Gilbert Richard J, Wedeen Van J, Magnusson Lee H, Benner Thomas, Wang Ruopeng, Dai George, Napadow Vitaly J, Roche Kenneth K
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge 02139, USA.
Anat Rec A Discov Mol Cell Evol Biol. 2006 Nov;288(11):1173-82. doi: 10.1002/ar.a.20387.
The anatomy of the mammalian tongue consists of an intricate array of variably aligned and extensively interwoven muscle fibers. As a result, it is particularly difficult to resolve the relationship between the tongue's microscopic anatomy and tissue-scale mechanical function. In order to address this question, we employed a method, diffusion spectrum imaging (DSI) with tractography, for displaying the macroscopic orientational properties of the tissue's constituting myofibers. DSI measures spatially variant proton displacement for a given 3D imaging segment (voxel), reflecting the principal orientation(s) of its myofibers. Tractography uses the angular similarity displayed by the principal fiber populations of multiple adjacent voxels to generate tract-like structures. DSI with tractography thus defines a unique set of tracts based on the net orientational behavior of the myofiber populations at different positions in the tissue. By this approach, we demonstrate a novel myoarchitectural pattern for the bovine tongue, consisting of short and orthogonally aligned crossing fiber tracts in the intrinsic core region, and longer, parallel-aligned fiber tracts on the tissue margins and in the regions of extrinsic fiber insertion. The identification of locally aligned myofiber populations by DSI with tractography allows us to reconsider lingual anatomy, not in conventional microscopic terms, but as a set of heterogeneously aligned and macroscopically resolved myofiber tracts. We postulate that the properties associated with these myofiber tracts predict the mechanical behavior of the tissue and thus constitute a method to relate structure and function for anatomically complex muscular tissues.
哺乳动物舌头的解剖结构由一系列错综复杂、排列方向各异且相互交织广泛的肌纤维组成。因此，要解析舌头的微观解剖结构与组织尺度力学功能之间的关系尤为困难。为了解决这个问题，我们采用了一种方法，即带有纤维束成像的扩散光谱成像（DSI），来显示构成组织的肌纤维的宏观取向特性。DSI测量给定三维成像段（体素）的空间变化质子位移，反映其肌纤维的主要取向。纤维束成像利用多个相邻体素的主要纤维群所显示的角度相似性来生成束状结构。因此，带有纤维束成像的DSI基于组织中不同位置的肌纤维群的净取向行为定义了一组独特的纤维束。通过这种方法，我们展示了牛舌一种新的肌构筑模式，其固有核心区域由短且正交排列的交叉纤维束组成，而在组织边缘和外部纤维插入区域则有更长的平行排列纤维束。通过带有纤维束成像的DSI识别局部排列的肌纤维群，使我们能够重新审视舌部解剖结构，不是从传统的微观角度，而是将其视为一组异质排列且宏观可分辨的肌纤维束。我们推测，与这些肌纤维束相关的特性预测了组织的力学行为，从而构成了一种将解剖结构复杂的肌肉组织的结构与功能联系起来的方法。
