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Neuroimage. 2016 Jul 1;134:281-294. doi: 10.1016/j.neuroimage.2016.03.051. Epub 2016 Apr 1.

Power estimation for non-standardized multisite studies.

Author information

1
Department of Neurology, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, USA. Electronic address: anisha.keshavan@ucsf.edu.
2
NeuroCure Clinical Research Center and Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité University Medicine Berlin, Berlin, Germany; Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité University Medicine Berlin, Berlin, Germany. Electronic address: Friedemann.Paul@charite.de.
3
Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway. Electronic address: mona.beyer@lyse.net.
4
Department of Neurology, University of California, San Francisco, CA, USA. Electronic address: Alyssa.Zhu@ucsf.edu.
5
Department of Neurology, University of California, San Francisco, CA, USA. Electronic address: Nico.Papinutto@ucsf.edu.
6
Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA. Electronic address: rshi@mail.med.upenn.edu.
7
Department of Neurology, University of California, San Francisco, CA, USA. Electronic address: William.Stern@ucsf.edu.
8
Department of Neurology, Basel University Hospital, University of Basel, Basel, Switzerland. Electronic address: michael.amann@usb.ch.
9
Brigham and Women's Hospital, MA, United States. Electronic address: rbakshi@post.harvard.edu.
10
Department of Neurology, University of California, San Francisco, CA, USA; Department of Neurology, Basel University Hospital, University of Basel, Basel, Switzerland; Clinical Immunology, University Hospital Basel,University of Basel, Basel, Switzerland. Electronic address: antje.Bischof@ucsf.edu.
11
Department of Translational Medicine, Department of Radiology, UPO University, Via Solaroli 17, 28100 Novara, Italy. Electronic address: alessandro.carriero@med.unipmn.it.
12
Hospital Universitari Vall d'Hebron, Barcelona, Spain. Electronic address: manuel.comabella@vhir.org.
13
Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA. Electronic address: Jason.Crane@ucsf.edu.
14
Department of Health Sciences, UPO University, Novara, Italy. Electronic address: sandra.dalfonso@med.uniupo.it.
15
Department of Radiology, University Hospitals Leuven, Leuven, Belgium. Electronic address: Philippe.Demaerel@uzleuven.be.
16
KU Leuven-University of Leuven, Department of Neurosciences, Leuven, Belgium. Electronic address: Benedicte.dubois@uzleuven.be.
17
Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy. Electronic address: zonca.lucia@hsr.it.
18
Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn2), University Medical Centre of the Johannes Gutenberg University Mainz, Germany. Electronic address: Vinzenz.Fleischer@unimedizin-mainz.de.
19
Hôpital Pitié-Salpêtrière, ICM, UPMC 06 UM 75, INSERM U 1127, CNRS UMR 7225, IHU-A-ICM, AP-HP: Pôle des maladies du système nerveux, 47 boulevard de l'Hôpital, 75013 Paris, France. Electronic address: bertrand.fontaine@upmc.fr.
20
Department of Neurology, Basel University Hospital, University of Basel, Basel, Switzerland; Medical Image Analysis Center (MIAC AG), Basel, Switzerland. Electronic address: laura.gaetanosf@gmail.com.
21
KU Leuven-University of Leuven, Department of Neurosciences, Leuven, Belgium. Electronic address: An.Goris@med.kuleuven.be.
22
Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn2), University Medical Centre of the Johannes Gutenberg University Mainz, Germany. Electronic address: Christiane.Graetz@unimedizin-mainz.de.
23
Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn2), University Medical Centre of the Johannes Gutenberg University Mainz, Germany. Electronic address: adriane.groeger@unimedizin-mainz.de.
24
Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn2), University Medical Centre of the Johannes Gutenberg University Mainz, Germany. Electronic address: Sergiu.Groppa@unimedizin-mainz.de.
25
Departments of Neurology and Immunobiology, Yale School of Medicine, CT, USA. Electronic address: david.hafler@yale.edu.
26
Department of Neurology, Oslo University Hospital and University of Oslo, Oslo, Norway. Electronic address: h.f.harbo@medisin.uio.no.
27
Dept. Neurology of the Klinikum rechts der Isar, Technische Universität München, Munich, Germany; Munich Cluster of Systems Neurology (SyNery), Germany. Electronic address: hemmer@tum.de.
28
Department of Neurology, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, USA. Electronic address: Kesshi.Jordan@ucsf.edu.
