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.

High-resolution functional MRI (fMRI) offers unique possibilities for studying human functional neuroanatomy. Although high-resolution fMRI has proven its potential at 7 T, most fMRI studies are still performed at rather low spatial resolution at 3 T. We optimized and compared single-shot two-dimensional echo-planar imaging (EPI) and multishot three-dimensional EPI high-resolution fMRI protocol...

In MRI, physiological noise which originates from cardiac and respiratory functions can induce substantial errors in detecting small signals in the brain. In this work, we explored the effects of the physiological noise and their compensation methods in gradient-echo myelin water imaging (GRE-MWI). To reduce the cardiac function induced inflow noise, flow saturation RF pulses were applied to th...

In this article we introduce the DRIFTER algorithm, which is a new model based Bayesian method for retrospective elimination of physiological noise from functional magnetic resonance imaging (fMRI) data. In the method, we first estimate the frequency trajectories of the physiological signals with the interacting multiple models (IMM) filter algorithm. The frequency trajectories can be estimated...

Introduction In fMRI studies, BOLD signal changes are often characterized by a low signal-to-noise ratio (SNR). Physiological artifacts such as cardiac and respiratory noise constitute an important confounding factor that may prevent the detection of significant activations. Moreover, the relatively low temporal resolution of standard fMRI acquisitions cannot adequately sample the artifactual s...