实时组织弹性超声成像定量评价猪离体心室心肌弹性

摘要

Objective To assess myocardial elasticity in the isolated porcine ventricular wall using real-time ultrasonic tis sue elastography (RTE) technology,and to explore the correlation between myocardial elasticity and the tissue element and three-dimension distribution of myocardial interstitial collagen fibers.Methods Ten isolated porcine hearts were collected.Cubical segments were excised from left and right ventricular (LV,RV) anterior walls and interventricular septum (IVS) at the base,respectively.Along the ventricular long and short-axis direction,the elastic strain ratio (SR) of 2％ agar with out collagen fibers to the myocardium were measured and calculated using RTE.Combined with the area (CA) and the area percentage (CA％) of collagen fibers in the three locations of patho-histological slice with Masson's Trichrome stain,SR,CA and CA％ were compared among the three locations.Correlations between SR of myocardial elasticity and CA,CA％ in the three locations were analyzed.Results Along the ventricular long-axis direction,there were statistically significant differences of SR among LV,RV and IVS,respectively (P＜0.01) and between the ventricular long-axis direction and short-axis direction at IVS (P＜0.01).Along the ventricular long-axis direction,there were statistically significant differences of CA and CA％ among LV,RV and IVS (all P＜0.05) and between the ventricular long-axis direction and short-axis direction at IVS (P＜0.05).Statistically significant positive linear correlations between SR and CA,CA％ were found (all P＜0.05).Conclusion SR of porcine myocardial tissue among LV,RV and IVS are different.Myocardial elasticity of porcine has correlation with tissue element and distribution of myocardial interstitial collagen fibers.%目的 应用实时组织弹性超声成像(RTE)技术定量评价猪离体心室心肌弹性,探讨心肌弹性与心肌间质胶原纤维含量及其三维分布的关系.方法 离体猪心10个,分别切取左、右心室前壁和室间隔基底部的心肌组织立方体块.应用RTE获取2％无胶原纤维琼脂与心肌组织块的弹性应变比值(SR).在组织病理切片上测量Masson染色心肌组织块的胶原纤维面积(CA)及胶原纤维面积百分比(CA％).比较3个部位心肌组织块的SR、CA、CA％,并分析心肌组织块SR与CA、CA％的相关性.结果 3个部位心肌SR在心室长轴方向上的差异均有统计学意义(P均＜0.01)；室间隔基底部心肌SR在心室长轴和短轴方向上差异有统计学意义(P＜0.01).心室长轴方向各部位心肌CA比较和CA％比较差异均有统计学意义(P均＜0.05)；室间隔基底部心肌在心室长轴和短轴方向上的CA比较和CA％比较差异均有统计学意义(P均＜0.05).心窒长轴方向上各部位心肌组织块的SR与CA、CA％呈正相关(P＜0.05)；心室短轴方向上左心室前壁和室间隔基底部的SR与CA、CA％呈正相关(P＜0.05).结论 猪离体心肌左、右心室和室间隔基底部心肌组织块SR存在明显差异,心肌弹性与心肌间质胶原纤维含量及其分布特征有关.