Lynne S. Steinbach

MR imaging findings in the follow-up of patients with different stages of knee osteoarthritis and the correlation with clinical symptoms

Objective: To assess the rate of cartilage loss, the change in bone marrow edema pattern and internal joint derangement at 1.5-T MRI in patients with knee osteoarthritis and to correlate these findings with the clinical Western Ontario and McMaster University Osteoarthitis (WOMAC) score. Methods: Forty subjects (mean age 57.7±15 years; 16 females and 24 males) were recruited: 6 healthy volunteers (OA0), 17 patients with mild osteoarthritis (OA1) and 17 with severe osteoarthritis (OA2) based on the Kellgren-Lawrence scale. MR scans, radiographs and WOMAC scores were obtained at baseline, first follow-up (1.4±0.67 years; n=40) and second follow-up (2.4±0.4 years; n=26). Cartilage morphology, bone marrow edema (BME), meniscal and ligamentous pathology were assessed on MR images and quantified by two radiologists in consensus. Results:Full-thickness cartilage lesions were observed in 12/17 OA2 at baseline, in 13/17 at the first follow-up and in 7/10 at the second follow-up. Cartilage loss was found in eight patients at the first follow-up and five at the second follow-up. BME was observed in 23/40 patients at baseline, in 22/40 at the first follow-up and in 12/26 at the second follow-up. Changes in BME were visualized in 19/22 and 4/13 patients at the first and second follow-up, respectively. Changes in WOMAC scores over time did not correlate significantly with the amount of cartilage loss and the change in BME (P>0.05). Conclusion:MRI is well suited to monitor the progression of OA in the longitudinal follow-up since it shows cartilage defects, BME and internal joint derangement, pathologies that are not visualized by radiographs. The lack of significant correlation between MRI findings and clinical findings is not unexpected, has been previously described and may in part be due to the fact that patients get more accustomed to their pain as the knee progressively degenerates.

Musculoskeletal manifestations of Hurler syndrome: long-term follow-up after bone marrow transplantation.

Bone marrow transplantation (BMT) is effective in ameliorating many of the clinical manifestations of Hurler syndrome. However, long-term data on the natural history of the musculoskeletal disorders of Hurler syndrome after BMT are limited. The authors report the orthopaedic outcomes in seven patients with Hurler syndrome who were successfully engrafted between 1990 and 1999, and have been followed for a mean of 7.6 years since transplantation. Medical records, clinical examinations, and imaging studies were reviewed to assess the development and management of hip dysplasia, genu valgum, spine abnormalities, hand abnormalities, and joint range of motion. BMT does not appear to alter the natural history of the musculoskeletal disorders in Hurler syndrome, although there may be a beneficial effect on upper extremity joint mobility.

Magnetic Resonance Imaging of the Elbow

Elbow injuries are common, especially in the athlete, and can be basically classified into acute or chronic injuries. The following discussion of magnetic resonance imaging (MRI) of the elbow will address variations in normal anatomy that represent pitfalls in imaging diagnosis, and commonly encountered osseous and soft-tissue pathology.

Imaging of sports-related muscle injuries

Muscle derangements in athletes have a wide variety of causes, treatments, and prognoses. Given that the cause and severity of sports-related injuries may be difficult to determine clinically in some cases, MR imaging is utilized increasingly to evaluate muscle injuries in athletes. After reviewing useful MR imaging techniques, this article focuses on MR imaging of the most common causes of muscle pain and disability in athletes, including myotendinous strain, delayed onset muscle soreness, muscle contusion, myositis ossificans, muscle laceration, muscle herniation, and compartment syndrome. The differential diagnosis of various signal intensity abnormalities in muscle also is reviewed.

Primary Osteoarthritis of the Hip: Etiology and Epidemiology

Primary osteoarthritis (OA) of the hip has a distinct etiology and epidemiology compared with other types of arthropathy in the hip joint. Arthritis of the hip can be secondary to conditions such as osteonecrosis, trauma, sepsis, or rheumatoid arthritis. Certain conditions, such as congenital hip disease and slipped capital femoral epiphysis, involve predisposing anatomic abnormalities; in such cases, the term “secondary OA” is used. When either an anatomic abnormality cannot be determined or other specific causative entities are not identified, primary OA is the diagnosis of exclusion. The prevalence of hip OA is about 3% to 6% in the Caucasian population and has not changed in the past four decades. In contrast, studies in Asian, black, and East Indian populations indicate a very low prevalence of hip OA. Statistics on patients who underwent total hip replacement for primary OA in San Francisco and Hawaii demonstrate a virtual absence of the condition in Asians and low rates in the black and Hispanic populations. Family studies from Sweden, Britain, and the United States show increased rates of hip OA in first‐degree relatives of the index patient when compared with the normal population. Occupations requiring heavy lifting, farming, and elite sports activity are associated with increased rates of hip OA. The low prevalence of hip OA in Asian and black populations in their native countries; the low incidence of total joint replacement for primary OA in Asian, black, and Hispanic populations in North America; and the familial association of hip OA in Caucasians all suggest that genetic factors may be involved in the occurrence of this disease.

Isotropic 3D fast spin-echo imaging versus standard 2D imaging at 3.0 T of the knee—image quality and diagnostic performance

The objective of this study was to compare a newly developed fat-saturated intermediate-weighted (IM-w) 3D fast spin-echo (FSE) sequence with standard 2D IM-w FSE sequences regarding image quality and diagnostic performance in assessing abnormal findings of the knee. MR imaging was performed at 3.0 T in 50 patients. Images were assessed independently by three radiologists. Image quality was rated significantly higher (p < 0.05) for the 2D versus the 3D FSE sequences. Sensitivity for cartilage lesions was slightly higher for the 3D sequence, but specificity was lower. Low contrast objects were better visualized with 2D sequences, while high contrast objects were better shown with the 3D sequence. Confidence scores were higher for 2D than for 3D sequences, but differences were not significant. In conclusion, isotropic 3D FSE IM-w imaging may enhance standard knee MRI by increased visualization of high contrast lesions; however, 3D FSE image quality was lower.

MRI of the sacroiliac joints in patients with moderate to severe ankylosing spondylitis.

OBJECTIVE The objectives of our study were to evaluate whether MRI findings of the sacroiliac joints are able to distinguish between active and inactive disease in patients with established ankylosing spondylitis and to determine whether these findings correlate with markers of clinical activity, disease duration, severity, and degree of radiographic damage. MATERIALS AND METHODS Eighteen patients with symptomatic moderate to severe ankylosing spondylitis were evaluated. MRI of the sacroiliac joint (1.5 T) was performed using fat-saturated T2-weighted, T1-weighted, STIR, and fat-saturated contrast-enhanced T1-weighted sequences. The sacroiliac joints were evaluated by two radiologists for enhancement, subchondral bone marrow edema, erosions, and subchondral fatty marrow infiltration. Findings on MRI were analyzed for correlation with multiple clinical characteristics and measures of disease activity, including radiographic scoring. RESULTS In 17 patients, MRI showed abnormal findings of the sacroiliac joint. Ten patients showed active disease on MRI as measured by abnormal enhancement and subchondral bone marrow edema. Disease activity detected using MRI correlated in a positive fashion with only C-reactive protein (CRP) level. There was no correlation with the other measures of disease activity or with disease duration. In 14 patients, fatty subchondral bone marrow was detected on MRI. These changes were seen in patients with active and chronic disease and correlated with higher radiographic scores but not with disease duration or markers of disease activity. CONCLUSION Contrast-enhanced MRI of the sacroiliac joint is sensitive in depicting sacroiliitis in patients with established ankylosing spondylitis. Subchondral edema and enhancement correlate with high CRP levels. Subchondral fatty bone marrow changes were seen in both active and chronic sacroiliitis and are correlated with higher radiographic scores; these changes may be a marker of more advanced disease.

Tumoral calcinosis: radiologic-pathologic correlation

ObjectiveTumoral calcinosis is a frequently misdiagnosed disorder. This study details the radiologic and pathologic characteristics of tumoral calcinosis that distinguish it from most other entities.DesignRadiologic and pathologic findings, and medical records of 12 patients with tumoral calcinosis were reviewed and compared with equivalent information about 5 patients with other calcified lesions.PatientsThe 12 patients ranged in age from 15 months to 62 years. Six had idiopathic tumoral calcinosis and 6 had secondary tumoral calcinosis.Results and conclusionsA consistent radiologic finding for tumoral calcinosis was a dense calcified mass that was homogeneous except for a “chicken wire” pattern of lucencies, which correlated histologically with thin fibrous septae. Other characteristics of tumoral calcinosis included fluid-calcium levels, demonstrated in four patients, and smooth osseous erosions adjacent to the mass, demonstrated in three patients. Five cases of tumoral calcinosis were originally confused with other calcified lesions; however, the radiologic findings were characteristic of tumoral calcinosis in retrospect.

Hibernoma: imaging characteristics of a rare benign soft tissue tumor.

Abstract. Hibernoma is a rare benign soft tissue tumor of brown fat. Awareness of the MR imaging appearances of this lesion may allow for improved preoperative diagnosis or at least inclusion of hibernoma as a possible benign differential diagnosis prior to surgery.

Musculoskeletal disorders associated with HIV infection and AIDS. Part I: Infectious musculoskeletal conditions

The musculoskeletal system can be affected by a variety of abnormalities in association with human immunodeficiency virus (HIV) infection. Although not as common as complications involving other organ systems, such as the pulmonary and the central nervous systems, HIV-associated musculoskeletal disorders are sometimes the initial presentation of the viral illness. Knowledge of the existence and the characteristic appearance of the conditions affecting bone, joint, and muscle in HIV-infected patients is valuable to radiologists for diagnosis and to clinicians for detection and appropriate treatment. We reviewed recent literature to provide a comprehensive assessment of the HIV-associated musculoskeletal disorders, and present radiologic examples from our own collection. This article is divided into two parts. In the first part we review the infectious musculoskeletal disorders associated with HIV illness and AIDS, including cellulitis, abscesses, pyomyositis, septic bursitis, septic arthritis, osteomyelitis, and bacillary angiomatosis. We also present a comprehensive spectrum of mycobacterial infections, consisting of tuberculous spondylitis and spondylodiskitis, arthritis, osteomyelitis, and tenosynovitis, as well as infections caused by atypical mycobacteria. Part II of this review will concentrate on non-infectious musculoskeletal conditions, including rheumatic disorders and neoplasms.