title: Thoracolumbar intradural disc herniation in eight dogs: clinical, low-field magnetic resonance imaging, and computed tomographic myelography findings.
abstract: Intradural disc herniation is a rarely reported cause of neurologic deficits in dogs and few published studies have described comparative imaging characteristics. The purpose of this retrospective cross sectional study was to describe clinical and imaging findings in a group of dogs with confirmed thoracolumbar intradural disc herniation. Included dogs were referred to one of four clinics, had acute mono/paraparesis or paraplegia, had low field magnetic resonance imaging (MRI) and/or computed tomographic myelography, and were diagnosed with thoracolumbar intradural disc herniation during surgery. Eight dogs met inclusion criteria. The prevalence of thoracolumbar intradural disc herniation amongst the total population of dogs that developed a thoracolumbar intervertebral disc herniation and that were treated with a surgical procedure was 0.5%. Five dogs were examined using low-field MRI. Lesions that were suspected to be intervertebral disc herniations were observed; however, there were no specific findings indicating that the nucleus pulposus had penetrated into the subarachnoid space or into the spinal cord parenchyma. Thus, the dogs were misdiagnosed as having a conventional intervertebral disc herniation. An intradural extramedullary disc herniation (three cases) or intramedullary disc herniation (two cases) was confirmed during surgery. By using computed tomographic myelography (CTM) for the remaining three dogs, an intradural extramedullary mass surrounded by an accumulation of contrast medium was observed and confirmed during surgery. Findings from this small sample of eight dogs indicated that CTM may be more sensitive for diagnosing canine thoracolumbar intradural disc herniation than low-field MRI.
authors.affiliation: Tamura Animal Clinic, 7-16 Yoshimien, Saeki-ku, Hiroshima, 731-5132, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Tamura
authors.forename: Shoko
authors.initials: S
authors.lastname: Doi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Tamura
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Takahashi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Enomoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ozawa
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Uchida
mesh_terms: D000818:Animals; D003287:Contrast Media; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000175:diagnosis*; D004285:Dogs; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007405:Intervertebral Disc Displacement / Q000175:diagnosis / Q000662:veterinary*; D008159:Lumbar Vertebrae / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D009192:Myelography / Q000662:veterinary; D020335:Paraparesis / Q000662:veterinary; D010264:Paraplegia / Q000662:veterinary; D010291:Paresis / Q000662:veterinary; D012189:Retrospective Studies; D013904:Thoracic Vertebrae / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000662:veterinary
chemical_list: D003287:Contrast Media
keywords: CT myelography; MRI; dog; intradural disc herniation