Somatotopic organization of thalamocortical projection fibers as assessed with MR tractography
Somatotopic organization of thalamocortical projection fibers as assessed with MR tractography
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DOI：
10.1148/radiol.2423060297
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发表时间：
2007-03-01
期刊：
影响因子：
19.7
通讯作者：
Nishimura, Tsunehiko
中科院分区：
文献类型：
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作者：
Yamada, Kei;Nagakane, Yoshinari;Nishimura, Tsunehiko
目的：前瞻性地评估通过幕上脑的感觉纤维的过程中，基于弥散张量tractography.Materials和方法：这项研究是由机构审查委员会批准。获得知情同意。7名健康志愿者（5名男性，2名女性;年龄范围，20-55岁）接受了1.5 T磁共振成像。通过使用单次激发回波平面成像技术获得具有各向同性体素（2 x 2 x 2 mm）的扩散张量图像，其中在15个方向上具有运动探测梯度，B值为1000 sec/mm（2），并采集9个信号。总成像时间约为30分钟。结果：所有锥体束在通过半卵圆中心时均向前旋转，并在半卵圆中心的锥体束上有明显的旋转。另一方面，感觉束在穿过半卵圆中心向皮质行进时向后旋转。当感觉运动束被视为一个单位，束的下肢形成的旋转轴周围的其他部分的锥体和感觉homunculusrotated.Conclusion：感觉运动纤维的下肢形成一个旋转轴，锥体纤维旋转向前和感觉纤维旋转向后。
Purpose: To prospectively evaluate the course of sensory fibers through the supratentorial brain with diffusion-tensor based tractography.Materials and Methods: This study was approved by the institutional review board. Informed consent was obtained. Seven healthy volunteers ( five men, two women; age range, 20-55 years) underwent 1.5-T magnetic resonance imaging. Diffusion-tensor images with isotropic voxels ( 2 x 2 x 2 mm) were obtained by using a single-shot echo-planar imaging technique, with a motion-probing gradient in 15 orientations, a b value of 1000 sec/mm(2), and nine signals acquired. The total imaging time was approximately 30 minutes. Fiber tracking of the sensorimotor pathways was performed with the fiber assignment by continuous tracking method.Results: All the pyramidal tracts rotated anteriorly as they traveled through the centrum semiovale. On the other hand, the sensory tracts rotated posteriorly as they coursed through the centrum semiovale toward the cortex. When the sensorimotor tracts were viewed as a unit, the tracts of the lower extremity formed the axis of rotation around which the other parts of the pyramidal and sensory homunculus rotated.Conclusion: Sensorimotor fibers of the lower extremity form an axis of rotation, around which the pyramidal fibers rotate anteriorly and the sensory fibers rotate posteriorly.