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Power estimation for non-standardized multisite studies

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Item Type:Article
Title:Power estimation for non-standardized multisite studies
Creators Name:Keshavan, A. and Paul, F. and Beyer, M.K. and Zhu, A.H. and Papinutto, N. and Shinohara, R.T. and Stern, W. and Amann, M. and Bakshi, R. and Bischof, A. and Carriero, A. and Comabella, M. and Crane, J.C. and D'Alfonso, S. and Demaerel, P. and Dubois, B. and Filippi, M. and Fleischer, V. and Fontaine, B. and Gaetano, L. and Goris, A. and Graetz, C. and Gröger, A. and Groppa, S. and Hafler, D.A. and Harbo, H.F. and Hemmer, B. and Jordan, K. and Kappos, L. and Kirkish, G. and Llufriu, S. and Magon, S. and Martinelli-Boneschi, F. and McCauley, J. and Montalban, X. and Muhlau, M. and Pelletier, D. and Pattany, P.M. and Pericak-Vance, M. and Rebeix, I. and Rocca, M. and Rovira, A. and Schlaeger, R. and Saiz, A. and Sprenger, T. and Stecco, A. and Uitdehaag, B.M.J. and Villoslada, P. and Wattjes, M.P. and Weiner, H. and Wuerfel, J. and Zimmer, C. and Zipp, F. and Hauser, S. and Oksenberg, J.R. and Henry, R.G.
Abstract:A concern for researchers planning multisite studies is that scanner and T1-weighted sequence-related biases on regional volumes could overshadow true effects, especially for studies with a heterogeneous set of scanners and sequences. Current approaches attempt to harmonize data by standardizing hardware, pulse sequences, and protocols, or by calibrating across sites using phantom-based corrections to ensure the same raw image intensities. We propose to avoid harmonization and phantom-based correction entirely. We hypothesized that the bias of estimated regional volumes is scaled between sites due to the contrast and gradient distortion differences between scanners and sequences. Given this assumption, we provide a new statistical framework and derive a power equation to define inclusion criteria for a set of sites based on the variability of their scaling factors. We estimated the scaling factors of 20 scanners with heterogeneous hardware and sequence parameters by scanning a single set of 12 subjects at sites across the United States and Europe. Regional volumes and their scaling factors were estimated for each site using Freesurfer's segmentation algorithm and ordinary least squares, respectively. The scaling factors were validated by comparing the theoretical and simulated power curves, performing a leave-one-out calibration of regional volumes, and evaluating the absolute agreement of all regional volumes between sites before and after calibration. Using our derived powerequation, we were able to define the conditions under which harmonization is not necessary to achieve 80% power. This approach can inform choice of processing pipelines and outcome metrics for multisite studies based on scaling factor variability across sites, enabling collaboration between clinical and research institutions.
Keywords:Algorithms, Artifacts, Brain, Computer Simulation, Equipment Design, Equipment Failure Analysis, Europe, Image Enhancement, Image Interpretation, Computer-Assisted, Magnetic Resonance Imaging, Models, Statistical, Reproducibility of Results, Sensitivity And Specificity, United States
Publisher:Academic Press
Page Range:281-294
Date:1 July 2016
Official Publication:https://doi.org/10.1016/j.neuroimage.2016.03.051
PubMed:View item in PubMed

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