Evaluation of dual-energy computed tomography in detection of calcification in solitary pulmonary nodule

Objective: To investigate a new method of detecting calcification in solitary pulmonary nodule (SPN) and to build a new standard of distinguishing benign from malignant SPN. Methods: Dual-energy CT (140 kVp, 80 kVp) was performed for water phantom, body phantom, normal volunteers and patients with SPN. The CT number changes were compared and their calcification contents were calculated. The shape and distribution of calcification were displayed by density mask processing and finally diagnosis of benign or malignant SPN was made. Results: On low energy CT scan the CT number increased as compared with high energy scan for tissue with high atomic number. The SPN containing calcification also demonstrated increased CT value on low energy scan (sensitivity 80% and specifith 80%; P<0.005). Conclusions: Dual-energy CT can demonstrate the calcifications in SPN as well as their appearance and distribution thereby it is a valuable imaging technique for detecting and diagnosing benign or malignant SPN