The diagnostic value of dynamic contrast-enhanced MRI for thyroid tumors

Abstract Background and purpose 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. Materials and 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, 0.93and 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.