MR imaging of temporomandibular joint (TMJ). Mandibular fracture and traumatic disk injury

Using an 1.5 Tesla superconducting MR unit and surface coil, 12 mandibular fracture patients were evaluated for TMJ disk change. Sagittal and coronal images of the TMJ with a slice thickness of 2 mm were obtained with FISP 2D or 3D. TR=30 msec, TE=12 msec, and flip angle=40 degrees were applied. Among 12 patients, FISP 3D revealed increased signal intensity of the disk in 70% of cases. Traumatic fluid collection at or adjacent to the TMJ showed high intensity. The disk was displaced anteromedially regardless of the site of fracture. (author)