Abstract 1902: Comparison of 256×0.5mm and 64×0.5mm Multidetector Computed Tomography Image Quality and Accuracy in a Custom-Designed, Motion-Simulating Phantom of Coronary Artery Stenosis
BACKGROUND: 256 multidetector computed tomography (256-MDCT) can image the entire heart volume in a single gantry rotation without table movement and therefore may eliminate helical imaging reconstruction artifacts. However, image quality and quantitative accuracy of coronary artery measurements by 256-MDCT relative to 64-MDCT has not been previously evaluated. The purpose of this study was to compare the accuracy and image quality of 256×0.5mm-MDCT versus 64×0.5mm-MDCT using a custom-designed, motion-simulating coronary artery phantom.
METHODS: Coronary artery phantoms with various reference diameter (1.5, 2, 3 and 4mm) and stenoses of various magnitude (0.8–3.1mm) and shape (half moon, concentric, eccentric, 0.13–10.2 mm2 in area) were scanned during simulated cardiac motion at 60 bpm using 256-MDCT (ECG-gated non-helical) and 64-MDCT (ECG-gated helical). Vessel diameter and cross-sectional area were measured in a total of 24 stenoses by two observers using multiplanar reformation of MDCT data.
RESULTS: 256-MDCT diameter and area measurements deviated from actual vessel size by 0.21±0.23mm and 0.46±0.45 mm2, respectively compared to 0.25±0.19 mm and 0.61± 0.57 mm2 for 64-MDCT (p=NS between 256 and 64-MDCT). However, 64-MDCT phantom vessel images contained consistent helical artifacts compared with 256-MDCT.
CONCLUSION: Coronary artery dimensions can be accurately measured by both 256-MDCT and 64-MDCT. However, 256-MDCT with non-helical acquisition demonstrated less artifact compared to 64-MDCT which employs helical interpolation and table movement. Figure⇓ Coronary artery phantom with 50% stenosis scanned by 256-MDCT (left) and 64-MDCT (right).