Measuring the corpus callosum in schizophrenia: a technique with neuroanatomical and cytoarchtectural basis

Background: Corpus Callosum (CC) abnormalities have been described in schizophrenia. Review of CC measurement methods in schizophrenia reveals inconsistency and lack of neuroanatomical basis.
Aims: The aims of the study are to describe a new CC measurement method with valid a neuroanatomical and cytoarchitectural basis and to demonstrate inter-rater reliability for the same.
Settings and Design: The study was performed in the National Institute of Mental Health & Neurosciences, Bangalore, India. Ours is a cross-sectional study in which both the first author and senior neuroradiologist were blind to clinical details.
Material and Methods: We report a reliable, semi-automated CC measuring technique with a neuroanatomical and cytoarchitectural basis tested in a group of 16 never-treated schizophrenia patients using 1-mm thick, objectively defined midsagittal MRI section. Measurement on coded slices using scion image software ensured elimination of rater bias.
Statistical Analysis Used: The statistical analysis used for assessing inter-rater reliability is intraclass correlation coefficient analysis.
Results: The intraclass correlation coefficients for the CC measurements were as follows: CC Area = 0.93; Anterior CC area = 0.84; Area of body of the CC = 0.83; Area of CC isthmus = 0.65; Area of CC splenium = 0.88; maximum antero-posterior distance of CC = 0.96.
Conclusion: Measurements showed good inter-rater reliability. The methodology demonstrated in our study is simple, relevant, reliable and can be used for future schizophrenia research.

Keywords
Schizophrenia, Corpus callosum, Neuroanatomy, Cytoarchitecture, Imaging