RT Journal Article
SR Electronic
T1 Constant-Infusion H<sub>2</sub><sup>15</sup>O PET and Acetazolamide Challenge in the Assessment of Cerebral Perfusion Status
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1344
OP 1350
VO 45
IS 8
A1 Weber, Bruno
A1 Westera, Gerrit
A1 Treyer, Valerie
A1 Burger, Cyrill
A1 Khan, Nadia
A1 Buck, Alfred
YR 2004
UL http://jnm.snmjournals.org/content/45/8/1344.abstract
AB Assessing the baseline perfusion and perfusion reserve after acetazolamide (ACZ) challenge is a common method for the evaluation of patients with cerebrovascular disease. Most previous studies using H215O PET applied the bolus injection technique. There is considerable discrepancy regarding the optimal time point of imaging after ACZ injection. The purpose of this study was to continuously monitor cerebral blood flow (CBF) after ACZ using constant-infusion H215O PET. Methods: Four patients with stenoses of an internal carotid artery and 6 with moyamoya disease were studied. H215O was continuously infused, and data were recorded in 1-min frames. After equilibration of H215O, 5 min of baseline data were acquired, and then 1 g of ACZ was administered intravenously and data collection continued for 10–22 min. Arterial blood was continuously drawn for absolute quantification of CBF. Results: The arterial 15O concentration remained generally stable during scanning, and the cerebellar blood flow fluctuations of the 5 baseline scans were small. The scan-to-scan difference was 6% (difference of 2 successive scans/mean). In the nonpathologic areas, the increase in CBF started 1–2 min after administration of ACZ. The largest fraction of the increase occurred from 0 to 10 min. The ratio of CBF in pathologic areas to CBF in cerebellum showed an initial decrease that stabilized after 5 min. Conclusion: A continuous-infusion protocol is a viable alternative to single bolus injections for the assessment of cerebral perfusion status. Such a protocol is advantageous when the time course of CBF after an intervention is not known. With continuous monitoring, the optimal time point for evaluation of a certain parameter can be chosen post hoc. Furthermore, the time course of CBF itself may allow the definition of new parameters for evaluating perfusion status in cerebrovascular patients, both for assessment before a revascularization procedure and for follow-up. A limitation of the present study is the relatively small number of patients with each type of cerebrovascular disease and the lack of healthy subjects.