Diagnostic value of 3.0T dynamic contrast-enhanced MRI and diffusion weighted imaging for common parotid tumors

Abstract

Thirty nine patients with pathologically confirmed parotid tumors, including 18 cases of pleomorphic adenomas, 12 cases of papillary cystadenoma lymphomatosum and 9 cases of malignant tumors, were enrolled in the study. Characteristics on routine MR image, diffusion weighted imaging (DWI), time-signal intensity curve (TIC) and apparent diffusion coefficient (ADC) value in different types of tumors were evaluated. There were significant differences in imaging features between benign and malignant tumors (P<0.01). The TIC types were A, B and C for pleomorphic adenomas, papillary cystadenoma lymphomatosum and malignant tumors, respectively. The mean ADC value of pleomorphic adenomas was significantly higher than that of papillary cystadenoma lymphomatosum and malignant tumors (P<0.01). No significant difference in ADC values between papillary cystadenoma lymphomatosum and malignant tumors was detected (P=0.73). The study indicates that MR plain scan combined with dynamic contrast enhanced MRI and DWI may be helpful in pre-operative differentiation of common parotid tumors. Key words: Parotid neoplasms; Magnetic resonance imaging; Image enhancement, dynamic; Diffusion magnetic resonance imaging