MRI and angiographic diagnosis of lupus cerebral vasculitis.

The authors present a patient with striking angiographic findings of systemic lupus erythematosus (SLE) cerebral vasculitis. Although lupus is often cited as part of the differential diagnosis for angiographically apparent cerebral vasculitis, true SLE cerebral vasculitis is rare in pathological and radiological series. The clinical spectrum and pathological findings of CNS lupus with particular attention to cerebral vasculitis are briefly discussed.

Elusive "stuck" disk in the temporomandibular joint: diagnosis with MR imaging.

PURPOSE: To determine the incidence of a "stuck" disk and its importance in the overall scheme of internal derangement. MATERIALS AND METHODS: Magnetic resonance (MR) images of 212 temporomandibular joints (TMJs) in 106 symptomatic patients were obtained and reviewed. Image analysis included assessment of disk position; disk mobility; and degree of condylar translation, with or without disk recapture in joints with displaced disks. RESULTS: Of the 127 joints with disks in a normal position, 94 had mobile disks and 23 had stuck disks. Ten joints revealed no condylar translation, which precluded assessment of disk mobility. Of 85 joints with displaced disks, 67 joints showed mobility, with recapture in 25 and no recapture in 42. Significant correlation existed between disk mobility and degree of condylar translation (P < .001). CONCLUSION: The TMJ disk may be stuck in a normal or displaced position and limits the normal degree of condylar translation, leading to restricted jaw opening. Recognition of a stuck TMJ disk could alter patient care.

Repair of Achilles tendon ruptures with a polylactic acid implant: assessment with MR imaging.

An investigational tendon repair device composed of a polymer of lactic acid (PLA) is currently undergoing multicenter clinical trials for use in repairing rupture of the Achilles tendon. The advantages of the PLA device include high tensile strength and the induction of a rapid proliferative tissue response resulting in a shorter rehabilitation period than with conventional surgical repair. We reviewed 16 MR examinations performed in 10 patients 3-35 months after repair to characterize the MR appearance. All 16 T1-weighted sagittal images revealed a thickened fusiform tendon with streaks of moderate signal within the tendon corresponding to the PLA device and its surrounding collagenogenic response. The double-echo T2-weighted axial images at the mid tendon level demonstrated progressive changes in the signal pattern of the central portion of the tendon that reflected the maturation of the healing tendon. All tendons repaired with PLA implants were uniformly hypertrophied relative to the contralateral normal side because of the induced proliferative collagenogenic ingrowth. Two follow-up MR examinations were performed in six patients and showed mean reductions in tendon caliber of 24% and 30% at the mid and inferior levels. MR imaging of the Achilles tendon repaired with PLA implants shows a diffusely thickened tendon with streaks of signal within the tendon that distinguish it from tendons repaired by conventional techniques.