【摘要】 目的 分析T₁ mapping技术对急性心肌梗死（AMI）的诊断价值及参考值范围。方法 选用5只家猪作为AMI模型,开胸直视下将左前降支远段结扎,制备AMI模型。造模后1 d行1.5T心脏磁共振（CMR）扫描,扫描序列包括对比剂注射前、后T₁ mapping和钆对比剂延迟增强（LGE） CMR检查结束立即处死模型,并切取左心室短轴位8 mm薄层切片并HE染色。对照病理图像,分析T₁ mapping诊断AMI的效能。结果 （1）以病理结果为金标准。LGE及对比剂注射前、后T₁ mapping主观评价AMI的灵敏度、特异度及约登指数分别是:LGE,93.33%、94.03%、0.873;对比剂注射前T₁ mapping,73.33%、88.06%、0.613;对比剂注射后T₁ mapping,86.66%、97.01%、0.837。（2）以病理结果为金标准,正常心肌与梗死心肌T₁值在对比剂注射前、后差异均有统计学意义;正常心肌与梗死心肌细胞外间质容积分数（ECV）值差异有统计学意义（P均<0.05）。（3）ROC曲线分析:对比剂注射前心肌T₁值诊断AMI的AUC、诊断界值及95%置信区间（95%CI）分别是0.916,1 065.9 ms,0.811～1;对比剂注射后是0.956,604.35 ms,0.891～1;ECV值是0.923,0.41,0.824～1。结论 T₁ mapping技术主观评价及客观值测量均能够较好地评价AMI,对比剂注射前、后T₁值及ECV值可用于梗死及非梗死心肌的鉴别诊断。更多还原

【Abstract】 Objective To investigate the diagnostic value and reference range of the acute myocardial infarction（AMI） using T₁mapping technique.Methods Five pigs were selected as AMI model, and the distal left anterior descending branch was ligated to make AMI model.One day after modeling, 1.5T CMR scanning was carried, and the scanning sequence included late gadolinium enhancement（LGE） and T₁mapping before and after contrast injection.At the end of CMR,the model was killed immediately, and the short axial 8 mm sections of the left ventricle were taken and stained with HE.Compared with pathological images, T₁mapping diagnosis of the efficiency of AMI was analyzed.Results（1）According to the pathological results as the gold standard, the sensitivity, specificity and Youden index of LGE and T₁mapping before and after contrast medium injection were as follows: LGE,93.33%,94.03%,0.873;pre-T₁mapping, 73.33%,88.06%,0.613;post-T₁mapping, 86.66%,97.01%,0.837,respectively.（2）According to the pathological results as the gold standard, there was significant difference on T₁ value between normal myocardium and infarction myocardium before and after contrast medium injection, and there was significant difference in ECV value between normal myocardium and infarction myocardium（P<0.05）.（3） ROC curve analysis: the AUC,the diagnostic boundary value and 95%CI of T₁ value before contrast medium injection were 0.916,1 065.9 ms and 0.811-1,respectively.After contras medium injection were 0.956,604.35 ms, 0.891-1,ECV were 0.923,0.41,0.824-1.Conclusion AMI can be nicely evaluated through subjective evaluation and objective measurement value of the T₁mapping technique, and T₁ value and ECV value compared with the before and after injection can be used to diagnose the infarction and non-infarction myocardium.更多还原