Search

Rationale and Objectives: The exact quantification of the amount of calcification in aortic valves may be useful for the identification of risk factors for the progression of aortic valve calcification and to evaluate new therapeutic approaches for aortic valve disease. Electron beam tomography (EBT) allows the in vivo detection of calcifications in coronary vessels and in the aortic valve. The aim of this study was to validate the quantification of aortic valve calcification by EBT with in vivo and in vitro investigations., Methods: In 15 patients (aortic stenosis in 13, aortic regurgitation in 2 cases), EBT was performed before aortic valve replacement (40 cross sections, 3-mm slice thickness, matrix 512 x 512, field of view 28 cm, ECG trigger at 40% of the cardiac cycle). EBT was repeated on the explanted aortic valve using the same protocol. In both data sets, the amount of aortic valve calcification was determined using a volumetric score. In serial cuts of the explanted valve (distance 1 mm), the calcified volume was determined by an independent investigator using histomorphometric analysis., Results: The mean calcified volume of the aortic valves as quantified by EBT was 1650.0 +/- 1401.0 mmł in vivo (EBT1) and 1544.4 +/- 1266.5 mmł in vitro (EBT2). Histomorphometric analysis showed a mean calcified volume of 1555.7 +/- 1272.5 mmł. The mean difference between EBT1 and EBT2 was 4.2 +/- 14.7%, between EBT1 and histomorphometry 3.6 +/- 12.1%, and between EBT2 and histomorphometry -0.5 +/- 5.9%., Conclusion: EBT allows accurate in vivo quantification of aortic valve calcifications.

Rationale and Objectives: To compare the image quality of electron beam tomography (EBT) and multislice spiral CT (MSCT) for coronary artery visualization., Materials and Methods: Two groups of 30 patients without coronary stenoses were studied by MSCT (4 x 1 mm collimation) or EBT (3 mm slice thickness). Contrast-to-noise ratio (CNR), overall length of the visualized arteries and vessel length free of motion artifacts were measured., Results: Length of visualized arteries was equal in MSCT and EBT. In EBT, longer segments were depicted free of motion artifacts (MSCT: 73%, EBT: 92% of visualized length, P< 0.001) and CNR was significantly higher than in MSCT (15.4 vs. 9.0; P< 0.001). In both modalities, vessel diameters correlated closely to quantitative coronary angiography., Conclusions: EBT and MSCT permit reliable coronary artery visualization and measurement of vessel diameters. For the used scan protocol, MSCT images had a lower CNR and were more frequently affected by motion.