抄録
CT examinations were performed in 621 cases of minor head injury within 3 days, and 26 cases (4%) exhibited hygroma-like CT findings. These 26 cases were divided into two patterns : Type A (12 cases) and Type B (14 cases). Type A showed smooth thin hygroma-like low density area beneath the skull with compression of the cerebral surface and cerebral sulci. Type B showed an irregular thin hygroma-like low density area beneath the skull with recognized cerebral sulci. Many of these cases changed into chronic subdural hematomas, i.e. Twelve cases (100%) of Type A and three cases (21%) of Type B changed into chronic subdural hematomas. It is highly possible to forecast the subsequent occurrence of the chronic subdural hematomas soon after a head injury.
