Objective: The purpose of this investigation was to study the MR imaging characteristics of various histologic types of parotid gland tumors in order to determine if MR findings can be used to categorize these tumors.
Material and methods: We retrospectively studied the MR images and pathologic findings in 20 patients with a variety of tumors of the parotid gland. Fat-suppressed T1-weighted images, T2-weighted images, and contrast-enhanced fat-suppressed T1-weighted images were acquired with a 1.5-T MR imager and an anterior neck coil.
Results: Carcinomas (n = 5) were characterized by infiltration into the muscles along the surface of the mandible and by contrast enhancement. Warthin's tumors (n = 4) showed areas of different signal intensity on T2-weighted images and did not enhance after injection of contrast material. Pleomorphic adenomas (n = 11) showed enhancement after injection of contrast material but did not infiltrate the muscles.
Conclusion: Our findings suggest that MR characteristics are helpful in categorizing parotid gland tumors according to histologic type.