Measurement and display of instantaneous regional motion of the myocardium

Quantitative assessment of regional heart motion has significant potential for more accurate diagnosis of heart disease and/or cardiac irregularities. Local heart motion may be studied from medical imaging sequences. Using functional parametric mapping, regional myocardial motion during a cardiac cycle can be color mapped onto a deformable heart model to obtain better understanding of the structure-to-function relationships in the myocardium. In this study, 3D reconstructions were obtained from the Dynamic Spatial Reconstructor (DSR) at 15 time points throughout one cardiac cycle. Deformable models were created from the 3-D images for each time point of the cardiac cycle. From these polygonal models, regional excursions and velocities of each vertex representing a unit of myocardium were calculated for successive time intervals. The calculated results were visualized through model animations and/or specially formatted static images. The time point of regional maximum velocity and excursion of myocardium through the cardiac cycle was displayed using color mapping. The absolute value of regional maximum velocity and maximum excursion were displayed in a similar manner. Using animations, the local myocardial velocity changes were visualized as color changes on the cardiac surface during the cardiac cycle. Moreover, the magnitude and direction of motion for individual segments of myocardium could be displayed. These results suggest that the ability to encode quantitative functional information on dynamic cardiac anatomy enhances the diagnostic value of 4D images of the heart. Myocardial mechanics quantified this way adds a new dimension to the analysis of cardiac functional disease, including diastolic filling deficits and/or disturbances in regional electrophysiology and contraction patterns.