The challenge of solitary pulmonary nodules: HRCT evaluation.

Both enhancement and morphologic analysis have been shown important in the HRCT study of solitary pulmonary nodules (SPNs). In our prospective study, 25 adult patients with benign (N = 8) or malignant (N = 17) SPNs were examined before and after contrast agent. We obtained three serial thin section CT scans every 60 s after the onset of the injection of contrast material. All 17 malignant nodules did enhance very significantly (P < 0.001). Benign nodules did not enhance significantly (P > 0.05). Using 20 HU as a threshold for positivity of the contrast test, our sensitivity was 100%, specificity was 74%, positive predictive value was 89.5%, negative predictive value was 100%, and accuracy was 92%; test bias was 1.118. In our opinion, HRCT evaluation of SPNs is the most widely available tool to save cost and decline in morbidity in management.