title: EFFECTS OF IMAGE PLANE, PATIENT POSITIONING, AND FORAMINAL ZONE ON MAGNETIC RESONANCE IMAGING MEASUREMENTS OF CANINE LUMBOSACRAL INTERVERTEBRAL FORAMINA.
abstract: Degenerative lumbosacral stenosis has been suspected to have a dynamic component, especially regarding encroachment of the L7 nerve roots exiting the lumbosacral foramina. Angled cross-sectional imaging of the neuroforamina has been found improve the accuracy of the diagnosis of stenosis in humans. In this anatomic study, foraminal apertures were evaluated by MRI at the entry, middle, and exit zones of the nerve roots in 30 dogs that were clinically affected by lumbosacral disease. Standard vs. oblique planar orientation and neutral vs. hyperextended positioning of the lumbosacral area were compared by measuring the median values for entry, middle, and exit zones. The neuroforaminal area acquired using oblique plane acquisition was significantly smaller than standard parasagittal measurements. Furthermore, standard parasagittal neuroforaminal dimensions in the hyperextended position were significantly smaller than standard parasagittal measurements in the neutral position. This statistical difference was even more pronounced for neuroforaminal dimension evaluated in the oblique plane and hyperextended position. Positioning of the dog during imaging has a significant effect on neuroforaminal dimension, corroborating the notion that spinal position may influence neural claudication in clinically affected patients. Reductions in neuroforaminal dimension are more evident on oblique planar image acquisition, suggesting that this approach may be more useful than parasagittal imaging as a tool for identifying subtle changes in L7 neuroforaminal dimensions in cases of canine lumbosacral stenosis.
authors.affiliation: Fitzpatrick Referrals Ltd., Godalming, Surrey, GU7 2QQ, UK.
authors.forename: Claudia
authors.initials: C
authors.lastname: Zindl
authors.affiliation: Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164, UK.
authors.forename: Russell L
authors.initials: RL
authors.lastname: Tucker
authors.affiliation: Fitzpatrick Referrals Ltd., Godalming, Surrey, GU7 2QQ, UK.
authors.forename: Jelena
authors.initials: J
authors.lastname: Jovanovik
authors.affiliation: School of Veterinary Medicine, University of Surrey, Guildford, Surrey, GU2 7XH, UK.
authors.forename: Constanza
authors.initials: C
authors.lastname: Gomez Alvarez
authors.affiliation: Department of Veterinary Medicine, Disease Dynamics Unit, University of Cambridge, Cambridge, CB3 0ES, UK.
authors.forename: David
authors.initials: D
authors.lastname: Price
authors.affiliation: Fitzpatrick Referrals Ltd., Godalming, Surrey, GU7 2QQ, UK.
authors.forename: Noel
authors.initials: N
authors.lastname: Fitzpatrick
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging*; D004285:Dogs; D005260:Female; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008161:Lumbosacral Region / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary*; D008297:Male; D056888:Patient Positioning / Q000662:veterinary; D012447:Sacrum / Q000000981:diagnostic imaging; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000662:veterinary*
keywords: MRI; dogs; hyperextended position; lumbosacral foraminal stenosis; sagittal oblique plane