Computerized radiographic assessment of pulmonary blood flow in patients with and those without mitral stenosis

The authors investigated whether a computerized analysis system can be used with chest radiography for estimating the redistribution of pulmonary blood flow in patients with and those without mitral stenosis (MS). Their system uses four-directional Laplacian-Gaussian filtering and binarization. As a physical measure, the radiographic index, which reflects the area of opacity in selected regions of interest (ROIs), was used. Fifteen men with MS and 15 men without MS were included in the study. ROIs were selected in the right upper and lower lung zones on radiographs, and the images were processed with the system. The radiographic indexes were determined in each ROI. As a measure of pulmonary blood flow redistribution, the upper-to-lower lung zone radiographic index ratio (U/L) was calculated. The U/L values correlated with pulmonary capillary wedge pressure values (r = .405, P = .025). The mean U/L value of the MS group was significantly higher than that of the non-MS group (1.16 +/- 0.14 vs 1.05 +/- 0.09, respectively; P = .016). These preliminary results indicate that this system can be used for quantitative estimation of the redistribution of pulmonary blood flow.