Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
Magn Reson Med. 2010 Oct;64(4):1182-90. doi: 10.1002/mrm.22477.
The aim of the present study was to evaluate a fast clinical protocol to enable diffusion tensor imaging of the human forearm and assess the reproducibility of six diffusion tensor imaging parameters, i.e., the tensor eigenvalues (λ(1), λ(2), and λ(3)), mean diffusivity, fractional anisotropy, and ellipsoid eccentricity. The right forearms of 10 healthy volunteers were scanned twice, with a 1-week interval. Reproducibility of the diffusion tensor imaging parameters was interpreted using Bland-Altman plots, coefficient of repeatability, repeatability index, and the intraclass correlation coefficient. Analysis was done for three regions of interest: the whole muscle volume, flexor digitorum profundus, and extensor digitorum. The Bland-Altman analysis showed that there is good agreement between the two measurements. Based on the intraclass correlation coefficients, agreement was substantial (0.59 < intraclass correlation coefficient < 0.92) for all six parameters of the whole muscle volume and flexor digitorum profundus but only fair (0.18 < intraclass correlation coefficient < 0.64) for the extensor digitorum. Using a 7 min 40 sec scan protocol, which was well tolerated by the volunteers, the reproducibility of diffusion tensor imaging parameters was demonstrated. However, repeatability varies, depending on the region of interest and diffusion tensor imaging parameters. This should be taken into account when a longitudinal study is designed.
本研究旨在评估一种快速临床方案，以实现人类前臂的弥散张量成像，并评估六个弥散张量成像参数（即张量本征值(λ(1), λ(2), 和 λ(3))、平均弥散度、各向异性分数和椭圆率）的可重复性。10 名健康志愿者的右侧前臂被扫描两次，间隔为 1 周。使用 Bland-Altman 图、可重复性系数、重复性指数和组内相关系数来解释弥散张量成像参数的可重复性。对三个感兴趣的区域进行了分析：整个肌肉体积、指深屈肌和指伸肌。Bland-Altman 分析表明，两次测量之间有良好的一致性。根据组内相关系数，对于整个肌肉体积和指深屈肌的六个参数，一致性很高（0.59 < 组内相关系数 < 0.92），但对于指伸肌，一致性仅为中等（0.18 < 组内相关系数 < 0.64）。使用志愿者耐受良好的 7 分 40 秒扫描方案，证明了弥散张量成像参数的可重复性。然而，可重复性因感兴趣区域和弥散张量成像参数而异。在设计纵向研究时应考虑到这一点。
