Method and apparatus for quantifying properties of an object through magnetic resonance imaging (mri)

Patent metadata

Field	Value
Publication number	US-2016131729-A1
Application number	US-201514938123-A
Country	US
Kind code	A1
Filing date	Nov 11, 2015
Priority date	Nov 11, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

Provided are a method and apparatus for processing a magnetic resonance (MR) image of an object including first and second materials on a magnetic resonance imaging (MRI) apparatus by using multi-parameter mapping including applying to the object a plurality of radio frequency (RF) pulses separated by a first repetition time and a second repetition time, the first repetition time and the second repetition time being determined based on the first material and the second material; undersampling first MR signals corresponding to the first material and second MR signals corresponding to the second material in a K-space; and performing matching between the undersampled first and the undersampled second MR signals and a signal model for the multi-parameter mapping to determine attribute values corresponding to the first and the second materials at at least one point in an MR image of the object.

First claim

What is claimed is:

1 . A method of processing a magnetic resonance (MR) image of an object including a first material and a second material on a magnetic resonance imaging (MRI) apparatus by using multi-parameter mapping, the method comprising:
applying to the object a plurality of radio frequency (RF) pulses separated by a first repetition time and a second repetition time, the first repetition time and the second repetition time being determined based on the first material and the second material; undersampling first MR signals corresponding to the first material and second MR signals corresponding to the second material in a K-space; and performing matching between the undersampled first and the undersampled second MR signals and a signal model for the multi-parameter mapping to determine attribute values corresponding to the first and the second materials at at least one point in an MR image of the object.

2 . The method of claim 1 , wherein the first and the second repetition times are determined in order to increase orthogonality between the first and the second MR signals.

3 . The method of claim 2 , wherein the first and the second repetition times are determined based on a difference between a resonant frequency of the first material and a resonant frequency of the second material.

4 . The method of claim 3 , wherein the first repetition time is determined so that the first and the second MR signals are in phase, and
wherein the second repetition time is determined so that the first and the second MR signals are out of phase.

5 . The method of claim 1 , wherein the plurality of RF pulses are separated by a number (n) of repetition times comprising the first and the second repetition times, and
wherein the n repetition times are determined in order to increase orthogonality between the first and the second MR signals.

6 . The method of claim 5 , wherein the n repetition times are determined so that the first and the second MR signals have a phase difference of (2πk)/n, and wherein k is a natural number from 1 to n.

7 . The method of claim 1 , wherein the plurality of RF pulses are separated by a first interval during which the first repetition time is repeated a first plurality of times and a second interval during which the second repetition time is repeated a second plurality of times.

8 . The method of claim 7 , wherein the first and the second intervals are alternately repeated.

9 . The method of claim 7 , wherein the first plurality of times is equal to the second plurality of times.

10 . The method of claim 1 , wherein the attribute values corresponding to the first and the second materials at the at least one point in the MR image of the object comprise at least one selected from fractions of the first and the second materials, T 1 and T 2 of the first material, T 1 and T 2 of the second material, and off-resonance between the first and second materials.

11 . An apparatus for processing a magnetic resonance (MR) image of an object including a first material and a second material on a magnetic resonance imaging (MRI) apparatus using multi-parameter mapping, the apparatus comprising:
a radio frequency (RF) controller configured to apply to the object a plurality of RF pulses separated by a first repetition time and a second repetition time, the first repetition time and the second repetition time being determined based on the first material and the second material; a data acquisition unit configured to undersample first MR signals corresponding to the first material and second MR signals corresponding to the second material in a K-space; and an image processor configured to perform matching between the undersampled first and the undersampled second MR signals and a signal model for the multi-parameter mapping to determine attribute values corresponding to the first and the second materials at at least one point in an MR image of the object.

12 . The apparatus of claim 11 , wherein the first and second repetition times are determined in order to increase orthogonality between the first and the second MR signals.

13 . The apparatus of claim 12 , wherein the first and the second repetition times are determined based on a difference between a resonant frequency of the first material and a resonant frequency of the second material.

14 . The apparatus of claim 13 , wherein the first repetition time is determined so that the first and the second MR signals are in phase, and
wherein the second repetition time is determined so that the first and the second MR signals are out of phase.

15 . The apparatus of claim 11 , wherein the plurality of RF pulses are separated by a number (n) of repetition times comprising the first and second repetition times, and
wherein the n repetition times are determined in order to increase orthogonality between the first and the second MR signals.

16 . The apparatus of claim 15 , wherein the n repetition times are determined so that the first and second MR signals have a phase difference of (2πk)/n, and wherein k is a natural number from 1 to n.

17 . The apparatus of claim 11 , wherein the plurality of RF pulses are separated by a first interval during which the first repetition time is repeated a first plurality of times and a second interval during which the second repetition time is repeated a second plurality of times.

18 . The apparatus of claim 17 , wherein the first and the second intervals are alternately repeated.

19 . The apparatus of claim 17 , wherein the first plurality of times is equal to the second plurality of times.

20 . A non-transitory computer-readable recording medium having recorded thereon a program for executing the method of claim 1 on a computer.

Assignees

• Samsung Electronics Co Ltd
• Univ Yonsei Iacf

Inventors

• Kang Lae-Hoon
• Kim Dong-Hyun
• Kim Min-Oh
• Han Dong-Yeob
• Hwang Do-Sik
• Park Yong-Sup
• Park Jong-Buhm
• Lee Jae-Sung

Classifications

• 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

• G01R33/4828

  Resolving the MR signals of different chemical species, e.g. water-fat imaging · CPC title

• G01R33/4824

  using a non-Cartesian trajectory · CPC title

• G01R33/50 Primary

  based on the determination of relaxation times {, e.g. T1 measurement by IR sequences; T2 measurement by multiple-echo sequences} · CPC title

• 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