Prognostic value of early magnetic resonance imaging in dogs after traumatic brain injury: 50 cases

Abstract

Background: The prognostic value of early magnetic resonance imaging (MRI) in dogs after traumatic brain injury (TBI) remains unclear.

Objectives: Determine whether MRI findings are associated with prognosis after TBI in dogs.

Animals: Fifty client-owned dogs.

Methods: Retrospective study of dogs with TBI that underwent 1.5T MRI within 14 days after head trauma. MRI evaluators were blinded to the clinical presentation, and all images were scored based on an MRI grading system (Grade I [normal brain parenchyma] to Grade VI [bilateral lesions affecting the brainstem with or without any lesions of lesser grade]). Skull fractures, percentage of intraparenchymal lesions, degree of midline shift, and type of brain herniation were evaluated. MGCS was assessed at presentation. The presence of seizures was recorded. Outcome was assessed at 48 h (alive or dead) and at 3, 6, 12, and 24 months after TBI.

Results: Sixty-six percent of the dogs had abnormal MRI findings. MRI grade was negatively correlated (P < .001) with MGCS. A significant negative correlation of MRI grade, degree of midline shift, and percentage of intraparenchymal lesions with follow-up scores was identified. The MGCS was lower in dogs with brain herniation (P = .0191). Follow-up scores were significantly lower in dogs that had brain herniation or skull fractures. The possibility of having seizures was associated with higher percentage of intraparenchymal lesions (P = 0.0054) and 10% developed PTE.

Conclusions and clinical importance: Significant associations exist between MRI findings and prognosis in dogs with TBI. MRI can help to predict prognosis in dogs with TBI.

Keywords: Dogs; MRI; Prognostic; Traumatic brain injury.

Figure 1

Brain magnetic resonance imaging (MRI) of dogs with traumatic brain injury. Transverse T2‐weighted images Fast Spin Echo (A–F) showing the MRI grading system. (A) Grade I—normal parenchyma. (B) Grade II—lesions only affecting the cerebral hemisphere, cerebellar parenchyma without midline shift or both. (C) Grade III—lesions only affecting the cerebral hemisphere, cerebellar parenchyma, or both and causing midline shift. (D) Grade IV—lesions affecting corpus callosum, thalamus, or basal nuclei with or without any of the foregoing lesions of lesser grades. (E) Grade V—unilateral lesions in the brainstem with or without any of the foregoing lesions of lesser grades. (F) Grade VI—bilateral lesions affecting the brainstem with or without any of the foregoing lesions of lesser grades.

Figure 2

Box and whisker diagram displaying follow‐up scores at 3 months (A) and at 6 months (B) with magnetic resonance imaging grade.

Figure 3

Box and whisker diagram displaying follow‐up scores at 3 months (A), 6 months (B), 12 months (C), and 24 months (D) with size of intraparenchymal lesions (IP).

Figure 4

Line graph of follow‐up scores at 3, 6, 12, and 24 months in dogs with brain herniation and in dogs without brain herniation (A). Line graph of follow‐up scores at 3, 6, 12, and 24 months in dogs with skull fractures and in dogs without skull fractures (B).