Reducing inter-scanner variability of activation in a multicenter fMRI study: role of smoothness equalization

Lee Friedman; Gary H Glover; Diana Krenz; Vince Magnotta

doi:10.1016/j.neuroimage.2006.03.062

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Reducing inter-scanner variability of activation in a multicenter fMRI study: role of smoothness equalization

Journal article

Peer reviewed

Reducing inter-scanner variability of activation in a multicenter fMRI study: role of smoothness equalization

Lee Friedman, Gary H Glover, Diana Krenz and Vince Magnotta

NeuroImage (Orlando, Fla.), Vol.32(4), pp.1656-1668

10/01/2006

DOI: 10.1016/j.neuroimage.2006.03.062

PMID: 16875843

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Abstract

Scanner-to-scanner variability of activation in multicenter fMRI studies is often considered undesirable. The purpose of this investigation was to evaluate the effect of a new procedure, "smoothness equalization", on reducing scanner differences in activation effect size as part of a multicenter fMRI project (FIRST BIRN). Five subjects were sent to 9 centers (10 scanners) and scanned on 2 consecutive days using a sensorimotor fMRI protocol. High-field (4 T and 3 T) and low-field (1.5 T) scanners from three vendors (GE, Siemens, and Picker) were included. The activation effect size of the scanners for the detection of neural activation during a sensorimotor task was evaluated as the percent of temporal variance accounted for by our model (percent of variance accounted for or PVAF). Marked scanner effects were noted for both PVAF as well as the degree of smoothness of the raw and processed images. After smoothness equalization, there was a dramatic (low field) or consistent (high-field) reduction in scanner-to-scanner variation of activation. It was shown that the likely basis of the scanner differences in smoothness was differences in k-space filtering algorithms. This work highlights the need to account for differences in smoothness when comparing scanners on activation effect size in multicenter fMRI studies.

Data Interpretation, Statistical

Magnetic Resonance Imaging - instrumentation

Image Processing, Computer-Assisted

Humans

Adult

Male

Factor Analysis, Statistical

Calibration

Phantoms, Imaging

Echo-Planar Imaging

Details

Title: Subtitle: Reducing inter-scanner variability of activation in a multicenter fMRI study: role of smoothness equalization
Creators: Lee Friedman - Department of Psychiatry and Human Behavior, University of California-Irvine, CA 92617, USA. lfriedman10@comcast.net
Gary H Glover
Diana Krenz
Vince Magnotta
Resource Type: Journal article
Publication Details: NeuroImage (Orlando, Fla.), Vol.32(4), pp.1656-1668
Publisher: United States
DOI: 10.1016/j.neuroimage.2006.03.062
PMID: 16875843
ISSN: 1053-8119
eISSN: 1095-9572
Grant note: 5 M01 RR 000827 / NCRR NIH HHS
Language: English
Date published: 10/01/2006
Academic Unit: Roy J. Carver Department of Biomedical Engineering; Radiology; Psychiatry; Iowa Neuroscience Institute
Record Identifier: 9984051792002771

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