previous avulsion of the iliopsoas tendon at its insertion into the lesser trochanter with accompanying ossification (arrow). There are no acute features and no significant underlying bone marrow oedema. The radiological diagnosis was an old iliopsoas avulsion with accompanying myositis ossificans. Avulsion of the lesser trochanter occurs due to hip flexion in adolescent sport participants causing failure of the apophysis. When this is seen in adults without a history of significant trauma, it should be considered as a secondary to a metastatic neoplasm unless proved otherwise. Chronic or old injuries may be associated with a protuberant mass of bone and may occasionally resemble a neoplastic or infectious process clinically.
Case 1 There is marked oedema in the medial patellar retinaculum (arrowheads) which is grossly intact. Normal lateral patellar retinaculum (arrow). There is bone marrow oedema in the lateral femoral condyle and around the femoral origin of the medial collateral ligament. Imaging features are in keeping with previous patellar dislocation. Disruption or sprain of the medial patellar retinaculum, lateral patellar tilt or subluxation, lateral femoral condyle contusion, osteochondral injury and joint effusion are the constellation of MRI findings that distinguish transient lateral patellar dislocation from other knee injuries.
Case 2 There is an accessory muscle (*) arising from the antebrachial fascia passing anterior to the ulnar artery and nerve in Guyon’s canal. This passes on the radial side of the pisiform and distally the fibers merge with the main abductor digiti minimi muscle. This represents an accessory abductor digiti minimi muscle. Accessory muscles are usually asymptomatic and represent incidental findings. Clinical presentation may be either as a swelling or due to neurovascular compression in fibroosseous tunnels.
oRTHOPAEDICS AND TRAUMA 23:2
Case 4 There is effusion, synovitis and focal haemosiderin deposition. There is synovitis lateral to the patella, posterior to the tibiofemoral joint (arrows), posteromedially and in the medial tibiofemoral joint. Menisci and cruciate ligaments were intact. The diagnosis is pigmented villonodular synovitis of the knee with anterior synovectomy performed six months ago. Pigmented villonodular synovitis is a benign condition resulting in a hyperplastic layer of synovium containing haemosiderin with the knee most commonly affected. Typical MRI findings are low signal intensity synovial masses on all sequences due to hemosiderin and include osseous cyst like areas or erosions. The differential diagnosis of so called “black synovium” include amyloid deposition and any condition where there is repeated intraarticular haemorrhage such as haemophilia.
125
© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Case 5 In the medial femoral condyle there is an osteochondral defect (bent arrow) with underlying cystic change and bone marrow oedema. The overlying cartilage is intact. There was no evidence of internal ligamentous disruption in the knee. An incidental finding is a well defined lesion involving the posteromedial diaphyseal region of the left femur (arrow) which is low in signal on T1 and high signal on T2 with a low signal intensity rim. The overlying periosteum, physis and epiphysis are intact. There is no significant soft tissue component. There are a few internal septations but no fluid fluid levels. The appearances are in keeping with a non ossifying fibroma. Non ossifying fibroma is a benign tumour which is usually asymptomatic. Symptoms arise only when it is large enough to cause a pathological fracture. These are mostly seen in the second decade of life. The lesions are metaphyseal or diametaphyseal and intracortical. They may have a lobulated soap bubble appearance with enlargement into the medullary cavity. They are usually oval with their long axes in the line of bone. On MRI the majority are low signal on T1w sequences while on T2w sequences 80% are hypointense and the remainder hyperintense. Marginal sclerosis appears as a hypointense rim.
oRTHOPAEDICS AND TRAUMA 23:2
126
© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Case 6 There are pseudomeningocoeles at C7/T1 (arrow) and T1/T2 levels (T1/T2 level not shown) consistent with avulsion of the nerve roots on the left. Nerve roots seen proximally and on the contralateral side were normal. Differentiation between pre-and post-ganglionic injury is crucial in the management of brachial plexus injury and imaging can play a significant role in this. The common causes of traction brachial plexus injuries include traffic accidents especially motor bike accidents and birth injuries. A traumatic meningocoele is caused by laceration in the dural sleeve of the nerve allowing CSF to leak in an extradural location and is a sign of a preganglionic lesion. Until recently, nerve transfers were the only treatment option for preganglionic injuries. Nerve root repair and reimplantation are some of the newer techniques which are being used for preganglionic injuries.
oRTHOPAEDICS AND TRAUMA 23:2
127
© 2008 Elsevier Ltd. All rights reserved.
Radiology quiz Questions
Case 2 A 20 year old man presented with an asymptomatic swelling on the volar aspect of the right wrist. What are the MRI findings?
Case 1 A 13 year old boy presented with a history of valgus injury to the knee one week ago. What are the main imaging features and the likely diagnosis?
Figure 1
Asha Ramakrishnan FRCR is a Specialist Registrar, Musculoskeletal Centre, Chapel Allerton Hospital, Leeds Teaching Hospitals, Leeds, UK. Philip Robinson FRCR is a Consultant Musculoskeletal Radiologist, Musculoskeletal Centre, Chapel Allerton Hospital, Leeds Teaching Hospitals, Leeds, UK.
oRTHOPAEDICS AND TRAUMA 23:2
Figure 2
122
© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Case 4 A 42 year old male presented with a two month history of swelling of the right knee. He underwent surgery of the right knee six months ago. What are the relevant findings and likely diagnosis?
