Magnetic resonance imaging as an alternative to computed tomography in select patients with traumatic brain injury: a retrospective comparison

Abstract

<jats:sec> <jats:title>OBJECT</jats:title> <jats:p>Traumatic head injury (THI) is a highly prevalent condition in the United States, and concern regarding excess radiation-related cancer mortality has placed focus on limiting the use of CT in the evaluation of pediatric patients with THI. Given the success of rapid-acquisition MRI in the evaluation of ventriculoperitoneal shunt malfunction in pediatric patient populations, this study sought to evaluate the sensitivity of MRI in the setting of acute THI.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>Medical records of 574 pediatric admissions for THI to a Level 1 trauma center over a 10-year period were retrospectively reviewed to identify patients who underwent both CT and MRI examinations of the head within a 5-day period. Thirty-five patients were found, and diagnostic images were available for 30 patients. De-identified images were reviewed by a neuroradiologist for presence of any injury, intracranial hemorrhage, diffuse axonal injury (DAI), and skull fracture. Radiology reports were used to calculate interrater reliability scores. Baseline demographics and concordance analysis was performed with Stata version 13.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>The mean age of the 30-patient cohort was 8.5 ± 6.7 years, and 63.3% were male. The mean Injury Severity Score was 13.7 ± 9.2, and the mean Glasgow Coma Scale score was 9 ± 5.7. Radiology reports noted 150 abnormal findings. CT scanning missed findings in 12 patients; the missed findings included DAI (n = 5), subarachnoid hemorrhage (n = 6), small subdural hematomas (n = 6), cerebral contusions (n = 3), and an encephalocele. The CT scan was negative in 3 patients whose subsequent MRI revealed findings. MRI missed findings in 13 patients; missed findings included skull fracture (n = 5), small subdural hematomas (n = 4), cerebral contusions (n = 3), subarachnoid hemorrhage (n = 3), and DAI (n = 1). MRI was negative in 1 patient whose preceding CT scan was read as positive for injury. Although MRI more frequently reported intracranial findings than CT scanning, there was no statistically significant difference between CT and MRI in the detection of any intracranial injury (p = 0.63), DAI (p = 0.22), or intracranial hemorrhage (p = 0.25). CT scanning tended to more frequently identify skull fractures than MRI (p = 0.06).</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>MRI may be as sensitive as CT scanning in the detection of THI, DAI, and intracranial hemorrhage, but missed skull fractures in 5 of 13 patients. MRI may be a useful alternative to CT scanning in select stable patients with mild THI who warrant neuroimaging by clinical decision rules.</jats:p></jats:sec>

Minimizing Radiation Exposure in Evaluation of Pediatric Head Trauma: Use of Rapid MR Imaging

“…While it had been previously thought that rMRI would be insensitive for detecting skull fracture, 23 our study did not reflect that supposition. Of the 101 patients, only 12 had a skull fracture found on CT that was not identified on rMRI.…”

“…23 However, this study was limited to 30 patients, often with worse presenting levels of injury, in whom the authors admit that an MR imaging may have been performed to allow prognostication or to find injuries not seen on CT that could explain the severity of neurologic injury.…”

Acute Brain Imaging in Children: Can MRI Replace CT as a Screening Tool?

“…Most importantly, the potential cancer risks of CT‐related ionizing radiation argue in favor of brain MRI in children . Brenner et al estimated the lifetime cancer mortality risk attributable to the radiation from a single CT scan of the head in a 1‐year‐old child to be .07% . This small risk translates into a large population‐level risk, given that, for example, traumatic head injury in children from 0 to 14 years accounts for nearly half a million emergency room visits in the United States annually …”

QuickBrain MRI for the detection of acute pediatric traumatic brain injury

“…17 The authors of that study noted MRI to be as sensitive as CT for identifying intracranial injuries, although skull fractures were missed by MRI in 5 of 13 patients. The authors did not detail the clinical course of each patient with a missed skull fracture, but they did note the rather benign nature of a nondepressed or nondisplaced skull fracture overall.…”