Simultaneous bilateral TMJ study using a high field MRI system

Abstract

Because of the high signal to noise ratio (S/N), images obtained using high-field magnetic resonance imaging (MRI) systems can be expected to provide high magnetic anatomical and contrast resolution. The purpose of this study was to evaluate the usefulness of 3.0 tesla (T) -MRI system imaging for the temporomandibular joint (TMJ), using a coil unit which we produced experimentally. The coil unit that we used in this study consisted of a dual 5-inch phased array surface coil and coil holder to achieve simultaneous imaging of bilateral TMJs.
The subjects were three males and one female volunteers. The sagittal bilateral TMJ images were taken simultaneously by using the 3.0 T-MRI system to decide the two fast-spin echo scan sequences. One sequence gave priority to image quality in a resting mouth position to examine the construction of TMJ in detail, and the other was to analyze the TMJ motion in a resting, mid-opening, and full-opening mouth position in a shorter imaging time.
The anatomical structures of TMJ such as disc, condyle, and posterior attachment were clearly delineated when using the sequence that gave priority to image quality. The scan time was shortened by almost half to obtain equal image quality of TMJ by using the 1.5 T-MRI clinical system under the sequence for analyzing TMJ motion.
As a result, it was concluded that the 3.0 T-MRI system with dual 5-inch surface unit was useful for imaging the anatomical structures of TMJ and for analyzing coordination of disc motion and condylar translation in several jaw positions. We expect this device will contribute to the diagnosis of TMJ disorders.