Interhemispheric differences in regional density of the normal brain

In a study of regional variations in cerebral X-ray attenuation as measured by computed tomography, a relationship between bone-related beam hardening and lateralized hemispheric density differences was sought. The CT scans of 22 normal right-handed individuals were evaluated by calculating regional mean attenuation values and regional left-right differences in attenuation, comparing these to regional measurements of skull thickness. A statistically insignificant number of significant correlations was found. This is interpreted to mean that observed left-right hemispheric density differences are not due to beam-hardening through bone. It was also found that left-right differences in density persisted over the entirety of the evaluated slices, suggesting that this finding is due to inherent hemispheric structural differences.