title: Agreement and repeatability of linear vertebral body and canal measurements using computed tomography (CT) and low field magnetic resonance imaging (MRI).
abstract: OBJECTIVE
  To evaluate agreement and repeatability of vertebral column measurements using computed tomography (CT) and magnetic resonance imaging (MRI).
  
  
  METHODS
  Retrospective observational study. ANIMALS; Dogs (n=18) with disc associated wobbler syndrome; Dog cadavers (n=3).
  
  
  METHODS
  Five measurements of the 5th cervical vertebra were performed: vertebral body length (VBL), vertebral canal height (VCH), vertebral body height (VBH), vertebral canal width (VCW), and vertebral body width (VBW). Measurements were performed independently twice by 2 observers. Bland-Altman plots were created to evaluate agreement. Cadaveric vertebrae with soft tissue removed had the same variables and actual dimensions measured.
  
  
  RESULTS
  The largest discrepancy between CT and MRI measurement was for VBL (mean difference+/-SD=1.262 mm+/-1.245; P<.001), with the difference for all the other variables being acceptable. The 1st measurement was significantly higher than the 2nd only for VBL using CT (mean difference=0.476 mm+/-1.120; P=.009), with all other variables having acceptable differences. Mean difference for all measurements between 2 observers was small, except for VBL using CT (mean difference=0.762 mm+/-1.042; P<.001). Only the difference for VBL between CT and cadaver specimens was statistically significant.
  
  
  CONCLUSIONS
  Our results suggest high repeatability and good agreement for most vertebral measurements of interest. VBL measurement using CT was considered problematic.
  
  
  CONCLUSIONS
  Provided limitations are understood, linear measurements of vertebral dimensions from CT and MRI images can be used clinically.
authors.affiliation: Faculty of Veterinary Medicine, Ghent University, Department of Small Animal Medicine and Clinical Biology, Merelbeke, Belgium. steven.dedecker@ugent.be
authors.forename: Steven
authors.initials: S
authors.lastname: De Decker
authors.forename: Ingrid M V L
authors.initials: IM
authors.lastname: Gielen
authors.forename: Luc
authors.initials: L
authors.lastname: Duchateau
authors.forename: Ingeborgh
authors.initials: I
authors.lastname: Polis
authors.forename: Henri J J
authors.initials: HJ
authors.lastname: Van Bree
authors.forename: Luc M L
authors.initials: LM
authors.lastname: Van Ham
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D004285:Dogs / Q000033:anatomy & histology*; D005260:Female; D008279:Magnetic Resonance Imaging / Q000662:veterinary*; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013115:Spinal Canal / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary; D013131:Spine / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000662:veterinary*