CN112244812B - Magnetic resonance imaging method, magnetic resonance imaging system and electronic device - Google Patents
Magnetic resonance imaging method, magnetic resonance imaging system and electronic device Download PDFInfo
- Publication number
- CN112244812B CN112244812B CN202011117988.1A CN202011117988A CN112244812B CN 112244812 B CN112244812 B CN 112244812B CN 202011117988 A CN202011117988 A CN 202011117988A CN 112244812 B CN112244812 B CN 112244812B
- Authority
- CN
- China
- Prior art keywords
- magnetic resonance
- radio frequency
- signal
- frequency pulse
- substance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/055—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/30—Assessment of water resources
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Engineering & Computer Science (AREA)
- Medical Informatics (AREA)
- Biophysics (AREA)
- Pathology (AREA)
- High Energy & Nuclear Physics (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Radiology & Medical Imaging (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
The application discloses a magnetic resonance imaging method, a magnetic resonance imaging system, an electronic device and a storage medium. Wherein the method comprises the following steps: modulating the radio frequency pulse into a first radio frequency pulse signal and a second radio frequency pulse signal with different center frequencies; applying the first radio frequency pulse signal and the second radio frequency pulse signal to an imaging field of view of the magnetic resonance imaging system in a time-sharing manner; acquiring first magnetic resonance data from an imaging field of view under the condition of applying a first radio frequency pulse signal, and reconstructing to obtain a first substance signal image according to the first magnetic resonance data; and acquiring second magnetic resonance data from the imaging field of view under the condition of applying a second radio frequency pulse signal, and reconstructing a second object signal image according to the second magnetic resonance data. The application solves the problem that the chemical shift imaging method of the related technology needs to simultaneously apply one radio frequency pulse signal for selectively inhibiting one substance and another radio frequency pulse signal for selectively exciting another substance.
Description
Technical Field
The present application relates to the field of magnetic resonance imaging, and in particular to a magnetic resonance imaging method, a magnetic resonance imaging system, an electronic device and a storage medium.
Background
Magnetic resonance chemical shift imaging is generally divided into two main categories: 1) Single tissue signal excitation and collection; 2) And (5) excitation and collection of various tissue signals. The following analysis takes as an example two common tissues of water and fat, with reference to the water signal, the chemical shift of water is 0ppm, whereas the (main spectral peak) chemical shift of fat is-3.5 ppm.
The first type of chemical shift imaging method is typically implemented by selectively suppressing or exciting the signal of one of the tissues, thereby directly obtaining a signal to a single type of tissue (water or fat). A common first class of methods includes:
fat Saturation (Fat Saturation) technique. The fat signal is first excited with a 90 degree RF pulse with the same center frequency as the fat frequency (the water signal is unaffected) and then completely dephased by the magnetic field gradient such that the fat signal is completely saturated (i.e. the excitation signal is 0) and does not contribute any signal after the second subsequent excitation pulse.
Water Excitation (Water Excitation) technique. By designing a set of RF pulses, the effect is that only the water signal will be excited, while the fat signal will not be excited (but the excitable signal will not be 0).
The second type of chemical shift imaging method is implemented by exciting signals of water and fat simultaneously without difference, and performing signal separation calculation through a chemical shift model (namely, the difference of water-fat chemical shift is 3.5 ppm) according to signal characteristics (signal amplitude and phase) corresponding to different acquisition parameters (generally a plurality of echo times) during data acquisition, so that respective signals of water and fat are separated. A second common class of methods includes:
water-fat separation (Water Fat Separation): such as Dixon, IDEAL, FACT.
Fat Fraction (FF for short).
However, in the above-described technique, different radio frequency pulse signals are required to be used for presaturation or excitation of the corresponding signals. For example, in the fat saturation technique of the first type of chemical shift imaging method, a set of radio frequency pulses that selectively suppress fat signals need to be applied simultaneously with the acquisition of signals, and another set of radio frequency pulses that selectively excite water signals need to be applied. In the second type of chemical shift imaging method, the signals of water and fat can be excited simultaneously by two groups of radio frequency pulse signals, but the excitation efficiency of the two groups of radio frequency pulse signals on the water and the fat is different, if quantitative calculation of the substance components (such as quantitative calculation of the fat content) is needed, the weighting factors of the excitation efficiency of the different radio frequency pulse signals on the water and the fat are needed to be determined, and once the weighting factors are inaccurate, the quantitative calculation result of the substance components is greatly deviated. The water excitation technology of the first type of chemical shift imaging method can only obtain water signal images, and quantitative calculation of substance components cannot be realized.
