| Research Abstract |
To determine the optimal blood pressure for hypertensive patients with cerebrovascular disease (CVD) is very important. For this purpose, oxygen extraction fraction (OEF) measured by PET had been considered as the most relable index. However, PET takes lots of costs and manpower. We had developed non-invasive SPECT method, split dose I-123 IMP SPECT, which enables to estimate perfuion reserve as %increase of CBF afar acetazolamide injection (PR). In this study, the relationship between the parameters obtained by this method and those of PET study.
Totlally 33 patients with CVD were investigated. In the first study, the MCA territories were divided into 3 groups by angiographic findings. Group A was consisted of the MCA areas with sever stenotic lesion (more than 75%) in the ipsilateral ICA system, Group NA in the contralateral ICA system, and Group NP with no lesions in both sides. PR of Group A was significantly decreased in comparison with that of Group NP.CBV of Group A was significantly increased compared with Group NA.There was sinificant negative correlation between CBV and PR, however, no correlation were found between OEF and PR.Secondary, we investigated the feasibility that OEF-elevated lesions were can be predicted by SPECT.In 7 lesions with more high OEF (more than 60%), decreased resting CBF and decreased OEF were shown. However, there was no significant differences in OEF between 2 groups, with and without low PR (less than 10%).
In concludion, the lesions with mild insufficiency of cerebral perfusion may be detected by PR, where CBV is increased without elevation of OEF.However, to discriminate the lesion with elevated OEF from that with normal OEF was difficult. For this purpose, other modality or clinical course have to be considered.
|
