Butanol is superior to water for performing positron emission tomography activation studies

[O-15]Butanol has been shown to be superior to [O-15]water for measuring ce rebral blood flow with positron emission tomography. This work demonstrates that it is also superior for performing activation studies. Data were coll ected under three conditions: a visual confrontation animal-naming task, no nsense figure size discrimination, and a nonvisual darkroom control task. T ime-activity curves (TAC) were obtained for regions known to be activated b y the confrontation naming task to compare absolute uptake and the differen t 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 chan ge and size of activated regions. Peak uptake in the whole-brain TAC were s imilar for the two tracers. For all regions and conditions, the washout rat e of [O-15]butanol was 41% greater than that of [O-15]water. At a threshold of 0, the [O-15]water and [O-15]butanol percent difference (nonnormalized) and t statistic (global normalization) images are nearly identical, indica ting that the same property is being measured with both tracers. The [O-15] butanol parametric images displayed at a threshold of \\t\\ = 5 look simila r to the [O-15]water parametric maps displayed at a threshold of \\t\\ = 4, which is consistent with the observation that t statistic values in [O-15] butanol images are generally greater. The t statistic values were equal whe n the [O-15]butanol parametric map was created from any subset of 6 subject s and the [[O-15]water parametric map was created from all 10 subjects. Few er subjects need to be studied with [O-15]butanol to reach the same statist ical power as an [O-15]water-based study.