Compressed sensing MR image reconstruction using constraint from prior acquisition

Patent metadata

Field	Value
Publication number	US-9733328-B2
Application number	US-201214006244-A
Country	US
Kind code	B2
Filing date	Feb 28, 2012
Priority date	Mar 24, 2011
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

The invention relates to a method of MR imaging of at least a portion of a body ( 10 ) of a patient placed in an examination volume of a MR device ( 1 ), the method comprising the steps of: —subjecting the portion of the body ( 10 ) to a first imaging sequence for acquiring a first signal data set ( 21 ); —subjecting the portion of the body ( 10 ) to a second imaging sequence for acquiring a second signal data set ( 23 ), wherein the imaging parameters of the second imaging sequence differ from the imaging parameters of the first imaging sequence; —reconstructing a MR image from the second signal data set ( 23 ) by means of regularization using the first signal data set ( 21 ) as prior information. Moreover, the invention relates to a MR device ( 1 ) and to a computer program for a MR device ( 1 ).

First claim

The invention claimed is:

1. Method of MR imaging of at least a portion of a body of a patient placed in an examination volume of a MR device, the method comprising the steps of:
subjecting the portion of the body to a first imaging sequence for acquiring a first signal data set;
subjecting the portion of the body to a second imaging sequence for acquiring a second signal data set, wherein the imaging parameters of the second imaging sequence differ from the imaging parameters of the first imaging sequence and wherein the first and/or second signal data sets are undersampled;
reconstructing a MR image from the second signal data set by means of compressed sensing and wherein the compressed sensing reconstruction is constrained by a support, which support is derived from the first signal data set and wherein the imaging parameters of the second imaging sequence differ from the imaging parameters of the first imaging sequence in such a manner that the second signal data set is of a different contrast type or of a different resolution than the first signal data set.

2. Method of claim 1 , wherein the first and second imaging sequences are selected from the group consisting of:
T 1 -weighted spin echo, T 2 -weighted spin echo, fluid-attenuated inversion-recovery, T 1 -weighted gradient-echo, T 2 *-weighted gradient echo, contrast enhanced T 1 -weighted gradient echo, contrast enhanced T 1 -weighted spin echo, diffusion-weighted spin echo.

3. Method of claim 1 wherein an image support in a sparse domain is identified from the first signal data set.

4. Method of claim 1 , wherein non-Cartesian sampling of k-space is applied during acquisition of the first and/or second signal data sets.

5. Method of claim 1 , wherein the first and/or second signal data sets are acquired by means of parallel imaging via two or more RF receiving antennas, wherein the MR image is reconstructed by taking the spatial sensitivity profiles of the RF receiving antennas into account.

6. Method of claim 1 , wherein a variable density k-space sampling pattern of the second imaging sequence is determined from the first signal data set.

7. Method of claim 1 , wherein background image regions containing no image intensity are determined from the first signal data set, and wherein the determined background image regions are used as a constraint in the reconstruction of the MR image.

8. Method of claim 1 , further comprising image registration and/or motion correction of the first and second signal data sets before reconstruction of the MR image.

9. MR device for carrying out the method as claimed in claim 1 , which MR device includes at least one main magnet coil for generating a uniform, steady magnetic field within an examination volume, a number of gradient coils for generating switched magnetic field gradients in different spatial directions within the examination volume, at least one RF coil for generating RF pulses within the examination volume and/or for receiving MR signals from a body of a patient positioned in the examination volume, a control unit for controlling the temporal succession of RF pulses and switched magnetic field gradients, a reconstruction unit, and a visualization unit, wherein the MR device is arranged to perform the following steps:
subjecting the portion of the body to a first imaging sequence comprising RF pulses and switched magnetic field gradients for acquiring a first signal data set;
subjecting the portion of the body to a second imaging sequence comprising RF pulses and switched magnetic field gradients for acquiring a second signal data set, wherein the imaging parameters of the second imaging sequence differ from the imaging parameters of the first imaging sequence, wherein the first and/or second signal data sets are undersampled;
reconstructing a MR image from the second signal data set by means of compressed sensing and wherein the compressed sensing reconstruction is constrained by a support, which support is derived from the first signal data set and wherein the imaging parameters of the second imaging sequence differ from the imaging parameters of the first imaging sequence in such a manner that the second signal data set is of a different contrast type or of a different resolution than the first signal data set.

10. Computer program to be run on a MR device, which computer program comprises instructions for:
generating a first imaging sequence for acquiring a first signal data set;
generating a second imaging sequence for acquiring a second signal data set, wherein the imaging parameters of the second imaging sequence differ from the imaging parameters of the first imaging sequence, and the first and/or second signal data sets are undersampled;
reconstructing a MR image from the second signal data set, by means of compressed sensing and wherein the compressed sensing reconstruction is constrained by a support, which support is derived from the first signal data set and wherein the imaging parameters of the second imaging sequent differ from the imaging parameters of the first imaging sequence in such a manner that the second signal data set is of a different contrast type or of a different resolution than the first signal data set.

Assignees

• Doneva Mariya Ivanova
• Remmele Stefanie
• Börnert Peter
• Mazurkewitz Peter
• Senegas Julien
• Keupp Jochen
• Nehrke Kay
• Koninklijke Philips Nv

Inventors

• Doneva Mariya Ivanova
• Remmele Stefanie
• Börnert Peter
• Mazurkewitz Peter
• Senegas Julien
• Keupp Jochen
• Nehrke Kay

Classifications

• G01R33/56 Primary

  Image enhancement or correction, e.g. subtraction or averaging techniques {, e.g. improvement of signal-to-noise ratio and resolution} · CPC title

• G01R33/4824

  using a non-Cartesian trajectory · CPC title

• G01R33/56509

  due to motion, displacement or flow, e.g. gradient moment nulling (G01R33/567 takes precedence) · CPC title

• G01R33/5608

  Data processing and visualization specially adapted for MR, e.g. for feature analysis and pattern recognition on the basis of measured MR data, segmentation of measured MR data, edge contour detection on the basis of measured MR data, for enhancing measured MR data in terms of signal-to-noise ratio by means of noise filtering or apodization, for enhancing measured MR data in terms of resolution by means for deblurring, windowing, zero filling, or generation of gray-scaled images, colour-coded images or images displaying vectors instead of pixels (image data processing or generation, in general G06T) · CPC title

• G01R33/5611

  Parallel magnetic resonance imaging, e.g. sensitivity encoding [SENSE], simultaneous acquisition of spatial harmonics [SMASH], unaliasing by Fourier encoding of the overlaps using the temporal dimension [UNFOLD], k-t-broad-use linear acquisition speed-up technique [k-t-BLAST], k-t-SENSE (structural details of arrays of sub-coils G01R33/3415) · CPC title