On MRI of the temporomandibular joint (TMJ), which sequence is MOST useful for evaluating the position of the articular disc?

• A T1-weighted axial with gadolinium
• B STIR coronal through both joints simultaneously
• C Proton density or T2-weighted sagittal oblique (in open and closed mouth positions) ✓
• D Gradient echo T2* weighted axial

Explanation

TMJ MRI uses sagittal oblique (perpendicular to the condylar long axis) proton density or T2-weighted sequences in both closed- and open-mouth positions. The low-signal fibrocartilaginous disc is identified relative to the condylar head: in the closed-mouth position, the posterior band of the disc should be at the 12 o'clock position of the condyle. Anterior disc displacement is evaluated by comparing disc position in open and closed views. Gadolinium is used for synovial inflammation, not primary disc assessment. STIR is less specific for disc morphology.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.