title: Magnetic resonance neurography in analysis of operative safety of transforaminal lumbar interbody fusion in Chinese subjects.
abstract: OBJECTIVE
  To measure relevant anatomical variables of lumbosacral nerve root and adjacent structures by magnetic resonance neurography (MRN) and analyze operative safety of transforaminal lumbar interbody fusion (TLIF) in Chinese subjects.
  
  
  METHODS
  Twelve normal healthy volunteers (six men, six women) underwent MRN of lumbosacral nerve roots at 3.0 T. Three-dimensional imaging was reconstructed with Osirix software and the following anatomic variables measured: (i) distance between nerve root and upper pedicle; (ii) distance between nerve root and lower pedicle; (iii) angle between nerve root and sagittal plane; (iv) distance between upper and lower nerve roots; and (v) distance between upper and lower pedicles.
  
  
  RESULTS
  Good images of the L(1)-L(5) nerve roots were obtained by MRN technology in all 12 volunteers. The distance between nerve root and upper pedicle and the angle between nerve roots and the sagittal plane gradually diminished from L(1) to L(5). However, there were no significant variations in the distance between nerve root and lower pedicle or between upper and lower pedicles. From L(1 -2) to L(4 -5), the distances between upper and lower pedicles, which are closely related to the operating space for TLIF in Chinese men and women, were less than 10 mm in most subjects and were significantly smaller in women than in men. The variables did not differ significantly between the left and right sides of the same segment.
  
  
  CONCLUSIONS
  Based on the above anatomical study and measurement analysis, we believe that TLIF puts the upper nerve root at risk in some Chinese patients. However, this conclusion requires confirmation by anatomical study of large samples and clinical validation.
authors.affiliation: Department of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Hong-li
authors.initials: HL
authors.lastname: Wang
authors.forename: Jian-yuan
authors.initials: JY
authors.lastname: Jiang
authors.forename: Fei-zhou
authors.initials: FZ
authors.lastname: Lv
authors.forename: Sheng-da
authors.initials: SD
authors.lastname: Yang
authors.forename: Xin
authors.initials: X
authors.lastname: Ma
authors.forename: Wen-jun
authors.initials: WJ
authors.lastname: Chen
authors.forename: Xiao-sheng
authors.initials: XS
authors.lastname: Ma
authors.forename: Xin-lei
authors.initials: XL
authors.lastname: Xia
authors.forename: Li-xun
authors.initials: LX
authors.lastname: Wang
mesh_terms: D000328:Adult; D019412:Anatomy, Cross-Sectional / Q000379:methods; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012016:Reference Values; D012727:Sex Characteristics; D013123:Spinal Fusion / Q000379:methods*; D013126:Spinal Nerve Roots / Q000033:anatomy & histology*; D055815:Young Adult
keywords: Anatomical study; Lumbar vertebrae; Lumbosacral nerve root; Magnetic resonance imaging; Spinal fusion