UCSF physicians are calling for rapid MRI, rather than repeat CT, when clinically stable children need surveillance imaging after traumatic brain injury.
For decades, CT scans have been the cornerstone of traumatic brain injury (TBI) evaluation. They are fast, widely available, and the first-line imaging test for children arriving at emergency departments with head trauma.
But CT exposes children to ionizing radiation, increasing their risk of developing blood cancers as the radiation dose increases.
A team of neurosurgeons and pediatric critical care physicians at UC San Francisco is now proposing rapid MRI for clinically stable children who require surveillance imaging after a TBI, reducing avoidable radiation exposure while preserving high diagnostic accuracy.
“There is often hesitancy to use MRI because CT is more familiar,” said Vijay Letchuman, MD, a senior neurosurgery resident at UCSF and the first author of the new Viewpoint article published this week in JAMA Pediatrics. “But we shouldn’t just do what we’re most accustomed to; we should do what’s best for our kids.”
In 2009, the Pediatric Emergency Care Applied Research Network (PECARN) developed widely used clinical decision rules to help identify children at very low risk of requiring neurosurgical intervention and safely reduce unnecessary CT scans during the initial evaluation of head trauma. However, the criteria do not address the choice of modality for follow-up imaging, leaving surveillance decisions largely to clinician judgment.
“Many children with an identified intracranial hemorrhage still undergo routine repeat CT imaging for surveillance, often four to six hours after the initial scan, even when they remain clinically stable,” said John Yue, MD, a co-author of the Viewpoint article, an assistant professor of Neurological Surgery, and a neurotrauma surgeon at UCSF.
Children have some of the highest rates of TBI-related emergency department visits. Although the absolute cancer risk to any one child remains small cumulative CT exposure across this large population represents a meaningful and potentially preventable public health burden.
Traditional MRI examinations often take 30 minutes or longer and may require sedation in young children. Rapid MRI changes that: streamlined, motion-tolerant protocols can be completed in five to seven minutes, often without sedation. A prospective study reported 93% sensitivity and 96% specificity in detecting TBIs, and accuracy for hemorrhage improves when the initial CT is available for comparison. Originally developed to monitor hydrocephalus, rapid MRI is now routine at many pediatric hospitals, including UCSF Benioff Children’s Hospitals.
“At UCSF, we already avoid repeat CT whenever rapid MRI can safely provide the information we need,” Letchuman said.
“Fortunately, most of these children remain neurologically stable and do not require operative intervention,” Yue said. “For appropriately selected patients, rapid MRI provides the surveillance information we need without adding another dose of ionizing radiation.”
Beyond the current Viewpoint, Winson Ho, MD, an associate professor of Neurological Surgery and senior author of the article, and Yue are collaborating with UCSF colleagues across the departments of radiology, pediatrics, and emergency medicine to quantify the cumulative radiation burden of repeat imaging in pediatric head trauma and develop practical imaging stewardship strategies to reduce exposure.
The authors emphasize that they are not a calling to eliminate CT, which remains the first-line diagnostic imaging modality whenever a child becomes clinically unstable, MRI cannot be obtained safely, or a detailed skull fracture assessment is essential.
“Every child deserves the safest imaging study that can reliably answer the clinical question,” Ho said.
Reference: Letchuman V, Yue JK, Mahendra M, Ho WS. Rapid MRI, Not Repeat CT, for Pediatric Head Trauma-A Call to Action. JAMA Pediatr. Published online August 10, 2026. doi:10.1001/jamapediatrics.2026.3401.