Myelo‐CT imaging findings in 15 dogs with surgically‐treated cervical acute compressive hydrated nucleus pulposus extrusion

Abstract Compressive hydrated nucleus pulposus extrusion (HNPE) is a sudden extrusion of hydrated, nondegenerated nucleus pulposus material with well‐known characteristic MRI findings. The appearance of compressive HNPE during contrast‐enhanced CT has already been described, but never its myelo‐CT characteristics. The aim of this retrospective multicenter case series is to describe the myelo‐CT findings in 15 dogs with compressive HNPE confirmed with gross surgical findings. A distinctive and consistent myelo‐CT appearance of cervical compressive HNPE in dogs that included a focal extradural “seagull”‐shaped extradural compression dorsal to the annulus fibrosus combined with a narrowing of the affected intervertebral disc space was found. The extruded material was hypoattenuating in the soft tissue algorithm. Myelo‐CT could be a useful diagnostic tool and influence the clinical decision to address cervical compressive HNPE conservatively or surgically when MRI is not available.