Distinguishing between tumors from parotid space and from parapharyngeal space based on the posterior belly of digastric muscle and its shift / 中华放射学杂志

ABSTRACT

Objective To seek an approach to differentiate between tumors from parotid space and from parapharyngeal space on axial CT or MR imaging. Methods Forty-five patients with tumors originated at the parotid or parapharyngeal space were reviewed retrospectively. The diagnosis was confirmed pathologically in all of the cases. The correlation among neoplasms and the posterior belly of digastric muscle and its shifting situation were evaluated on axial CT or MRI scans by two senior radiologists. All of the estimations were compared with the results of operation. Results Twenty-seven tumors from parotid space were located in the superficial side to the posterior belly of digastric muscle and pushed it medially. On the contrary, 18 neoplasms from parapharyngeal space were situated at the profound side to the posterior belly and shifted it laterally. Conclusion Tumors superficial to the posterior belly of digastric muscle and pushing it medially indicate that they come from parotid space. While neoplasms profound to the posterior belly of digastric muscle and shifting it laterally mean that they come from parapharyngeal space.