title: The diagnostic value of dynamic contrast-enhanced MRI for thyroid tumors.
abstract: OBJECTIVE
  The exact place for dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the diagnosis and management of thyroid tumors is still under debate. We performed the study to analyze and compare the parameters generated from DCE-MRI for thyroid lesions.
  
  
  METHODS
  For each thyroid lesion, time intensity curves (TIC), time of peak enhancement (Tpeak), maximum enhancement ratio (ERmax) and maximum rise slope (Slopemax) were plotted and calculated. Receiver operator characteristics (ROC) analysis was conducted to assess the diagnostic ability and appropriate cut-off value. The area under the ROC curve (AUC) and the confidence intervals (CIs) were also assessed.
  
  
  RESULTS
  Forty-two patients were consecutively included. All 21 lesions demonstrated the rapid inflow and washout pattern (type-I) were benign. The 12 cases with delayed inflow pattern (type-III) were all malignant. When compared with the benign lesions, the thyroid carcinoma showed significantly lower Slopemax and higher Tpeak (P<0.05). No statistical difference of ERmax was found between malignant and benign ones (P=0.15). The AUC of ERmax, Slopemax and Tpeak in differentiating benign thyroid lesions from malignant ones were 0.63, 0.93 and 1, respectively. The ERmax cut-off value of 73.86 (sensitivity, 71.4%; specificity, 64.3%), Slopemax cut-off value of 2.4126 (sensitivity, 92.9%; specificity, 82.1%) and Tpeak value of 28 (sensitivity, 100%; specificity, 100%) offered the best diagnostic performances.
  
  
  CONCLUSIONS
  DCE-MRI, especially the pattern of TIC and the value of Slopemax and Tpeak, could be helpful in differentiating thyroid carcinoma from benign thyroid lesions.
authors.affiliation: Department of Radiology, Shanghai Ninth People's Hospital, Affiliated to JiaoTong University School of Medicine, Shanghai 200011, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yuan
authors.forename: Xiu-Hui
authors.initials: XH
authors.lastname: Yue
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Tao
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000473:pathology*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA