Case Report: Cervical internal vertebral venous plexus thrombosis diagnosed using time-of-flight magnetic resonance angiography in a dog

Background: Time-of-Flight (TOF) magnetic resonance angiography (MRA) is a non-contrast imaging technique used for vascular assessment but underexplored in veterinary spinal imaging. This case report presents the use of TOF-MRA at 3 Tesla to diagnose cervical internal vertebral venous plexus (IVVP) thrombosis in a dog, advancing the application of three-dimensional imaging in veterinary neurology. Case presentation: A 13-year-old castrated male Siberian Husky presented with acute cervical pain, left thoracic limb lameness, and generalized tonic-clonic epileptic seizures. Laboratory findings revealed mild neutrophilia (10.83 × 10^9/L), elevated fibrinogen (404 mg/dL), and a urinary tract infection (bacteriuria, leukocyturia, and proteinuria). Diagnosis and outcome: Pre- and post-contrast MRI examination of the head revealed no abnormalities of the brain. A delayed post-contrast conventional T2-weighted MRI sequence of the cervical spine demonstrated focal loss of normal flow void of the left IVVP at the C4-C5 level. Three-dimensional TOF-MRA showed a corresponding focal signal void in the left ventral IVVP from C4 to C5 and an associated venous dilation consistent with thrombosis. Conclusion: This case demonstrates TOF-MRA's potential as a non-invasive, contrast-free method for diagnosing spinal venous thrombosis in dogs. It underscores the importance of vascular imaging in dogs with acute neurological signs, offering valuable insights for veterinary practice and future research.