Three-dimensional visualization of coronary arteries in excised hearts

Objective: We sought to image coronary arteries in excised hearts. Methods: Twelve excised pigs' hearts were imaged in a water bath. The aorti c valve was closed surgically. A contrast agent (Echovist) was Injected int o the aortic root and selectively into single coronary arteries. Three-dime nsional (3D) imaging was performed with TomTec Echoscan equipment. Mechanic al rotations were performed at 1 degrees intervals. The hearts were visuali zed by InVivo software. Selective coloring of coronary arteries in 3D data sets was obtained by using color superpositioning, which differentiates inf ormation before and after injection of contrast. Distance measurements were performed in conventional 3D echocardiograms of coronary arteries and colo r-superimposed echocardiograms and compared with those from angiograms and casts. Results: After a learning curve, during which optimal conditions for the vi sualization of coronary arteries were determined, a quick display of all ma jor parts of the coronary tree was obtained. Distance measurements (n >400) revealed that fundamental contrast echocardiography overestimated angiogra phy by 25% +/- 5% and casts by 28% +/- 6%. However, distances in color-supe rimposed echocardiograms (flow mode 4) were not significantly different fro m those obtained from angiograms and casts. In harmonic contrast echocardio grams, color super-positioning gave smaller distances compared with those f rom fundamental contrast echocardiograms, though they were still significan tly larger than the reference diameters. Conclusions: The 3D Imaging of epicardial coronary arteries under ideal con ditions in a water bath seems feasible and provides insight into coronary v isualization with the use of ultrasonography.