MRI of the TMJ Disc with Intravenous Administration of Gadopentetate Dimeglumine

Purpose: The purpose of this study was to ascertain whether MR imaging with intravenous administration of gadopenetate dimeglumine (Gd-DTPA) is useful in the demonstration of the temporomandibular joint (TMJ) disc. Method: Sagittal T1-weighted MR images of 50 TMJs (25 patients) were obtained using a 0.5-T system both before and after intravenous injection of Gd-DTPA. The authors depicted the TMJ in which intravenous injection of Gd-DTPA improved visualization of the disc. Results: Intravenous injection of Gd-DTPA increased intensity in the retrodiscal space, the pterygoid venous plexus, as well as joint effusion by diffused Gd-DTPA. The technique improved visualization of 10 (50%) of 20 normal discs and 20 (67%) of 30 anterior disc displacements in closed-mouth position, and also 23 (74%) of 31 normal discs and 12 (63%) of 19 anterior disc displacements in open-mouth position. There were 12 TMJs (24% of the 50 TMJs) in which equivocal findings became highly diagnostic. The incidence in marked contrast effect was higher in TMJs with severe internal derangement than in those with normal or mild internal derangement (p < 0.005). Conclusion: Using a 0.5-T MR imager, Tl-weighted imaging with intravenous injection of Gd-DTPA showed more anatomic details than imaging without the contrast agent.