Magnetic Resonance Imaging Features of Discospondylitis in Dogs

Abstract

The diagnosis of discospondylitis is based mainly on diagnostic imaging and laboratory results. Herein, we describe the magnetic resonance imaging (MRI) findings in 13 dogs with confirmed discospondylitis. In total there were 17 sites of discospondylitis. Eleven (81.1%) of the dogs had spinal pain for >3 weeks and a variable degree of neurologic signs. Two dogs had spinal pain and ataxia for 4 days. Radiographs were available in nine of the dogs. In MR images there was always involvement of two adjacent vertebral endplates and the associated disk. The involved endplates and adjacent marrow were T1-hypointense with hyperintensity in short tau inversion recovery (STIR) images in all dogs, and all dogs also had contrast enhancement of endplates and paravertebral tissues. The intervertebral disks were hyperintense in T2W and STIR images and characterized by contrast enhancement in 15 sites (88.2%). Endplate erosion was present in 15 sites (88.2%) and was associated with T2-hypointense bone marrow adjacent to it. In two sites (11.8%) endplate erosion was not MR images or radiographically. The vertebral bone marrow in these sites was T2-hyperintense. Epidural extension was conspicuous in postcontrast images at 15 sites (88.2%). Spinal cord compression was present at 15 sites (88.2%), and all affected dogs had neurologic signs. Subluxation was present in two sites (11.8%). MRI shows characteristic features of discospondylitis, and it allows the recognition of the exact location and extension (to the epidural space and paravertebral soft tissues) of the infection. Furthermore, MRI increases lesion conspicuity in early discospondylitis that may not be visualized by radiography.

Medical management of spinal epidural empyema in five dogs

“…13,14,[20][21][22][23][24][25] Similarly, MRI findings were consistent with those previously reported for dogs with spinal epidural empyema, including hyperintense extradural lesions on T2-weighted images and contrast enhancement in a diffuse or ring-like pattern on T1-weighted images after IV administration of gadolinium-based contrast medium. 5,13,18,19 However, lesions on precontrast T1-weighted images varied from mildly hyperintense (dogs 1, 2, and 3) to hypointense (dogs 4 and 5). In veterinary patients, lesions associated with spinal epidural empyema have previously been reported to be hypointense on T1-weighted images.…”

“…27,28 Experimental studies 27,29 have suggested that compression plays a larger role than ischemia, because neurologic improvement is observed after surgical decompression, and in dogs, diskospondylitis results in neurologic deficits when granulation tissue extends into the spinal canal, causing compression. 18 However, a study 1 examining spinal cord compression associated with diskospondylitis found that the degree of spinal cord compression did not correlate with the severity of neurologic signs and the outcome was similar between dogs treated with decompressive surgery and those managed medically. In the present case series, one of the dogs with the most severe neurologic deficits had a minimally compressive lesion (dog 2), and another dog (dog 4) with no deep pain sensation in the pelvic limbs nevertheless made a full recovery without surgery.…”

CLINICAL AND DIAGNOSTIC IMAGING FINDINGS IN AN ITALIAN WOLF (CANIS LUPUS ITALICUS) WITH DISCOSPONDYLITIS

“…Percutaneous aspiration of disc or biopsy may have a higher success range. 4 Hematogenous spread is responsible for a large number of discospondylitis lesions. A less common route of infection is by penetrating wounds or by migrating plant material.…”

Pathological findings in low-field magnetic resonance imaging of the canine spine – a study of 112 patients

“…Magnetic resonance imaging, the golden standard in diagnosing pathological changes in the spine, supports 3D visualization, diagnosis of epidural and intradural diseases and earlier detection of changes than in conventional radiography (Carrera et al 2011). The changes visible in radiographic images, such as narrowing of the space between intervertebral…”