title: Minor salivary gland tumors in the oral cavity: diagnostic value of dynamic contrast-enhanced MRI.
abstract: OBJECTIVE
  To evaluate the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for minor salivary gland tumors in the oral cavity.
  
  
  METHODS
  Thirty-two patients with minor salivary gland tumors were examined preoperatively using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), Tpeak; i.e., the time that corresponded to the CImax×0.90, and washout ratios (WR300 and WR600) were determined from contrast index (CI) curves. We compared these parameters between benign and malignant tumors and among the different histopathological types of minor salivary gland tumors. Then, we categorized the patients' CI curves into four patterns (gradual increase, rapid increase with high washout ratio, rapid increase with low washout, and flat).
  
  
  RESULTS
  Statistically significant differences in Tmax (P=0.004) and Tpeak (P=0.002) were observed between the benign and malignant tumors. Regarding each histopathological tumor type, significant differences in Tmax (P<0.001), Tpeak (P<0.001), and WR600 (P=0.026) were observed between the pleomorphic adenomas and mucoepidermoid carcinomas. It was difficult to distinguish between benign and malignant tumors using our CI curve classification because that two-thirds of the cases were classified into the same type (gradual increase).
  
  
  CONCLUSIONS
  The DCE-MRI parameters of minor salivary gland tumors contributed little to their differential diagnosis compared with those for major salivary gland tumors. During the diagnosis of minor salivary gland tumors, Tmax is useful for distinguishing between benign and malignant tumors.
authors.affiliation: Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital, 5-1 Shikata-cho, 2-chome, Okayama 700-8525, Japan.
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Matsuzaki
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Yanagi
authors.forename: Marina
authors.initials: M
authors.lastname: Hara
authors.forename: Naoki
authors.initials: N
authors.lastname: Katase
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Asaumi
authors.forename: Miki
authors.initials: M
authors.lastname: Hisatomi
authors.forename: Teruhisa
authors.initials: T
authors.lastname: Unetsubo
authors.forename: Hironobu
authors.initials: H
authors.lastname: Konouchi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Takenobu
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nagatsuka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000473:pathology*; D015203:Reproducibility of Results; D012468:Salivary Gland Neoplasms / Q000473:pathology*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media