Purpose: To characterize parotid tumors with dynamic susceptibility contrast perfusion-weighted magnetic resonance (MR) imaging and diffusion-weighted MR imaging.
Material and Methods: Prospective study was conducted upon 48 consecutive patients (27 men, 21 women; aged 15–75 years; mean, 45 years) with parotid tumors that underwent dynamic susceptibility contrast perfusion-weighted MR imaging was performed after bolus injection of gadopentate dimeglumine and diffusion-weighted MR imaging. The dynamic susceptibility contrast percentage (DSC%) and apparent diffusion coefficient (ADC) values of parotid tumors were calculated and correlated with histopathological findings.
Results: The DSC% of malignant parotid tumors (33.53% ± 3.99%) was significantly different (P = 0.001) from that of benign parotid tumors (22.29% ± 4.13%). The threshold values of DSC% and ADC used in differentiating malignant from benign parotid tumors were 26.5% and 1.07 × 10−3 mm2/s, respectively, with area under the curve (AUC) of 0.96 and 0.81, respectively. The DSC% of malignant parotid tumors was significantly different from that of Warthin tumors (P = 0.001). The cutoff DSC% used to differentiate malignancy from Warthin tumors was 26.9% with an AUC of 0.99. There was a significant difference in DSC% and ADC values between pleomorphic adenomas and Warthin tumors (P = 0.001). The threshold values of DSC% and ADC used in differentiating pleomorphic adenomas from Warthin tumors was 22.5% and 0.99 × 10−3 mm2/s, respectively, with AUC of 0.88 and 0.98, respectively.
Conclusions: Dynamic susceptibility contrast-enhanced perfusion-weighted MR imaging and diffusion-weighted MR imaging are noninvasive promising methods that are used for differentiation of malignant from benign parotid tumors and for characterization of some benign parotid tumors.
From the Department of Diagnostic Radiology, Mansoura Faculty of Medicine, Mansoura, Egypt.
Received for publication March 23, 2016; accepted May 16, 2016.
Correspondence to: Ahmed Abdel Khalek Abdel Razek, MD, Diagnostic Radiology Department, Mansoura Faculty of Medicine, Mansoura 13551, Egypt (e-mail: firstname.lastname@example.org).
The authors declare no conflict of interest.