Reliability of brain structure morphometry in hydrocephalic children using MR images

To assess the ability of human operators to make decisions about region boundaries in significantly malformed brains, we performed a study of the reliability of morphometric measurements of specific brain structures from MRI in children with hydrocephalus and controls. Cross-sectional area measures of the corpus callosum, internal capsules and centrum semiovale, and volumes of the lateral ventricles were made in 50 children. Independent measurements were made by two raters on T1 and T2-weighted MR images. Pearsonʹs correlation coefficients (r) and intraclass correlation coefficients (ICC) between the two raterʹs sets of measures were computed for each structure across all subjects. ICCs ranged from a low of 0.7502 to a high of 0.9895. All ICCs were significant at the p < .0001 level and were generally less than or equal to the corresponding Pearsonʹs r value in every case. Therefore, the Pearsonʹs r may overestimate the reliability. The results of this study support the claim that the ICC should be used rather than the Pearsonʹs r when assessing interater reliability in situations where large between-group differences are present. In addition, the results show that brains malformed by disorders, such as hydrocephalus, can be reliably assessed using morphometric measures of MR images.