Case 3 This 24 year old woman gave a three month history of pain along the left proximal thigh. What do the MRI images show? What is the likely diagnosis?
Figure 3
Figure 4
oRTHOPAEDICS AND TRAUMA 23:2
123
© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Case 5 This 14 year old boy presented with a history of trauma to the left knee. What is the demonstrated abnormality?
Case 6 This 27 year old man developed clinical signs of brachial plexus injury and Horner’s syndrome following a motor bike accident one month ago. What are the findings on axial and coronal MRI images? What is the likely diagnosis?
Figure 5
Figure 6
oRTHOPAEDICS AND TRAUMA 23:2
124
© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Answers
Case 3 On MRI, there is evidence of previous avulsion of the iliopsoas tendon at its insertion into the lesser trochanter with accompanying ossification (arrow). There are no acute features and no significant underlying bone marrow oedema. The radiological diagnosis was an old iliopsoas avulsion with accompanying myositis ossificans. Avulsion of the lesser trochanter occurs due to hip flexion in adolescent sport participants causing failure of the apophysis. When this is seen in adults without a history of significant trauma, it should be considered as a secondary to a metastatic neoplasm unless proved otherwise. Chronic or old injuries may be associated with a protuberant mass of bone and may occasionally resemble a neoplastic or infectious process clinically.
Case 1 There is marked oedema in the medial patellar retinaculum (arrowheads) which is grossly intact. Normal lateral patellar retinaculum (arrow). There is bone marrow oedema in the lateral femoral condyle and around the femoral origin of the medial collateral ligament. Imaging features are in keeping with previous patellar dislocation. Disruption or sprain of the medial patellar retinaculum, lateral patellar tilt or subluxation, lateral femoral condyle contusion, osteochondral injury and joint effusion are the constellation of MRI findings that distinguish transient lateral patellar dislocation from other knee injuries.
Case 2 There is an accessory muscle (*) arising from the antebrachial fascia passing anterior to the ulnar artery and nerve in Guyon’s canal. This passes on the radial side of the pisiform and distally the fibers merge with the main abductor digiti minimi muscle. This represents an accessory abductor digiti minimi muscle. Accessory muscles are usually asymptomatic and represent incidental findings. Clinical presentation may be either as a swelling or due to neurovascular compression in fibroosseous tunnels.
oRTHOPAEDICS AND TRAUMA 23:2
Case 4 There is effusion, synovitis and focal haemosiderin deposition. There is synovitis lateral to the patella, posterior to the tibiofemoral joint (arrows), posteromedially and in the medial tibiofemoral joint. Menisci and cruciate ligaments were intact. The diagnosis is pigmented villonodular synovitis of the knee with anterior synovectomy performed six months ago. Pigmented villonodular synovitis is a benign condition resulting in a hyperplastic layer of synovium containing haemosiderin with the knee most commonly affected. Typical MRI findings are low signal intensity synovial masses on all sequences due to hemosiderin and include osseous cyst like areas or erosions. The differential diagnosis of so called “black synovium” include amyloid deposition and any condition where there is repeated intraarticular haemorrhage such as haemophilia.
125
© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Case 5 In the medial femoral condyle there is an osteochondral defect (bent arrow) with underlying cystic change and bone marrow oedema. The overlying cartilage is intact. There was no evidence of internal ligamentous disruption in the knee. An incidental finding is a well defined lesion involving the posteromedial diaphyseal region of the left femur (arrow) which is low in signal on T1 and high signal on T2 with a low signal intensity rim. The overlying periosteum, physis and epiphysis are intact. There is no significant soft tissue component. There are a few internal septations but no fluid fluid levels. The appearances are in keeping with a non ossifying fibroma. Non ossifying fibroma is a benign tumour which is usually asymptomatic. Symptoms arise only when it is large enough to cause a pathological fracture. These are mostly seen in the second decade of life. The lesions are metaphyseal or diametaphyseal and intracortical. They may have a lobulated soap bubble appearance with enlargement into the medullary cavity. They are usually oval with their long axes in the line of bone. On MRI the majority are low signal on T1w sequences while on T2w sequences 80% are hypointense and the remainder hyperintense. Marginal sclerosis appears as a hypointense rim.
oRTHOPAEDICS AND TRAUMA 23:2
126
© 2008 Elsevier Ltd. All rights reserved.
self-assessment
Case 6 There are pseudomeningocoeles at C7/T1 (arrow) and T1/T2 levels (T1/T2 level not shown) consistent with avulsion of the nerve roots on the left. Nerve roots seen proximally and on the contralateral side were normal. Differentiation between pre-and post-ganglionic injury is crucial in the management of brachial plexus injury and imaging can play a significant role in this. The common causes of traction brachial plexus injuries include traffic accidents especially motor bike accidents and birth injuries. A traumatic meningocoele is caused by laceration in the dural sleeve of the nerve allowing CSF to leak in an extradural location and is a sign of a preganglionic lesion. Until recently, nerve transfers were the only treatment option for preganglionic injuries. Nerve root repair and reimplantation are some of the newer techniques which are being used for preganglionic injuries.
oRTHOPAEDICS AND TRAUMA 23:2
127
© 2008 Elsevier Ltd. All rights reserved.