Patients with traumatic brain injury need quick and accurate diagnosis. Interpreting computed tomography images is widely used for diagnosis, by detecting structural abnormalities on the images with human eyes. This conventional method may miss the subtle differences in radiodensity(defined as Hounsfield unit) of the images, and can result in failure of preventing secondary brain injuries, namely ischemia and edema. This study used computed tomography scans of 19 pediatric patients and 10 normal children to test whether the quantification of the radiodensity of images can detect ischemia and/or edema or not. The Hounsfield unit distributions of typical grey matter region did not show statistical differences between patients group and control group, but 84%(16) of patients group showed increase and change in overall Hounsfield unit between the initial and follow up imaging studies. The distribution of Hounsfield unit can be used as an effective tool for confirming the existence of cerebral edema.