title: Predictions of the length of lumbar puncture needles.
abstract: BACKGROUND
  The lumbar puncture is a well-known neurological procedure. The purpose of this study is to build an accurate mathematical formula to estimate the appropriate depth for inserting a lumbar puncture needle for a beginner.
  
  
  METHODS
  This is a retrospective study of patients who underwent magnetic resonance imaging (MRI) of the L-spine. The depth from the skin to the posterior and anterior margin of the spinal canal at the level of L4-L5 and L3-L4 interspaces of the spine was estimated using MRI.
  
  
  RESULTS
  Three hundred sixty-eight patients aged between 20 and 89 years were studied. The optimal puncture depths of the lumbar puncture needle were moderately strongly related to weight and BMI. The most accurate models with the highest coefficient of determination were 1.27 + 0.18 × BMI and 1.68 + 0.067 × weight (kg) for man and woman, respectively.
  
  
  CONCLUSIONS
  The best formula for men and women provides the most accurate estimates for adults based on the MRI of the L-spine.
authors.affiliation: Emergency Department, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Road, Zhonghe District, New Taipei City 235, Taiwan ; Department of Emergency Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Hon-Ping
authors.initials: HP
authors.lastname: Ma
authors.affiliation: Emergency Department, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Road, Zhonghe District, New Taipei City 235, Taiwan ; Graduate Institute of Injury Prevention and Control, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yun-Fei
authors.initials: YF
authors.lastname: Hung
authors.affiliation: Emergency Department, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Road, Zhonghe District, New Taipei City 235, Taiwan ; Department of Emergency Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan ; Graduate Institute of Injury Prevention and Control, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan.
authors.forename: Shin-Han
authors.initials: SH
authors.lastname: Tsai
authors.affiliation: Emergency Department, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Road, Zhonghe District, New Taipei City 235, Taiwan.
authors.forename: Ju-chi
authors.initials: JC
authors.lastname: Ou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008159:Lumbar Vertebrae / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009339:Needles / Q000592:standards*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013129:Spinal Puncture / Q000295:instrumentation*