title: EVALUATION OF MAGNETIC RESONANCE IMAGING GUIDELINES FOR DIFFERENTIATION BETWEEN THORACOLUMBAR INTERVERTEBRAL DISK EXTRUSIONS AND INTERVERTEBRAL DISK PROTRUSIONS IN DOGS.
abstract: Four MRI variables have recently been suggested to be independently associated with a diagnosis of thoracolumbar intervertebral disk extrusion or protrusion. Midline intervertebral disk herniation, and partial intervertebral disk degeneration were associated with intervertebral disk protrusion, while presence of a single intervertebral disk herniation and disk material dispersed beyond the boundaries of the intervertebral disk space were associated with intervertebral disk extrusion. The aim of this retrospective, cross-sectional study was to determine whether using these MRI variables improves differentiation between thoracolumbar intervertebral disk extrusions and protrusions. Eighty large breed dogs with surgically confirmed thoracolumbar intervertebral disk extrusions or protrusions were included. Randomized MRI studies were presented on two occasions to six blinded observers, which were divided into three experience categories. During the first assessment, observers made a presumptive diagnosis of thoracolumbar intervertebral disk extrusion or protrusion without guidelines. During the second assessment they were asked to make a presumptive diagnosis with the aid of guidelines. Agreement was evaluated by Kappa-statistics. Diagnostic accuracy significantly improved from 70.8 to 79.6% and interobserver agreement for making a diagnosis of intervertebral disk extrusion or intervertebral disk protrusion improved from fair (κ = 0.27) to moderate (κ = 0.41) after using the proposed guidelines. Diagnostic accuracy was significantly influenced by degree of observer experience. Intraobserver agreement for the assessed variables ranged from fair to excellent and interobserver agreement ranged from fair to moderate. The results of this study suggest that the proposed imaging guidelines can aid in differentiating thoracolumbar intervertebral disk extrusions from protrusions.
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England. sdedecker@rvc.ac.uk.
authors.forename: Steven
authors.initials: S
authors.lastname: De Decker
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Gomes
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: Rowena Ma
authors.initials: RM
authors.lastname: Packer
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Kenny
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: Elsa
authors.initials: E
authors.lastname: Beltran
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: Birgit
authors.initials: B
authors.lastname: Parzefall
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: Joe
authors.initials: J
authors.lastname: Fenn
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: Devi
authors.initials: D
authors.lastname: Nair
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: George
authors.initials: G
authors.lastname: Nye
authors.affiliation:  Department of Veterinary Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA North Mymms, Hatfield, England.
authors.forename: Holger A
authors.initials: HA
authors.lastname: Volk
mesh_terms: D000818:Animals; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000000981:diagnostic imaging*; D004285:Dogs; D005260:Female; D017408:Guidelines as Topic; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000662:veterinary*; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000662:veterinary*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary*; D008297:Male; D012189:Retrospective Studies
keywords: accuracy; agreement; intervertebral disk disease; intervertebral disk herniation; reliability