MR imaging diagnosis of triangular fibrocartilage pathology with arthroscopic correlation.

OBJECTIVE: The goal of this study was to compare MR imaging with arthroscopy in evaluating triangular fibrocartilage (TFC) pathology. MATERIALS AND METHODS: The results of 178 MR imaging examinations of the wrist were independently reviewed by two musculoskeletal radiologists who were unaware of the the clinical history, including any subsequent surgery. One hundred forty-nine of these studies were obtained from symptomatic patients. Of these patients, 56 underwent arthroscopic evaluation of the TFC. The remaining 29 studies were obtained from control volunteers and duplicate cases to reduce bias. The data were divided into categories based on Palmer's classification of TFC injury. Diagnostic sensitivity, specificity, and accuracy were calculated for each category. RESULTS: Of the 56 patients who underwent arthroscopic evaluation of the TFC, 27 had TFCs that were intact at surgery. Also, 27 complete perforations and two partial defects were found at surgery. Sensitivity for detecting central degenerative perforations was 91% for both observers I and II. Sensitivity for detecting radial slitlike tears was 100% and 86% for observers I and II, respectively. Sensitivity for detecting ulnar-sided avulsions was 25% and 50% for observers I and II, respectively. CONCLUSION: MR imaging is accurate in revealing TFC perforations.

MR imaging of the wrist: normal findings that may simulate disease.

Twenty-six normal wrists in young adults were studied with magnetic resonance (MR) imaging. The following conclusions were drawn regarding normal anatomic features: (a) Multiple slips of the abductor pollicis longus tendon simulate longitudinal tears; (b) the extensor pollicis longus and extensor carpi ulnaris tendons normally demonstrate increased signal intensity simulating tendinitis; (c) small quantities of fluid in the extensor tendon sheaths may be normal and not indicative of tenosynovitis; (d) the triangular fibrocartilage normally demonstrates increased signal intensity simulating tears at its radial and ulnar attachment sites; (e) the volar ulnocarpal ligaments are often indistinct, thereby simulating injury; and (f) the median nerve has signal intensity equivalent to that of fat, nor of muscle as commonly believed. Awareness of these normal features is critical in making the correct interpretation of MR images of the wrist.

MR imaging of the painful wrist.

Magnetic resonance (MR) imaging is an effective method for helping determine the cause of wrist pain by demonstrating a broad spectrum of abnormalities, including those of bone, cartilage, ligaments, and tendons. MR imaging is useful in the detection, characterization, and staging of osseous injury and disease, although computed tomography provides superior detail in the depiction of bone. MR imaging may demonstrate irregular cartilage loss in noninflammatory arthropathies such as osteoarthritis, and its superior soft-tissue contrast makes it the method of choice for evaluating the synovial processes. Although arthrography remains the standard of reference in the detection of perforations of the principal intrinsic ligaments of the wrist, three-dimensional MR imaging has shown promise in depicting the small interosseous ligaments. Tendinitis, tenosynovitis, ganglia, and anatomic variants can be diagnosed and accurately assessed with MR imaging. Radiologists need to be aware of the full spectrum of wrist abnormalities and the characteristic MR imaging findings that accompany them.

MR imaging interpretation of the Palmer classification of triangular fibrocartilage complex lesions.

The triangular fibrocartilage complex (TFCC) is a complex anatomic and biomechanical structure. Injury to the TFCC is a recognized cause of ulnar wrist pain. The TFCC may be injured in its horizontal portion, in its peripheral portions, or at its attachments. In the Palmer classification, TFCC lesions are categorized as traumatic or degenerative. Traumatic lesions are subclassified according to the location of the injury; degenerative lesions are subclassified according to the extent of degeneration. This classification is helpful in determining the mechanism of injury and directing clinical management. Magnetic resonance (MR) imaging may be more useful than arthrography in prospective evaluation of TFCC lesions. MR images accurately demonstrate the structural abnormalities that contribute to ulnocarpal instability and pain. The presence or absence of chondromalacia is a factor in the Palmer classification and is also considered in treatment planning. However, only advanced cases of chondromalacia are reliably detected with MR imaging.

Helical CT: clinical performance and imaging strategies.

For nonelectron beam systems, scan speed and image quality have reached a relative plateau of performance. Helical CT makes rapid coverage of the z axis possible, allowing scanning to occur during the optimal phase of vascular and organ enhancement. With the split breath-hold variable-mode approach, extended helical coverage across multiple anatomic regions is possible. The technique adds flexibility in choice of collimation, milliamperage, and breath-hold interval. It is easily tolerated by patients and reproducible, and the intersegment delays produce less heat loading on the x-ray tube.

MR angiography of Takayasu arteritis.

We describe MR angiographic findings utilizing a three-dimensional time-of-flight technique and compare the results with angiography in a case of suspected Takayasu arteritis involving vessels to the neck and upper extremities.