@article{3e8c50470d0a4bae968651d28f752381,
title = "Comparison of phantom and registration scaling corrections using the ADNI cohort",
abstract = "Rates of brain atrophy derived from serial magnetic resonance (MR) studies may be used to assess therapies for Alzheimer's disease (AD). These measures may be confounded by changes in scanner voxel sizes. For this reason, the Alzheimer's Disease Neuroimaging Initiative (ADNI) included the imaging of a geometric phantom with every scan. This study compares voxel scaling correction using a phantom with correction using a 9 degrees of freedom (9DOF) registration algorithm. We took 129 pairs of baseline and 1-year repeat scans, and calculated the volume scaling correction, previously measured using the phantom. We used the registration algorithm to quantify any residual scaling errors, and found the algorithm to be unbiased, with no significant (p = 0.97) difference between control (n = 79) and AD subjects (n = 50), but with a mean (SD) absolute volume change of 0.20 (0.20) % due to linear scalings. 9DOF registration was shown to be comparable to geometric phantom correction in terms of the effect on atrophy measurement and unbiased with respect to disease status. These results suggest that the additional expense and logistic effort of scanning a phantom with every patient scan can be avoided by registration-based scaling correction. Furthermore, based upon the atrophy rates in the AD subjects in this study, sample size requirements would be approximately 10-12% lower with (either) correction for voxel scaling than if no correction was used.",
keywords = "Alzheimer's disease, Boundary shift integral, Brain atrophy, Registration, Scanner drift",
author = "Clarkson, {Matthew J.} and S{\'e}bastien Ourselin and Casper Nielsen and Leung, {Kelvin K.} and Josephine Barnes and Whitwell, {Jennifer L.} and Gunter, {Jeffrey L.} and Hill, {Derek L.G.} and Weiner, {Michael W.} and Jack, {Clifford R.} and Fox, {Nick C.}",
note = "Funding Information: Data collection and sharing for this project was funded by the Alzheimer's Disease Neuroimaging Initiative (ADNI; Principal Investigator: Michael Weiner; NIH grant U01 AG024904). ADNI is funded by the National Institute on Aging, the National Institute of Biomedical Imaging and Bioengineering (NIBIB), and through generous contributions from the following: Pfizer Inc., Wyeth Research, Bristol-Myers Squibb, Eli Lilly and Company, GlaxoSmithKline, Merck & Co. Inc., AstraZeneca AB, Novartis Pharmaceuticals Corporation, Alzheimer's Association, Eisai Global Clinical Development, Elan Corporation plc, Forest Laboratories, and the Institute for the Study of Aging, with participation from the U.S. Food and Drug Administration. Industry partnerships are coordinated through the Foundation for the National Institutes of Health. The grantee organization is the Northern California Institute for Research and Education, and the study is coordinated by the Alzheimer's disease Cooperative Study at the University of California, San Diego. ADNI data are disseminated by the Laboratory of Neuro Imaging at the University of California, Los Angeles. This work was undertaken at UCL/UCLH which received a proportion of funding from the Department of Health's NIHR Biomedical Research Centres funding scheme. The Dementia Research Centre is an Alzheimer's Research Trust Co-ordinating centre. MC and KL were supported by TSB grant M1638A, JB is supported by an Alzheimer{\textquoteright}s Research Trust (UK) Research Fellowship and NCF by the MRC (UK). The authors would like to thank Shona Clegg, Raivo Kittus and Lois Kim at the Dementia Research Centre for their invaluable help in assessing registration quality and statistical analysis, and also the ADNI study subjects and investigators for their participation.",
year = "2009",
month = oct,
day = "1",
doi = "10.1016/j.neuroimage.2009.05.045",
language = "English (US)",
volume = "47",
pages = "1506--1513",
journal = "NeuroImage",
issn = "1053-8119",
publisher = "Academic Press Inc.",
number = "4",
}