Method for determining an attenuation map and homogeneity information relating to the magnetic resonance magnetic field

A technique of attenuation map and uniformity, applied in magnetic resonance measurement, measurement using MRI system, measurement of magnetic variables, etc., which can solve the problems of patient burden, time-consuming, and no movement allowed.

Active Publication Date: 2010-03-03
SIEMENS HEALTHCARE GMBH
View PDF7 Cites 18 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The implementation of these two measurements is time-consuming and places a further burden on the patient, who is not allowed to...

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
  • Method for determining an attenuation map and homogeneity information relating to the magnetic resonance magnetic field
  • Method for determining an attenuation map and homogeneity information relating to the magnetic resonance magnetic field

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0027] figure 1 A flow chart of the method according to the invention is shown. In particular, the method can be carried out fully automatically, for example by means of a computer of the combined magnetic resonance-positron emission tomography system.

[0028] First, in step 1, an MR image acquisition is performed. For this purpose, a three-dimensional gradient echo sequence is used, in which a first and a second image data record are recorded after a single excitation at different echo times, ie respectively at a first and a second echo time. This first image data record is recorded if the phase difference between the water signal and the fat signal is zero ("in-phase condition"). The second echo time then shows that the phase difference between the water signal and the fat signal is exactly 180° ("inversion condition").

[0029]In this case, both the attenuation map and the shim adjustment are to be determined from the two image data sets recorded from the one magnetic r...

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

A method is disclosed for determining an attenuation map for use in positron emission tomography and for the use of homogeneity information relating to the magnetic resonance magnetic field, in particular for the purpose of determining shim settings, within the scope of a single magnetic resonance image recording. In at least one embodiment of the method, a first and a second image data record are firstly recorded with a three-dimensional gradient echo sequence during a first and a second echo time, respectively, with the phase difference between the water and the fat signal amounting to zeroduring the first echo time and amounting to 180 degrees during the second echo time. The attenuation map is determined from fat/water ratios obtained from the image data records by way of a Dixon technology, in particular a 2-point Dixon technology. In at least one embodiment, all voxels with a signal intensity below a first threshold value are excluded at least for the second image data record by using a mask and only the non excluded voxels of the first and second image data record are taken into consideration in order to determine the homogeneity information from the phase differences of adjacent voxels.

Description

technical field [0001] The present invention relates to a method for determining attenuation maps for positron emission tomography ( ) and the homogeneity information of the magnetic resonance field, in particular for the purpose of determining the shim adjustment. Background technique [0002] Combined magnetic resonance-positron emission tomography systems (MR-PET systems), as recently proposed, allow the combination of two imaging methods that interact particularly well. However, within the framework of this combined MR-PET examination, several preliminary measurements on the magnetic resonance image are usually required. [0003] On the one hand, in order to analyze the results of the PET measurement, a location-resolved knowledge of the attenuation values ​​of the tissue of the current patient is required, a so-called attenuation map. With the aid of this information, the PET data are corrected accordingly in the analysis. It is therefore known to perform an MR imag...

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
IPC IPC(8): A61B5/055A61B5/00G01R33/54
CPCA61B6/5247A61B6/037G01R33/4828G01R33/543G01R33/56563G01R33/481
Inventor 弗拉迪米尔·杰勒斯迈克尔·西姆特宁斯
Owner SIEMENS HEALTHCARE GMBH
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