Lung perfused blood volume with spectral CT imaging as a new quantitative tool assess the contrast material distribution of the pulmonary parenchyma in patients with lung cancer

OBJECTIVE:To quantitatively investigate the pulmonary blood flow and its change induced by lung cancer by measuring the iodine concentration distribution in pulmonary parenchyma on lung perfused blood volume(LPBV)images with spectral CT imaging.METHODS:Thirty patients with lung cancer(ten cases central lung cancer,twenty cases peripheral lung cancer),confirmed by pathology and underwent spectral CT imaging with a standard injection protocol,were enrolled in this stud-y.LPBV images were generated by analysis of the iodine content of the lung parenchyma.The average diameter of lung cancer was measured in plain CT scan.We evaluated the quantification of lung PBV using a workstation including lung tumor,pulmonary pa-renchyma in the distal end of lung cancers and the corresponding area in the contra-lateral normal lung on the LPBV images.RE-SULTS:Mean lung PBVs[(0.74±0.56)mg/mL]for the pulmonary parenchyma in the distal end of lung cancers was signifi-cantly lower than that in the corresponding area in the contra-lateral normal lung[(1.20±0.53)mg/mL,t=-5.60,P0.01]. In peripheral lung cancer,it was not significantly lower than that in central lung cancer(t=-1.79,P=0.08).The lower PBVs were not related to the sizes of tumor(r=-0.31,P=0.09).However,there was a positive correlation between tumor PBVs and lung PBVs for the pulmonary parenchyma in the distal end of lung cancers(r=0.42,P=0.02)and a negative correlation be-tween tumor PBVs and the sizes(r=-0.57,P0.01).CONCLUSIONS:LPBV with spectral CT imaging can be used to quanti-tatively evaluate the pulmonary blood flow and its change induced by lung cancers.There is a correlation between tumor perfusion and pulmonary blood flow of the affected lung areas.