Noise characteristics of arterial spin labeling fMRI using spiral SENSE at 3T
Bydder M, Perthen J, Liu T, Restom K
In this study, the effect of parallel imaging on the noise characteristics of ASL fMRI data was investigated. Whilst thermal noise increased as the length of the acquisition window shortens, the contribution of respiratory noise was found to decrease, possibly reflecting the fact that there is less time for accrual of global phase errors induced by expansion of the thoracic cavity. Functional data show that in areas of the brain contaminated by respiratory noise, the use of physiological noise correction schemes gives the largest improvement in SNR when using long readout windows.