Objective: To review results of MRI performed within 48 hours after head trauma in dogs and identify associations between MRI findings and outcome.
Design: Retrospective case series.
Animals: 18 dogs that underwent MRI within 48 hours after known head trauma.
Procedures: Medical records were reviewed for information on signalment, history, clinical findings, MRI findings, treatment, and outcome.
Results: 2 dogs were euthanized, 1 died, and 1 had major persistent deficits. The remaining 14 dogs had a good outcome, including 9 that recovered completely and 5 that had minor persistent deficits. The most common MRI abnormalities were intra-axial changes (n = 13) and extra-axial hemorrhage (13). Intra-axial changes were best seen on T2-weighted and fluid attenuation inversion recovery (FLAIR) images. A mass effect was detected in 9 dogs, 6 of which had a midline shift (mean, 2.18 mm). Three dogs had transtentorial herniation, and 2 had transcranial herniation. Extra-axial hemorrhage was best seen on FLAIR images. The most common location was subdural, with subdural extra-axial hemorrhage most often seen on the same side as the injury. Epidural hemorrhage was seen in 2 dogs. The affected area was larger in these dogs than in dogs with subdural hemorrhage. One dog required surgery and the other was euthanized.
Conclusions and clinical relevance: Results suggested that in dogs with acute (< 48 hours' duration) head trauma, T2-weighted and FLAIR images provided the most diagnostic information. Dogs with injuries affecting the caudal fossa or affecting both the rostral and caudal fossae typically had poorer outcomes.