Wilson, DavidCrowley, Caroline Mary Helen2019-11-262019-11-261997http://hdl.handle.net/2440/1220981. MR imaging of the TMJ has a high diagnostic accuracy and should be considered as the prime imaging modality for soft and hard tissue changes of the TMJ. Howevel MR imaging is dependent on technical factors such as magnetic field strength, gradient coil strength, software and surface coils to achieve a high quality image. The small number of false diagnoses in this study were consistently related to underestimation of the pathologic conditions. All of the false diagnoses were false negative's and included an underestimation of disc displacements, disc deformations or osseous changes. The underestimations were usually due to the inability of MR imaging to depict the most lateral or most medial part of the joint. The most lateral and most medial parts of the joint were not depicted with the same high quality images as the central zone. Although the diagnostic accuracy in this study was high, it may be possible to further improve the MR images. One possibility would be to use MR imaging sections that are thinner than 3mm. In this way volume averaging of oblique structures would be reduced, and the image quality of the most lateral and most medial parts of the joint would be improved. Another way to improve MR imaging would be to use a smaller field of view, resulting in higher spatial resolution. 2. The most accurate imaging modality for normal and pathologic joints was the sagittal and coronal T2 weighted sequences which were highly sensitive to at'ticular surface changes, disc displacements and perforations. When the images were compared to the histologic sections of the same joint this accuracy was highlighted. The results also showed that the use of sagittal MR images alone does not provide sufficient accuracy in the evaluation of disc position and articular surface changes. Consequently a full MR examination of the TMJ for positional disc abnormalities ancl osseous changes should include imaging in both coronal and sagittal planesenThesis