MAGNETIZATION-TRANSFER CONTRAST ON GRADIENT-ECHO MR-IMAGING OF TEMPOROMANDIBULAR-JOINT

Thirty-nine temporomandibular joints (TMJ) from 20 patients with suspe cted internal derangements were imaged by a 1.5 T MR imager. The on-re sonance binomial magnetization transfer contrast (MTC) pulse was appli ed to gradient echo images with a dual receiver coil (9 s/section). Wi th the use of an opening device, a series of sequential images were ob tained at increments of mouth opening and closing. The tissue signal i ntensities with (Ms) and without (Mo) MTC were measured and subjective image analysis was performed. Compared with the standard images, MTC technique provided selective signal suppression of disks. The average of Ms/Mo ratio of the disks (0.56) was lower than that of the retrodis kal pad (0.79) and of the effusion (0.89). With MTC technique, fluid c onspicuity was superior to standard image. However, no significant sup eriority was found in disk definition subjectively.