■应力动态计算机断层扫描心肌灌注成像(CT-MPI)是诊断冠状动脉疾病(CAD)中心肌缺血的准确定量方法。然而,其临床应用受到限制,部分原因是绝对心肌血流量(MBFa)的临界值不同和相对心肌血流量比(MBF比)的不确定值。这项研究旨在比较MBFa的诊断功效,并研究CT-MPI中MBF比率在血流动力学显着CAD患者中诊断心肌缺血的最佳临界值。
■在2020年10月至2023年12月期间接受了CT-MPI+CT血管造影和有创冠状动脉血管造影(ICA)/血流储备分数(FFR)的疑似或已知有血流动力学意义的CAD患者进行回顾性评估。将ICA≥80%或FFR≤0.8作为功能性缺血的诊断标准。患者和血管分为缺血组和非缺血组,比较两组之间MBFa和MBF比率的差异。计算曲线下面积(AUC)和最佳截止值。诊断效能参数,比如灵敏度,特异性,和准确性,也进行了比较。此外,进行了一致性检验.
■共评估了46例患者(平均年龄:65.37±8.25岁;120支血管)。在30/46例患者(48%)和81/120例血管(67.5%)中检测到血液动力学显着的狭窄。缺血组的MBFa和MBF比值明显低于非缺血组;在血管分析中,MBFa值为73vs.128(P<0.001),MBF比值为0.781vs.0.856(P<0.001),分别。MBFa和MBF比率的最佳截止值分别为117.71和0.67。MBFa表现出敏感性,特异性,准确度,AUC,正预测值,负预测值,Kappa值为97.44%,74.07%,81.66%,0.936[95%置信区间(CI):0.876-0.973,P<0.001],63.33%,98.36%,和0.631(95%CI:0.500-0.762),分别。MBF比率的相应值为92.31%,85.19%,87.5%,0.962(95%CI:0.911-0.989,P<0.001),75%,95.83%,和0.731(95%CI:0.606-0.857,P<0.001),差异无统计学意义(P=0.1225)。
■MBFa和MBF-ratio对具有血液动力学意义的CAD患者的心肌缺血均表现出优异的诊断性能。MBF比MBFa更可靠地解释临床实践中的CT-MPI发现。这对实施CT-MPI的放射科医生和临床医生很有用。
UNASSIGNED: Stress dynamic computed tomography myocardial perfusion imaging (CT-MPI) is an accurate quantitative method for diagnosing myocardial ischemia in coronary artery disease (CAD). However, its clinical application has been limited, partly due to the varied cutoff values for absolute myocardial blood flow (MBFa) and the uncertain value of the relative myocardial blood flow ratio (MBF-ratio). This study aimed to compare the diagnostic efficacy of and investigate the optimal cutoff values for MBFa and the MBF-ratio in CT-MPI for diagnosing myocardial ischemia in patients with hemodynamically significant CAD.
UNASSIGNED: Patients with suspected or known hemodynamically significant CAD who underwent CT-MPI + CT angiography and invasive coronary angiography (ICA)/fractional flow reserve (FFR) between October 2020 and December 2023 were retrospectively evaluated. ICA ≥80% or FFR ≤0.8 were set as the diagnostic standards for functional ischemia. The patients and vessels were categorized into ischemic and non-ischemic groups, and differences in MBFa and the MBF-ratio were compared between the groups. The area under the curve (AUC) and optimal cutoff values were calculated. Diagnostic efficacy parameters, such as sensitivity, specificity, and accuracy, were also compared. In addition, a consistency test was performed.
UNASSIGNED: A total of 46 patients (mean age: 65.37 ± 8.25 years; 120 vessels) were evaluated. Hemodynamically significant stenosis was detected in 30/46 patients (48%) and 81/120 vessels (67.5%). The MBFa and MBF-ratio values were significantly lower in the ischemic than in the non-ischemic group; in the per-vessel analysis, the MBFa values were 73 vs. 128 (P < 0.001) and the MBF-ratio values were 0.781 vs. 0.856 (P < 0.001), respectively. The optimal cutoff values for MBFa and the MBF-ratio were 117.71 and 0.67, respectively. MBFa demonstrated a sensitivity, specificity, accuracy, AUC, positive predictive value, negative predictive value, and kappa value of 97.44%, 74.07%, 81.66%, 0.936 [95% confidence interval (CI): 0.876-0.973, P < 0.001], 63.33%, 98.36%, and 0.631 (95% CI: 0.500-0.762), respectively. The corresponding values for the MBF-ratio were 92.31%, 85.19%, 87.5%, 0.962 (95% CI: 0.911-0.989, P < 0.001), 75%, 95.83%, and 0.731 (95% CI: 0.606-0.857, P < 0.001), with no significant difference (P = 0.1225).
UNASSIGNED: Both MBFa and the MBF-ratio exhibit excellent diagnostic performance for myocardial ischemia in patients with hemodynamically significant CAD. The MBF-ratio is more robust than MBFa for interpreting CT-MPI findings in clinical practice, which is useful for radiologists and clinicians implementing CT-MPI.