Dynamic CT perfusion imaging in the study of perihematomal hypoperfusion injury in subacute and chronic intracerebral hemorrhage

Objective: To study the alteration of cerebral blood flow adjacent to the hematoma in subacute and chronic intracerebral hemorrhage (ICH), and to investigate its correlative factors. Methods: Pre-contrast and dynamic perfusion CT were performed in 12 cases of ICH with the basal ganglia. The volume of hematomas were measured, and the ratios of side-to-side of the regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), mean transit time (MTT) and time-to-peak (TTP) were calculated in 11 of 12 cases. Results: The maximum and minimum of hematoma were 72.21 ml and 13.68 ml respectively, and the mean was 26.83 ml. The gradient of perihematomal hypoperfusion was revealed by rCBF maps in 11 cases, and by rCBV maps in 10 cases. The perihematomal hyperperfusion was demonstrated by rCBV maps in 1 case. The hypoperfusion of the affected hemisphere was observed in 2 cases. The areas of delayed TTP and MTT were revealed in 11 cases and 10 cases, respectively. In the regions surrounding the hemorrhage, the reduction in rCBF and the delay in MTT were most pronounced within 2 mm of the hematoma perimeter, and the reduction in rCBV correlated with the volume of hemorrhage clearly. There was no correlation between the changes in rCBF, rCBV, MTT and TTP and the time from symptom onset to CT perfusion imaging. Conclusion: In the phases of subacute and chronic intracerebral hemorrhage, the hypoperfusion surrounding the hematoma remains existing. The changes of rCBV in the perilesional regions correlate with the volume of hemorrhage. Perfusion CT and its parameters analysis may play an increasing role in delineating the hypoperfusion around hematomas, and may provide valuable information on the individual clinic therapy and prognostic evaluation of ICH. (authors)