CT perfusion imaging of perihematomal cerebral blood flow and early ischemic injury in experimental intracerebral hemorrhage

Objective To investigate the relationship between the changes of regional cerebral blood flow and the ischemic injury in the early stage after intracerebral hemorrhage (ICH) in rats. Methods Seventy male Sprague-Dawley rats were randomly divided into ICH group and sham-operated group. ICH was produced by microinjection of fresh autologous blood into the right caudatum in rats. CT perfusion imaging and computer aided mapping in measurements of regional cerebral blood flow adjacent to the hematomas were performed in rats. The parameters of regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV) and mean transit time (MTT) were calculated respectively. After the CT examination, the histopathological examination of TTC and HE staining were carried out. Results The gradient of perihematomal hypoperfusion was revealed by rCBF and rCBV maps in ICH groups. The alternation of rCBF around the hematomas was fluctuated, the rCBF and rCBV reduction were most pronounced at 1 hour after ICH, then gradually returned. TTC staining did not show infarction around the hematomas. Histopathological study demonstrated the cellular edema, astrocytic swelling and neuronal degeneration in the peri-ICH regions. Conclusion The perihemorrhagic ischemic injury can be induced by the pronounced reduction of cerebral blood flow in the early stage of ICH. CT perfusion imaging can clearly demonstrate the abnormal cerebral hemodynamic change occurred in the region surrounding the hematomas in vivo, and can provide valuable information to the clinical treatment after intracerebral hemorrhage.