title: Butanol is superior to water for performing positron emission tomography activation studies.
abstract: [15(O)]Butanol has been shown to be superior to [15(O)]water for measuring cerebral blood flow with positron emission tomography. This work demonstrates that it is also superior for performing activation studies. Data were collected under three conditions: a visual confrontation animal-naming task, nonsense figure size discrimination, and a nonvisual darkroom control task. Time-activity curves (TAC) were obtained for regions known to be activated by the confrontation naming task to compare absolute uptake and the different kinetics of the two tracers. Also, t statistic maps were calculated from the data of 10 subjects for both tracers and compared for magnitude of change and size of activated regions. Peak uptake in the whole-brain TAC were similar for the two tracers. For all regions and conditions, the washout rate of [15(O)]butanol was 41% greater than that of [15(O)]water. At a threshold of 0, the [15(O)]water and [15(O)]butanol percent difference (nonnormalized) and t statistic (global normalization) images are nearly identical, indicating that the same property is being measured with both tracers. The [15(O)]butanol parametric images displayed at a threshold of /t/ = 5 look similar to the [15(O)]water parametric maps displayed at a threshold of /t/ = 4, which is consistent with the observation that t statistic values in [15(O)]butanol images are generally greater. The t statistic values were equal when the [15(O)]butanol parametric map was created from any subset of 6 subjects and the [15(O)]water parametric map was created from all 10 subjects. Fewer subjects need to be studied with [15(O)]butanol to reach the same statistical power as an [15(O)]water-based study.
authors.affiliation: Emory Center for PET and Department of Radiology, Emory University, Atlanta, Georgia, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Votaw
authors.forename: T R
authors.initials: TR
authors.lastname: Henry
authors.forename: T M
authors.initials: TM
authors.lastname: Shoup
authors.forename: J M
authors.initials: JM
authors.lastname: Hoffman
authors.forename: J L
authors.initials: JL
authors.lastname: Woodard
authors.forename: M M
authors.initials: MM
authors.lastname: Goodman
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology; D000440:Butanols; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D010103:Oxygen Isotopes; D011859:Radiography; D014055:Tomography, Emission-Computed; D014867:Water
chemical_list: D000440:Butanols; D010103:Oxygen Isotopes; D014867:Water