Measuring and mapping cardiac fiber and laminar architecture using diffusion tensor MR imaging
Measuring and mapping cardiac fiber and laminar architecture using diffusion tensor MR imaging
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DOI：
10.1196/annals.1341.026
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发表时间：
2005-01-01
期刊：
影响因子：
--
通讯作者：
Winslow, RL
中科院分区：
文献类型：
--
作者：
Helm, P;Beg, MF;Winslow, RL
已知心室肌表现出复杂的空间组织，其中纤维取向作为透壁位置的函数而变化。现在已经确定，扩散张量磁共振成像（DTMRI）可以用于测量这种纤维的方向在高空间分辨率。还已知心脏纤维被组织成具有在整个心室中变化的表面取向的薄片。本文回顾了使用DTMRI测量心室纤维方向的结果，并提出了新的结果，提供了强有力的证据表明扩散张量的第三特征向量与心脏片表面法线局部对齐。综合考虑，这些数据表明，DTMRI可用于重建心室纤维和片组织。这篇文章还提出了大变形几何形态度量映射（LDDMM）算法，并表明该算法可用于使成像和重建心脏的集合相对应（例如，配准），从而可以量化心室几何形状、纤维和片取向的可变性。已知心室几何形状和纤维结构在一系列疾病过程中重塑;然而，对这种重塑的描述仍然是主观和定性的。我们预计，使用DTMRI重建心室解剖结构，再加上应用LDDMM方法进行图像体积配准，将能够检测和量化心脏解剖结构的变化，这些变化是心脏特定疾病过程的特征。最后，我们表明，心外膜电标测和DTMRI成像可以在同一心脏。然后，解剖数据可以用于模拟电标测的同一心脏的计算模型中的电传导。这有助于直接比较和测试模型与实验结果，并打开了定量测量，建模和分析心室微解剖结构重塑影响心脏电传导的方式的大门。
The ventricular myocardium is known to exhibit a complex spatial organization, with fiber orientation varying as a function of transmural location. It is now well established that diffusion tensor magnetic resonance imaging (DTMRI) may be used to measure this fiber orientation at high spatial resolution. Cardiac fibers are also known to be organized in sheets with surface orientation varying throughout the ventricles. This article reviews results on use of DTMRI for measuring ventricular fiber orientation, as well as presents new results providing strong evidence that the tertiary eigenvector of the diffusion tensor is aligned locally with the cardiac sheet surface normal. Considered together, these data indicate that DTMRI may be used to reconstruct both ventricular fiber and sheet organization. This article also presents the large deformation diffeomorphic metric mapping (LDDMM) algorithm and shows that this algorithm may be used to bring ensembles of imaged and reconstructed hearts into correspondence (e.g., registration) so that variability of ventricular geometry, fiber, and sheet orientation may be quantified. Ventricular geometry and fiber structure is known to be remodeled in a range of disease processes; however, descriptions of this remodeling have remained subjective and qualitative. We anticipate that use of DTMRI for reconstruction of ventricular anatomy coupled with application of the LDDMM method for image volume registration will enable the detection and quantification of changes in cardiac anatomy that are characteristic of specific disease processes in the heart. Finally, we show that epicardial electrical mapping and DTMRI imaging may be performed in the same hearts. The anatomic data may then be used to simulate electrical conduction in a computational model of the very same heart that was mapped electrically. This facilitates direct comparison and testing of model versus experimental results and opens the door to quantitative measurement, modeling, and analysis of the ways in which remodeling of ventricular microanatomy influences electrical conduction in the heart.