Development of a Simple MRI Scoring Tool in Severe Pediatric Traumatic Brain Injury: Secondary Analysis of the 2014–2017 “Approaches and Decisions in Acute Pediatric TBI Trial (ADAPT)” Multicenter Study

OBJECTIVES: We aimed to describe the frequency, depth, and co-occurrence of different intracerebral injury types detected on the first clinical brain MRI in children with severe traumatic brain injury (TBI) and to derive a simple MRI scoring system associated with 12-month functional outcome. DESIGN: Secondary analysis of the Approaches and Decision in Acute Pediatric TBI (ADAPT) multicenter 2014 to 2017 study. SETTING: A total of 24 ADAPT sites in the United States, United Kingdom, and Australia. PATIENTS: Children (< 18 yr) with severe TBI who received intracranial pressure monitoring and clinical brain MRI within 30 days of injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: MRI was evaluated for lesion type and location, and maximal depth of any lesion was determined for each subject (grade 1, lobar gray and white matter; grade 2, deep gray matter and corpus callosum; grade 3, brainstem). The primary outcome was Glasgow Outcome Scale Extended Pediatric version (GOSE-P) at 12 months, dichotomized to favorable (GOSE-P 1-3) vs. unfavorable (GOSE-P 4-8). In the cohort of 279 patients, we found that the three most frequent lesion types were contusion (78.5%), diffuse axonal injury (70.3%), and ischemia (38.0%). When evaluating maximal injury grade, grade 1 was present in 48 children (17.2%), grade 2 in 103 children (36.9%), and grade 3 in 113 children (40.5%). Injury grade and presence of ischemia were associated with increased odds of unfavorable outcome. Injury depth and ischemia on MRI (IDIOM) were incorporated into a novel six-category MRI Injury Scale, with scores ranging from 1 to 3+ (injury grades 1-3, + indicates presence of any ischemia). We found that score 3+, that is, brainstem injury with ischemia in any location, increased the risk of unfavorable outcome 22.3-fold (95% CI, 6.81-87.37; p < 0.0001) compared with score 1 (injury isolated to lobar gray and white matter, without ischemia). CONCLUSIONS: Increased depth of injury and presence of ischemia on MRI are important risk factors for unfavorable outcome in children with severe TBI. We propose a simple MRI scoring system (IDIOM) that incorporates depth of injury and presence of ischemia that may be useful for neuroprognostication, but further validation is required.