29
Department of Neurology, Basel University Hospital, University of Basel, Basel, Switzerland. Electronic address: Ludwig.Kappos@usb.ch.
30
Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA. Electronic address: Gina.Kirkish@ucsf.edu.
31
Center for Neuroimmunology, Hospital Clinic Barcelona, IDIBAPS, Barcelona, Spain. Electronic address: SLLUFRIU@clinic.ub.es.
32
Department of Neurology, Basel University Hospital, University of Basel, Basel, Switzerland. Electronic address: Stefano.Magon@usb.ch.
33
Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy. Electronic address: martinelli.filippo@hsr.it.
34
John P. Hussman Institute for Human Genomics and the Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, USA. Electronic address: jmccauley@med.miami.edu.
35
Hospital Universitari Vall d'Hebron, Barcelona, Spain. Electronic address: xavier.montalban@cem-cat.org.
36
Dept. Neurology of the Klinikum rechts der Isar, Technische Universität München, Munich, Germany; TUM-Neuroimaging Center, Technische Universität München, Munich, Germany. Electronic address: muehlau@lrz.tu-muenchen.de.
37
Departments of Neurology and Immunobiology, Yale School of Medicine, CT, USA. Electronic address: daniel.pelletier@yale.edu.
38
Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USA. Electronic address: PPattany@med.miami.edu.
39
John P. Hussman Institute for Human Genomics and the Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, USA. Electronic address: MPericak@med.miami.edu.
40
Hôpital Pitié-Salpêtrière, ICM, UPMC 06 UM 75, INSERM U 1127, CNRS UMR 7225, IHU-A-ICM, AP-HP: Pôle des maladies du système nerveux, 47 boulevard de l'Hôpital, 75013 Paris, France. Electronic address: isabelle.rebeix@upmc.fr.
41
Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy. Electronic address: rocca.mara@hsr.it.
42
Hospital Universitari Vall d'Hebron, Barcelona, Spain. Electronic address: alex.rovira@idi.gencat.cat.
43
Department of Neurology, University of California, San Francisco, CA, USA; Department of Neurology, Basel University Hospital, University of Basel, Basel, Switzerland; Clinical Immunology, University Hospital Basel,University of Basel, Basel, Switzerland. Electronic address: regina.schlaeger@ucsf.edu.
44
Center for Neuroimmunology, Hospital Clinic Barcelona, IDIBAPS, Barcelona, Spain. Electronic address: ASAIZ@clinic.ub.es.
45
Department of Neurology, Basel University Hospital, University of Basel, Basel, Switzerland; DKD Helios Klinik Wiesbaden, Wiesbaden, Germany. Electronic address: Till.sprenger@usb.ch.
46
Section of Neuroradiology, Department of Radiology, Maggiore Hospital, Corso Mazzini 18, 28100, Novara, Italy. Electronic address: a.stecco@libero.it.
47
MS Center Amsterdam, VU University Medical Center Amsterdam, The Netherlands. Electronic address: bmj.uitdehaag@vumc.nl.
48
Center for Neuroimmunology, Hospital Clinic Barcelona, IDIBAPS, Barcelona, Spain. Electronic address: Pablo.VillosladaDiaz@ucsf.edu.
49
MS Center Amsterdam, VU University Medical Center Amsterdam, The Netherlands. Electronic address: m.wattjes@vumc.nl.
50
Brigham and Women's Hospital, MA, United States. Electronic address: hweiner@rics.bwh.harvard.edu.
51
NeuroCure Clinical Research Center and Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité University Medicine Berlin, Berlin, Germany; Medical Image Analysis Center, Basel, Switzerland. Electronic address: jw@miac.ch.
52
Dept. Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. Electronic address: claus.zimmer@tum.de.
53
Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn2), University Medical Centre of the Johannes Gutenberg University Mainz, Germany. Electronic address: Frauke.zipp@unimedizin-mainz.de.
54
International Multiple Sclerosis Genetics Consortium, USA, EU, AU.
55
Department of Neurology, University of California, San Francisco, CA, USA. Electronic address: Stephen.Hauser@ucsf.edu.
56
Department of Neurology, University of California, San Francisco, CA, USA. Electronic address: Jorge.Oksenberg@ucsf.edu.
57
Department of Neurology, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA. Electronic address: Roland.Henry@ucsf.edu.

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 power equation, 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.

PMID:
27039700
PMCID:
PMC5656257
DOI:
10.1016/j.neuroimage.2016.03.051
[Indexed for MEDLINE]
Free PMC Article

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