Patent ID: 7253627
Filing Date: 2007-08-07
Classification: G01R

Abstract:
1. A method for removing noise from nuclear magnetic resonance signals and images, comprising the steps of: (a) estimating a noise variance associated with a nuclear magnetic resonance (NMR) signal; (b) sampling the nuclear magnetic resonance signal; (c) digitizing the nuclear magnetic resonance signal; (d) selecting a set of analysis sampling rates, each of the rates varying in the number of samples in frequency so that each element of the set has a compact signal representation for at least one component according to differing component relaxation times of the signal; (e) for each element of the set of sampling rates, performing a stable linear time-frequency (SLTF) transform in order to determine transform coefficients for the element; (f) for each element of the set of sampling rates, applying threshold criteria to the transform coefficients, setting coefficients below a noise threshold value equal to zero in order to denoise the coefficients; (g) for each element of the set of sampling rates, performing an inverse SLTF transform on the denoised coefficients in order to form a denoised signal; and (h) averaging the denoised SLTF transform signals to form a denoised nuclear magnetic resonance signal.