Comparison of SE and short TE three-dimensional gradient-echo imaging of the temporomandibular region

Conventional spin-echo (SE) images and three-dimensional (3D) gradient-echo images with short TE obtained at 1.5 T were obtained of temporomandibular (TMJ) regions in four volunteers and 10 patients. Short TE (echo time = 5.5 msec), 3D, gradient-echo images with nearly symmetric data acquisition caused negligible susceptibility artifacts. The TMJ disk was better visualized with 3D, gradient, fast-low-angle-shot (FLASH) images with small (Ernst) angles than it was with 3D, gradient-echo, fast- imaging-with-steady-precession (FISP) images. T1-weighted SE imaging revealed higher contrast resolution of the disk than did 3D gradient-echo images and is the preferred method to evaluate TMJ disorders. However, short TE 3D gradient-echo images revealed marked improvement in the delineation of the facial nerve canal in the temporomastoid region