64层螺旋CT在陈旧性心肌梗死患者左心室整体功能评价中的应用价值

Assessment of Global Left Ventricular Function by 64-slice Spiral CT in Patients with Old Myocardial Infarction

目的以磁共振成像(MRI)为参考标准,探讨64层螺旋CT(64SCT)在陈旧性心肌梗死(OMI)患者左心室整体功能评价中的应用价值。方法对28例OMI患者同期行心脏64SCT、MRI及超声心动图(Echo)检查,测量左室舒张末容积(EDV)、收缩末容积(ESV)、每搏量(SV)、射血分数(EF)和舒张末心肌质量(MM)。结果64SCT和MRI在测定左室功能参数方面(EDV、ESV、SV、EF和MM)具有高度相关性(r=0.788～0.976,P<0.001),两种方法的心功能指标差异无显著性,一致性可被临床接受。Echo与MRI的一致性界限显著大于64SCT与MRI的一致性界限(P<0.05)。64SCT诊断EF<50%的敏感性、特异性及准确性分别是84.6%,100%和92.9%,Echo分别是61.5%,66.7%和64.3%。配对McNemar检验示64SCT的诊断准确性显著高于Echo(P<0.01)。Echo较64SCT更大地高估了EDV、ESV及SV(P<0.05),但EF的均值差差异无显著性。结论64SCT在定量评价OMI患者左心功能方面准确、可靠,准确性高于Echo,64SCT与MRI相关性及一致性好,优于Echo与MRI的相关性及一致性。

Objective To investigate the clinical value of 64-slice spiral CT （64SCT） in assessing global left ventricular function in patients with old myocardial infarction （OMI） , with magnetic resonance imaging （MRI） as the reference standard. Methods A total of 28 patients （23 men and 5 women） with OMI underwent contrast-enhanced 64SCT with retrospective electrocardiographic-gating, MRI, and transthoracic echocardiography （Echo）. The data sets of 64SCT and MRI were reconstructed at both end-diastole and end-systole to measure left ventricular end-diastolic volume （ EDV）, end-systolic volume （ ESV）, stroke volume （SV）, ejective fraction （EF）, and myocardial mass at end-diastole （MM）. The data acquired with 64SCT and Echo were compared with the results obtained on MRI as the standard of reference respectively. Results The parameters of global left ventricular function obtained with 64SCT were significantly correlated with the MRI data （ r = 0. 788-0. 976, P 〈0. 001 ）. EDV, ESV, SV, EF, and MM were slightly overestimated by 64SCT compared with MRI; however, there was no significant difference among the measurements. 64SCT was in good agreement with MRI. For the EDV, ESV, SV, and EF, the limits of agreement with Echo were significantly larger than with 64SCT compared with MRI （P 〈 0.05 ）. The sensitivity, specificity, and accuracy of 64SCT to identify EF value less than 50% were 84.6%, 100% and 92.9%, respectively, whereas those of Echo were 61.5%, 66.7% and 64.3%, respectively. The accuracy of 64SCT was significantly higher than that of Echo （ P 〈 0.01 ）. There was a significantly larger overestimation of EDV, ESV, and SV with Echo than with 64SCT compared with MRI （ P 〈 0.05 ）, whereas EF was not significantly different. Conclusions A strong correlation between 64SCT and MRI is found for all parameters. 64SCT agrees well with MRI, and allows more reliable and accurate evaluation of global left ventricular function in patients with OMI than Echo compared with MRI.