Analytically exact correction scheme for signal extraction from noisy magnitude MR signals.
An analytically exact method is proposed to extract the signal intensity and the noise variance simultaneously from noisy magnitude MR signals. This method relies on a fixed point formula of signal-to-noise ratio (SNR) and a correction factor. The correction factor, which is a function of SNR, establishes a fundamental link between the variance of the magnitude MR signal and the variance of the underlying Gaussian noise in the two quadrature channels. A more general but very similar method is developed for parallel signal acquisitions with multiple receiver coils. In the context of MR imaging, the proposed method can be carried out on a pixel-by-pixel basis if the mean and the standard deviation of the magnitude signal are available.
Koay
Cheng Guan
CG
National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA. guankoac@mail.nih.gov
Basser
Peter J
PJ
D000465:Algorithms; D016477:Artifacts; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D012815:Signal Processing, Computer-Assisted