US 8,427,156 B2 · Systems and methods for image reconstruction of sensitivity encoded MRI data

Abstract

Methods and systems in a parallel magnetic resonance imaging (MRI) system utilize sensitivity-encoded MRI data acquired from multiple receiver coils together with spatially dependent receiver coil sensitivities to generate MRI images. The acquired MRI data forms a reduced MRI data set that is undersampled in at least a phase-encoding direction in a frequency domain. The acquired MRI data and auto-calibration signal data are used to determine reconstruction coefficients for each receiver coil using a weighted or a robust least squares method. The reconstruction coefficients vary spatially with respect to at least the spatial coordinate that is orthogonal to the undersampled, phase-encoding direction(s) (e.g., a frequency encoding direction). Values for unacquired MRI data are determined by linearly combining the reconstruction coefficients with the acquired MRI data within neighborhoods in the frequency domain that depend on imaging geometry, coil sensitivity characteristics, and the undersampling factor of the acquired MRI data. An MRI image is determined from the reconstructed unacquired data and the acquired MRI data.

Claims20

Dependent claims

A method for reconstructing an actual image from sensitivity encoded magnetic resonance imaging (MRI) data capable of being represented in a frequency domain, the frequency domain comprising at least a phase-encoding direction and a frequency-encoding direction, the phase-encoding and frequency-encoding directions corresponding to a first spatial dimension and a second spatial dimension, respectively, the method comprising:

acquiring an undersampled MRI data set undersampled in at least the phase-encoding direction;
determining reconstruction coefficients of the undersampled MRI data set, wherein the reconstruction coefficients have values that vary across at least the second spatial dimension, which corresponds to the frequency-encoding direction, wherein variation of the values of the reconstruction coefficients is based on variation of coil sensitivities;
determining a reconstructed MRI data set by combining the reconstruction coefficients and the undersampled MRI data set;
determining a complete MRI data set by combining the undersampled MRI data set and the reconstructed MRI data set;
and
outputting at least a portion of the complete MRI data set to an output device configured for display or onto a non-transitory computer readable medium.

3 more elements

acquiring a undersampled MRI data set undersampled in at least the phase-encoding direction;
determining reconstruction coefficients of the undersampled MRI data set, wherein the reconstruction coefficients spatially vary in values in at least the second spatial dimension, which corresponds to the frequency-encoding direction, and the reconstruction coefficients are determined based on receiver coil sensitivities and coordinate values of at least one non-phase encoding direction;
determining a reconstructed MRI data set by combining the reconstruction coefficients and the undersampled MRI data set;
determining a complete MRI data set by combining the undersampled MRI data set and the reconstructed MRI data set;
and
outputting at least a portion of the complete MRI data set to an output device configured for display or onto a non-transitory computer readable medium.

3 more elements

Dependencies are inferred from the claim text.

Systems and methods for image reconstruction of sensitivity encoded MRI data

Life of this patent

Systems and methods for image reconstruction of sensitivity encoded MRI data

Life of this patent

Abstract

Claims20