离体心脏心室肌纤维结构的实验研究

发布时间：2018-06-18 08:30

本文选题：弥散张量磁共振成像 + 心舒期　；参考：《中国人民解放军军医进修学院》2011年硕士论文

【摘要】：目的：研究探讨利用弥散张量磁共振成像(diffusion tensor magnetic resonance imaging, DT-MRI)技术对离体猪心及人体心脏行可视化追踪扫描,获取心室肌纤维整体的三维空间分布规律,同时测量相关心肌纤维成角角度,进一步定量定性分析舒张期离体猪心及人体心室肌纤维的排列方式及空间分布的变化规律。方法：1.10只成年猪开胸后即刻在主动脉根部左右冠状动脉窦口灌注冷停搏液使心脏停搏使心脏停跳静止于舒张末期,经心脏修剪后以硫酸铜琼脂混合液固定于容器中,于20分钟内行DT-MRI扫描并行心肌纤维三维重建,观察心室肌纤维的空间走行规律,选定相关部位的纤维追踪点,测量该处的心肌纤维的螺旋角及横切角进行统计分析。 2.正常成年尸检病人心脏8例行DT-MRI扫描及三维重建,测量各纤维追踪点处心肌纤维的螺旋角及横切角,行定量统计分析,明确心肌纤维的空间走行及分布规律。结果：1.离体猪心经DT-MRI扫描后行三维重建后心肌纤维的结构及走形在各个部位及层面上大体上呈现一致性和相似性。左室各个室壁都呈现近乎垂直交叉的两层心肌纤维束,整体心室肌纤维在整体上保持连续,都具有特定的走形分布规律。 2.离体猪心从室壁内层到外层,心肌纤维的螺旋角有着明显的差异,内层最大,中层最小,外层介于两者之间。内层纤维在基底部,左室中部及心尖部的平均螺旋角逐渐减小,但内层纤维在基底部,左室中部的螺旋角明显大于心尖部的螺旋角(P0.05),而两者之间的角度无统计学差异(P0.05),中层心肌纤维螺旋角的变化同样有此规律,但外层则相反,心肌纤维螺旋角则呈现由基底到心尖部位螺旋角逐渐增大的趋势。外层纤维在心尖部,左室中部的螺旋角明显大于基底部的螺旋角(P0.05),而其两者之间的角度比较无统计学差异(P0.05)。内层纤维,中层纤维及外层纤维的横切角在基底部和中部的改变高度一致。而心尖部的纤维横切角平均角度明显大于基底部和中部。 3.人体离体心脏的心肌纤维结构及心肌纤维空间分布规律的特点,心肌纤维螺旋角及横切角的变化规律与猪心有相似性。结论：1.弥散张量磁共振成像(DT-MRI)可成功用于心肌纤维的三维重建。 2.离体猪心及人体心脏的心肌纤维结构具有有序分层特点,且在整体上具有连续性,各层纤维束都有特定的走形方向,与心肌带理论的描述相一致。 3.离体猪心及人心的心肌纤维螺旋角度及横切角度的测量具有重要意义,可从定量分析心肌纤维的空间走行及分布特点,而两种角度大小及其变化规律也体现了心脏的双螺旋结构特点。
[Abstract]:Objective: to investigate the three-dimensional spatial distribution of ventricular fibers in isolated pig heart and human heart by using diffusion Zhang Liang diffusion tensor magnetic resonance imaging, DT-MRI technique. At the same time, the angle of related myocardial fibers was measured, and the spatial distribution and arrangement of isolated pig heart and human ventricular muscle fibers during diastolic phase were analyzed quantitatively. Methods immediately after 1. 10 adult pigs opened the chest, cold cardioplegia was infused into the coronary sinus orifice at the root of the aorta. The cardioplegia was stopped at the end of diastole. After the heart was pruned, it was fixed in the container with copper sulfate Agar mixture. DT-MRI scanning was performed within 20 minutes and myocardial fiber 3D reconstruction was performed to observe the spatial pattern of ventricular fibers, and to select the fiber tracing points of the related sites. The helical and transverse angles of myocardial fibers were measured and analyzed statistically. 2. DT-MRI scanning and 3D reconstruction were performed in 8 normal adult autopsy patients. The helix angle and transverse angle of myocardial fibers at each fiber tracing point were measured, and quantitative statistical analysis was performed to determine the spatial movement and distribution of myocardial fibers. The result is 1: 1. After DT-MRI scanning in vitro, the structure and shape of myocardial fibers after 3D reconstruction in pig hearts showed consistency and similarity in all parts and levels. Each wall of the left ventricle presents two layers of myocardial fiber bundles which are nearly perpendicular to each other. The whole ventricular fibers remain continuous and have a specific pattern distribution law. 2. From the inner wall to the outer layer of isolated porcine heart, the helical angle of myocardial fiber was significantly different, the inner layer was the largest, the middle layer was the smallest, and the outer layer was between the two. The mean helical angle of the inner fiber was gradually decreased at the base of the base, and the mean helical angle of the middle and apical part of the left ventricle gradually decreased, but the inner fiber was at the base of the base. The spiral angle in the middle of the left ventricle was obviously larger than that in the apical part of the heart, but there was no statistical difference in the angle between them. The change of the helical angle of the middle myocardial fiber was the same, but the change of the spiral angle in the outer layer was the opposite. The spiral angle of myocardial fiber increased gradually from the base to the apex. The helical angle of the outer fiber in the apical part and the middle part of the left ventricle was significantly larger than that in the base (P 0.05), but there was no significant difference in the angle between the two. The cross-cutting angles of the inner, middle and outer fibers are highly consistent at the base bottom and the middle of the base. The mean angle of transverse angle of fibers in the apical part was significantly greater than that in the base and the middle of the base. The characteristics of myocardial fiber structure and the spatial distribution of myocardial fiber in human isolated heart, and the changes of spiral angle and transverse angle of myocardial fiber are similar to those of pig heart. Conclusion 1. Diffusion Zhang Liang magnetic resonance imaging (DT-MRI) can be successfully used in three dimensional reconstruction of myocardial fibers. 2. The cardiac fiber structure of isolated pig heart and human heart has the characteristics of orderly stratification and continuity in the whole. The fiber bundles in each layer have a specific conformal direction, which is consistent with the description of myocardial band theory. It is of great significance to measure the spiral and crosscutting angles of cardiac fibers in isolated pig hearts and hearts, which can be used to quantitatively analyze the spatial walking and distribution characteristics of myocardial fibers. The double helix structure of the heart is also reflected by the changes of the two angles.
【学位授予单位】：中国人民解放军军医进修学院
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R361

【共引文献】