Kurzfassung

Quantitation of reduced FDG uptake in dementia patients isusually performed by single subject analysis compared to an FDG reference database. Since FDG uptake in human brain changes with age, ideally, age-matched subjects should be used as controls. However in practice, the reference database consists of normal subjects covering a wide range of age. In this case, the age effect can be modelled by regression leading to an age-adjusted reference FDG database as implemented in the Alzheimer's...Quantitation of reduced FDG uptake in dementia patients is usually performed by single subject analysis compared to an FDG reference database.  Since FDG uptake in human brain changes with age, ideally, age-matched subjects should be used as controls. However in practice, the reference database consists of normal subjects covering a wide range of age. In this case, the age effect can be modelled by regression leading to an age-adjusted reference FDG database as implemented in the Alzheimer's Discrimination Tool of PMOD (PALZ). This approach was used in our previously constructed brain FDG database (NC37) in order to construct an age-adjusted database (NC37a) for comparison to the PALZ reference database.
Parametric map of r-values (r-map) was calculated by regression analysis of the NC37 with age. Age-adjustment of the NC37 database was performed by image correcting each of the 37 subjects using r-map. FDG-PET datasets of 20 patients with Alzheimer’s disease (AD) were tested using either PALZ or the SPM8 single subject analysis and NC37a.
Despite different constitution of the PALZ database and the NC37a database, the results of the analysis of AD-related hypometabolism in the AD datasets were similar. Therefore, diagnosis of dementia using our age-adjusted database NC37a is feasible. Age-dependence is more prominent in PALZ as compared to NC37a leading to higher PETscores in younger AD patients.» weiterlesen» einklappen