title: Colour Doppler imaging of the interspinous and epidural space.
abstract: OBJECTIVE
  In recent studies, ultrasonic diagnostic imaging has proved useful in the screening of the trajectory of the epidural needle. With regard to possible side-effects of spinal and epidural anaesthesia caused by vessel injury, we aimed to evaluate the usability of Colour Doppler imaging for the depiction of interspinous vessels in prepuncture examination.
  
  
  METHODS
  Ultrasonic examination of the L3/4 interspace area was performed in 20 volunteers. Using a 4-MHz and a 7-MHz probe with B-mode and Colour Doppler imaging, respectively, we compared four settings for the quality of vessel depiction in the puncture area. Overall resolution was evaluated according to the distinction of landmarks. Vascular structures were identified by pulsation (B-mode) or blood flow (Doppler).
  
  
  RESULTS
  Colour Doppler imaging of the L3/4 interspace was unachievable using the 7-MHz transducer. Vessel detection was possible in 50% of the B-mode images and in all of the 4-MHz Doppler images. Vessels were perceptible from a diameter of 0.5 mm. Veins were the predominantly visible structures. Overall vessel visibility was best using 4-MHz Colour Doppler.
  
  
  CONCLUSIONS
  Prepuncture Doppler imaging can provide the epiduralist with information regarding the position of vessels in the needle trajectory. This might help to reduce complications in regional anaesthesia.
authors.affiliation: University of Heidelberg, Department of Anaesthesiology, Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany. thomas_grau@med.uni-heidelberg.de
authors.forename: T
authors.initials: T
authors.lastname: Grau
authors.forename: R W
authors.initials: RW
authors.lastname: Leipold
authors.forename: J
authors.initials: J
authors.lastname: Horter
authors.forename: E
authors.initials: E
authors.lastname: Martin
authors.forename: J
authors.initials: J
authors.lastname: Motsch
mesh_terms: D000328:Adult; D000767:Anesthesia, Epidural / Q000009:adverse effects / Q000379:methods*; D001808:Blood Vessels / Q000293:injuries*; D004824:Epidural Space / Q000098:blood supply / Q000000981:diagnostic imaging*; D005260:Female; D006406:Hematoma / Q000517:prevention & control; D006801:Humans; D008159:Lumbar Vertebrae / Q000098:blood supply / Q000000981:diagnostic imaging*; D008297:Male; D018615:Ultrasonography, Doppler, Color