University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120, Germany.
Eur J Radiol. 2011 Oct;80(1):143-50. doi: 10.1016/j.ejrad.2010.08.007. Epub 2010 Sep 3.
We sought to investigate stent lumen visibility of 56 coronary stents with the newest 256-multi-slice-CT (256-MDCT) technology for different reconstruction algorithms in an in vitro model.
Early identification of in-stent restenosis (ISR) is important to avoid recurrent ischemia and prevent acute myocardial infarction (AMI). Since angiography has the disadvantage of high costs and its invasiveness, MDCT could be a convenient and safe non-invasive alternative for detection of ISR.
Percentages of in-stent lumen diameter and in-stent signal attenuation (measured as contrast-to-noise ratio (CNR)) of 56 coronary stents (group A ≤2.5mm; group B=2.75-3.0mm; group C=3.5-4.0mm) were evaluated in a coronary vessel in vitro phantom (iodine-filled plastic tubes) employing four different reconstruction algorithms (XCD, CC, CD, XCB) on a novel 256-MDCT (Philips-iCT, collimation=128 mm × 0.625 mm; rotation time=270 ms; tube current=800 mAs with 120 kV). Analysis was conducted with the semi-automatical full-width-at-half-maximum (FWHM) method. P-values <0.05 were regarded statistically significant.
In-stent lumen diameter >60% for group C stents was significantly larger and CNR was significantly lower (both p<0.05) for sharp kernels (CD; XCD) when compared to groups A/B. The FWHM-method showed significantly smaller in-stent lumen diameter (p<0.05) when compared to the manual method.
256-MDCT could potentially be employed for clinical assessment of stent patency in stents >3.0mm when analysed with cardio-dedicated sharp kernels, although clinical studies corroborating this claim should be performed. However, stents ≤3.0mm reconstructed by soft kernels revealed insufficient in-stent lumen visualisation and should not be used in clinical practice. Further improvements in spatial and temporal image resolution as well as reductions of radiation exposure and image noise have to be accomplished for the ambitious goal of characterising both CT coronary artery anatomy and in-stent lumen.
我们通过体外模型，利用最新的 256 层多排 CT（256-MDCT）技术，针对不同的重建算法，对 56 种冠状动脉支架的支架内腔可视性进行研究。
早期识别支架内再狭窄（ISR）对于避免再次缺血和预防急性心肌梗死（AMI）非常重要。由于血管造影术具有成本高和侵入性的缺点，MDCT 可能是一种方便且安全的非侵入性替代方法，用于检测 ISR。
我们对 56 种冠状动脉支架（A 组≤2.5mm；B 组=2.75-3.0mm；C 组=3.5-4.0mm）进行了评估，通过四种不同的重建算法（XCD、CC、CD、XCB）在体外冠状动脉血管模型（充满碘的塑料管）中对支架内腔直径和支架信号衰减（以对比噪声比（CNR）表示）进行评估。使用新型 256-MDCT（Philips-iCT，准直器=128mm×0.625mm；旋转时间=270ms；管电流=800mA，管电压=120kV）进行分析。采用半自动全宽半最大值（FWHM）方法进行分析。P 值<0.05 被认为具有统计学意义。
与 A/B 组相比，对于 C 组支架，锐利内核（CD；XCD）的支架内腔直径>60%明显更大，CNR 明显更低（均 P<0.05）。与手动方法相比，FWHM 方法显示支架内腔直径明显更小（P<0.05）。
在分析>3.0mm 的支架时，256-MDCT 可能可用于临床评估支架通畅性，尽管应进行证实该结论的临床研究。然而，使用软内核重建的≤3.0mm 支架显示出支架内腔可视化不足，不应在临床实践中使用。为了实现对 CT 冠状动脉解剖结构和支架内腔进行特征描述的雄心勃勃的目标，还需要进一步提高空间和时间图像分辨率，并降低辐射暴露和图像噪声。
