University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg, 69120, Germany.
Eur J Radiol. 2013 Apr;82(4):601-7. doi: 10.1016/j.ejrad.2012.04.039. Epub 2012 Dec 30.
Invasive coronary angiography is the reference method for identification of in-stent restenosis (ISR) bearing the disadvantages of high costs and invasiveness. New approaches like dual-source CT (DSCT) and 256-multi-slice CT (256-MSCT) may potentially be the future methods of choice to reliably exclude ISR in patients with low or intermediate risk of restenosis. We sought to compare the performance of DSCT and 256-MSCT for the in vitro assessment of stent lumen diameter and basic scan parameters in stents of various diameters and designs.
In 16 coronary artery stents we evaluated relative in-stent lumen diameter, attenuation, noise, attenuation-/signal-to-noise ratio (ANR/SNR) and radiation dose (CTDIvol) in an acknowledged coronary vessel in vitro phantom (iodine-filled plastic tubes) with DSCT (Siemens, SOMATOM Definition, collimation=2×64×0.6mm, pitch=0.26, current=400mAs/rot, voltage=120kV, tube-rotation-time=330ms) and 256-MSCT (Philips Brilliance, iCT, tube collimation=2×128×0.625mm, pitch=0.18, current=800mAseff, voltage=120kV, tube-rotation-time=270ms). Diameter analysis was conducted with the observer-independent full-width-at-half-maximum (FWHM) technique.
DSCT and 256-MSCT revealed similar stent lumen diameters (50.7±7.2% vs. 50.8±7.4%, p=0.98). Attenuation (-19±25HU vs. 54±29HU), ANR (-0.9±1.2 vs. 2.9±1.8) and SNR (12.1±2.4 vs. 17.4±1.9) were better in the DSCT (all p<0.001) at the expense of significantly higher radiation doses (CTDIvol=87 vs. 51mGy, p<0.01). Noise was comparable (21±2HU vs. 20±2HU, p=n.s.). Only stents with a diameter >3mm allowed sufficient stent lumen assessment in both scanners and showed a relative lumen diameter of 60-66%.
The measured stent lumen diameter and image noise were similar in both scanners. Yet the DSCT offered a more truthful stent lumen visualization at the cost of higher radiation dose. Applying the FWHM approach only stents with a diameter >3mm offered sufficient stent lumen assessment.
经皮冠状动脉血管造影术是识别支架内再狭窄（ISR）的参考方法，但存在成本高和有创的缺点。双源 CT（DSCT）和 256 层多排 CT（256-MSCT）等新技术可能成为未来可靠排除低危和中危再狭窄患者 ISR 的方法。我们旨在比较 DSCT 和 256-MSCT 在不同直径和设计的支架中体外评估支架管腔直径和基本扫描参数的性能。
在 16 个冠状动脉支架中，我们在体外认可的冠状动脉血管体模（充满碘的塑料管）中评估相对支架内管腔直径、衰减、噪声、衰减/信噪比（ANR/SNR）和辐射剂量（CTDIvol），使用 DSCT（西门子，SOMATOM Definition，准直=2×64×0.6mm，螺距=0.26，电流=400mAs/转，电压=120kV，管旋转时间=330ms）和 256-MSCT（飞利浦 Brilliance，iCT，管准直=2×128×0.625mm，螺距=0.18，电流=800mAseff，电压=120kV，管旋转时间=270ms）。直径分析采用观察者独立的全宽半最大值（FWHM）技术进行。
DSCT 和 256-MSCT 显示相似的支架管腔直径（50.7±7.2%对 50.8±7.4%，p=0.98）。衰减（-19±25HU 对 54±29HU）、ANR（-0.9±1.2 对 2.9±1.8）和 SNR（12.1±2.4 对 17.4±1.9）在 DSCT 中更好（均 p<0.001），但辐射剂量明显更高（CTDIvol=87 对 51mGy，p<0.01）。噪声相当（21±2HU 对 20±2HU，p=n.s.）。仅直径>3mm 的支架在两种扫描仪中均能充分评估支架管腔，且相对管腔直径为 60-66%。
两种扫描仪的支架管腔直径和图像噪声相似。然而，DSCT 以更高的辐射剂量为代价提供了更真实的支架管腔可视化。采用 FWHM 方法，仅直径>3mm 的支架才能充分评估支架管腔。
