第二代双源CT冠状动脉成像结合双能量心肌灌注评价猪急性心肌梗死的实验研究

Evaluation of combined coronary CT angiography and dual-energy myocardial perfusion imaging for detection of acute myocardial infarction via second-generation dual-source CT: an experimental study in a porcine phantom model

  • 摘要:
    目的 通过建立猪急性心肌梗死模型,以组织病理学和冠状动脉造影(CAG)结果为金标准,评价第二代双源CT双能量“一站式”冠状动脉CT血管造影(CCTA)结合心肌灌注成像(MPI)检测急性心肌梗死的准确率。
    方法 7只健康小型猪,采用导管介入冠状动脉明胶海绵栓塞方法制作急性心肌梗死模型,分别在造模前20 min、心肌梗死后即刻、心肌梗死后24 h行CAG及双能量模式CCTA和MPI。采用心肌17节段法评价心肌碘图灌注缺损。双盲法由2名放射科医师对图像进行评价,以病理和CAG结果为金标准,计算双能量CCTA结合心肌灌注碘图诊断心肌灌注缺损节段的灵敏度和特异度。
    结果 5只小型猪成功建成急性心肌梗死模型。双能量碘图显示45个梗死节段和40个非梗死节段。以病理和CAG结果为金标准,基于节段分析得出灵敏度、特异度、阳性预测值、阴性预测值分别为93%、95%、95%、93%;基于血管分布区域分析,双能量CT心肌灌注检测心肌梗死的灵敏度、特异度、阳性预测值、阴性预测值分别为100%、86%、89%、100%。单次双能量扫描平均有效射线剂量为(3.07±0.85)mSv(2.21~4.49 mSv)。
    结论 以病理和CAG结果为金标准,第二代双源CT双能量“一站式”CCTA结合心肌灌注碘图检测急性心肌梗死准确率较高,CCTA的图像质量好。

     

    Abstract:
    Objective To evaluate the diagnostic accuracy of dual-energy "one-step"combined CT coronary angiography(CCTA) and myocardial perfusion imaging(MPI) for the detection of acute myocardial infarction via second-generation dual-source CT compared with histopathological and conventional coronary angiography(CAG) findings in a porcine phantom.
    Methods Seven minipigs underwent transcatheter embolization of the coronary arteries by using gelatin sponge to produce acute myocardial infarction. CAG, dual-energy CCTA, and MPI were performed 20 min before, immediately after, and 24 h following the modeling procedure, respectively. A color-coded iodine map was used to evaluate the myocardial perfusion defects on the 17-segment model. In consensus, two radiologists interpreted all iodine map imaging results from MPI and CCTA. Considering CAG and pathological staining as gold standards, the sensibility and specificity of the CCTA and iodine maps from MPI were evaluated using dual-energy CT.
    Results Models of acute myocardial infarction were successfully made in five minipigs. Following coronary embolization, dual-energy CT iodine maps showed 45 infarcted segments and 40 non-infarcted segments. Per-segment analysis indicated the sensitivity, specificity, positive predictive value and negative predictive value as 93%, 95%, 95% and 93%, respectively. The corresponding values obtained by per-territory analysis were 100%, 86%, 89% and 100%, with CAG and histopathological findings as reference standards. The effective radiation dose of each dual-energy scan was 3.07±0.85 mSv(2.21-4.49 mSv).
    Conclusions Dual-energy"one-step"combined CCTA and MPI iodine maps for the detection of acute myocardial infarction via second-generation dual-source CT showed enhanced diagnostic accuracy with CAG and histopathology as gold standards.

     

/

返回文章
返回