心肌组织背向散射积分及回声强度与心肌纤维走行的关系

Relationship between orientation of ventricular myofiber and values of myocardial ultrasonic integrated backscatter and echo intensity

目的 探讨心肌组织超声背向散射积分及回声强度与心肌纤维走行的关系。方法 16只犬 ,随机分为 2组 ,静脉注射高钾、高钙溶液 ,使心脏分别停搏于舒张、收缩状态 ,取胸骨旁乳头肌短轴观方位左心室前壁心肌立方体组织块 ,分别从该组织块垂直矢状切面、垂直冠状切面及侧冠状切面采集超声射频、视频图像 ,用HP5 5 0 0型超声诊断仪声学密度定量 (AD)技术和“DFY型超声图像定量分析诊断仪” ,获得感兴趣区超声背向散射积分 (IBS)及回声强度 (EI)值 ,切取相应位置心肌组织行光镜观察。结果 收缩、舒张状态侧冠状切面心肌中层与垂直矢状切面及垂直冠状切面心肌中层比较 ,其IBS、EI值的差异均具有显著性意义 (均P <0 .0 5 )。病理检查结果可见与胸骨旁乳头肌短轴观相对应切片心肌中层为环行肌纤维纵截面 ;与之相垂直面切片心肌中层为环行肌纤维横截面。中层心肌走行方向在垂直矢状切面、垂直冠状切面与入射声波垂直 ,在侧冠状切面与之平行。结论 心肌组织IBS、EI值与心肌纤维走行方向密切相关。超声束与心肌纤维垂直时IBS、EI值最大 ,平行时最小 。

Objective To explore the relationship between the values of myocardial ultrasonic integrated backscatter (IBS) and echo intensity (EI) and the orientation of ventricular myofiber.Methods Sixteen canines were divided randomly into two groups.Hyper calcium solution or hyper potassium solution were injected to make hearts arrest at systole or at diastole.Cubical segments were excised from left ventricular anterior wall by parasternal papillary muscles short axis view.Specimens were insonified,traversing the cubes perpendicularly by sagittal and coronal section,from one lateral side to another by coronal section to acquire radio and video frequency images,respectively.IBS and EI were obtained by “Acoustic Densitometry technique” and “DFY quantitative analysis system”.Tissue segments of corresponding positions were excised,observed by microscope.Results At systole and diastole state,IBS and EI of middle layer myocardium obtained by coronal section from one lateral side to another had significant difference with those obtained perpendicularly by sagittal and coronal section(P< 0.05 ).The pathology showed that in the slice corresponding to the parasternal papillary muscles short axis views the myofiber of middle layer was longitudinal section that was circular orientation.In the slice that was perpendicular to the parasternal papillary muscles short axis view the myofiber of middle layer was cross section that was circular orientation.In the section traversing the cube perpendicularly by sagittal and coronal the orientation of myofiber was perpendicular to the ultrasound.In the section that was from one lateral side to another by coronal section was parallel to the ultrasound.Conclusions The values of IBS and EI have significant correlation with the orientation of ventricular myofiber.The values of IBS and EI were maximum when the ultrasound was perpendicular to myofiber and minimum when the ultrasound was parallel to myofiber.