Spectral CT Primary Study On Perfusion Of Pulmonary Parenchyma In Periphery Of The Lung Cancer

Objective To study quantitatively the perfusion of pulmonary parenchyma in periphery of the lung cancer by Spectral CT and to investigate the changes of the perfusion and to compare the difference of pulmonary parenchyma perfusion in distinct classification of the lung cancer.Methods Eighty-one patients with lung cancer confirmed by pathology underwent chest unenhanced CT and enhanced CT scanning with spectral CT.The iodine contribution of pulmonary parenchyma from the lung cancer and corresponding mirror area in iodine-based material decomposition images of arterial phase were measured,then the ICa were obtained.The difference of ICa between periphery of lung cancer and corresponding mirror area in all patients、central and peripheral type were analyzed and compared respectively.And the difference of ICa in periphery of lung cancer in different locations(central and peripheral type)、 size(A group was d≤3 cm,B group was 3<d≤7 cm)、pathological types(squamous carcinoma,adenocarcinoma and small cell lung cancer)and degree of differentiation(low,low-middle and middle differentiation)were analyzed and compared.Results(1)The ICa in periphery of the 81 lung cancer [(1.26±0.42)mg/ml],the 32 central lung cancer [(1.12±0.33)mg/ml] and 49 peripheral lung cancer [(1.35±0.45)mg/ml] were all significantly lower than that in the corresponding mirror area [(1.65±0.61)mg/ml,(1.63±0.69)mg/ml and(1.66±0.56)mg/ml](P<0.01).(2)The ICa in periphery of the central lung cancer [(1.12±0.33)mg/ml] was significantly lower than that in periphery of the peripheral lung cancer [(1.35±0.45)mg/ml](P<0.01),and the ICa in periphery of the 10 small cell lung cancer [(0.94±0.20)mg/ml] was lower than that in periphery of the 37 squamous cell carcinoma [(1.23±0.40)mg/ml] and the 34 adenocarcinoma [(1.37±0.45)mg/ml](P<0.05),but there was no significant difference between the latter two(P > 0.05).(3)The ICa in periphery of cancer was no significant difference(P > 0.05)between different tumor size or between different degree of differentiation.Conclusion The perfusion of periphery of the lung cancer is generally reduced,furthermore,it is lower in periphery of the central lung cancer than that in periphery of the peripheral lung cancer,and it is lower in periphery of the small cell lung cancer than that in periphery of the non-small-cell lung cancer.The features of the spectral CT perfusion in periphery of the lung cancer have theoretical and clinical values.