Evaluation of contrast wash-in and peak enhancement in adenosine first pass perfusion CMR in patients post bypass surgery.
Evaluation of contrast wash-in and peak enhancement in adenosine first pass perfusion CMR in patients post bypass surgery.
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DOI：
10.1186/1532-429x-12-28
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发表时间：
2010-05-13
期刊：
影响因子：
--
通讯作者：
Klein C
中科院分区：
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作者：
Kelle S;Graf K;Dreysse S;Schnackenburg B;Fleck E;Klein C
腺苷第一次通过灌注心血管磁共振（CMR）对重大冠状动脉疾病（CAD）的检测效果非常好。在冠状动脉旁路移植术（CABG）患者中，造影剂的动力学可能仅由于与原生血管相比通过旁路移植术的距离不同而改变，从而可能模仿灌注缺陷。本研究的目的是评估半定量灌注参数，以评估在原生冠状动脉和冠脉搭桥提供的区域心外膜造影剂动力学的可能差异，两者都没有明显的狭窄。回顾性研究纳入了20例侵入性排除明显CAD的患者（对照组）和38例未旁路冠状动脉或移植物无血管造影明显（≥50%）狭窄的冠状动脉搭桥患者。在有创冠状动脉造影前1天行腺苷第一次（0.05 mmol/kg Gd-DTPA）灌注（3短轴位/心跳）和晚期钆增强（LGE）成像。使用16段模型在x线血管造影中确定原生冠状动脉和/或不同旁路灌注的区域。计算各区域相对于左心室参数的上坡和最大信号强度（SImax），达到50%最大信号强度的时间（TSI50%max）和达到最大信号强度的时间（TSImax）。在冠状动脉旁路灌注区，相对上斜度和相对SImax没有明显差异。原生冠状动脉和旁路的TSI50%max分别为7.2s±1.9s vs. 7.5s±1.9s （p < 0.05）和12.s±3.0s vs. 13.1s±3.0s （p < 0.05）。当调整到心率时，Tmax延迟导致0.5±1.1次心跳（=图像）的显著延迟（p < 0.05）。时间上的差异在左乳内动脉移植物灌注的区域比静脉冠脉搭桥灌注的区域更明显，但在没有冠心病的患者中，原生血管区域之间也存在差异，尽管差异较小。冠脉搭桥后患者的腺苷灌注CMR可能与造影剂到达的短暂延迟有关。然而，一旦造影剂进入心肌，就会出现类似的冲洗动力学和峰值增强。因此，由于延迟时间很短，通过移植物和原生血管可能存在的造影剂动力学差异似乎并不是CABG后患者首过腺苷灌注准确性的限制因素。
Adenosine first pass perfusion cardiovascular magnetic resonance (CMR) yields excellent results for the detection of significant coronary artery disease (CAD). In patients with coronary artery bypass grafts (CABG) the kinetics of a contrast bolus may by altered only due to different distances through the bypass grafts compared to native vessels, thereby possibly imitating a perfusion defect. The aim of the study was to evaluate semiquantitative perfusion parameters in order to assess possible differences in epicardial contrast kinetics in areas supplied by native coronaries and CABG, both without significant stenosis. Twenty patients with invasive exclusion of significant CAD (control group) and 38 patients with CABG without angiographically significant (≥50%) stenosis in unbypassed coronaries or grafts were retrospectively included in the study. They underwent adenosine first pass (0.05 mmol/kg Gd-DTPA) perfusion (3 short axis views/heart beat) and late gadolinium enhancement (LGE) imaging 1 day before invasive coronary angiography. Areas perfused by native coronaries and/or the different bypasses were identified in X-ray angiography using the 16 segment model. In each of these areas upslope and maximal signal intensity (SImax) relative to the left ventricular parameters, time to 50% maximal signal intensity (TSI50%max) and time to maximal signal intensity (TSImax) were calculated. In areas perfused by coronary arteries with bypasses compared to native coronaries relative upslope and relative SImax did not show a significant difference. TSI50%max and TSImax in native coronaries and bypasses were 7.2s ± 1.9s vs. 7.5s ± 1.9s (p < 0.05) and 12.6s ± 3.0s vs. 13.1s ± 3.0s (p < 0.05), respectively. The delay in Tmax resulted in a significant (p < 0.05) delay of 0.5 ± 1.1 heart beats (=images) when adjusted to the heart rate. Differences in time were most pronounced in areas perfused by left internal mammary artery grafts rather than by venous CABG, but were also present between native vessel territories in patients without CAD, albeit with smaller variability. Adenosine perfusion CMR in patients post CABG may be associated with a short delay in contrast arrival. However, once the contrast is in the myocardium there is similar wash-in kinetics and peak enhancement. Therefore, since the delay is only short, the possibly differing contrast kinetics through grafts and native vessels does not seem to be a limiting factor for the accuracy of first pass adenosine perfusion in patients post CABG.