CT findings and the prognostic value of the Koret CT score in cats with traumatic brain injury

Abstract

Objectives: The aims of this study were to evaluate associations between abnormal head CT findings and outcome, and to examine the prognostic value of the Koret CT score (KCTS) in cats sustaining acute traumatic brain injury (TBI).

Methods: The medical records of cats hospitalised with TBI that underwent head CT scans within 72 h of admission were retrospectively reviewed. CT scans were evaluated independently by a radiologist and a neurologist who were blinded to the outcome. A KCTS and modified Glasgow Coma Scale (MGCS) were assigned to each cat and the association between abnormal CT findings, KCTS, MGCS and outcome were analysed.

Results: Fourteen cats were included in the study: nine (64.2%) survivors and five (35.7%) non-survivors. Of the nine cats that were discharged, one was a short-term survivor (10 days) and eight (57.1%) were long-term survivors (⩾6 months). Abnormal CT findings included lateral ventricle asymmetry/midline shift (42.8%), intracranial haemorrhage (35.7%), caudotentorial lesions (14.2%) and cranial vault fractures (14.2%), all of which were depressed. Intracranial haemorrhage was found to be significantly and negatively associated with short-term (P = 0.005) and long-term (P = 0.023) survival. KCTS was significantly associated with short-term survival (P = 0.002) and long-term survival (P = 0.004). A KCTS cut-off value of 2 yielded a 100% sensitivity and 100% specificity for short-term survival and 100% sensitivity and 80% specificity for long-term survival. A MGCS cut-off value of ⩾13 was associated with a 100% sensitivity and 100% specificity for short-term survival, and with a 100% sensitivity and 80% specificity for long-term survival.

Conclusions and relevance: KCTS, performed up to 72 h from injury, can be used as an additional diagnostic tool for the prediction of survival in cats with TBI.

Keywords: CT; intracranial haemorrhage; prognosis; traumatic brain injury.

Figure 1

Transverse unenhanced CT image of the head of a 2-year-old castrated male domestic shorthair cat following traumatic brain injury. A brain-windowed image at the level of the interthalamic adhesion shows a hyperattenuating lesion (white arrows) surrounded by a hypoattenuating area (white arrowheads) consistent with acute parenchymal haemorrhage with surrounding parenchymal oedema; lateral ventricular asymmetry (black arrows) is also noted. The presence of haemorrhage and lateral ventricular asymmetry at this location each grants 1 point to the Koret CT score

Figure 2

Transverse unenhanced CT image of the head of a 4.5-month-old intact female Ragdoll cat following traumatic brain injury. A brain-windowed image at the level of the tentorium shows a caudotentorial hyperattenuating lesion (white arrows) surrounded by mild hypoattenuating focal area (arrowhead) consistent with acute haemorrhage surrounded by mild oedema. On the Koret CT score, 3 points are granted for caudotentorial oedema and 1 point for parenchymal haemorrhage