title: DTI metrics can be used as biomarkers to determine the therapeutic effect of stem cells in acute peripheral nerve injury.
abstract: 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.
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Yue-Yao
authors.initials: YY
authors.lastname: Chen
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Lin
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Duan
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Chu-Shan
authors.initials: CS
authors.lastname: Zheng
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Mei-Wei
authors.initials: MW
authors.lastname: Chen
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Dong-Ye
authors.initials: DY
authors.lastname: Wang
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Wei-Ke
authors.initials: WK
authors.lastname: Zeng
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Shen
mesh_terms: D000465:Algorithms; D000818:Animals; D056324:Diffusion Tensor Imaging / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D059348:Peripheral Nerve Injuries / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033581:Stem Cell Transplantation / Q000379:methods*; D013234:Stem Cells / Q000473:pathology*; D016896:Treatment Outcome
keywords: diffusion tensor imaging; magnetic resonance imaging; mesenchymal stem cells; peripheral nerve injuries; stem cell transplantation