摘要
目的 :建立心肌慢性缺血动物模型 ,探讨超声背向散射积分 (IBS)和多普勒组织成像 (DTI)技术检测慢性心肌缺血的价值。 方法 :健康家猪 5头。在猪冠状动脉左旋支放置Ameroid环 ,应用IBS检测置环后 2、4、6、8周左心室侧后壁标化平均IBS(%AⅡ )、IBS周期变化幅度 (CVIB)及CVIB跨壁梯度指数 (TGI)的变化 ;应用DTI检测各阶段左心室乳头肌短轴观和心尖四腔观左心室侧后壁DTI频谱 [收缩期峰值速度 (VS)、舒张早期峰值速度(VE)、舒张晚期峰值速度 (VA) ]的变化。 结果 :正常心肌 %AⅡ为 2 .2 9± 0 .32 ,CVIB为 (9.6 9± 2 .2 2 )dB ,TGI为0 .2 2± 0 .0 8。置环后 %AⅡ逐渐增加 ,CVIB逐渐减小 ,心内膜下CVIB减小幅度大于心外膜下 ,使TGI亦逐渐减小 ,置环后 2～ 4周减小幅度最大 ,至 8周跨壁梯度消失 (P <0 .0 1) ;正常心尖四腔观VS 大于左心室短轴观VS(P <0 .0 1) ,VE 小于左心室短轴观VE(P <0 .0 5 )。置环后 2周 ,两者VS、VE 均显著减小 (P <0 .0 5 ) ,心尖四腔观VS 减小幅度大于左心室短轴观VS。以后各阶段两者VS、VE 继续减小 ,仍以心尖四腔观VS 减小幅度最大。 结论 :用Ameriod环建立猪心肌慢性缺血模型 ,能很好模拟人类冠心病的病变过程 ;超声IBS和DTI技术从回声和心室壁运动等不同方面检测慢性心肌?
Objective: To establish porcine chronic ischemic myocardium model and to evaluate ultrasonic integrated backscatter(IBS) and Doppler tissue imaging(DTI) in detecting this model. Methods: An Ameroid constrictor was placed around the porcine proximal left circumflex artery. The calibrated average image intensity (%AⅡ), cyclic variation of IBS (CVIB), the subendo-epicardical gradient index (TGI) and the spectrum of left ventricular papillary muscle level short axis view (LVPM-SAM) and apical four chamber view (AP-4CV) were measured at normal state, 2 w, 4 w, 6 w and 8 w after Ameroid placement. Results: Normal %AⅡ, CVIB and TGI were 2.29±0.32,(9.69±2.22)dB and 0.22± 0.08 respectively. After Ameroid placement, the %AII increased gradually, the CVIB decreased gradually, and the decrease was higher in subepicardium than that in subendocardium. The most obvious decrease of TGI occurred from 2 w to 4 w after Ameroid placement and became zero at 8 w(P<0.01); Normal V S of AP-4CV was greater than that of LVPM-SAM(P<0.01). V E of AP-4CV was lower than that of LVPM-SAM(P<0.05). After placing Ameroid, V S and V E were all decreased (P<0.01). The decrease of V S in AP-4CV was greater than that of LVPM-SAM. Conclusion:The pathological changes of the myocardium in human coronary heart disease(CHD) are similar to that of myocardium model created by Ameriod; IBS and DTI can detect echo and function changes of chronic ischemic myocardium, and provide information for clinical investigation and treatment of CHD.
出处
《医学研究生学报》
CAS
2004年第10期880-883,886,共5页
Journal of Medical Postgraduates
关键词
心肌慢性缺血
背向散射积分
多普勒组织成像
Chronic myocardium ischemia
Integrated backscatter
Doppler tissue imaging
