title: Evaluation of radiation-induced peripheral nerve injury in rabbits with MR neurography using diffusion tensor imaging and T2 measurements: Correlation with histological and functional changes.
abstract: To investigate the potential of diffusion tensor imaging (DTI) and T2 measurements in the evaluation of radiation-induced peripheral nerve injury (RIPNI).
  
  
  
  RIPNI was produced in a randomly selected side of sciatic nerve in each of 21 rabbits while the contralateral side served as the control. The limb function and MR parameters were evaluated over a 4-month period. Fractional anisotropy (FA), axial diffusivity (λ∥ ), radial diffusivity (λ⊥ ) and T2 values were obtained using 3T MR for quantitative analysis. Two animals were randomly killed for histological evaluation at each timepoint.
  
  
  
  The T2 value of irradiated nerve increased at 1 day (63.95 ± 15.60, P = 0.012) and was restored at 1 month (52.34 ± 5.38, P = 0.105). It increased progressively at 2 to 4 months (60.39 ± 10.60, 66.96 ± 6.08, 75.51 ± 7.39, all P < 0.01). λ⊥ significantly increased at 1 day (0.82 ± 0.44, P = 0.046) and slightly decreased at 1 month (0.61 ± 0.17, P < 0.001). It increased gradually from 2 to 3 months (0.84 ± 0.29, 1.13 ± 0.33, both P < 0.001) followed by a decline at 4 months (0.83 ± 0.17, P < 0.001). FA was statistically lower than the contralateral sides at 1 to 4 months (0.72 ± 0.08, 0.60 ± 0.12, 0.51 ± 0.11, 0.62 ± 0.06, all P < 0.01). Changes in FA and λ⊥ correlated well with the functional and pathological changes in irradiated nerve.
  
  
  
  DTI may be a more sensitive and accurate method to evaluate RIPNI compared with T2 measurements. FA and λ⊥ are promising quantitative indices in monitoring RIPNI. J. Magn. Reson. Imaging 2016;43:1492-1499.
authors.affiliation: Department of Radiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wan
authors.affiliation: Department of Radiology, Medical Center of University of Chicago, Chicago, Illinois, USA.
authors.forename: Shiyang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Radiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Jiaxuan
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Radiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Zou
authors.affiliation: Department of Radiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Yingshi
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Radiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Shouyang
authors.initials: S
authors.lastname: Wang
authors.affiliation: 75660 Unit, Xiangshan District, Guilin, Guangxi, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Radiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Xinchun
authors.initials: X
authors.lastname: Li
mesh_terms: D000818:Animals; D003943:Diagnostic Techniques, Neurological; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D059348:Peripheral Nerve Injuries / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D011817:Rabbits; D011832:Radiation Injuries / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic
keywords: diffusion tensor imaging; magnetic resonance imaging; peripheral nerve; rabbits; radiation injuries