US 2013/0076352 A1Published application

Method to select an undersampling scheme for magnetic resonance imaging, and magnetic resonance imaging method and system using such a selected undersampling scheme

AssigneeSiemens Aktiengesellschaft

InventorsKai Tobias Block, Stephan Kannengiesser, Marcel Dominik Nickel

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Abstract

In a method to select an undersampling scheme of k-space and an associated set of reconstruction kernels to acquire reduced magnetic resonance (MR) data sets with multiple coils, a calibration data set is acquired for each of the respective coils, a noise covariance is determined from autocorrelations and correlations of the noise of the various coils. At least one set of reconstruction kernels is calculated for each of the multiple undersampling schemes from the calibration data sets of the various coils. For each set of reconstruction kernels, a characteristic value is calculated from the noise covariance and the respective reconstruction kernels of the coils, with the characteristic value being proportional to a spatial mean value of a signal noise of an MR image. A selected undersampling scheme and a selected set of reconstruction kernels are selected based on the calculated characteristic values.

Claims9

Dependent claims

A method to select an undersampling scheme for entering data into k-space, and to select an associated set of reconstruction kernels to acquire reduced magnetic resonance data sets with multiple acquisition coils, comprising:

operating a magnetic resonance data acquisition unit, comprising a plurality of magnetic resonance data acquisition coils, to acquire a calibration data set for each of said plurality of coils, each calibration data set embodying noise therein;
in a processor, determining, from the noise in the respective calibration data sets, a noise covariance by measuring autocorrelations and correlations of the respective noise of the respective coils respectively represented in the calibration data sets;
in said processor, calculating at least one set of reconstruction kernels for each of a plurality of undersampling schemes from said calibration data sets of the respective coils;
in said processor, for each of said reconstruction kernels, calculating a characteristic value from the noise covariance and the respective reconstruction kernels of the coils, said characteristic value being proportional to a spatial mean value of signal noise of an MR image to be reconstructed using the respective reconstruction kernels;
and
in said processor, choosing a selected undersampling scheme and a selected set of associated reconstruction kernels from the calculated characteristic values, and making an electronic representation of the selected undersampling scheme and the selected set of reconstruction kernels available at an output of said processor.

3 more elements

A method for acquiring magnetic resonance image data, comprising:

operating a magnetic resonance data acquisition unit, comprising a plurality of magnetic resonance data acquisition coils, to acquire a calibration data set for each of said plurality of coils, each calibration data set embodying noise therein;
in a processor, determining, from the noise in the respective calibration data sets, a noise covariance by measuring autocorrelations and correlations of the respective noise of the respective coils respectively represented in the calibration data sets;
in said processor, calculating at least one set of reconstruction kernels for each of a plurality of undersampling schemes from said calibration data sets of the respective coils;
in said processor, for each of said reconstruction kernels, calculating a characteristic value from the noise covariance and the respective reconstruction kernels of the coils, said characteristic value being proportional to a spatial mean value of signal noise of an MR image to be reconstructed using the respective reconstruction kernels;
in said processor, choosing a selected undersampling scheme and a selected set of associated reconstruction kernels from the calculated characteristic values, and making an electronic representation of the selected undersampling scheme and the selected set of reconstruction kernels available at an output of said processor;
for each coil, acquiring a reduced magnetic resonance data set with the selected undersampling scheme;
for each coil, applying the respective reconstruction kernel to the reduced magnetic resonance data set acquired thereby, in order to obtain a reconstructed magnetic resonance data set;
and
calculating a magnetic resonance image from the reconstructed magnetic resonance data sets of the respective coils.

6 more elements

Dependencies are inferred from the claim text.