title: Needle echogenicity in ultrasound-guided lumbar spine injections: a cadaveric study.
abstract: BACKGROUND
  Echogenicity of regional anesthesia needles has been tested on different preclinical models; however, previous studies were done in an ideal experimental setting utilizing high-frequency insonation and superficially located targets. Because steep-angle deep injections are typically required for spinal and other chronic pain procedures, and low-frequency transducers are used, further feasibility study is warranted.
  
  
  OBJECTIVE
  To determine effectiveness of steep-angle deep injections, typically required for spinal and other chronic pain procedures.
  
  
  METHODS
  Experimental laboratory study.
  
  
  METHODS
  Willed Body Program, University of Washington.
  
  
  METHODS
  In-plane lumbar spine procedures with 50° and 70° angles were performed on a human cadaver. The images and video clips of a non-echogenic (Quincke-type) and echogenic (SonoPlex, StimuQuick, and EchoStim) needle placements were presented to 3 blinded assessors who rated the needle visibility on a 4-point scale. The data was statistically analyzed to determine the differences in visibility between the needles with and without the digital image enhancement, and to compare the video clips to captured images.
  
  
  RESULTS
  ANOVA analysis demonstrated that overall SonoPlex was significantly better (P = 0.02) than other needles. SonoPlex maintained its superiority in the subset of facet joint injections (P = 0.02), followed by Quincke-type, then the StimuQuik, and EchoStim needles. In deep procedures, EchoStim was comparable with SonoPlex (P = 0.03), and they both were better than the other 2 needles. The enhanced images received higher rates, with a 0.6 point mean improved rating (P = 0).
  
  
  CONCLUSIONS
  This study is limited by choice of needles, number of experiments performed, and potential postmortem changes of echogenicity.
  
  
  CONCLUSIONS
  The SonoPlex needle appeared to have better echogenicity in this study. While non-echogenic Quincke-type needle visibility was adequate in superficial placements, it was limited in deep injections. An imaging enhancement is effective in improving needle visibility and should be used whenever possible.
authors.affiliation: Department of Anesthesiology and Pain Medicine University of Washington, Seattle, WA.
authors.forename: Michael
authors.initials: M
authors.lastname: Gofeld
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Krashin
authors.forename: Sangmin
authors.initials: S
authors.lastname: Ahn
mesh_terms: D000775:Anesthesia, Spinal / Q000295:instrumentation*; D002102:Cadaver; D006801:Humans; D008159:Lumbar Vertebrae; D009339:Needles; D018084:Ultrasonography, Interventional / Q000295:instrumentation*