Chen Yue-Yao, Zhang Xiang, Lin Xiao-Feng, Zhang Fang, Duan Xiao-Hui, Zheng Chu-Shan, Chen Mei-Wei, Wang Dong-Ye, Zeng Wei-Ke, Shen Jun
Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
J Magn Reson Imaging. 2017 Mar;45(3):855-862. doi: 10.1002/jmri.25395. Epub 2016 Jul 23.
To determine the role of diffusion tensor imaging (DTI) metrics as biomarkers for the therapeutic effects of mesenchymal stem cells (MSCs) in acute peripheral nerve injury.
Forty-four adult rats received subepineurial microinjection of MSCs (n = 22) or phosphate buffered saline (PBS, n = 22) 1 week after the sciatic nerve trunk crush injury. Sequential fat-suppressed T2-weighted imaging, T2 measurement, DTI and sciatic nerve functional assessment were performed at a 3.0 Tesla MR unit over an 8-week follow-up, with histological assessments performed at regular intervals. The sciatic nerve function index, T2 value, and DTI metrics, including fractional anisotropy (FA), axial diffusivity, radial diffusivity (RD), and mean diffusivity values of the distal stumps of crushed nerves were measured and compared between the two groups.
Nerves treated with MSCs showed better functional recovery and exhibited more pronounced nerve regeneration compared with nerves treated with PBS. T2 values in nerves treated with MSCs or PBS showed a similar change pattern (P = 0.174), while FA and RD values in nerves treated with MSCs showed more rapid return (one week earlier) to baseline level than nerves treated with PBS (P = 0.045; 0.035). Nerves treated with MSCs had higher FA and lower RD values than nerves treated with PBS during the period from 2 to 3 weeks after surgery (P ≤ 0.0001, 0.004; P = 0.004, 0.006).
FA and RD values derived from DTI might be used as sensitive biomarkers for detecting the therapeutic effect of stem cells in acute peripheral nerve crush injuries.
2 J. Magn. Reson. Imaging 2017;45:855-862.
确定扩散张量成像（DTI）指标作为间充质干细胞（MSCs）治疗急性周围神经损伤疗效生物标志物的作用。
44只成年大鼠在坐骨神经干挤压伤1周后接受神经外膜下微量注射MSCs（n = 22）或磷酸盐缓冲盐水（PBS，n = 22）。在3.0特斯拉磁共振成像设备上进行连续脂肪抑制T2加权成像、T2测量、DTI和坐骨神经功能评估，随访8周，定期进行组织学评估。测量并比较两组大鼠坐骨神经功能指数、T2值以及DTI指标，包括分数各向异性（FA）、轴向扩散率、径向扩散率（RD）和挤压神经远端残端的平均扩散率值。
与PBS治疗的神经相比，MSCs治疗的神经功能恢复更好，神经再生更明显。MSCs或PBS治疗的神经T2值呈现相似的变化模式（P = 0.174），而MSCs治疗的神经FA和RD值比PBS治疗的神经更快（提前1周）恢复到基线水平（P = 0.045；0.035）。术后2至3周期间，MSCs治疗的神经比PBS治疗的神经具有更高的FA值和更低的RD值（P≤0.0001，0.004；P = 0.004，0.006）。
DTI得出的FA和RD值可能用作检测干细胞治疗急性周围神经挤压伤疗效的敏感生物标志物。
2 J.Magn.Reson.Imaging 2017；45：855 - 862。
