title: Characterization of Parotid Tumors With Dynamic Susceptibility Contrast Perfusion-Weighted Magnetic Resonance Imaging and Diffusion-Weighted MR Imaging.
abstract: OBJECTIVE
  To characterize parotid tumors with dynamic susceptibility contrast perfusion-weighted magnetic resonance (MR) imaging and diffusion-weighted MR imaging.
  
  
  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 mm/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 mm/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.
authors.affiliation: From the Department of Diagnostic Radiology, Mansoura Faculty of Medicine, Mansoura, Egypt.
authors.forename: Ahmed Abdel Khalek
authors.initials: AA
authors.lastname: Abdel Razek
authors.forename: Sieza
authors.initials: S
authors.lastname: Samir
authors.forename: Germeen Albair
authors.initials: GA
authors.lastname: Ashmalla
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D010307:Parotid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA