FIG 1. Axial nonenhanced T1-weighted MR image (700/10 [TR/TE]) obtained in a 50-year-old man with mucoepidermoid carcinoma of the parotid gland, a mass posterior to the left mandible, and no symptoms of TMJ dysfunction or neurologic signs related to V₃ or the facial nerve. The image demonstrates a soft-tissue mass (straight arrows) posterior to the left mandibular ramus (curved arrow) that extends along the expected course of the left auriculotemporal nerve. MR examination revealed no signs of V₃ or facial nerve involvement. These findings were interpreted as suggesting isolated perineural tumor spread along the auriculotemporal nerve; this was confirmed at pathologic examination. Note the normal appearance of the auriculotemporal nerve on the right side, with its two rootlets (small arrowheads) and trunk (large arrowhead).