Can a Blood Test Replace the CT Scan?

Soon, patients with mild traumatic brain injuries (mTBIs) may not need an expensive CT scan to understand the severity of their injury. The FDA recently approved the first blood test to measure mTBIs in adults: the Banyan Brain Trauma Indicator.

As Swedish American headache specialist Jeffrey Royce, MD, explained for WREX, “What this test allows us to do is say who may or may not need a cat scan.” The new blood test determines levels of specific proteins, UCH-L1 and GFAP, two biomarkers of a mTBI that can be measured “within 12 hours of head injury.” These levels indicate whether or not a patient would demonstrate intracranial lesions in a CT scan.

This is an important distinction, because reducing the frequency of CT scans limits patients’ exposure to radiation. According to FDA Commissioner Scott Gottlieb, MD, the new blood test “supports the FDA’s Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging—an effort to ensure that each patient is getting the right imaging exam, at the right time, with the right radiation dose.”

The test results are available in just three to four hours, and the results are reliable. The Brain Trauma Indicator predicted the presence of intracranial lesions 97.5 percent of the time and predicted the absence of lesions 99.6 percent of the time.

Not only could the availability of a blood test for mTBI reduce the number of CT scans, it could also save healthcare facilities money. The new test could “potentially [save] our healthcare system the cost of often unnecessary neuroimaging tests,” observes Dr. Gottlieb.