Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kajii-cho, Kawaramachi Hirokoji Agaru, Kamigyo-ku, Kyoto City, Kyoto, 602-8566, Japan.
Neuroradiology. 2010 Aug;52(8):723-8. doi: 10.1007/s00234-010-0670-0. Epub 2010 Mar 23.
We sought to investigate the optimum b value for resolving crossing fiber using high-angular resolution diffusion imaging (HARDI)-based multi-tensor tractography. The study tested the standard b values that are commonly used in the routine clinical setting.
Ten normal volunteers (five men and five women) with a mean age of 26.3 years (range, 22-32 years) were scanned using a 1.5-T clinical magnetic resonance unit. Single-shot echo-planar imaging was used for diffusion-weighted imaging with a diffusion-sensitizing gradient in 32 orientations. The b values of 700, 1,400, 2,100, and 2,800 s/m(2) were used. Data postprocessing was performed using multi-tensor methods. The depiction of the optic nerves, optic tracts, and decussation of superior cerebellar peduncles were assessed.
The depictions of the nerve fibers were independent of the b values tested.
The depiction of crossing fibers by HARDI-based multi-tensor tractography is not substantially influenced by b values ranging from 700 to 2,800 s/m(2). Thus, the optimum b value within this range may be the lowest one considering the higher signal to noise ratio.
我们旨在研究使用基于高角分辨率扩散成像（HARDI）的多张量追踪技术来解决交叉纤维的最佳 b 值。本研究测试了常规临床设置中常用的标准 b 值。
10 名正常志愿者（男 5 名，女 5 名），平均年龄 26.3 岁（范围 22-32 岁），在 1.5T 临床磁共振仪上进行扫描。单次激发回波平面成像用于扩散加权成像，扩散敏感梯度在 32 个方向上。使用了 700、1400、2100 和 2800 s/m 2 的 b 值。使用多张量方法进行数据后处理。评估了视神经、视束和上小脑脚交叉的描绘。
纤维的描绘与测试的 b 值无关。
基于 HARDI 的多张量追踪技术对交叉纤维的描绘不受 700 至 2800 s/m 2 范围内 b 值的显著影响。因此，考虑到更高的信噪比，该范围内的最佳 b 值可能是最低值。