Aiming at the problem that a chemical shift imaging method in the related art needs to simultaneously apply one radio frequency pulse signal for selectively suppressing one substance and another radio frequency pulse signal for selectively exciting another substance, no effective solution has been proposed at present.
Disclosure of Invention
In an embodiment of the present application, a magnetic resonance imaging method, a magnetic resonance imaging system, an electronic device, and a storage medium are provided to at least solve the problem that a chemical shift imaging method of the related art needs to apply one rf pulse signal that selectively suppresses one substance and another rf pulse signal that selectively excites another substance at the same time.
In a first aspect, an embodiment of the present application provides a magnetic resonance imaging method, including: modulating the radio frequency pulse into a first radio frequency pulse signal and a second radio frequency pulse signal with different center frequencies, wherein the first radio frequency pulse signal is used for exciting a first substance signal and inhibiting a second substance signal, and the second radio frequency pulse signal is used for inhibiting the first substance signal and exciting the second substance signal; applying the first radio frequency pulse signal and the second radio frequency pulse signal to an imaging field of view of a magnetic resonance imaging system in a time-sharing manner; acquiring first magnetic resonance data from the imaging field of view under the condition of applying the first radio frequency pulse signals, and reconstructing a first substance signal image according to the first magnetic resonance data; and acquiring second magnetic resonance data from the imaging field of view under the condition of applying the second radio frequency pulse signals, and reconstructing a second object signal image according to the second magnetic resonance data.
In some of these embodiments, the excitation efficiency of the first rf pulse signal and the second rf pulse signal is the same; and a maximum excitation-to-suppression ratio of the first species signal intensity to the second species signal intensity with the application of the first radio frequency pulse is equal to a maximum suppression-to-excitation ratio of the first species signal intensity to the second species signal intensity with the application of the second radio frequency pulse.
In some of these embodiments, the radio frequency pulse comprises at least one of: a non-central resonant double rectangular pulse, a non-central non-resonant single rectangular pulse.
In some of these embodiments, the first radio frequency pulse signal and the second radio frequency pulse signal are applied to an imaging field of view of a magnetic resonance imaging system in a time-shared manner; acquiring first magnetic resonance data from the imaging field of view under the condition of applying the first radio frequency pulse signals, and reconstructing a first substance signal image according to the first magnetic resonance data; and acquiring second magnetic resonance data from the imaging field of view with the application of the second radio frequency pulse signal, reconstructing a second object signal image from the second magnetic resonance data comprising: applying the first radio frequency pulse signal to the imaging field of view in a first scanning period, acquiring the first magnetic resonance data from the imaging field of view, and reconstructing the first substance signal image according to the first magnetic resonance data; and applying the second radio frequency pulse signal to the imaging field of view in a second scanning period, acquiring the second magnetic resonance data from the imaging field of view, and reconstructing the second object signal image according to the second magnetic resonance data.
In some of these embodiments, the first radio frequency pulse signal and the second radio frequency pulse signal are applied to an imaging field of view of a magnetic resonance imaging system in a time-shared manner; acquiring first magnetic resonance data from the imaging field of view under the condition of applying the first radio frequency pulse signals, and reconstructing a first substance signal image according to the first magnetic resonance data; and acquiring second magnetic resonance data from the imaging field of view with the application of the second radio frequency pulse signal, reconstructing a second object signal image from the second magnetic resonance data comprising: the following steps are circularly executed to acquire each K-space signal line corresponding to the first substance signal image and the second substance signal image respectively until the first K-space corresponding to the first substance signal image and the second K-space corresponding to the second substance signal image are filled: applying the first radio frequency pulse signal to the imaging field of view during a scanning period, acquiring a K-space signal line from the imaging field of view and filling the first K-space; applying the second radio frequency pulse signal to the imaging field of view in the next scanning period, acquiring a K space signal line from the imaging field of view and filling the K space; reconstructing the first substance signal image according to the signal of the first K space; and reconstructing the second object signal image according to the signal of the second K space.
In some of these embodiments, the first substance and the second substance are chemically displaced; wherein the chemically displaced material comprises at least two of: water, fat, silica gel.
In some of these embodiments, after reconstructing a first material signal image from the first magnetic resonance data and a second material signal image from the second magnetic resonance data, the method further comprises: and generating a substance ratio image of the first substance and the second substance according to the first substance signal image and the second substance signal image.
