biostudies-literatureUnknown43(3)Heeman FAlzheimer's disease is characterized by regional reductions in cerebral blood flow (CBF). Although the gold standard for measuring CBF is [¹⁵O]H₂O PET, proxies of relative CBF, derived from the early distribution phase of amyloid and tau tracers, have gained attention. The present study assessed precision of [¹⁵O]H₂O derived relative and absolute CBF, and compared precision of these measures with that of (relative) CBF proxies. Dynamic [¹⁵O]H₂O, [¹⁸F]florbetapir and [¹⁸F]flortaucipir PET test-retest (TrT) datasets with eleven, nine and fourteen subjects, respectively, were included. Analyses were performed using an arterial input model and/or a simplified reference tissue model, depending on the data avJournal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism369-378https://www.ebi.ac.uk/biostudies/studies/S-EPMC9941867biostudies-literaturePrecision estimates of relative and absolute cerebral blood flow in Alzheimer's disease and cognitively normal individuals.PMC9941867Visser Dvan der Flier WMVerfaillie SLammertsma AAGolla SSHeeman FTimmers TPijnenburg YAvan Berckel BNYaqub MBoellaard RfalsePrecision estimates of relative and absolute cerebral blood flow in Alzheimer's disease and cognitively normal individuals.Alzheimer's disease is characterized by regional reductions in cerebral blood flow (CBF). Although the gold standard for measuring CBF is [¹⁵O]H₂O PET, proxies of relative CBF, derived from the early distribution phase of amyloid and tau tracers, have gained attention. The present study assessed precision of [¹⁵O]H₂O derived relative and absolute CBF, and compared precision of these measures with that of (relative) CBF proxies. Dynamic [¹⁵O]H₂O, [¹⁸F]florbetapir and [¹⁸F]flortaucipir PET test-retest (TrT) datasets with eleven, nine and fourteen subjects, respectively, were included. Analyses were performed using an arterial input model and/or a simplified reference tissue model, depending on the data av2023-01-01T00:00:00Z2023 Mar2025-04-05T11:31:51.235Z2025-02-18T22:53:19.036ZS-EPMC99418673627159810.1177/0271678X221135270