Abstract
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Objectives: We evaluated serial cerebral hemodynamic changes after successful EC-IC bypass surgery in symptomatic patients with atherosclerotic occlusion of internal carotid (ICA) or middle cerebral artery (MCA) using Acz-SPECT.
Methods: 32 symptomatic patients with ICA or MCA occlusion prospectively underwent Acz-SPECT using Tc-99m ECD before and 1 week after unilateral EC-IC bypass surgery. Of these, 16 (M:F=13:3; unilateral:bilateral=12:4; major stroke:TIA=12:4) underwent additional Acz-SPECT 3 months later. All SPECT images were normalized to MNI template and mean counts of MCA territory and cerebellum were obtained by Automated Anatomical Labelling. Cerebral perfusion index (PI=Cregion/Ccerebellum) and perfusion reserve index (RI=(PIAcz-PIbasal)/PIbasal) of frontal and temporoparietal cortex of the MCA territory were calculated.
Results: Preoperative PIs of ipsilateral frontal and temporoparietal cortex (1.12±0.03 and 1.14±0.03, respectively) were significantly lower than those (1.33±0.05 and 1.33±0.06, respectively) of contralateral sides, and did not change until 3 months after surgery. RIs of ipsilateral frontal and temporoparietal cortex (-0.12±0.02 and –0.11±0.01, respectively) were significantly lower than those (0.01±0.02 and 0.02±0.01, respectively) of contralateral sides (p<0.05). After surgery, RIs of ipsilateral frontal and temporoparietal cortex increased significantly (86.7% and 87.2%, respectively) at 1 week after surgery (p<0.05), and did not significantly change until 3 months after surgery.
Conclusions: Cerebral perfusion and perfusion reserve changed with different manner during 3 months after EC-IC bypass surgery and perfusion reserve changed more dramatically than perfusion at early postoperative period. The reason ipsilateral perfusion did not improve may be unrecovered metabolism by previous incomplete infarction or diaschisis.
- Society of Nuclear Medicine, Inc.