As per the study published in The Lancet Neurology,a simple drop of bblood may daignose accurately a brain injury after trauma over head as a Ct Scan does so it may be very important for diagnosis in rural area where ct scan is not available or contraindicated for radiation or making CT SCAN optional one.

                    Investigators studied close to 2000 adult patients who presented to the emergency department (ED) with suspected TBI and who had undergone both head CT and blood collection within 12 hours of the injury.They measured ubiquitin C-terminal hydrolase-L1 (UCH-L1) and glial fibrillary acidic protein (GFAP), 2 biomarker proteins that are released into the bloodstream after TBI or Traumatic Brain Injury.

                      They found that in more than 96% of patients, a blood test combining both of these biomarkers accurately predicted the absence of acute intracranial injury, as confirmed by CT scan."We see this test not as a substitute for head CT scan, but as an accurate and objective way to help emergency care providers decide which patients really need one," Jeffrey Bazarian, MD, of  New York.

                      "Our results suggest that this blood test holds potential for ruling out the need for head CT scan among head-injured patients presenting to EDs, in whom a head CT scan is felt to be clinically indicated; in fact, up to a third of head CT scans done in the acute setting of TBI could be avoided, with very low false-negative rates," he said.

                      In the United States, TBI results in more than 2.5 million ED visits annually, with most being mild TBI (concussion), the authors write.