巨噬细胞CT靶向定量对斑块易损性风险预测的研究

A research to predict the risk of plaque vulnerability by targeted quantification for macrophages on CT

目的通过特异性靶向CT对比剂,对斑块内巨噬细胞进行分子影像学量化,进而探讨量化指标与斑块稳定性的相关关系及对斑块破裂风险的预测价值。方法应用靶向对比剂对活体动物模型斑块内巨噬细胞进行CT成像,以斑块CT值50Hu为界点,将斑块分为稳定组和易损组;对原始数据进行重组,测量血管面积(vessel area,VA)及对比剂存留区域面积(contrast agent retention area,CARA),并计算CARA/VA值。结果 (1)CARA/VA值与斑块CT值具有较高的相关关系(r=0.765,P <0.05);(2)易损斑块组中CARA/VA值曲线下面积(area under the curve,AUC)明显大于CT值,差异具有统计学意义(P <0.05)。结论基于靶向对比剂的CT成像技术,能够在活体内实现对粥样斑块内巨噬细胞的成像与量化。CARA/VA值与斑块稳定性密切相关,且在斑块破裂风险预测方面具有较高的敏感性及特异性。

Objective:To quantify the macrophages in the plaque by molecular imaging,and then investigate the correlation between quantitative index and plaque stability and the predictive value of the former for the risk of plaque rupture.Methods:CT imaging using targeted contrast agent was performed for macrophages in plaques of vivo animals.Those plaques were divided into two groups,the stable group and the vulnerable group,using the critical point of 50Hu.The original data was recombined to measure the vessel area(VA)and contrast agent retention area(CARA),and the CARA/VA value was calculated.Results:①The CARA/VA value is highly correlated with the plaque CT value(r=0.765,P<0.05);②For the vulnerable plaque group,the area under the curve(AUC)value was obviously higher than the CT value and the difference was statistically significant(P<0.05).Conclusion:The CT based on the targeted contrast agent can achieve the imaging and quantification of macrophages in the atherosclerotic plaques of living animals.The CARA/VA value is closely related to the stability of plaques and has high sensitivity and specificity in the prediction of plaque rupture.