Objective To quantitatively investigate pulmonary blood flow and its change induced by liver cirrhosis by measuring the iodine concentration distribution in pulmonary parenchyma on lung perfused blood volume (LPBV) images with spectral CT imaging.Methods Twenty-five patients with liver cirrhosis and fifteen normal volunteers,who had no detectable intrinsic lung and heart disease,underwent dual-energy CT lung angiography using spectral imaging mode with a standard injection protocol.