Topographic Display and Quantitative Analysis of Blood Flow Marker Distribution in Normal and Infarcted Hearts

Computer-based image processing methods have been applied to describe blood flow marker distribution in ischemic and nonischemic hearts. The processing begins with digitization of flow marker images derived from a heart slice containing the marker. Then, amplitude bands corresponding to intensity ranges of the indicator are created by Fourier-based filtration and amplitude mapping which together remove noise and demonstrate marker distribution topographically. Next, Cartesian plots of flow marker values averaged across transmural lines and lines normal to them are made to show marker distribution along selected radial and circumferential directions in heart walls. Finally, histograms of marker intensity are obtained to describe distnrbution of marker within regions bounded by arbitrarily shaped contours drawn on images. Flow marker distributions derived from photographs of Thioflavin S fluorescence and autoradiographs produced by 85Sr-labeled microspheres show both heterogeneity and distinct gradients in normal hearts, at infarct margins, and within ischemic zones. The local distribution of flow implied by Thioflavin S appeared more inhomogeneous than that indicated by the 85Sr-microspheres, probably as a consequence of the Thioflavin S fluorescence being a surface phenomenon. The available results indicate that this computer-based processing may provide a means of topographically relating flow marker and structural changes and also provide a high-resolution quantitative description of flow marker distribution in a flexible and efficient way for handling large amounts of data.