Background: Xenon-CT is a quantitive technique for estimating cerebral blood flow. To investigate whether penumbra exists around hematoma, regional cerebral blood flow (ICBF) was measured by Xenon-CT in patients with intracerebral hemorrhage (ICH).
Methods: Xenon-CT was performed on 15 patients with basal ganglia hemorrhage and hematoma volume < 50 mL. rCBF was measured within 36 h of onset and an average of 13 days later by 27-pixel rings in perihematomal area and its enantiomorph in contralateral hemisphere. Penumbra was defined as rCBF 8-20 mL x 100 g(-1) x min(-1).
Results: Average ICH volume was 13 +/- 7 mL (6.4-23.7 mL). First rCBF examination was conducted at 21.7 +/- 9.4 h (5-37 h), second rCBF examination was conducted at 13.4 +/- 1.8 days (11-18 days) after onset. Within 36h of onset, mean perihematomal rCBF was 28.4 +/- 7.8 mL x 100 g(-1) x min(-1); contralateral region was 34.2 +/- 12.2 mL x 100 g(-l) x min(-1) (p = 0.11). Average 13 days after onset, mean rCBF close to hematoma was 19.4 +/- 8.1 mL x 100 g(-1) x min(-1); rCBF in contralateral region was 40.1 +/- 11.3 mL x 100 g(-1) x min(-1) (p < 0.0001). rCBF in distal perihematomal region was 27.8 +/- 9.5 mL x 100 g(-1) x min(-1); the difference was significant compared to contralateral region (p = 0.0003). One patient's rCBF in area of edema around hematoma was less than 20 mL x 100 g(-1) x min(-1) at first examination. At second examination, 6 patients had same occurrence in region adjacent to hematoma and 2 patients experienced it in distal perihematomal region.
Conclusions: Reduced perihematomal rCBF was shown after ICH; this phenomenon lasted at least 14 days. A number of ICH patients experienced penumbra around hematoma.