Determining whether a parotid tumor is in the superficial or deep lobe using magnetic resonance imaging

This study examined the usefulness of magnetic resonance imaging (MRI) in assessing whether parotid tumors were located in the superficial or deep lobe.

Eight patients with parotid gland tumors underwent MRI using a spin echo pulse sequence. T1- and T2-weighted images were obtained. To assess tumor localization in the parotid gland, two anatomic landmarks were used: 1) a line connecting the lateral surface of posterior belly of digastric muscle and lateral surface of the cortical bone of ascending ramus (facial nerve [FN] line) and 2) the relationship to the retromandibular vein (RV). Results of all MRI examinations were compared with the surgical findings.

Seven of eight cases were correctly diagnosed using the FN line criterion. Five of eight cases were correctly diagnosed using the RV criterion.

MRI is an excellent modality to show tumor localization in the parotid gland.