Many military personnel who experience blast-related traumatic brain injury (MTBI) have lasting brain damage as seen by MRI, according to a study published in Radiology.

Researchers from the National Capital Neuroimaging Consortium, the National Intrepid Center of Excellence, the Center for Neuroscience and Regenerative Medicine, the Uniformed Services University of the Health Sciences, the Henry M. Jackson Foundation, and Walter Reed National Military Medical Center, in Bethesda, MD, sought to describe initial neuroradiology findings among members of the military service who had experienced a primary chronic mild TBI (MTBI) caused by a blast.

MRI was performed on 834 subjects who were diagnosed with chronic TBI (mean of 1,381 days and median of 888 days after blast injury). Ninety-two percent (768 subjects) were diagnosed as mild TBI. Forty-two control subjects also underwent scans.

A total of 84.2% of 817 subjects reported one or more blast-related incidents, while 63.0% (515 of 817) reported loss of consciousness at the time of injury. The researchers found the presence of white matter T2 hyperintensities among 51.8% of those with MTBI, and cerebral microhemmorhages in 7.2%, increasing in incidence with TBI severity. The researchers also found pituitary abnormalities in 29.0% of TBI subjects.Susceptibility-weighted image shows extensive microhemorrhage (arrows) consistent with diffuse axonal injury in a 25-year-old man with blast-related mild TBI. ©RSNA, 2015.

“We were really surprised to see so much damage to the brain in the MTBI patients,” Gerard Riedy, MD, PhD, National Intrepid Center of Excellence at the Walter Reed National Military Medical Center, said in a release. “It’s expected that people with MTBI should have normal MRI results, yet more than 50 percent had these abnormalities.”

Riedy, also noted that these findings represent the first in a series of new studies on advanced brain imaging in patients with MTBI.

“This paper is just the tip of the iceberg,” he said. “We have several more papers coming up that build on these findings and look at brain function, brain wiring, connectivity and perfusion, or brain blood flow.”