Review of the use of transrectal ultrasonography for evaluation of the caudal lumbar – including lumbosacral – intervertebral discs and symphyses: Normal and abnormal ultrasonographic appearance

Summary Transrectal ultrasonography of the lumbosacroiliac area is routinely performed for the diagnosis of the cause of low back pain and poor hindlimb impulsion and engagement. The ventral aspect of the caudal lumbar intervertebral discs and vertebrae can be easily assessed transrectally with ultrasound while other imaging modalities have limitations for diagnosis of intervertebral disc injuries. This paper is a review of the ultrasonographic procedure for imaging the ventral aspect of the caudal lumbar and lumbosacral symphyses, especially the intervertebral discs. Normal images, findings and lesions of the three caudalmost lumbar intervertebral discs are described (between the 4th lumbar and the 1st sacral vertebrae).