Harmonization of Multi-Site DTI and NODDI Data Using the Combined Association Test [Proceedings of the 2022 Young Investigator Award]

When analyzing the multi-site diffusion MRI (dMRI) data, metrics should be harmonized to remove site effect. In this study, we applied combined association test (ComBat), which used regression of covariates with an empirical Bayes framework for based on tensor imaging (DTI), neurite orientation dispersion, and density (NODDI). The results showed that ComBat could harmonize site-related effects in DTI NODDI dMRI while preserving biological information participant, such as sex differences correlation age. Thus, large studies identify subtle white matter changes.