Early Diagnosis of Mortality Using Admission CT Perfusion in Severe Traumatic Brain Injury Patients (ACT-TBI Study)

Background: Severe traumatic brain injury (TBI) is a principal cause of post-injury hospitalization, disability, and death throughout the world. TBI is the leading cause of death and disability among young healthy people under 45 years of age and is predicted to be the most prevalent and costliest neurological condition in Canada through the year 2031. TBI is commonly classified into mild, moderate, and severe categories using the Glasgow Coma Scale (GCS), with "severe TBI" defined as a GCS score ≤ 8. Severe TBI is a clinical emergency, during which the trauma team works swiftly to provide the appropriate care. Outcome assessment after TBI is complex and is influenced by pre-injury and injury factors as well as the patient's response at various stages of recovery. The first 48 hrs in hospital, despite being the most resource-intensive period, unfortunately result in the highest mortality. These patients are on life support at the time of their hospital admission and adequate and reliable clinical examination is impossible. Thus, patients receive treatment despite lack of a clear understanding of their prognoses. Hypothesis: Admission Computed Tomographic Perfusion (CTP) can diagnose brain death reliably in severe TBI patients in early stage upon hospital admission, which is not recognised in the usual clinical practice due to inadequate reliable clinical examination. In a small prospective pilot study of 19 patients with severe TBI, admission CTP could predict early in hospital mortality with 75% sensitivity, 100% specificity, 100% positive predictive value (PPV) and 94% negative predictive value (NPV) and perfect inter-rater reliability (kappa=1). We propose ACT-TBI study to evaluate CTP as a triage tool to diagnose early mortality at the time of admission in patients with severe TBI. Primary Objective: To validate admission CTP features of brain death, relative to the clinical examination outcome, for characterizing early in-hospital mortality. Secondary objec