Internal derangements of the temporomandibular joint: comparison of assessment with three-dimensional gradient-echo and spin-echo MRI

Abstract Our purpose was to assess the diagnostic accuracy of three-dimensional (3D) gradient-echo (GRE) MRI in the diagnosis of internal derangements of the temporomandibular joint (TMJ). We studied 140 joints in 70 patients with TMJ internal derangements. We obtained 3D-GRE and spin-echo (SE) images in the closed-mouth position; the images were reviewed for disc displacement as well as bone and cartilage abnormalities. The 3D-GRE and SE images were interpreted independently by different radiologists. The sensitivity and specificity of 3D-GRE imaging for assessing mediolateral disc displacement was 100 %, whereas the sensitivity and specificity of sagittal SE images were 82 % and 72 %, respectively (P < 0.001). The 3D-GRE images also demonstrated more bone abnormalities (in 112 condyles or 80 %) than did SE images (in 79 condyles or 56 %) (P < 0.001). Furthermore, 3D-GRE imaging revealed articular cartilage abnormalities in 46 condyles (33 %) that were not visible on SE images. The frequency of pain was significantly higher in joints with bone and cartilage abnormalities (P < 0.05 and P < 0.001, respectively). For assessment of disc displacement, 3D-GRE images were superior to sagittal SE images alone, and comparable to combined sagittal and coronal SE images, while for bone and cartilage abnormalities, they were superior to sagittal and coronal SE images.