DYNAMIC SCANNING OF O-15-BUTANOL WITH POSITRON-EMISSION-TOMOGRAPHY CAN IDENTIFY REGIONAL CEREBRAL ACTIVATIONS

To determine task-specific activations of the human brain in individua l subjects, we applied pixel-by-pixel t-map statistics to the regional cerebral perfusion data obtained sequentially by dynamic scanning of [O-15]-butanol with positron emission tomography (PET). The listmode d ata were binned into frames of 2 sec, and multiple corresponding pixel -by-pixel activation-minus-control subtractions were used for t-map ca lculation. The subtraction frames covering 10-40 sec after tracer arri val in the brain showed the activation-related increase of regional ce rebral perfusion. A mismatch of the activation and control data by 2 s ec resulted in a mean error of <5% of the integrated activity increase . To validate these results, we simulated images with a spatial resolu tion and signal-to-noise ratio equivalent to that of the [O-15]-butano l subtraction images. By means of these simulated images, we determine d the minimal data requirements for t-map analysis, the degree of spat ial correlations in the image matrix, and the distribution of noise in the t-maps. The simulation results provided a measure to estimate the significance of regional cerebral perfusion changes recorded with [O- 15]-butanol. The location and spatial extent of regional cerebral acti vations obtained from dynamic data corresponded closely to those obtai ned with quantitative measurements of regional cerebral blood flow (rC BF). Our results show that statistical parametric mapping of [O-15]-bu tanol scanning data allows the detection of significant, task-specific brain activations in single activation-control comparisons in individ ual subjects. (C) 1997 Wiley-Liss, Inc.