Coherence filtering for magnetic resonance imaging (MRI) signals

1 . A device configured to filter magnetic resonance (MR) signals, the device comprising at least one electronic processor programmed to:

receive at least one MR signal excited in a subject disposed in an MR imaging device;

transform the at least one MR signal with a coherence function representing the at least one MR signal as an instantaneous frequency spectrum as a function of time;

apply spectral filtering to the transformed at least one MR signal; and

reconstruct at least one medical image from the filtered at least one MR signal,

wherein the at least one MR signal comprises a plurality of MR signals, and the coherence function comprises a cross-coherence function; and

wherein each MR signal of the plurality of MR signals is received from a corresponding channel in a MR coil, and the cross-coherence function comprises a mean-squared coherence used on a channel-pair basis.

2 . The device of claim 1 , wherein the transforming includes transforming the at least one MR signal into the frequency domain using a Fast Fourier Transform (FFT), and filtering comprises:

calculating the coherence function on a predetermined scale for a selected time window around each datapoint in time of the at least one MR signal to generate a coherence value; and

multiplying the FFT of the at least one MR signal in the selected time window by the coherence value.

3 . The device of claim 2 , wherein the filtering further includes:

prior to the multiplying, thresholding the coherence value to completely suppress the signal at time intervals where the coherence is below a predetermined threshold.

4 . A magnetic resonance (MR) receive coil, comprising:

at least one MR coil element configured to receive MR signals excited in a subject disposed in an MR imaging device; and

electronics configured to:

receive a MR signal excited in a subject disposed in an MR imaging device;

transform the MR signal with a coherence function representing the MR signal as an instantaneous frequency spectrum as a function of time;

apply spectral filtering to the transformed MR signal; and

reconstruct at least one medical image from the filtered MR signal, wherein the at least one MR signal comprises a plurality of MR signals, and the coherence function comprises a cross-coherence function; and

wherein each MR signal of the plurality of MR signals is received from a corresponding channel in a MR coil, and the cross-coherence function comprises a mean-squared coherence used on a channel-pair basis.

5 . The MR receive coil of claim 4 , wherein the filtering further includes:

prior to the multiplying, thresholding the coherence value to completely suppress the signal at time intervals where the coherence is below a predetermined threshold.

6 . A magnetic resonance imaging system configured to image a subject, the system comprising the magnetic resonance receive coil of claim 4 .