Where in-vivo imaging meets cytoarchitectonics: The relationship between cortical thickness and neuronal density measured with high-resolution [18F]flumazenil-PET

► GABA-receptors were assessed with HRRT-PET as a surrogate for neuronal density (ND). ► ND was correlated with MRI-based cortical thickness measurement (SCT). ► In one subset ND was relatively constant and mainly independent of SCT. ► However, in another subset ND negatively correlated with SCT. ► Morphometry studies should be interpreted cautiously with regard on neuronal density.