Lasya P Sreepada1,2, Sam H Jiang1, Huijun Vicky Liao1, Katherine M Breedlove1, Eduardo Coello1, and Alexander P Lin1
1Radiology, Center for Clinical Spectroscopy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States, 2Radiology, Center for Biomedical Image Computing and Analytics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
1Radiology, Center for Clinical Spectroscopy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States, 2Radiology, Center for Biomedical Image Computing and Analytics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
Basic harmonization increased within-site variance and was not able to bring metabolite means closer together or remove significant site effects. ComBat successfully estimated and removed significant site effects, verified ANOVA and Tukey HSD tests.
ComBat Harmonization: Box plots illustrating the means and significance with * or p-values (A) before harmonization and (B) after harmonization in all 4 sites, for (i) tNAA (ii) tCr (iii) Glx; (C) Visualization of Site effects that are removed by ComBat.
(A) Voxel placement of PCG within the brain (B) LCModel output showing the processed spectrum in one subject at SITE 1. The selected scan passed all the manual QA measures and had an FWHM of 8 after pre-processing, the lowest in our dataset.
