低剂量增强多层螺旋CT对陈旧性心肌梗死心肌活性的评价

目的 前瞻性评价低剂量增强多层螺旋CT(MSCT)显示陈旧性心肌梗死心肌活性的可行性和可靠性,并与MR心肌灌注和心肌活性成像进行对照研究.方法 对32例临床明确诊断为陈旧性心肌梗死的患者行前瞻性首过和延迟增强64层MSCT及MR心肌灌注成像,在短轴面上将左心室分为16个心肌段进行分析,所有患者的MSCT和MR影像资料被双盲分析,确定早期心肌灌注缺损区和晚期延迟增强区的大小及范围.采用一致性检验的Kappa检验,评价两种方法对显示心肌活性的一致性.结果 32例患者,首过灌注期MSCT提示灌注缺损为41个节段,无灌注缺损为471个节段;首过灌沣期MRI提示灌注缺损为47个节段,无灌注缺损为465个节段,两种方法一致性Kappa值为0.650,符合率为94.5%(484/512).延迟期MSCT显示延迟增强为135个节段,其中非透壁性梗死为50个节段,透壁性梗死为85个节段,未出现延迟增强为377个节段;延迟期MRI显示延迟增强为120个节段,其中非透壁性梗死为56个节段,透壁性梗死为64个节段,未出现延迟增强为392个节段,两种方法一致性Kappa值为0.609,符合率为80.7%(413/512).结论 低剂量增强螺旋MSCT与MRI对心肌活性的评价有较好的相关性,MSCT对陈旧性心肌梗死的存活心肌和非存活心肌的检测是呵行和可靠的,减少不必要的X线辐射剂量是该研究的重要方面.

Evaluation of myocardial viability in myocardial infarction by low kilovoltage contrast-enhanced multi-slice CT

Objective To prospectively evaluate the feasibility and reliablity of low kilovoltage contrast-enhanced multi-slice CT(MSCT)to detect the myocardial viability in chronic myocardial infarcetion.with comparison to magnetic resonance(MR)myocardial perfusion and viability imaging.Methods Thirty-two patients with clinical diagnosed chronic myocardial infarction underwent the first pass and delayenhanced myocardial imaging with 64-slice MSCT and MR Left ventricle was divided into 16 segments.MSCT and MR images of all the patients were blindly analyzed.The size and extent of hypoenhanced regions in first pass phase and hyperenhanced regions in delayed phase were define.The Kappa test was used to assess the ability of identifying the viable myocardium between the two methods.Results In 32 patients with chronic myocardial infarction,MSCT showed hypoenhanced regions in 41 segments and normal in 471 segments during the first phase,while MRI revealed hypoenhanced regions in 47 segments and normal regions in 465 segments.The Kappa value was 0.650 and the concordance rate of the two techniques was 94.5%(484/512).MSCT showed 135 hyperenhanced regions which were non-transmural in 50 segments and transmural in 85 segments.And the other 377 normal segments showed no enhancement in the delayed phase.MRI revealed 120 hyperenhanced regions which were non-transmural in 56 segments and transmural in 64 segments.And the other 392 normal segments showed no enhancement in the delayed phase.The Kappa value of the two techniques was 0.609 and the concordance rate of the two techniques was 80.7% (413/512).Conclusion The study showed that low kilovolrage CE MSCT has a good concordance with MRI and has high feasibility and reliability in evaluating the myocardial viability in chronic myocardial infarction.The radiation dose is still the important aspect of MSCT application.