Computed Tomography Features of Incidentally Detected Diffuse Thyroid Disease

Figure 4

Receiver-operating characteristic (ROC) analysis for the cut-off Hounsfield unit (HU) values of the thyroid parenchyma in nonenhanced CT images. When 80, 90, or 100 HU is considered as a cut-off value, the values are 0.6091 (unbroken line), 0.6831 (dashed line), and 0.7378 (dotted and dashed line), respectively. When 100 HU is determined as a cut-off value, the sensitivity, specificity, positive and negative predictive values, and accuracy of US diagnosis are 65.4%, 82.2%, 54.8%, 87.8%, and 78.0%, respectively.