High-field MR imaging of the temporomandibular joint using an optimized imaging technique

In four healthy volunteers and eleven patients both temporomandibular joints (TMJ) were simultaneously imaged with MR imaging. All patients had conventional radiographs prior to MR imaging. MR imaging was performed at high field using a TMJ double coil for simultaneous investigation of both joints. Proton density weighted images (TR, TE=1000/15 ms) were obtained with closed and open mouth position. To improve the evaluation of soft tissue changes, namely discal lesions, the individual angle of the condylar head of the mandibula was considered when the imaging planes were selected (approximately 10 sagitto-coronal angulation). There were 15 cases of internal derangement with and without subluxation of the meniscus (open mouth position). In addition, a case of posttraumatic hemorrhage in the bilaminar zone as well as a case of degenerative osseous changes of the TMJ were diagnosed. MR images not only showed soft tissue changes but also osseous changes could nicely be diagnosed. When compared to conventional radiographs, MR imaging was superior in showing soft tissue changes, namely lesions of the meniscus and osteonecrosis. Conventional tomography is a valuable technique to show osseous changes of the TMJ. (orig.)