心脏磁共振对比剂灌注及延迟增强对早期心肌缺血的诊断价值

Diagnostic value of cardiac magnetic resonance contrast medium perfusion and delayed contrast enhancement for early myocardial ischemia

目的探讨心脏磁共振(CMR)对比剂灌注及延迟增强对早期心肌缺血的检出及价值。方法选取义乌市中心医院2020年3月至2022年3月收治的通过冠状动脉造影(CAG)显示有冠状动脉狭窄的患者91例为研究对象,对患者行CMR对比剂首过心肌灌注及延迟增强检查。统计分析CMR对比剂正常灌注节段组与低灌注节段组的对比剂到达时间(t_(0))、累积信号强度(ASI)、相对峰值强化率(SI%)、信号增强最大强度(SIp)及最大曲线上升斜率Slope(α)等指标。评估CMR对比剂灌注与CAG诊断早期心肌缺血的价值,分析CMR对比剂灌注延迟扫描强化区与无强化区的信号强度值。结果正常灌注节段与低灌注节段ASI、SI%、SIp和Slope(α)参数差异均有统计学意义(t=9.62、10.65、8.67、6.93,均P<0.05)。CMR对比剂灌注检出早期心肌缺血病变血管检出率[50.42%(120/238)]与CAG的检出率[51.68%(123/238)]差异无统计学意义(χ^(2)=1.32,P=0.163)。CMR对比剂灌注与CAG两种方法在检出早期心肌缺血病变血管方面差异有统计学意义(χ^(2)=15.31,P<0.001,r=0.71)。延迟增强节段信号值(598.43±40.19)显著高于无延迟增强节段(298.64±70.58)(t=19.85,P=0.001)。结论CMR对比剂灌注可有效评估早期心肌缺血程度和病变血管部位,延迟增强可确定早期心肌缺血部位和面积,能客观反映心肌缺血程度。

Objective To investigate the diagnostic value of cardiac magnetic resonance(CMR)contrast medium perfusion and delayed contrast enhancement for early myocardial ischemia.Methods Ninety-one patients with coronary artery stenosis diagnosed by coronary angiography(CAG)between March 2020 and March 2022 in Yiwu Central Hospital were included in this study.These patients underwent first-pass perfusion cardiac magnetic resonance imaging and delayed enhancement examination.Arrival time(t_(0)),accumulative signal intensity(ASI),relative peak enhancement rate(SI%),maximum intensity of signal enhancement(SIp),and maximum curve slope(α)were statistically analyzed in the CMR contrast agent normal-dose perfusion and low-dose perfusion segments.The diagnostic value of CMR contrast agent perfusion versus CAG for early myocardial ischemia was determined.The signal intensity was compared between enhanced and non-enhanced areas of CMR contrast agent perfusion.Results There were significant differences in ASI,SI%,SIp,and Slope(α)between normal perfusion and low perfusion segments(t=9.62,10.65,8.67,6.93,all P<0.05).There was no significant difference in the detection rate of lesioned vessels in early myocardial ischemia between CMR contrast agent perfusion and CAG[50.42%(120/238)vs.51.68%(123/238),χ^(2)=1.32,P=0.163].There was a significant difference in the detection rate of lesioned vessels in myocardial ischemia between CMR contrast agent perfusion and CAG(χ^(2)=15.31,P<0.001,r=0.71).The signal intensity value in the delayed enhancement segment was significantly higher than that in the non-delayed enhancement segment[(598.43±40.19)vs.(298.64±70.58),t=19.85,P=0.001].Conclusion CMR contrast agent perfusion can effectively evaluate the severity of early myocardial ischemia and locate the diseased blood vessels.Delayed enhancement can determine the location and area of early myocardial ischemia,and can objectively reflect the severity of myocardial ischemia.