Index of Brain Injury Aids Trauma Surgeons

A computerized method of quantifying the severity of brain injuries may help trauma surgeons quickly identify patients at risk for continued cerebral bleeding so they can provide treatment to prevent the injury from expanding. Called the brain planimetry index (BPI), the method was described at the annual Clinical Congress of the American College of Surgeons in Chicago (USA).

BPI uses a compterized program from the U.S. National Institutes of Health (NIH) and a computed tomography (CT) scan of a patient's brain to calculate the total volume of brain injury and detect tissue damage so severe it may cause disseminated intravascular coagulopathy (DIC). DIC is a clotting disorder that produces further hemorrhage within the brain. Treatment is often delayed, however, while surgeons wait for the results of blood tests.

BPI was developed by Rebecca A. Prince, a medical student at Oregon Health Sciences University School of Medicine. In a pilot study, Prince superimposed the NIH Image program over CT images of 18 brain-injured patients, traced the borders of each abnormality as well as the entire brain, and obtained the BPI for each patient. She then statistically analyzed the relationship between the index scores and abnormalities in coagulation tests, finding that BPI correlated directly with D-dimer levels. The index predicted 70% of the variance in the initial D-dimer level, and every increase in BPI was associated with a 1.58 ng/ml increase in the D-dimer. The index was also inversely related to fibrinogen. The NIH Image computer program is a public domain image-processing and analysis program available on the Internet.

Although the study indicates that BPI may be a simple measure of the severity of brain injury, larger studies are needed to validate its ability to predict DIC, said Prince. "This kind of radiographic score may help us to identify quickly those patients who need treatment for DIC without waiting for the results of blood tests.”