Automatic optimization of parallel imaging acceleration parameters

Patent metadata

Field	Value
Publication number	US-10107884-B2
Application number	US-201414774187-A
Country	US
Kind code	B2
Filing date	Mar 12, 2014
Priority date	Mar 13, 2013
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A parallel magnetic resonance imaging system (1) includes at least one radio frequency (RF) coil (10, 12) with a plurality of coil elements, a smart select unit (24), a parallel imaging parameter unit (28), and a sequence control (16). The smart select unit (24), from a pre-scan or prior scan of a subject with the at least one RF coil, constructs (60) a signal map and a plurality of noise maps based on different sets of reduction factors. The parallel imaging parameter unit (28) selects a set of reduction factors corresponding to a noise map which includes a highest signal-to-noise ratio (SNR). The sequence control (16) performs a magnetic resonance imaging scan of the subject based on the selected reduction factors.

First claim

What is claimed is:

1. A magnetic resonance imaging system, comprising:
a user interface configured to receive a user input from a medical professional, the user input corresponding to one of a maximum imaging time, an overall reduction factor, or a minimum signal-to-noise ratio;
at least one radio frequency coil with a plurality of coil elements configured to perform a scan of a subject; and
at least one electronic processor programmed to:
generate a plurality of sets of reduction factors along corresponding reduction directions from the received one of the maximum imaging time, the overall reduction factor, or the minimum signal-to-noise ratio, wherein the reduction directions correspond to at least one encoded direction;
construct a signal map from the scan of the subject and a plurality of noise maps corresponding to the sets of reduction factors from the scan of the subject and the sets of reduction factors, wherein at least one of the noise maps optimizes signal-to-noise ratio and scanning speed;
select one of the sets of reduction factors corresponding to one of the noise maps that optimizes the signal-to-noise ratio and the scanning speed;
perform a magnetic resonance imaging scan of the subject based on the selected reduction factors.

2. The system according to claim 1 , wherein the set of reduction factors includes two reduction factors for two reduction directions.

3. The system according to claim 1 , wherein the set of reduction factors include a plurality of reduction factors, each reduction factor corresponding to the encoded direction.

4. The system according to claim 1 , wherein a parallel imaging parameter unit selects the overall reduction factor which minimize imaging time to generate images with at least the received minimum signal-to-noise ratio.

5. The system according to claim 1 , wherein the selection of reduction factors includes a search along each encoded direction.

6. The system according to claim 1 , wherein a smart select unit is configured to:
construct a set of 3-dimensional data from the prior scan;
perform multi-planar reformatting of the 3-dimensional data to determine channel with a geometry of the imaging scan;
calculate coil sensitivity and regularization data based on the determined channel data; and
generate a signal map and a noise map based on the determined coil sensitivity and regularization data.

7. The system according to claim 1 , wherein the highest SNR includes an average SNR of all voxels.

8. The system according to claim 1 , wherein the at least one electronic processor is programmed to select one of the sets of reduction factors corresponding to one of the noise maps corresponding to the minimum signal-to-noise ratio and a scanning speed by:
calculating the signal-to-noise ratio by dividing the signal map by one of the noise maps based on the different reduction factors along the one or more reduction directions.

9. A method of parallel magnetic resonance imaging, comprising:
with a user interface, receiving a user input from a medical professional, the user input corresponding to one of a maximum imaging time, an overall reduction factor, or a minimum signal-to-noise ratio;
with at least one electronic processor:
generating one of a plurality of sets of reduction directions based on the received maximum imaging time, the received overall reduction factor, or on the overall reduction factor which meets the received signal-to-noise ratio, wherein the reduction directions correspond to at least one or more encoded directions;
constructing a signal map from a prior scan of a subject and a plurality of noise maps from the prior scan of a subject and the generated reduction directions;
selecting reduction factors corresponding to one of the noise maps which satisfies a signal-to-noise ratio criterion calculated by dividing the signal map by the noise map and a scanning speed criterion;
and
performing a magnetic resonance imaging scan of the subject based on the selected reduction factors.

10. The method according to claim 9 , wherein selecting the reduction factors includes selecting two reduction factors, each reduction factor for a reduction direction.

11. The method according to claim 9 , wherein each set of reductions factors includes a plurality of reduction factors, each reduction factor corresponding to an encoding direction.

12. The method according to claim 9 , further including:
selecting the reduction factors and/or reduction directions which minimize imaging time to generate images which at least meet the received minimum signal-to-noise ratio criterion.

13. The method according to claim 9 , further including:
searching the reduction factors along each encoding direction in discrete steps; and
refining the reduction factor search around the highest signal-to-noise ratio in smaller steps.

14. The method according to claim 9 , further including:
constructing a set of 3-dimensional data from the prior scan;
performing multi-planar reformatting of the 3D data to determine channel with a geometry of the imaging scan;
calculating coil sensitivity and regularization data based on the determined channel data; and
generating a signal map and a noise map based on the determined coil sensitivity and regularization data.

15. A non-transitory computer-readable storage medium carrying software which controls one or more electronic data processing devices to perform the method according to claim 9 .

16. An electronic data processing device configured to perform the method according to claim 9 .

17. The method according to claim 9 , wherein the method further includes: with the at least one electronic processor:
calculating the signal-to-noise ratio by dividing the signal map by one of the noise maps based on the different reduction factors along the one or more reduction directions.

18. A parallel magnetic resonance imaging system, comprising:
at least one RF coil with a plurality of coil elements;
a user interface configured to receive at least one of a minimum image quality and/or a maximum time to generate image data;
one or more processors programmed to:
generate a plurality of reduction factors along one or more reduction directions from the received minimum image quality or the received maximum time to generate image data, wherein the reduction directions correspond to at least one encoded direction;
construct a signal map and a plurality of noise maps for each of the plurality reduction factors from a prior scan of a subject using the at least one radio frequency coil;
select reduction factors which generate image data with at least the received minimum image quality and/or within the received maximum time;
control the imaging system in order to perform a magnetic resonance imaging scan of the subject based on the selected reduction factors.

19. A magnetic resonance imaging system, comprising:
a user interface which receives a minimum signal-to-noise ratio;
at least one radio frequency coil with a plurality of coil elements;
at least one electronic processor programmed to:
generate an overall reduction factor which meets the received minimum signal-to-noise ratio and different sets of reduction factors along one or more reduction directions, wherein the reduction directions correspond to at least one encoded direction;
construct a signal map and a plurality of noise maps from a prior scan of a subject, the prior scan using the at least one radio frequency oil, and the different sets of reduction factors;
select a set of reductio

Assignees

• Koninklijke Philips Nv
• Philips Gmbh

Inventors

• Boernert Peter
• Jurrissen Michel Paul Jurriaan
• Doneva Mariya Ivanova
• Duijndam Adrianus Joseph Willibrordus
• Nehrke Kay

Classifications

• G01R33/34092

  RF coils specially adapted for NMR spectrometers · CPC title

• G01R33/5611 Primary

  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

• 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