Publication:

Role of combined wash-in and wash-out threshold criteria on dynamic multislice CECT for solitary pulmonary nodule characterisation: data from Indian tertiary care hospital

Background To prospectively assess the accuracy of combined wash-in and washout characteristics at dynamic contrast material–enhanced multi– detector row computed tomography (CT in distinguishing benign from malignant solitary pulmonary nodule (SPN).

Methods Institutional review board approval and informed consent were obtained. The study included 30 patients (16 men, 14 women; mean age, 52 years; range, 25-80 years) with SPN. After unenhanced CT (1.25mm collimation) scan, dynamic CT was performed (series of images obtained throughout the nodule, with 0.6mm collimation, at 30, 60, 90, and 120 seconds and 4, 5, 9, 12, and 15 minutes) after intravenous injection of contrast medium (120 mL). The HU value of nodule was noted at each of the scans. Data was analyzed for dynamic enhancement characteristics. FNAC from the nodule was done in all patients. The data were correlated with the cytopathological and follow –up results. The significance of various dynamic enhancement features and different threshold criteria for wash-in and wash-out of contrast medium for differentiation between benign and malignant nodules were derived.

Results There were 16 malignant and 14 benign nodules. When diagnostic criteria for malignancy of both wash-in of 25 HU or greater and washout of 5-34 HU were applied, sensitivity, specificity, and accuracy for malignancy were 100%, 92.8% and 96.7% respectively.

Conclusions Evaluation of solitary pulmonary nodules by analyzing combined wash-in and washout characteristics at dynamic contrast-enhanced multi– detector row CT showed 96.7% accuracy (p<0.001) for distinguishing benign nodules from malignant nodules.