Signal amplitude feature-based method for fast reconstructing a magnetic particle imaging and device

Patent metadata

Field	Value
Publication number	US-12136145-B2
Application number	US-202217811738-A
Country	US
Kind code	B2
Filing date	Jul 11, 2022
Priority date	Jul 20, 2021
Publication date	Nov 5, 2024
Grant date	Nov 5, 2024

Abstract

The present disclosure includes: transforming a time-domain voltage signal collected by an MPI system device to a frequency domain; calculating a square root of a square sum of a real part and an imaginary part at each frequency point of a frequency domain signal; arranging acquired amplitudes in a descending order, and acquiring a screening threshold by an amplitude ratio method; screening an amplitude through the screening threshold and constructing frequency domain signal data; acquiring a row vector of a system matrix corresponding to each frequency point of the data, so as to construct an update system matrix; and solving, based on the frequency domain signal array and the update system matrix, an inverse problem in a form of a least square based on an L2 constraint to obtain a three-dimensional magnetic particle concentration distribution result, so as to achieve a fast reconstruction of the MPI system.

First claim

What is claimed is:

1. A signal amplitude feature-based method for fast reconstructing a magnetic particle imaging, comprising:
transforming a time-domain voltage signal collected by an MPI system device to a frequency domain, so as to obtain a frequency domain complex voltage signal u;
respectively calculating a square root of a square sum of a real part and an imaginary part at each frequency point of the frequency domain complex voltage signal u, so as to obtain an amplitude at the each frequency point;
arranging the amplitude at the each frequency point in a descending order so as to obtain an amplitude matrix D, and acquiring a screening threshold i 0 by an amplitude ratio method;
screening an element of the amplitude matrix D based on the screening threshold i 0 , and constructing a frequency domain signal array u 0 based on the screened elements D 1˜i 0 ;
selecting row vectors a 1˜i 0 of a system matrix A corresponding to each frequency point of the frequency domain signal array u 0 , so as to construct an update system matrix A 0 ; and
solving, based on the frequency domain signal array u 0 and the update system matrix A 0 , an inverse problem in a form of a least square based on an L2 constraint by an convex optimization method to obtain a three-dimensional magnetic particle concentration distribution result, so as to achieve a fast reconstruction of the MPI system.

2. The method according to claim 1 , wherein the acquiring a screening threshold i 0 by an amplitude ratio method comprises:
calculating a sum N of all amplitudes of the amplitude matrix D, and dividing a sum of amplitudes sorted in a descending order of 1-th to i-th by N as a value of an amplitude proportion element M i ; and
selecting a value i corresponding to m elements in the amplitude ratio element M i to be recorded as a screening threshold i 0 , wherein a difference value between the value i and a set first threshold is smaller than a set second threshold.

3. The method according to claim 2 , wherein the set first threshold is 0.8.

4. The method according to claim 2 , wherein the amplitude proportion element M i is expressed as:

M
i

=

∑

k
=
1

i

⁢

D
k

⁢

/

⁢
N

wherein D k represents a k-th amplitude in the amplitude matrix D, N represents the sum of all amplitudes in the amplitude matrix D, and i represents an i-th amplitude of the amplitudes sorted in the descending order of 1-th to i-th.

5. The method according to claim 1 , wherein the convex optimization method is one of a Kaczmarz method, an ADMM method and a TV-L2 method.

6. A signal amplitude feature-based system for performing an MPI fast reconstruction, comprising:
a signal transforming module configured to transform a time-domain voltage signal collected by an MPI system device to a frequency domain, so as to obtain a frequency domain complex voltage signal u;
an amplitude calculating module configured to respectively calculate a square root of a square sum of a real part and an imaginary part at each frequency point of the frequency domain complex voltage signal u, so as to obtain an amplitude at the each frequency point;
a screening threshold acquiring module configured to arrange the amplitude at the each frequency point in a descending order so as to obtain an amplitude matrix D, and acquiring a screening threshold i 0 by an amplitude ratio method;
an amplitude screening module configured to screen an element of the amplitude matrix D based on the screening threshold i 0 , and constructing a frequency domain signal array u 0 based on the screened elements D 1˜i 0 ;
a system matrix updating module configured to select row vectors a 1˜i 0 of a system matrix A corresponding to each frequency point of the frequency domain signal array u 0 , so as to construct an update system matrix A 0 ; and
a reconstructing module configured to solving, based on the frequency domain signal array u 0 and the update system matrix A 0 , an inverse problem in a form of a least square based on an L2 constraint by an convex optimization method to obtain a three-dimensional magnetic particle concentration distribution result, so as to achieve a fast reconstruction of the MPI system.

7. An electronic device, comprising:
at least one processor; and
a memory in communication with the at least one processor;
wherein the memory has an instruction executable by the processor stored therein, and the instruction is configured to be executed by the processor so as to implement the signal amplitude feature-based method for fast reconstructing a magnetic particle imaging according to claim 1 .

8. A non-transitory computer-readable storage medium, wherein the computer-readable storage medium has a computer instruction stored therein, and the computer instruction is configured to be executed by the computer so as to implement the signal amplitude feature-based method for fast reconstructing a magnetic particle imaging according to claim 1 .

Assignees

• Inst Automation Cas

Inventors

• Tian Jie
• Zhang Peng
• Hui Hui
• Li Yimeng
• Yin Lin
• Feng Xin

Classifications

• G06T12/20 Primary

  Inverse problem, i.e. transformations from projection space into object space · CPC title

• G06T12/00 Primary

  Tomographic reconstruction from projections · CPC title

• A61B5/7257

  using Fourier transforms · CPC title

• A61B5/0515 Primary

  Magnetic particle imaging · CPC title

• G01R33/0094

  Sensor arrays · CPC title