Brain perfusion SPECT: Age-and sex-related effects correlated with voxel-based morphometric findings in healthy adults

PURPOSE: To investigate brain perfusion at single photon emission computed tomography (SPECT) as a function of age and sex in healthy adult volunteers and to correlate perfusion with gray matter concentration determined by us ing voxel-based morphometry (VBM). MATERIALS AND METHODS: Eighty-one healthy volunteers underwent both technet ium 99m ethylene cysteine dimer SPECT and three-dimensional magnetization p reparation rapid acquisition gradient-echo magnetic resonance (MR) imaging. Statistical parametric mapping was used to conduct VBM analysis of the mor phologic data, which were compared voxel by voxel with the results of a sim ilar analysis of the perfusion data and more specifically in brain areas sh owing significant perfusion changes. RESULTS: VBM data, as compared with perfusion changes, indicated a more sym metric age-related gray matter volume decrease along the Sylvian fissure an d in subcortical regions (P < .001). The combination of functional and stru ctural changes indicated a relatively lower functional decrease with aging, as compared with the structural atrophy in the visual, parietal, sensorimo tor, and right prefrontal cortices. Significant relative morphologic sex-ba sed differences were found in the cerebellar and temporal cortices, but the comparison did not reveal significant differences between the functional a nd morphometric data. CONCLUSION: Age-related perfusion changes are paralleled by similar more sy mmetric changes in gray matter concentration, which are more prominent than the perfusion changes in some regions. No sex-based differences between pe rfusion and gray matter concentration were found.