The Open Magnetic Resonance Journal

2008, 1 : 54-59
Published online 2008 May 27. DOI: 10.2174/1874769800801010054
Publisher ID: TOMRJ-1-54

Optimum Voxel Volume for Maximizing Contrast-to-Noise Ratio in BOLD Functional MRI

Norihiko Fujita , Kouji Okada , Hisashi Tanaka and Kenya Murase
Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.

ABSTRACT

Recent studies suggest that physiological noise, which determines the SNR of the fMRI time course at commonly used spatial resolutions, is largely spatially coherent. It is theoretically shown that the ratio of such a spatially coherent physiological to thermal noise determines the optimum voxel volume for maximizing BOLD CNR, relatively independent of the size of activation.

Keywords:

MRI, BOLD, functional MRI.