MRI image inhomogeneity correction method based on regularization

A non-uniformity correction and non-uniform technology, applied in image enhancement, image data processing, instruments, etc., can solve problems such as difficulty in determining the frequency threshold of low-pass filtering, estimating non-uniform field errors, and low-frequency information aliasing, etc. Small boundary effects, accurate non-uniform field estimation, and the effect of avoiding overfitting

Active Publication Date: 2014-03-12
UNIV OF SCI & TECH OF CHINA
View PDF2 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Disadvantages of the algorithm: the second scan requires additional hardware equipment, which increases the scan time; and the displacement of the patient during the two scans causes image mismatch, which requires image registration, making errors in estimating the non-uniform field and causing artifacts
[0011] Disadvantages of the algorithm: there is aliasing between the non-uniform field and the low-frequency information of the image, and the frequency threshold of the low-pass filter is difficult to determine
[0015] Disadvantages of the algorithm: poor universality, only suitable for images of special parts

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • MRI image inhomogeneity correction method based on regularization
  • MRI image inhomogeneity correction method based on regularization
  • MRI image inhomogeneity correction method based on regularization

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0050] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0051] By improving the low-pass filtering method, the present invention selects a part of the region with little difference in grayscale value for low-pass filtering to obtain the initial estimation of the non-uniform field, and then extrapolates through a regularized polynomial fitting method, Obtain a non-uniform field estimate for the whole image. The specific process is as follows:

[0052] 1. Determination of the region of interest

[0053] The method of directly filtering the image is easy to cause boundary effects, that is, the non-uniformity distortion in the high-contrast area is easy to cause large errors in the subsequent interpolation, but in fact, most of the data in the interpolation fitting are is redundant and unnecessary. Therefore, in the present invention, we avoid the boundary effect by selecting a part of the region with ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides an MRI image inhomogeneity correction method based on regularization. A lowpass filtering method is improved, part of an area with low grey-value difference is selected and is subjected to lowpass filtering to obtain an initial estimate for a inhomogeneous field, and then extrapolation is performed through a regularized polynomial fitting method to obtain an estimate for an inhomogeneous field of a whole image. According to the method provided by the invention, an area-of-interest is determined and is subjected to filtering, so the boundary effect in the global image filtering method can be avoided, and fitting is performed through a regularization method, thus overfitting is guaranteed not to happen under the condition of improving the fitting order.

Description

technical field [0001] The present invention relates to the technical field of nuclear magnetic resonance and image processing, in particular to a method for correcting non-uniformity of MRI images based on regularization. Background technique [0002] In the past ten years, MRI has been widely used in medical diagnosis due to its high resolution, no ionizing radiation damage, and imaging at any angle. With the demand for higher resolution scanned images, scanners have increasingly higher magnetic field strengths and finer magnetic field gradients. However, the accompanying problem is that the interference of non-uniform fields suffered by MRI images is becoming more and more serious. The non-uniform field is the deviation field caused by the non-uniformity of the transmitted spatial magnetic field or the non-uniform sensitivity of the receiving coil. This deviation field is generally assumed to be a smooth, slowly changing multiplicative deviation field, which will lead to...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G06T5/00
Inventor 凌强李朝辉宋凯凯李峰
Owner UNIV OF SCI & TECH OF CHINA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap