Curriculum for musculoskeletal radiology

Although general suggestions have been made regarding a radiology residency curriculum, no specific list of entities has been offered. Over the past ten years, we have developed a resident-run morning conference in musculoskeletal radiology that is supervised by faculty and covers a specific curriculum. We offer our curriculum as an example that may assist other departments in developing their own curricula.

Abnormalities of the foot in patients with diabetes mellitus: findings on MR imaging

The MR appearances of foot problems in patients with diabetes mellitus are illustrated. MR has been found to be effective in the diagnosis of osteomyelitis, the most common indication for imaging the feet of diabetic patients. MR has the ability to image numerous pathologic processes, especially subtle soft-tissue changes, that are not detectable with other imaging methods.

Calcaneal insufficiency avulsion fractures in patients with diabetes mellitus

Radiographs and clinical records of 61 patients with calcaneal fractures were studied. Twenty-one patients had diabetes mellitus, and 40 were nondiabetic. All diabetic patients were insulin dependent for more than 5 years and had clinically evident peripheral neuropathy. Eighteen of the diabetic patients had no history of significant trauma. Fourteen had calcaneal insufficiency avulsion (CIA) fractures limited to the posterior third of the calcaneus. The fracture pattern in this group occurred in the same plane as a fatigue-type calcaneal fracture. Fragments of the posterior tuberosity were usually displaced 10-30 mm and were frequently rotated. The mean time from diagnosis of diabetes mellitus to CIA fracture was 20 years. Fractures in the nondiabetic group and in the three diabetic patients with a history of trauma did not resemble the CIA pattern. In the nondiabetic group, there were no insufficiency fractures; 39 fractures occurred with significant force (eg, motor vehicle accident or fall from height), and 33 had extension to subtalar or calcaneocuboid joints.

Magnetic resonance imaging of peripheral T-cell lymphoma

We report magnetic resonance (MR) findings of two unusual cases of peripheral T-cell lymphoma, one initially presenting as a soft-tissue mass in the neck and the other in the foot. MR imaging provides better tissue contrast and lesion delineation than CT. However, MR signal characteristics cannot differentiate this lymphoma from other soft-tissue tumours. Although it is rare, peripheral T-cell lymphoma should be included in the differential diagnosis of a soft-tissue mass.

Intraspinal synovial cysts. Magnetic resonance evaluation

Five intraspinal synovial cysts in four patients were evaluated with noncontrast magnetic resonance imaging and magnetic resonance imaging with the contrast agent gadolinium diethylenetriaminepentaacetic acid. Useful findings included demonstration of both solid and cystic components, early enhancement of the solid component and cyst periphery, delayed enhancement of the cyst, persistent enhancement of the solid component and cyst capsule, enhancement of the apophyseal joint, and recognition of a possible connection between the cyst and apophyseal joint. Although computed tomographic findings of synovial cysts are quite characteristic for the diagnosis in most cases, contrast magnetic resonance imaging may provide additional information for a more definitive diagnosis.

Sarcoma in Paget disease of bone: clinical, radiologic, and pathologic features in 22 cases

The clinical, radiologic, and histologic features of 22 cases of Paget sarcoma were reviewed to determine in which patients with Paget disease these tumors are most likely to develop and what radiologic findings suggest the diagnosis. Clinical findings at presentation included pain and/or a mass (11 patients), pathologic fracture (seven), and neurologic symptoms (four). Survival time in 20 patients ranged from 5 days to 2.5 years. Two patients were lost to follow-up: one at 2 years and one at 8 years. There were 16 high-grade osteosarcomas, three chondrosarcomas, two fibrosarcomas, and one malignant fibrous histiocytoma. The most common site was the femur. Tumors also were observed in unusual sites. In one case of multifocal osteosarcoma, the tumor involved only pagetic bone. In 15 patients, Paget disease was polyostotic, clinically significant, and had been documented previously. In four patients, a sarcoma developed near the site of a fracture that had occurred between 2 months and 15 years previously. All cases showed radiologic evidence of a destructive lesion; other findings included a mass and evidence of tumor mineralization. Periosteal reaction was not observed. All but one tumor developed in a site of osteoblastic or mixed osteoblastic and lytic Paget disease. Our results suggest that sarcomas can develop in any part of any bone affected by Paget disease but are more likely to occur with advanced disease and to present with a destructive lesion without periosteal reaction.

Glenoid labrum: evaluation with MR imaging

Fifteen patients with shoulder instability and nine asymptomatic volunteers were studied with magnetic resonance (MR) imaging. The shoulder joint was visualized by means of arthroscopy or surgery in all patients. Ten patients had abnormalities of the glenoid labrum. Two musculoskeletal radiologists interpreted the MR images of the patients and volunteers without knowledge of the clinical history or surgical results. The surgical and arthroscopic results were used as the standard of reference in symptomatic patients. Observer A achieved a sensitivity of 44.4% and a specificity of 66.7%; observer B had a sensitivity of 77.8% and a specificity of 66.7%. In addition to the poor sensitivities and specificities, there was substantial intra- and interobserver variability. Assuming that the shoulders of the asymptomatic volunteers were normal, the specificities were 100.0% and 88.9% for observers A and B respectively. In this small study, axial MR imaging was relatively insensitive and nonspecific in the evaluation of labral lesions. Further study will be necessary to determine the utility and limits of MR imaging in this regard.

Correct placement of epidural steroid injections: fluoroscopic guidance and contrast administration

We prospectively evaluated 316 caudal-approach epidural steroid injections given by staff radiologists and residents in our department over a 1-year period. Needle placement was checked with fluoroscopy and corrected if necessary. When the needle tip was within the sacral canal, nonionic contrast material was injected. If epidural contrast was not observed, the needle tip was repositioned. Of 111 procedures performed by physicians who had given fewer than 10 epidural steroid injections, 53 (47.7%) resulted in correct nonfluoroscopically directed placement of the needle. For physicians who had performed between 10 and 50 such procedures, 62 (53.4%) of 116 had correct nonfluoroscopically directed placement. For staff physicians, 55 (61.7%) of 89 placements were correct. Even when the sacral hiatus was easily palpated and a staff physician was confident that he or she was within the epidural space, fluoroscopy revealed incorrect placement 14.2% of the time (seven of 49 procedures). In addition, when the needle was positioned within the sacral canal and no blood was evident on Valsalva maneuver or aspiration, the injection was venous in 29 of 316 procedures (9.2%). The presence of blood on the needle stylus was not a reliable indicator of venous placement of the needle. Our findings indicate that fluoroscopy is essential for correct placement of epidural steroid injection. Contrast administration is necessary to avoid venous injection of steroids.

Post-traumatic cysts and cyst-like lesions of bone

We describe two patients with cyst-like lesions of bone that developed at sites of healed or healing fractures. One case showed histological features of a unicameral bone cyst, which, to the best of our knowledge, is a previously unreported finding in a post-traumatic cyst. It is suggested that there are two principal clinical and radiological types of post-traumatic cyst, of which each of our cases represents an example: (1) asymptomatic transient cortical lesions, found only in children, and (2) more central expanding lesions, found in a wider age group and associated with pain, swelling, and pathological fractures.

Subacute pyogenic osteomyelitis

Records of 110 cases of subacute osteomyelitis were reviewed. Twenty percent of the cases with a subacute clinical course had diffuse radiological changes more characteristic of an acute disease. Classic metaphyseal (Brodie) abscesses were most common. Diaphyseal lesions, of which over half were in adults, had a significantly higher rate of recurrence. The distribution by site and age of metaphyseal lesions resembled that of acute osteomyelitis. Staphylococcus aureus was the most common isolate, but 10% of lesions grew S. epidermidis. A modification of current classification is suggested which offers a basis for management and studies of outcome.

The functional significance of sacroiliitis and ankylosing spondylitis in Reiter's syndrome

The frequent development of sacroiliitis and ankylosing spondylitis (AS) in patients suffering from Reiter's Syndrome (RS) has been stressed by a number of authors. This study was designed to ascertain the frequency of these problems in our RS patients, whether they were related to other clinical features of RS and what was the extent of the resulting disability. Fifty-five patients (50 men and 5 women) with RS with a mean duration of 9.3 years were assessed radiologically to determine the prevalence of sacroiliitis and thoracolumbar syndesmophyte formation. These radiological findings were correlated with HLA-B27, clinical features and functional status. Sacroiliitis was found in 22 patients (40%) but was mild in severity, frequently asymmetrical and very rarely associated with syndesmophyte formation. Sacroiliitis occurred significantly more commonly in patients with iritis and/or a prolonged disease duration (p less than 0.05) but although it was also found more frequently in HLA-B27 positive patients this was not significant (0.1 greater than p greater than 0.05). Some restriction in back movement was observed in 31 patients (56.3%) but only two patients satisfied New York criteria for AS and just one was functionally impaired by his back disease. Although the frequent finding of sacroiliitis in RS may provide an interesting insight into the interrelationship between RS and AS, our study shows that this sacroiliitis is commonly asymptomatic and does not provide a problem in management.