能谱CT成像在兔缺血性心脏病模型中的应用

Spectral CT Imaging of Ischemic Heart Disease in Rabbit Model

目的:评价CT心肌能谱成像在兔缺血性心脏病模型中的价值。方法:建立40只新西兰大白兔缺血性心脏病模型,均分为4组,分别在建模后6h、3d、7d、14d于对比剂注入后10s、1min、3min进行CT心肌能谱扫描。扫描结束后行HE及CD31检查。将不同缺血时间缺血心肌碘基值除以同层面主动脉的碘基值标化后(nICIM)进行统计分析,分析nICIM与微血管密度(MVD)的关系。结果:延迟10s扫描,nICIM随着缺血时间的延长而降低,延迟1min及3min扫描,其值随着缺血时间的延长而增加。缺血6h组与其他各组nIC值存在显著性差异P6h-3d=0.01,P6h-7d=0.01,P6h-14d=0.00。延迟10s扫描,nICIM与MVD存在负相关(r=-0.54,P=0.00),延迟1min及3min扫描,nICIM与MVD存在正相关(延迟1min r=0.57,P=0.00,延迟3min r=0.48,P=0.00)。结论:CT心肌能谱成像可有效评价缺血性心脏病的不同阶段。

Purpose： To evaluate the capability of spectral CT imaging in detecting the different stages of ischemic heart disease （IHD） in rabbit model. Methods： IHD was surgically induced in forty rabbits and the rabbits were divided into 4 groups, they were undergone CT on 6 hours （6H）, 3 days （3D）, 7 days （7D） and 14 days （14D） after the model was established. Spectral CT imaging was done at 10s, lmin, 3min after contrast injection was performed. CD31 immunohistochemistry was used for the micro-vessel density （MVD） measurement. Iodine concentrations of the myocardium were normalized to the aorta as nIC. The relationships between the nIC and MVD were analyzed. Results： The nIC of ischemic myocardium decreased with infarction time in 10s phase and increased in the late-phases. There were significant differences between the 6H and other groups （P6h-3d=0.01, P6h-7d=0.01, P6h-14d=0.00）. In the 10s phase, the nIC of infarct myocardium was negatively correlated with MVD （r =-0.54, P=0.00）, while in the late-phases, there was positive correlation between them （r=0.57, P=0.00 in lmin phase, r=0.48, P=0.00 in 3min phase）. Conclusions： Spectral CT imaging of the myocardium can be used to evaluate the different stages of the ischemic heart disease.