Focal radial styloid abnormality as a manifestation of de Quervain tenosynovitis.

OBJECTIVE: de Quervain disease is a stenosing tenosynovitis of the first dorsal wrist compartment. The purpose of this study was to determine whether focal radial styloid abnormality (cortical erosion, sclerosis, or periosteal bone apposition) as shown by radiography can be an indicator of de Quervain tenosynovitis. MATERIALS AND METHODS: A retrospective review of 49 radiographs from 45 patients in whom the clinical diagnosis of de Quervain tenosynovitis was confirmed (positive findings on Finkelstein's test) and 64 radiographs from 62 asymptomatic patients was carried out independently by two musculoskeletal radiologists in a blinded fashion. Findings on radiographs were assessed for focal radial styloid abnormality and assigned a diagnostic grade (1, definitely normal; 2, probably normal; 3, equivocal; 4, probably abnormal; 5, definitely abnormal). Receiver operating characteristic curves were constructed and compared. Kappa statistics for interobserver and intraobserver variability were calculated. RESULTS: The presence of focal radial styloid abnormality correlated significantly with the presence of de Quervain tenosynovitis (p < 0.05). The areas under the receiver operating characteristic curves for each reviewer equaled 0.71 and 0.76. Kappa values for interobserver variability equaled 0.44 (moderate agreement), and intraobserver variability equaled 0.62 (substantial agreement). CONCLUSION: Focal radial styloid abnormality is an indicator of de Quervain stenosing tenosynovitis of the wrist.

Tumoral calcinosis: radiologic-pathologic correlation.

OBJECTIVE: Tumoral calcinosis is a frequently misdiagnosed disorder. This study details the radiologic and pathologic characteristics of tumoral calcinosis that distinguish it from most other entities. DESIGN: Radiologic 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. PATIENTS: The 12 patients ranged in age from 15 months to 62 years. Six had idiopathic tumoral calcinosis and 6 had secondary tumoral calcinosis. RESULTS AND CONCLUSIONS: A 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.

The rich tradition of radiology at the University of Michigan.

The evolution of radiology at the University of Michigan after Roentgen's discovery in 1895 has had a profound influence on radiology. The school has had notable firsts in medicine: it was among the first of the state-supported universities to have a medical school (1850), had the first teaching hospital owned by a university (1869), and had the first university department of roentgenology (1917). Given these circumstances, teaching and research were early high priorities. The original small hospital, a remodeled private residence in Ann Arbor (1869), proved inadequate and was replaced in 1891 by the Catherine Street Hospital, viewed then as the largest teaching hospital in the nation. This served the medical school well for many years but was succeeded by the magnificent new University Hospital in 1925. Built for $4.4 million with a bed capacity of 700 in a double-Y architecture, it was an entirely new concept in hospital design and was the pride of the state [1].

Dialysis-related Arthropathy in Patients on Long-term Hemodialysis: Radiographic Features.

The purpose of this study was to evaluate the character and evolution of bone lesions attributable to amyloid deposition in patients on long-term dialysis. Thirty-five patients who were treated with hemodialysis for 5 to 22 years were studied by a review of medical records and hand radiographs. The frequency, distribution, character, and evolution of skeletal cyst-like lesions believed to be secondary to amyloid deposition were evaluated in relation to dialysis duration. The number and size of these lesions increased with dialysis duration, present in 28% of the patients after 5 through 9 years of hemodialysis and in 91% after 15 through 22 years. In contrast, the changes of hyperparathyroidism decreased. Of patients with skeletal wrist lesions, radiographs of symptomatic large joints were available in 15; five had bone abnormalities. Skeletal amyloid deposition was verified pathologically in nine sites (five patients). It is concluded that skeletal lesions believed to be due to amyloid deposition increase with dialysis duration and most commonly affect the wrists. They have a distinctive character, distribution, and evolution and are often associated with carpal tunnel syndrome.

Monarticular erosive osteoarthritis: a possible source of confusion with infectious arthritis.

Although monarticular erosive osteoarthritis is uncommon, it is not rare. In our example, there was a monarticular presentation of cartilage destruction, soft tissue swelling, and linear periosteal bone apposition. Such bone apposition adjacent to affected joints is not uncommon in erosive osteoarthritis. However, when observed in the context of monarticular disease, particularly when accompanied by soft tissue swelling, it could easily be mistaken for an infectious arthritis.

Reactive soft-tissue mass associated with osteoid osteoma: correlation of MR imaging features with pathologic findings.

The authors retrospectively reviewed three cases of histologically documented osteoid osteoma in which magnetic resonance (MR) imaging was performed prior to surgical excision. In all three cases, MR imaging demonstrated abnormal signal intensity characteristics, and use of gadopentetate dimeglumine resulted in enhancement. These findings correlated with a reactive soft-tissue mass with myxomatous change, as well as with cell-depleted, juxtanidal bone marrow that contained proteinaceous material. These MR imaging findings can easily be confused with those of a malignant tumor or osteomyelitis.

Precision of hyaline cartilage thickness measurements.

Measurement of cartilage thickness in vivo is an important indicator of the status of a joint as the various degenerative and inflammatory arthritides directly affect the condition of the cartilage. In order to assess the precision of thickness measurements of hyaline articular cartilage, we undertook a pilot study using MR imaging, plain radiography, and ultrasonography (US). We measured the cartilage of the hip and knee joints in 10 persons (4 healthy volunteers and 6 patients). The joints in each patient were examined on two separate occasions using each modality. In the hips as well as the knee joints, the most precise measuring method was plain film radiography. For radiographs of the knees obtained in the standing position, the coefficient of variation was 6.5%; in the hips this figure was 6.34%. US of the knees and MR imaging of the hips were the second best modalities in the measurement of cartilage thickness. In addition, MR imaging enabled the most complete visualization of the joint cartilage.

Some commonly unrecognized manifestations of metabolic arthropathies.

The metabolic arthropathies are characterized by the deposition of abnormal substances in or around joints. Certain features of some of these arthropathies and their significance have only recently been recognized and others have been insufficiently emphasized. An important group of conditions are the arthropathies related to renal failure and its treatment, namely, aluminum toxicity, periarticular calcification and crystal deposition, hyperparathyroidism, and dialysis-related amyloidosis. Crystal deposition diseases, specifically, gouty arthritis, calcium pyrophosphate deposition, and calcium hydroxyapatite deposition, are also reviewed.

Dialysis-related amyloid arthropathy: MR findings in four patients.

Dialysis-related amyloidosis is a recently recognized complication of long-term hemodialysis. It is caused by the deposition of a unique form of amyloid derived from circulating beta 2-microglobulin. This study describes the MR imaging characteristics in five articular sites of four symptomatic patients with biopsy-proved (three patients) or clinically and radiographically suspected (one patient) dialysis-related amyloidosis. Three wrists, one knee, and one cervical spine were examined. The extent of osseous and soft-tissue involvement at each joint site was well shown by MR imaging. Lesions that were apparently intraosseous on conventional radiographs were shown to be caused by well-defined erosions that extended to the articular surface. The MR signal characteristics of the amyloid deposition were intermediate between those of fibrocartilage and muscle on all sequences, distinguishing the deposition from cellular lesions or those containing large amounts of water, such as inflammatory masses, acute or chronic synovitis, and brown tumors of hyperparathyroidism. The intraarticular masses were associated with a moderate joint effusion in the large joint imaged, and small effusions were present in the wrist. Use of a fat-suppression sequence enhanced visualization of amyloid deposits within the wrist of one patient but provided no additional information in the knee of a second patient. Our experience suggests that MR imaging is well suited to showing the extent and distribution of articular disease in dialysis-related amyloidosis.

Distal interphalangeal joint abnormalities in children with polyarticular juvenile rheumatoid arthritis.

Involvement of the distal interphalangeal (DIP) joints was noted radiographically in 24 (43.6%) of 55 patients with polyarticular juvenile rheumatoid arthritis. DIP changes were apparent later in the course of the disease and were less severe than in other affected joints. Soft tissue swelling and joint space narrowing were the most frequent abnormalities in the DIP joints. Erosive changes and angular deformities were uncommon. There was no significant correlation between DIP joint involvement and sex, age at presentation, involvement of the hands and wrists at presentation, or positivity of either rheumatoid factor or antinuclear antibody. There was a strong correlation between the presence of extraarticular signs and symptoms and involvement of the DIP joints; however, this may reflect the greater severity of the disease in these patients generally.

Overview: new methods in imaging osteoarthritis.

The new imaging modalities, namely computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US) provide potentially powerful tools for in vivo assessment of osteoarthritis (OA), monitoring the progress of the disease and understanding its natural course. However, to use these tools effectively, we need more prospective research focused on correlating imaging data with biochemical and gross and microscopic pathologic findings. MRI is clearly the most powerful tool for demonstrating the various articular components which may be affected in OA. CT is excellent for delineating osseous abnormalities and with US we are able to evaluate the thickness and surface characteristics of those portions of articular cartilage that are accessible. The advantages and limitations of these 3 modalities are discussed as they pertain to OA of the hip and knee.

Magnetic resonance imaging of the normal craniovertebral junction.

Sagittal magnetic resonance images of the normal craniovertebral junction in 25 patients were examined for visualization of bony, synovial, and ligamentous structures. The excellent delineation of soft tissue by magnetic resonance imaging enabled recognition of the joint space between the dens and anterior arch of C1 in 14 out of 25 patients. High-signal-intensity tissue was noted immediately superior to the dens in all patients; an anatomic specimen confirmed the fibrofatty nature of this tissue. The medullary space of the dens had lower signal intensity than did the marrow in the body of C2 in more than one half of the cases. Additional thin-section images suggested that this was a partial-volume artifact. Understanding of the normal appearances of structures in this region is necessary to assess correctly the presence or absence of disease.

Magnetic resonance imaging appearance of the muscles in childhood dermatomyositis.

Documentation of muscle involvement in a child thought to have dermatomyositis may require the performance of invasive procedures such as electromyography and/or muscle biopsy. We describe four patients with dermatomyositis in whom magnetic resonance imaging (MRI) demonstrated the muscle involvement. The involved muscles had increased signal intensity on the T2-weighted images (SE 2500/80) and normal appearance on the T1-weighted images (SE 600/20). The involvement of the muscles was not uniform. There was good correlation between the distribution of muscle involvement by MRI and functional testing. Follow-up MRI scans in patients with favorable outcome demonstrated that the affected muscles had returned to normal signal intensity. Although the MRI findings are not specific, in the proper clinical context they may be helpful in establishing the diagnosis of dermatomyositis. MRI may also be used in establishing an appropriate muscle biopsy site. In addition, MRI may be used for monitoring the progress of the disease.

MR imaging of early fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva is a rare disorder characterized by progressive heterotopic bone formation in connective tissue and muscle in association with congenital skeletal anomalies. The disease usually leads to extensive immobility and eventual disability. We report the magnetic resonance findings in a boy prior to ossification of his soft tissue masses.