Computed tomographic evaluation of dynamic alteration of the canine lumbosacral intervertebral neurovascular foramina

Abstract

Positioning the LS junction in full extension decreases the volume of the lumbosacral IVF. This dynamic narrowing was more pronounced in GSDs with signs of DLSS than in GSDs not overtly affected by DLSS.

CT measures of lumbosacral paraspinal muscle size are not correlated with CT measures of lumbosacral stability in military working Labrador Retrievers

“…Since initiation of our study, other studies have reported the use of neutral hip positioning to measure dynamic CT changes in the canine lumbosacral vertebral column . Our study made measurements only from flexed and extended hip positions because of limitations imposed by using dogs and CT scans from a previous study.…”

“…This choice was based on a pilot study and low observer confidence in repeatability for tracing bony margins for calculating parasagittal and parasagittal oblique areas of the middle and exit zones, especially for the L5‐6 and L6‐7 intervertebral foramina. After initiation of our study, a recent publication described a method for quantifying intervertebral foraminal volume changes in dogs using hip flexion/extension CT scans . Whether our results would have been repeatable with this method is unknown.…”

Repeatability of Three-Dimensional Computed Tomographic Volumetric Measurement of Lumbosacral Intervertebral Foramina in German Shepherd Dogs

“…A greater degree of narrowing appears to occur in the presence of degenerative lumbosacral stenosis. 5,6 Greater foraminal narrowing implies increased impingement of the nerve roots and exacerbation of associated clinical signs. 5 The cross-sectional area of the intervertebral neurovascular foramina can be measured in vivo using computed tomography (CT).…”

“…An alternative approach to quantification of the minimal cross-sectional area of a three-dimensional (3D) tunnel is to calculate its volume. A novel technique of volumetric analysis was developed by Worth and colleagues, 6 to generate 3D volumes of the lumbosacral intervertebral neurovascular foramina using CT data. A comparison between German shepherd dogs (GSD) clinically affected by degenerative lumbosacral stenosis and unaffected GSD showed that the foramen was narrowed in extension to a greater degree in the affected dogs.…”

“…Both groups of GSD had smaller lumbosacral intervertebral neurovascular foramina in extension than similarly sized greyhounds. 6 A regression analysis indicated that the method had good intra-observer repeatability but this was for the one individual that had developed the technique and complete blinding to the case records was not possible introducing a potential for bias. Inter-observer repeatability by observers with a range of experience evaluating CT images was not assessed.…”