Tsuchiya Kazuhiro, Imai Masamichi, Tateishi Hidekatsu, Nitatori Toshiaki, Fujikawa Akira, Takemoto Shuhei
Department of Radiology, Kyorin University School of Medicine.
Magn Reson Med Sci. 2007;6(1):1-5. doi: 10.2463/mrms.6.1.
Diffusion-weighted (DW) magnetic resonance (MR) imaging of the nerve roots and peripheral nerves has been reported. We applied a sequence similar to brain diffusion tensor (DT) tractography to such a technique and assessed its feasibility.
On a 1.5-T MR system, we acquired DW images in the axial plane using a single-shot echo-planar short tau inversion-recovery (STIR)-based sequence. Motion-probing gradients (MPGs) were applied in 6 directions with a b-value of 500 s/mm(2). For postprocessing, we performed maximum-intensity projection to reconstruct the images. We obtained cervical spine images from 3 volunteers and 8 patients and thoracolumbar spine images from 3 volunteers and 6 patients. On the source images of the cervical spine obtained from the volunteers, we compared the signal-to-noise ratios (SNRs) of the neural structures between images obtained applying MPG in 6 directions and in 3 directions. We visually assessed the nerve roots and proximal portions of the contiguous peripheral nerves in the images from volunteers and patients.
The SNRs were significantly superior in the images obtained with the application of MPGs in 6 directions to those obtained with the application of MPGs in 3 directions (P<0.01). Visual assessment demonstrated the nerve roots as well as the nerve ganglia and the contiguous peripheral nerves up to 3 cm or more from the respective neural foramina in each subject. Image distortion was minimal.
Our technique provides neurographic images of the nerve roots and proximal portions of the contiguous peripheral nerves, and images obtained using our sequence applying MPGs in 6 directions are superior to those obtained in 3 directions.
已有关于神经根和周围神经的扩散加权（DW）磁共振（MR）成像的报道。我们将一种类似于脑扩散张量（DT）纤维束成像的序列应用于该技术，并评估其可行性。
在1.5-T MR系统上，我们使用基于单次激发回波平面短反转恢复（STIR）的序列在轴位平面采集DW图像。在6个方向上施加运动探测梯度（MPG），b值为500 s/mm²。对于后处理，我们进行最大强度投影以重建图像。我们从3名志愿者和8名患者获取了颈椎图像，从3名志愿者和6名患者获取了胸腰椎图像。在从志愿者获得的颈椎源图像上，我们比较了在6个方向和3个方向施加MPG所获得图像中神经结构的信噪比（SNR）。我们对志愿者和患者图像中的神经根及相邻周围神经的近端进行了视觉评估。
在6个方向施加MPG所获得的图像中，SNR显著优于在3个方向施加MPG所获得的图像（P<0.01）。视觉评估显示了每个受试者中神经根以及神经节和距各自神经孔3 cm或更远的相邻周围神经。图像失真最小。
我们的技术提供了神经根及相邻周围神经近端的神经成像图像，并且使用我们在6个方向施加MPG的序列所获得的图像优于在3个方向获得的图像。
