A Study on the Diagnostic Value of Dynamic Contrast-Enhanced CT in the Solitary Pulmonary Nodules

Objective To explore the value of dynamic contrast-enhanced CT for differentially diagnosing benign and malignant the solitary pulmonary nodules. Methods 117 solitary pulmonary nodules proved by histopathological examination were enrolled in this study. Thin-section CT scanning was performed before and 1,2,3,4 and 5 minutes after contrast enhancement. Results The enhanced value of malignant nodules (39.6±15.8)Hu was significantly higher than that of benign nodules (19.18±17.23)Hu (P0.01).When 15Hu served as the threshold,the sensitivity, specificity and accuracy of contrast-enhanced CT for differential diagnosis were 100%(57/57), 63.3%(38/60) and 82.9%(97/117), respectively. The enhanced value of the nodules was positively related to central microvascular density of the nodules(P0.01). Conclusion The absence of significant lung noldue enhancement(≤15Hu) at CT strongly suggested benign nodules. Malignant nodules enhanced significantly more than benign nodules because there was more central microvessels in the malignant nodules. The pulmonary inflammatory pseudotumor and hamartoma were the main cause of false-positive result, and analysis of time-attenuation curve would be helpful to differentiate them from malignant nodules.