Atypical CT findings of acute epidural hematomas

One of the classic CT findings is characterized by a lenticular high density in acute epidural hematomas. However, several atypical CT findings in acute epidural hematomas have been reported lately. We have ourselves met three cases of acute epidural hematomas, in which there were low-or isodensity spots within typical high-density areas. Case 1: a 74-year-old male, a victim of a traffic accident, showing a high degree of anemia (Ht: 14%, Hb: 2.8 g/dl.) secondary to massive subcutaneous hemorrhage resulting from traumatic DIC. His CT, taken 12 hours after the head injury, disclosed bubble-like low density spots in a typical high-density area. Case 2: a 9-month-old baby boy, who had fallen to the ground from a height of 25 cm, was also anemic on admission (Ht: 17%, Hb: 5.2 g/dl.). An initial CT-scan, 7 hours after head injury, again disclosed a huge low density spot in the center of a typical high-density area. Case 3: an 11-year-old girl, involved in a car accident. A CT-scan, taken 4.5 hours after head injury, showed a low-density spot in the center of a high-density area. In her case, however, there was no evidence of significant anemia. In these three cases, the CT findings were close to one another in appearance, namely, classic lenticular high-density areas, spotted with round low-or isodensity areas within those hematomas. The causative factors have been thought be one of the following: a markedly low hemoglobin value, a time difference in the coagulation process within the same hematomas, or a possible leakage of CSF into the hematomas from a dural tear. It seemed that no single causative factor was responsible in these three cases; rather, it seems that multiple factors had progressed simultaneously. (author)