728-3 Contrast-enhanced Electron Beam Tomography for 3-D Reconstruction of Coronary Arteries: Detection of Stenoses and Documentation of Angioplasty Success

Abstract

Non-invasive imaging of coronary arteries is complicated by their very fast movements. We evaluated the potential of contrast-enhanced Electron Beam Tomography (EBT, Ultrafast-CT) for the visualization of coronary artery stenoses. 24 patients with angiographically documented coronary artery disease were investigated. In 5 patients, EBT was repeated after angioplasty, Contrast agent was administered via a peripheral vein and ECG-triggered axial EBT scans were obtained during breathhold (acquisition time 100 ms/slice, table movement 2 mm/slice, slice thickness 3 mm). 3-D reconstruction of the coronary arteries was performed as shaded surface display with a density threshold chosen to consider only the vessels’ contrast enhanced inner lumen. By administration of contrast agent, the mean density within the coronary artery lumen was significantly increased from 18 ± 9.7 HU (mean value of native vessels) to 212 ± 78.3 HU (p < 0.001). 3-D reconstruction with a threshold of 80 HU permitted selective visualization of the coronary arteries’ inner lumen in all cases. 9/11 hi9h grade stenoses and 5/5 occlusions of the proximal and mid LAD were clearly identified, as well as 3/4 high grade stenoses of the proximal and mid RCA (with decreased image quality due to rapid vessel movement). 2 high grade lesions of the LCX could not be identified. A followup investigation after angioplasty in 5 patients (4 pts. LAD, 1 pt. RCA) clearly visualized the increase in vessel lumen in all cases. Electron Beam Tomography with intravenous application of contrast agent permits the non-invasive imaging of high grade LAD stenoses. RCA and LCX stenoses can be visualized with limited success. The outcome of angioplasty can be documented.