IMAGE QUALITY VERSUS STATISTICAL POWER

We investigated whether SPET studies of neuroactivation might benefit from a similar approach used in PET; that is, increase the number of s cans per task and accept poorer individual scan quality. Different stu dy paradigms were simulated by varying the scanning parameters: (1) ad ministered radiation activity per scan, (2) number of scans per task a nd (3) scan acquisition time. The maximum total dose received by each simulated subject remained the same. Areas of activation of varying si gnal strength were added to the scans using a customized graphics pack age. To establish the statistical benefits of a replication paradigm v ersus a non-replication paradigm, the datasets were analysed using SPM 95 statistics software. This simulation was able to show that, when an SPM investigation is used for data analysis, study replication is mor e important than the individual image quality typically available from a high-performance SPET system.