Fig. 1

A 42-year-old man who was hit by a car while riding a bicycle. His GCS on admission to the emergency room was 14 out of 15. Two hours after admission, the patient’s GCS remained the same. The patient showed any of the New Orleans guideline’s items, therefore, his New Orleans score was 0. This is in contrast to the Canadian guideline, in which the patient had a GCS score of less than 15 at 2 h after admission (scored +1) and his mechanism of accident (car versus bicycle) fits the dangerous mechanism item (scored +1), leading to a Canadian Score of 2. On CT, the patients shows acute subarachnoid hemorrhages in the left Sylvian fissure (left panel, arrow) and on the surface of the left frontal lobe (middle, arrow). More importantly, some hyperdense foci that are suspected to represent a diffuse axonal injury are seen in the corpus callosum (middle panel, dashed arrow). The follow-up MRI study performed later, confirms the presence of DAI lesions on T2*WI (right panel, dashed arrow)