Application of zero-TE MRI for the disk calcification of the temporomandibular joint: two case reports.

While articular disk calcification is rare in the TMJ (temporomandibular joint), its etiology and frequency remain unclear. The most common calcification in the TMJ is a calcification associated with synovial chondromatosis, a tumorous disease. It is essential to distinguish articular disk calcifications from loose bodies associated with synovial chondromatosis because each treatment procedure is entirely different. However, it is challenging to distinguish the articular disk calcification from the other entities on MRI, where these structures appear as low signal intensity. Until now, CT scans have been used for differential diagnostics. However, recent advancements, such as zero-time echo (ZTE) MRI, enable improved visualization of short-T2 tissues, potentially enhancing the detection of bone and calcifications. We applied the ZTE-MRI to three joints in two patients with articular disk calcification in TMJ and obtained findings similar to those in CT images. In conclusion, we could confirm the usefulness of the ZTE-MRI for differential diagnostics of calcification in TMJ.