BackgroundThe accuracy of absolute myocardial blood flow (MBF) from dynamic contrast-enhanced cardiac computed tomography acquisitions has not been fully characterized. We evaluate computed tomography (CT) compared with rubidium-82 positron emission tomography (PET) MBF estimates in a high-risk population.MethodsIn a prospective trial, patients receiving clinically indicated rubidium-82 PET exams were recruited to receive a dynamic contrast-enhanced cardiac computed tomography exam. The CT protocol included a rest and stress dynamic portion each acquiring 12 to 18 cardiac-gated frames. The global MBF was estimated from the PET and CT exam.ResultsThirty-four patients referred for cardiac rest-stress PET were recruited. Of the 68 dynamic contrast-enhanced cardiac computed tomography scans, 5 were excluded because of injection errors or mismatched hemodynamics. The CT-derived global MBF was highly correlated with the PET MBF (r=0.92; P<0.001) with a mean difference of 0.7±26.4%. The CT MBF estimates were within 20% of PET estimates (P<0.02) with a mean of (1) MBF for resting flow of PET versus CT of 0.9±0.3 versus 1.0±0.2 mL/min per gram and (2) MBF for stress flow of 2.1±0.7 versus 2.0±0.8 mL/min per gram. Myocardial flow reserve was −14±28% underestimated with CT (PET versus CT myocardial flow reserve, 2.5±0.6 versus 2.2±0.6). The proposed rest+stress+computed tomography angiography protocol had a dose length product of 598±76 mGy×cm resulting in an approximate effective dose of 8.4±1.1 mSv.ConclusionsIn a high-risk clinical population, a clinically practical dynamic contrast-enhanced cardiac computed tomography provided unbiased MBF estimates within 20% of rubidium-82 PET. Although unbiased, the CT estimates contain substantial variance with an standard error of the estimate of 0.44 mL/min per gram. Myocardial flow reserve estimation was not as accurate as individual MBF estimates.

中文翻译：

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动态对比增强型心脏CT与PET相比估计心肌血流的准确性。

背景技术动态对比度增强的心脏计算机断层扫描所采集的绝对心肌血流（MBF）的准确性尚未得到充分表征。我们在高危人群中评估计算机断层扫描（CT）与rub 82正电子发射断层扫描（PET）MBF估计的方法。在一项前瞻性试验中，招募了接受临床指征的rub 82 PET检查的患者，以接受动态对比增强检查心脏计算机体层摄影术检查。CT协议包括一个休息和压力动态部分，每个部分都获取12至18个心脏门控帧。通过PET和CT检查评估了总体MBF。结果招募了34位因心脏静息压力PET转诊的患者。在68项动态对比增强的心脏计算机断层扫描中，由于注射错误或血液动力学不匹配，排除了5例。CT衍生的整体MBF与PET MBF高度相关（r = 0.92；P <0.001），平均差异为0.7±26.4％。CT MBF估计值在PET估计值的20％以内（P<0.02），平均（1）PET的静流MBF与CT的关系为每克0.9±0.3对1.0±0.2 mL / min和（2）应力流的MBF 2.1±0.7对2.0±0.8 mL / min每克。CT评估心肌血流储备为-14±28％（PET与CT心肌血流储备为2.5±0.6对2.2±0.6）。拟议的休息+压力+计算机断层扫描血管造影方案的剂量长度乘积为598±76 mGy×cm，因此有效剂量约为8.4±1.1 mSv。计算机断层扫描提供了82 82 PET的20％以内的无偏MBF估计值。尽管无偏，但CT估计值包含很大的方差，估计值的标准误为0.44 mL / min /克。