Magnetic Resonance Imaging of the Caudal Lumbar and Lumbosacral Spine in 13 Dogs (1990–1993)

Abstract

The caudal lumbar and lumbosacral spine of 13 dogs with pain or neurologic deficits were evaluated using magnetic resonance imaging (MRI). Spin echo T1, proton density, and T2 weighted and gradient echo T2* imaging sequences were utilized. MRI permitted direct, multiplanar, tomographic visualization of the spine facilitating evaluation of all components of degenerative caudal lumbar and lumbosacral stenosis. Abnormalities detected included intervertebral disc degeneration, intervertebral disc protrusion involving both the vertebral canal and intervertebral foramina, articular process osteophytosis, articular process fracture, nerve root impingement by spondylosis deformans, and the presence of low signal material within the vertebral canal of 2 dogs with recurrent pain following previous spinal surgery. In all 7 dogs treated surgically, MRI findings were consistent with surgical findings.

Lumbosacral disease

“…Postoperative scarring has been reported in several studies (Adams et al, 1995;Danielsson and Sjostrom, 1999;. Herniation of the dural sac through the laminectomy defect has also been reported; this may be secondary to tearing of the dura (Lang, 1988;Markwalder, 1993;Fox et al, 1996).…”

“…Slice thickness is often greater than for CT, however, which increases volume averaging artefacts . Transverse images provide the best visualization of disc or foraminal anatomy (Adams et al, 1995) (1.9). They also reveal lesions in a foramen that cannot be detected by myelography or epidurography (Chambers et al, 1997).…”

“…MRI is the best, single imaging modality overall for humans (Kent et al, 1992). The position of the dog in the scanner can be very important; a neutral or flexed position reduces compression compared to an extended position (Adams et al, 1995;. If CT or MRI is not available, myelography is performed followed by discography and epidurography if necessary (Sisson et al, 1992;Sjostrum, 2003).…”

“…An increase in soft tissue within the foramen, loss of epidural fat or facet osteophytosis are indicators of probable radiculopathy (Adams et al, 1995;Jones et al, 1996b). Contrast enhancement after CT or MRI further increases preoperative suspicion of foraminal disease (Jones et al, 1999 (10.40).…”

Visualization of the Topographical Structure of the Anesthetized Mouse Brain by MR Microimaging.

“…In brief, Magnetic resonance imaging (MRI) is now widely employed as a useful technique for clinical diagnosis in veterinary medicine much as in human medicine [1,3,11,12]. This non-invasive technique is quite useful for medium-sized animals, but it is hard to visualize the detailed structures in tissues and organs of small laboratory animals such as rats and mice since they must be imaged by small voxels with weak MR signals and low signal/noise (S/N) ratios [5,12].…”