The impact of different 18FDG PET Healthy Subject scans for comparison with single XXXX in SPM analysis.

@entity1 @entity419 @entity73 @entity392 @entity195 @entity209
AIM: Statistical Parametric Mapping (SPM) has been applied for single--subject evaluation of @entity419 uptake in @entity195 ( @entity195 ). In a single--subject framework, the @entity1 is compared to a dataset of @entity419 PET images from @entity392 ( @entity392 ) evaluating brain @entity209 . No studies exist that assess the effects on SPM analysis of @entity392 @entity419 PET datasets acquired from different subjects and using different PET scanners including the same or different PET scanners than those used for @entity1 . This work aims to elucidate this issue from a methodological perspective. METHODS: We considered six different @entity419 PET datasets, from different @entity392 populations, acquired by different PET scanners. We applied SPM5 procedures for single--subject comparison with each of the six @entity392 datasets in 10 probable @entity195 @entity1 showing the typical @entity419 pattern. We also implemented the same comparison in 3 probable @entity195 @entity1 and in 7 @entity1 with a clinical diagnosis of @entity73 ( @entity73 ), showing subtle changes on visual inspection of @entity419 distribution. RESULTS: Considering the 10 @entity1 with the typical @entity419 pattern, the results were comparable for all the SPM maps. In the 3 probable @entity195 @entity1 with subtle changes in @entity419 distribution, no significant @entity195 pattern emerged when a small number (<20) of @entity392 was used, whereas a significant @entity195 pattern appeared when a large (>50) @entity392 image set was used. In the 7 considered @entity73 @entity1 the use of a large (>50) @entity392 image set allowed to assess significant hypo metabolic patterns related to a probable neurodegenerative pathology. CONCLUSION: The use of large @entity392 datasets of PET scans (>50) is recommended for single--subject SPM analysis. On condition that appropriate pre--processing steps are provided, large @entity392 datasets can include @entity392 images acquired with different PET systems, not including images from the same scanner of that used for @entity1 .
