Coronary artery fly-through using electron beam computed tomography

Background-Virtual reality techniques have recently been introduced into cl inical medicine, This study examines the possibility of coronary artery fly -through using a dataset obtained by noninvasive coronary angiography with contrast-enhanced electron-beam computed tomography, Methods and Results-Ten patients were examined, and 40 to 60 transaxial tom ograms (thickness, 1.5 mm; in-plane pixel dimensions, approximate to 0.5x0. 5 mm) were obtained after intravenous contrast injection. The datasets were processed on a graphics workstation using volume-rendering software. For f ly-throughs, the contrast-enhanced lumen was made transparent and other tis sue was made opaque. Then, key frames were selected in a path through the v essel, with software interpolation of frames between key frames. A typical movie contained 150 to 300 frames (10 to 15 key frames). Fly-throughs of co ronary bypass grafts (n=3), left anterior descending arteries (LAD; n=6), a nd the intermediate branch (n=1) were reconstructed. Coronary calcification s were seen in 3 patients. The fly-through of the intermediate branch, the bypass grafts, and one of the LADs did not show any irregularities. In 2 ca ses, a stenosis was visible in the LAD; its presence was confirmed by conve ntional coronary angiography. Conclusions-Recent developments in fast-volume rendering using special-purp ose hardware in combination with noninvasive coronary angiography with elec tron beam computed tomography have provided the possibility of performing c oronary artery fly-throughs.