DIXON water-fat separation method in magnetic resonance imaging
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A technology for magnetic resonance imaging and water-fat separation, which can be used in the measurement of magnetic variables, measuring devices, instruments, etc., and can solve the problems of water-fat separation failure and errors.
Active Publication Date: 2014-01-15
SHANGHAI UNITED IMAGING HEALTHCARE
View PDF9 Cites 32 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
However, because the binary system involved in water-fat imaging is nonlinear, the least-squares optimization algorithm adopted by IDEAL is prone to errors caused by local minimum interference, resulting in the failure of water-fat separation
Although many improved methods have emerged in recent years to reduce the possibility of errors, they still cannot completely solve the fundamental problem of water-fat separation failure caused by local valley bottoms.
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
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0089] figure 2 It is a schematic diagram of the magnetic resonance three-field echo imaging sequence in the embodiment of the present invention. Fig. 3 is an effect diagram of water and fat separation achieved by using three field echoes in the embodiment of the present invention, wherein, Figure 3a For images of water and fat together, Figure 3b is the separated water image, Figure 3c is the separated fat image.
[0090] Please refer to figure 1 and figure 2 , the magnetic resonance DIXON water-fat separation method provided by the embodiment of the present invention uses three field echoes to realize water-fat separation, specifically including the following steps:
[0091] Step S101: apply such as figure 2 In the magnetic resonance field echo imaging sequence shown, by setting 2πΔfT1=α, 2πΔfT2=β and 2πΔfT3=α+2nπ, three field echo data of [α, β, α+2nπ] combination can be acquired. The [α, β, α+2nπ] combination means that among the three echo signals, the phase ...
Embodiment 2
[0096] Figure 4 It is a schematic diagram of three spin-echo imaging sequences of magnetic resonance in another embodiment of the present invention; FIG. 5 is an effect diagram of water-fat separation achieved by using three spin-echos in an embodiment of the present invention, wherein, Figure 5a For images of water and fat together, Figure 5b is the separated water image, Figure 5c is the separated fat image.
[0097] Please refer to figure 1 and Figure 4 , the magnetic resonance DIXON water-fat separation method provided by the embodiment of the present invention uses three spin echoes to realize water-fat separation, specifically comprising the following steps:
[0098] Step S101: select Figure 4 In the magnetic resonance imaging sequence shown, by setting 2πΔfT1=α, 2πΔfT2=β and 2πΔfT3=α+2nπ, three spin echo data of [α, β, α+2nπ] combination can be obtained. The [α, β, α+2nπ] combination means that in the three echo signals, the phase relationship between the wa...
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
Login to view more
Abstract
The invention discloses a DIXON water-fat separation method in magnetic resonance imaging. The method comprises the following steps: a) in the magnetic resonance scanning process, three different echo signals including the first echo signal S1, the second echo signal S2 and the third echo signal S3 are acquired, wherein the water-fat signal procession phase difference of the first echo signal S1 and the third echo signal S3 is 2npi, and n is a natural number; b) the acquired k space signals are converted into image signals through Fourier transform; c) effective image signal pixels are extracted in a image domain, the phase diagram of the effective image signal pixel composite signal is extracted, and phase unwrapping is performed on the phase diagram to obtain a static magnetic field distribution diagram delta B0; d) and the water image and the fat image in the echo signals are separated by utilizing the static magnetic field distribution diagram delta B0. According to the DIXON water-fat separation method provided in the invention, the echo time can be set flexibly according to a magnetic resonance imaging sequence and application requirements, so not only data can be processed by applying the conventional DIXON algorithm, and but also the limitation on imaging sequence parameter setting can be reduced at the same time.
Description
technical field [0001] The invention relates to a water-fat separation method in magnetic resonance imaging, in particular to an improved DIXON water-fat separation method. Background technique [0002] Human MRI (magnetic resonance imaging) signals are mainly derived from two components: water and fat. The chemical bond of hydrogen protons in water molecules is O-H bond, while the chemical bond of hydrogen protons in fat molecules is C-H bond. Due to the difference in the distribution of electron clouds around the hydrogen protons in these two structures, the magnetic field strength felt by the hydrogen protons in the water molecules is slightly higher, and finally the precession frequency of the hydrogen protons in the water molecules is slightly faster than that of the hydrogen protons in the fat molecules Some, the difference is 3.5ppm, equivalent to 150Hz / T, this precession frequency difference increases with the increase of field strength. For example, the field stre...
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
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to view more 
Login to view more