Comparison of normalized mean values and CVs of CT-derived PBF versus CT-derived PBV in two animals studied with the lung inflation model, which was used to achieve a range of pulmonary perfusion values and heterogeneities. Values are percentages of summed total voxel values. (a, b) Normalized mean values for animals 3 and 4, respectively. (c, d) CVs of normalized values for animals 3 and 4, respectively.