Distribution of cortical benzodiazepine receptor binding in right-handed healthy humans: a voxel-based statistical analysis of iodine 123 iomazenil SPECT with partial volume correction.

BACKGROUND AND PURPOSE CBR imaging is highly susceptible to a PVE produced by morphologic changes in the brain related to aging and brain laterality. We assessed the influence of PVE produced by regional age-related changes in gray matter volume on I-123 iomazenil SPECT and elucidated the age-related changes in human CBR binding by using PVE-corrected SPECT images. MATERIALS AND METHODS Nineteen right-handed healthy volunteers (range, 25-82 years; mean, 55 ± 21 years) underwent MR imaging and quantitative I-123 iomazenil SPECT imaging. The influence of age-related changes in rGMC on SPECT images before PVE correction was assessed. PVE correction of the SPECT images was performed by using an MR imaging-based method. Voxel-based linear regression analyses of the PVE-corrected SPECT images were performed by using SPM5. RESULTS The age-related reductions in rGMC and BP without PVE correction revealed a significant direct proportional correlation. Voxel-based statistical analysis with PVE correction showed no significant age-related changes in BP. CONCLUSIONS PVE correction was indispensable for the analysis of I-123 iomazenil SPECT images. PVE-corrected quantitative I-123 iomazenil SPECT images revealed no age-related changes in CBR binding in right-handed healthy humans.