心肌纤维束DTI的实验研究

Experimental study of myocardial fiber architecture using DTI technique

目的尝试使用MR弥散张量成像(DTI)显示离体心肌纤维束结构的可能性。方法使用25个方向的DTI序列扫描离体1h和24h的猪心脏,使用脑白质纤维束成像重建方式显示心肌纤维的走行、分布和排列方式。结果DTI可以清晰显示离体1h心肌的排列特征为分层、螺旋、扭转和发散,与广义上心肌纤维的排列方式吻合;离体24h后由于心肌发生溶解,DTI显示的心肌纤维的完整性被破坏,表现为心肌纤维长度缩短、外形皱缩、排列扭曲。结论DTI技术可以显示离体心肌纤维的完整性和排列方式,其潜在的应用领域为心肌纤维的形态功能的试验研究。

Objective To investigate the feasibility of MR diffusion tensor imaging （DTI） technique in displaying myocardial fiber architecture. Methods On an ex vivo swine heart, DTI was acquired in 25 directions 1 hour and 24 hours after excision. The myocardial fiber was reconstructed using brain white matter tractography algorithm to display its course, distribution and arrangement. Results On the heart 1 hour after excision, DTI revealed the arrangement of the myocardial fiber showing laminar, helix, twist and dispersal patterns, which is consistent with the array of the myocardial fiber in general anatomical descriptions. After 24 hours, because of the myocardium dissolving, DTI revealed the disintegration of the myocardial fiber, showing shortening, shrinking and distortion. Conclusion MR DTI could reveal the myocardial fiber architecture, showing its integrity and arrangement. It has potential in the study of myocardial structure-function.