Flow Pattern and Vascular Resistive Index as Predictors of Malignancy Risk in Thyroid Follicular Neoplasms

Abstract

In FNs, there were significant positive associations between predominantly central flow and malignancy and between predominantly peripheral flow and benign disease (P < .0001, Fisher exact test). However, power Doppler characteristics could not be used to rule out malignancy because 20% of malignant nodules had predominantly peripheral flow. For predicting malignancy, an RI cutoff of 0.75 had good accuracy, specificity, and negative predictive value but had low sensitivity and positive predictive value (respectively, 91%, 97%, 92%, 40%, and 67%). Resistive index values in non-neoplastic nodules were lower than in adenomas and malignant nodules (P < .001, chi(2) test).