9 Miscellaneous QUESTIONS. 1 Which of the following is the most common tumor complication associated with the disorder depicted by the radiograph?

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1 9 Miscellaneous QUESTIONS 1 Which of the following is the most common tumor complication associated with the disorder depicted by the radiograph? A. Lymphoma B. Sarcoma C. Giant cell tumor D. Enchondroma 2 Which disease is characterized by periarticular tendinous thickening, thickened synovium, and large erosions? A. Rheumatoid arthritis B. Hemophilic arthropathy C. Amyloidosis D. Gout 3 Which of the following diseases most likely manifests as a diffuse bony sclerosis? A. Mastocytosis B. Osteomalacia C. Multiple myeloma D. Vitamin C deficiency 209

2 210 Musculoskeletal Imaging: A Core Review 4 A 57-year-old female presents with lower extremity pain. Based on the images below, which of the following is the next most appropriate study? A. Cervical spine radiograph B. Lumbar spine MRI C. Abdomen and pelvis CT D. Chest radiograph 5 Sagittal MR images of the cervical spine of a 16-month-old patient demonstrate which of the following osseous findings? A. Sagittal T1 weighted B. Sagittal T2 weighted A. Leukemic infiltration B. Postradiation changes C. Rickets D. Red marrow conversion INDD 210 5/14/2014 1:55:55 PM

3 Miscellaneous Which of the following best describes the imaging appearance of sarcoidosis in the hand? A. Soft tissue swelling and periarticular erosions with overhanging edges B. Periarticular osteoporosis and marginal erosions C. Lace-like trabecular pattern and cortical erosions D. Joint space narrowing and subluxations 7a The radiograph of the pelvis below demonstrates the imaging findings characteristic of what diagnosis? A. Slipped capital femoral epiphysis B. Osteonecrosis C. Trauma D. Osteoarthrosis 7b The MR images below depict what sign that is typically associated with osteonecrosis of the hip? A B A. Coronal proton density B. Coronal T2 weighted fat saturated A. Crescent sign B. Joint effusion sign C. Increased T2 cortex signal sign D. Double-line sign INDD 211 5/14/2014 1:55:56 PM

4 212 Musculoskeletal Imaging: A Core Review 8a The following radiograph demonstrates the blade of grass sign, characteristic of which of the following pathologies? A. Radiation osteonecrosis B. Paget disease C. Acute myeloid leukemia D. Sarcoidosis 8b Which of the following is the best definition for the term blade of grass? A. Site of sarcomatous degeneration B. Site of pathologic fracture C. Thickened cortex in long bones D. Sharp demarcation in long bones between lesion and normal bone 9 A 10-year-old male presents with thickening of the skin of the face. Radiographs of the forearm demonstrate periosteal reaction of the distal radial and ulnar metaphyses. These findings are most characteristic of which of the following diseases? A. Primary hypertrophic osteoarthropathy B. Rickets C. Juvenile idiopathic arthritis D. Fluorosis

5 Miscellaneous 213 ANSWERS AND EXPLANATIONS 1 Answer B. Neoplastic complications associated with Paget disease are relatively rare and have been reported to occur in <1% of cases with limited skeletal involvement and up to 5% to 10% of cases with widespread skeletal involvement. Sarcomatous transformation is the most common manifestation of a neoplastic complication. The most common type of sarcomatous transformation is osteosarcoma. Imaging findings that would be concerning for sarcomatous transformation include aggressive osteolysis, cortical destruction, and an associated soft tissue mass. References: Smith SE, Murphey MD, Motamedi K, et al. From the archives of the AFIP. Radiologic spectrum of Paget disease of bone and its complications with pathologic correlation. Radiographics. 2002;22: Theodorou DJ, Theodorou SJ, Kakitsubata Y. Imaging of Paget disease of bone and its musculoskeletal complications: review. AJR Am J Roentgenol. 2011;196:S64 S75. 2 Answer C. Amyloidosis is a multisystem disorder caused by abnormal extracellular deposition of protein and protein derivatives. Amyloid arthropathy is an erosive and destructive arthropathy. Periarticular tendon thickening, due to amyloid infiltration, joint effusions, bursitis, capsular thickening, thickened synovium, and large erosions are musculoskeletal characteristics of this disease. On MR imaging, the tendons, capsule, and synovium will be low in signal intensity on all sequences. Erosions are typically filled with low signal intensity material. Muscular infiltration may also occur and cause hypertrophy, chronic pain, and weakness, which preferentially involve the shoulder girdle. Patients usually appear to have well-developed shoulder musculature, which is asymmetric to the patient s other musculature, and is termed the shoulder pad sign. In contradistinction to amyloid arthropathy, erosions in rheumatoid arthritis contain high signal intensity material on fluid-sensitive sequences, and rheumatoid nodules are typically subcutaneous and are often adjacent to a bony prominence such as the olecranon. In hemophilic arthropathy, chronic hemosiderin deposition results in blooming artifact on gradient echo imaging. Gout is characterized by soft tissue tophi, which may contain calcifications, and juxta-articular erosions with overhanging margins. References: Georgiades CS, Neyman EG, Barish MA, et al. Amyloidosis: review and CT manifestations. Radiographics. 2004;24: Manaster BJ, Roberts CC, Petersilge CA, et al. Diagnostic Imaging: Musculoskeletal: Non- Traumatic Disease. Manitoba, Canada: Amirsys; 2010:1: Answer A. Bone involvement in mastocytosis may be lytic, sclerotic, or a mixed process due to the release of histamine and prostaglandins. Diffuse involvement tends to be more common, but the involvement of the axial skeleton is predominant. Usually, the radiographic appearance is that of sclerosis involving primarily the axial skeleton and the ends of long bones. In some patients, there is generalized osteoporosis with a risk for pathologic fractures. Imaging is helpful to establish the extent of the disease. Osteomalacia causes abnormal bone mineralization and may result in Looser zones (fractures) in adults. Multiple myeloma is characterized by widespread, osseous lytic lesions. Vitamin C deficiency and scurvy result in abnormal epiphyseal and metaphyseal development such as metaphyseal cupping and dense metaphyseal lines in infants and children. Musculoskeletal manifestations of scurvy in adults include severe joint pain and hemarthrosis. Reference: Fritz J, Fishman EK, Carrino JA, et al. Advanced imaging of skeletal manifestations of systemic mastocytosis. Skeletal Radiol. 2012;41(8):

6 214 Musculoskeletal Imaging: A Core Review 4 Answer D. The images depict diffuse periosteal reaction without an underlying osseous abnormality, consistent with hypertrophic osteoarthropathy. Hypertrophic osteoarthropathy may be primary in etiology in 3% to 5% of cases, while 95% to 97% of cases are the result of a secondary etiology. 90% of secondary hypertrophic osteoarthropathy cases are the result of malignancy, with non small cell lung cancer being the most common cause. Therefore, imaging of the chest is the most appropriate next study. In this case, imaging of the chest revealed a large primary lung malignancy. The most common locations for diffuse periosteal reaction to be noted are the tibia and fibula followed by the radius and ulna. In this case, the findings were also present in the tibia and fibula, but were more obvious in the femur. Reference: Manaster BJ, Roberts CC, Petersilge CA, et al. Diagnostic Imaging: Musculoskeletal: Non-Traumatic Disease. Manitoba, Canada: Amirsys; 2010:1: Answer B. The sagittal MR images show homogeneously hyperintense T1- and T2-weighted signal in five consecutive vertebral bodies. This sharp demarcation of fatty marrow is secondary to a radiation port for the treatment of neuroblastoma. Bone marrow changes induced by therapeutic radiation have a predictable evolution because of the direct effects on the cellular components of bone as well as the indirect effects of vascular injury. The T1-weighted signal is increased in the involved bone due to replacement of the hematopoietic marrow with fat, which may be seen 3 months after initiation of therapy and remain indefinitely. Over time, marrow fibrosis can develop; fibrosis should have low T1-weighted and T2-weighted signal intensities. Other effects of radiation therapy include osteonecrosis, insufficiency fractures, and radiationinduced neoplasms. In the growing skeleton, radiation may cause bone growth cessation, fractures (i.e., slipped capital epiphysis), and scoliosis. Reference: Mitchell MJ, Logan PM. Radiation-induced changes in bone. Radiographics. 1998;18: Answer C. The characteristic lace-like or honeycomb appearance is caused by the presence of multiple granulomatous lesions in the bones of the hands or feet. Granulomas within or next to the bone may erode the cortex or cause lytic lesions with nonaggressive features within the medullary cavity. Sarcoidosis affects the bones in 10% of patients with pulmonary findings, but sarcoidosis more often causes transient migratory polyarticular arthralgias without radiographic changes. Additional skeletal findings include joint abnormalities and marrow infiltration of small and large bones. Long bone and axial skeletal involvement may be occult on conventional radiography, but the MRI appearance may resemble that of osseous metastases. Reference: Moore SL, Teirstein AE. Musculoskeletal sarcoidosis: spectrum of appearances at MR imaging. Radiographics. 2003;23: a Answer B. Osteonecrosis is also known as ischemic necrosis, aseptic necrosis, and avascular necrosis. It results in necrosis of the cellular elements of bone secondary to ischemia. This ischemia may be posttraumatic in nature, resulting in a disrupted blood supply. Alternatively, it may be the result of corticosteroid use, which causes enlargement of the intramedullary fat cells and consequently leads to increased intramedullary pressure and inhibition of blood flow. Patchy sclerosis of the femoral head is an early radiographic finding. Late radiographic findings in the hip include femoral head irregularity and fragmentation, collapse of the femoral head articular surface, and secondary osteoarthrosis. References: Manaster BJ, May DA, Disler DG. Musculoskeletal Imaging: The Requisites. 4th ed. Philadelphia, PA: Saunders; 2013: Manaster BJ, Roberts CC, Petersilge CA, et al. Diagnostic Imaging: Musculoskeletal: Non- Traumatic Disease. Manitoba, Canada: Amirsys; 2010:10:8 13.

7 Miscellaneous 215 7b Answer D. On MR imaging, the double-line sign is classically seen in association with osteonecrosis. This finding is depicted by a low signal intensity line along the periphery of the infarct and a brighter signal line at the interface with the infarcted bone. The crescent sign is a radiographic finding in osteonecrosis indicating a subchondral fracture. References: Manaster BJ, May DA, Disler DG. Musculoskeletal Imaging: The Requisites. 4th ed. Philadelphia, PA: Saunders; 2013: Manaster BJ, Roberts CC, Petersilge CA, et al. Diagnostic Imaging: Musculoskeletal: Non- Traumatic Disease. Manitoba, Canada: Amirsys; 2010:10: a Answer B. The blade of grass sign or flame sign represents a wedge or V-shaped area of radiolucency typically located in the diaphysis of a long bone. The sign is characteristic of the lytic phase of Paget disease. Paget disease is typified by an increase in osteoclast-mediated bone resorption, which is accompanied by a compensatory increase in bone formation. There are three phases to Paget disease: lytic, sclerotic, and mixed. Most often, affected bones demonstrate a coarsened trabecular pattern and cortical thickening that encroaches on the medullary cavity. The most commonly affected bones are the pelvis, lumbar spine, femur, tibia, and skull. Paget disease is polyostotic in most cases but may be monostotic in 10% to 35% of cases. References: Manaster BJ, Roberts CC, Petersilge CA, et al. Diagnostic Imaging. Musculoskeletal: Non-Traumatic Disease. Manitoba, Canada: Amirsys; 2010:2: Wittenberg K. The blade of grass sign. Radiology. 2001;221: b Answer D. The blade of grass sign is the demarcation between pagetoid bone and normal bone. References: Manaster BJ, Roberts CC, Petersilge CA, et al. Diagnostic Imaging. Musculoskeletal: Non-Traumatic Disease. Manitoba, Canada: Amirsys; 2010:2: Wittenberg K. The blade of grass sign. Radiology. 2001;221: Answer A. Primary hypertrophic osteoarthropathy, also known as pachydermoperiostosis, is a self-limited, autosomal dominant disease characterized by generalized and symmetric periosteal reaction with marked thickening of the skin of the extremities, face, and scalp. This disease is not associated with a secondary cause, such as lung disease. Most commonly, children or young adult males are affected with bone and joint pain. The pain typically decreases or resolves in adulthood. The periosteal reaction primarily involves the distal ends of the radius, ulna, tibia, and fibula. References: Manaster BJ, Roberts CC, Petersilge CA, et al. Diagnostic Imaging: Musculoskeletal: Non-Traumatic Disease. Manitoba, Canada: Amirsys; 2010: Rana RS, Wu JS, Eisenberg RL. Periosteal reaction. AJR Am J Roentgenol. 2009;193(4): W259 W272.

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