Privacy-preserving harmonization via distributed ComBat

• Published in: NeuroImage (Orlando, Fla.) Vol. 248; p. 118822
• Main Authors: Chen, Andrew A., Luo, Chongliang, Chen, Yong, Shinohara, Russell T., Shou, Haochang
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2022; Elsevier Limited; Elsevier
• Subjects: Algorithms; Alzheimer's disease; ComBat; Datasets; Distributed analysis; Estimates; Harmonization; Humans; Information Dissemination; Magnetic fields; Medical imaging; Methods; Neurodegenerative diseases; Neuroimaging; Privacy; Privacy-preserving; Scanners; Site effect; Structure-function relationships; Systems Integration; Privacy-preserving; Distributed analysis; Site effect; ComBat; Harmonization
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2021.118822

Challenges in clinical data sharing and the need to protect data privacy have led to the development and popularization of methods that do not require directly transferring patient data. In neuroimaging, integration of data across multiple institutions also introduces unwanted biases driven by scanner differences. These scanner effects have been shown by several research groups to severely affect downstream analyses. To facilitate the need of removing scanner effects in a distributed data setting, we introduce distributed ComBat, an adaptation of a popular harmonization method for multivariate data that borrows information across features. We present our fast and simple distributed algorithm and show that it yields equivalent results using data from the Alzheimer’s Disease Neuroimaging Initiative. Our method enables harmonization while ensuring maximal privacy protection, thus facilitating a broad range of downstream analyses in functional and structural imaging studies.