Application of magnetic resonance T2 mapping in the temporomandibular joints

The objective of this study was to apply magnetic resonance (MR) T2 mapping to the normal temporomandibular joint (TMJ) disk and to determine its T2 character.Fourteen volunteers with 28 healthy TMJs were selected for this study. MR T2 maps of all of the disks were acquired. The global disk area and 6 zonal regions of interest (ROIs) of superior, inner, and inferior layers and anterior, middle, and posterior bands were defined for each disk. T2 values of the global disk and each zonal ROI were calculated. Comparisons of the T2 values among the 3 layers and among the 3 bands were performed using the general linear model.The T2 value for the whole disk was 40.21 ± 2.95. The T2 values of the superior (39.42 ± 3.73) and inferior layers (40.11 ± 3.29) were significantly higher than the inner layer (37.28 ± 3.54) (P < .05). The T2 values of the anterior (36.96 ± 3.43) and posterior bands (36.01 ± 3.72) were significantly lower than the middle band (41.04 ± 5.51) (P < .05).Preliminary determinations of T2 values for the bands and layers of normal TMJ disks were calculated.