title: [Intraoperative sonography for examination of intervertebral disk extrusion in the dog].
abstract: OBJECTIVE
  It has been shown that the components of the vertebral canal (dura mater, pia mater, subarachnoid space, spinal cord parenchyma and central canal) can be visualized intraoperatively with the help of ultrasonography. This study was conducted to document the intraoperative sonographical findings of disc extrusion and to determine imaging criteria for the localisation of the extrusion and the consecutive changes of the spinal cord parenchyma.
  
  
  METHODS
  43 dogs of different breeds with a diagnosed disc extrusion were sonographically examined immediately after establishing the surgical decompression (hemilaminectomy, laminectomy, ventral slot) (examination 1) and again after removal of disc material (examination 2).
  
  
  RESULTS
  In all 34 patients the extruded disc material could be imaged sonographically appearing as inhomogenous, hyperechoic areas of moderate echogenicity. There was a distal shadowing dependent on the grade of calcification in 53% of the patients in examination 1 and in 79% at examination 2. Furthermore, a tendency towards a central localisation of the disc prolapse (67.6% in examination 1 and 57.1% examination 2) was observed. Intraoperative identification of disc extrusion could be accomplished in 79% of the cases. Intraoperative haemorrhage highly significantly impaired the assessment of the spinal cord (p<0.0001).
  
  
  CONCLUSIONS
  Intraoperative spinal ultrasonography using a linear probe with a frequency from 5 to 10 MHz is a valuable tool for the visualization of spinal structures. It provides information for intraspinal navigation and evaluation of the extent of spinal lesions as well as the state of decompression. Bleeding has a negative influence on the visualization of the spinal canal.
authors.affiliation: Klinikum Veterinärmedizin der Justus-Liebig-Universität Gießen, Frankfurter Straße 108, 35392 Gießen. martin.kramer@vetmed.uni-giessen.de
authors.forename: M
authors.initials: M
authors.lastname: Kramer
authors.forename: T
authors.initials: T
authors.lastname: Golla
authors.forename: M J
authors.initials: MJ
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D016063:Blood Loss, Surgical / Q000662:veterinary; D019299:Decompression, Surgical / Q000662:veterinary; D004283:Dog Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D004285:Dogs; D004388:Dura Mater / Q000000981:diagnostic imaging; D005260:Female; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000601:surgery / Q000662:veterinary*; D007430:Intraoperative Care / Q000662:veterinary*; D007796:Laminectomy / Q000662:veterinary; D008297:Male; D010841:Pia Mater / Q000000981:diagnostic imaging; D013115:Spinal Canal / Q000000981:diagnostic imaging; D013116:Spinal Cord / Q000000981:diagnostic imaging; D013346:Subarachnoid Space / Q000000981:diagnostic imaging; D018084:Ultrasonography, Interventional / Q000662:veterinary*