CT perfusion in patients with lung neoplasms

Objective To evaluate the significance of CT perfusion in 46 patients with lung neoplasms.Methods A prospective study was undertaken in patients with pulmonary nodules using cine dynamic scan of MSCT. They were histologically proven as peripheral lung cancer in 23 cases,central lung cancer in 6 cases,tubercle in 7 cases,lung abscess in 3 cases,unspecific inflammation in 3 cases,inflammatory pseudotumor in 1 case,aspergilloma in 1 case and hamartoma in 2 cases. The diameter of lesions was 2-7 cm (mean 4 cm) for malignancy and 2-5 cm (mean 3 cm) for benignancy. Using 8-row detector spiral CT,cine scan was performed with 5 mm slice thick /4 slices,1 second scan time per circle,40 s acquisition time and 120 kV,80 mA. Total 50 ml contrast medium (300 mgI/ml) was administered at a delay 5.6 s and a rate of 4 ml/s from forearm superficial vein with hyperbaric injector. The CT data were transferred to a workstation and analyzed with a CT perfusion 2-body tumor software. The parameters of CT perfusion include blood flow (BF),blood volume (BV),mean transit time (MTT) and permeability surface (PS).Results In patients with lung cancer,BF,BV,MTT and PS of the lesions were (38.7±31.9) ml/(min·100 g),(10.1±4.2) ml/100 g,(21.8±10.8) s and (47.3±22.3) ml/(min·100 g).When BV≥6 ml/100g was set as a diagnostic threshold,the sensitivity,specificity,positive predict values and negative predict values were 100%,64.7%,82.9% and 100% respectively. When PS≥30 ml/(min·100g) was set as a diagnostic threshold,the sensitivity,specificity,positive predict values and negative predict values were 86.2%,88.2%,92.6% and 79% respectively.Conclusion BV and PS measured by CT perfusion might be as parameters of diagnosis of lung cancer.