title: Association of preoperative magnetic resonance imaging findings with surgical features in Dachshunds with thoracolumbar intervertebral disk extrusion.
abstract: OBJECTIVE
  To evaluate the accuracy of specific magnetic resonance imaging (MRI) sequences in determining the site, lateralization, and extent of extruded intervertebral disk material (EIDM), compared with surgical findings, in Dachshunds with thoracolumbar intervertebral disk extrusion (TLIDE).
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  16 Dachshunds with clinical signs of intervertebral disk disease.
  
  
  METHODS
  Preoperative T1-weighted, T2-weighted, and short tau inversion recovery (STIR) MRI measurements and description of the location of EIDM were compared with intraoperative measurements and determination of the EIDM position.
  
  
  RESULTS
  The T12-13 intervertebral disk space was the most frequent site of EIDM (6/16 dogs). The EIDM lateralized with equal frequency to the left and right sides; no central extrusions were seen. There was moderate to substantial agreement (kappa, 0.59) between MRI and surgical findings for evaluation of the craniocaudal distribution of the EIDM. For measurement of the length of EIDM, the T1-weighted, T2-weighted, and STIR sequences had a mean error of -1.15, -0.38, and -1.93 mm, respectively; concordance correlation coefficients were 0.666, 0.904, and 0.458, respectively. Mean absolute errors were 2.54, 1.35, and 2.90 mm, respectively; these values did not differ significantly.
  
  
  CONCLUSIONS
  In the thoracolumbar vertebral column of Dachshunds with clinical signs of intervertebral disk disease, MRI is a valuable technique for determining location and craniocaudal length of EIDM. Compared with T1-weighted and STIR images, T2-weighted images appeared to be more accurate and precise and are potentially more reliable for determination of the length of EIDM in those dogs.
authors.affiliation: Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa, 0110.
authors.forename: Stephanus H
authors.initials: SH
authors.lastname: Naudé
authors.forename: Nicolaas E
authors.initials: NE
authors.lastname: Lambrechts
authors.forename: Wencke M
authors.initials: WM
authors.lastname: Wagner
authors.forename: Peter N
authors.initials: PN
authors.lastname: Thompson
mesh_terms: D000818:Animals; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000175:diagnosis* / Q000601:surgery; D004285:Dogs; D005260:Female; D007403:Intervertebral Disc / Q000473:pathology*; D007405:Intervertebral Disc Displacement / Q000175:diagnosis / Q000601:surgery / Q000662:veterinary*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards / Q000662:veterinary*; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013904:Thoracic Vertebrae; D016896:Treatment Outcome