In a second aspect, embodiments of the present application provide a magnetic resonance imaging system comprising: a magnetic resonance scanner having a bore with an imaging field of view; and a processor configured to operate the magnetic resonance scanner when the subject is located in the magnetic resonance scanner, perform a diagnostic scan by acquiring magnetic resonance signals from a region of interest of the subject, and a memory storing a computer program; wherein the processor is further configured to run the computer program to perform the magnetic resonance imaging method of the first aspect.
In a third aspect, embodiments of the present application provide an electronic device comprising a memory and a processor, in some embodiments of which the memory has stored therein a computer program, the processor being arranged to run the computer program to perform the magnetic resonance imaging method of the first aspect.
In a fourth aspect, embodiments of the present application provide a storage medium having stored thereon computer program instructions which, in some of these embodiments, when executed by a processor, implement a magnetic resonance imaging method as described in the first aspect.
According to the magnetic resonance imaging method, the magnetic resonance imaging system, the electronic device and the storage medium provided by the embodiment of the application, radio frequency pulses are modulated into the first radio frequency pulse signals and the second radio frequency pulse signals with different center frequencies, wherein the first radio frequency pulse signals are used for exciting the first material signals and inhibiting the second material signals, and the second radio frequency pulse signals are used for inhibiting the first material signals and exciting the second material signals; applying the first radio frequency pulse signal and the second radio frequency pulse signal to an imaging field of view of the magnetic resonance imaging system in a time-sharing manner; acquiring first magnetic resonance data from an imaging field of view under the condition of applying a first radio frequency pulse signal, and reconstructing to obtain a first substance signal image according to the first magnetic resonance data; and under the condition of applying a second radio frequency pulse signal, acquiring second magnetic resonance data from an imaging visual field, and reconstructing according to the second magnetic resonance data to obtain a second substance signal image, thereby solving the problem that a chemical shift imaging method in the related art needs to simultaneously apply one radio frequency pulse signal for selectively inhibiting one substance and another radio frequency pulse signal for selectively exciting another substance, and realizing the independent acquisition of different substance signals based on the same pulse signal.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the related art, the drawings required for the description of the embodiments will be briefly described, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.
Figure 1 is a schematic diagram of a magnetic resonance imaging system according to an embodiment of the present application;
figure 2 is a flow chart of a magnetic resonance imaging method according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a BORR pulse in accordance with an embodiment of the application;
FIG. 4 is a schematic diagram of the frequency response of water and fat after application of BORR pulses in accordance with an embodiment of the application;
FIG. 5 is a schematic illustration of a magnetic resonance image of a knee image in accordance with an embodiment of the present application;
fig. 6 is a schematic diagram of a hardware structure of an electronic device according to an embodiment of the present application.
Detailed Description
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application. All other examples, based on examples in this application, which a person of ordinary skill in the art would obtain without making any inventive effort, are within the scope of the application.
It is apparent that the drawings in the following description are only some examples or embodiments of the present application, and it is apparent to those of ordinary skill in the art that the present application may be applied to other similar situations according to the drawings without inventive effort. Moreover, it should be appreciated that while such a development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as having the benefit of this disclosure.
Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. The terms "a," "an," "the," and the like, are not intended to be limiting, but rather are used to denote either the singular or the plural.
The word "comprising" or "comprises", and the like, is intended to mean that elements or items that are immediately preceding the word "comprising" or "comprising", are included in the word "comprising" or "comprising", and equivalents thereof, without excluding other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.
As used herein, "plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.
The system and method of the present application are applicable not only to non-invasive imaging, such as diagnosis and study of diseases, but also to industrial fields and the like, where the processing system involved may include a magnetic resonance imaging system (MR system), a positron emission computed tomography-magnetic resonance multi-modality hybrid system (PET-MR system), and the like. The methods, apparatus, systems, or storage media described herein may be integral to or separate from the processing systems described above.
Embodiments of the present application will be described below by taking a magnetic resonance imaging system as an example.
The embodiment of the application provides a magnetic resonance imaging system. Fig. 1 is a schematic structural diagram of a magnetic resonance imaging system according to an embodiment of the present application, as shown in fig. 1, the magnetic resonance imaging system includes: a scanner and a computer, wherein the computer comprises a memory 125, a processor 122 and a computer program stored on the memory 125 and executable on the processor 122. Wherein the processor 122 is configured to run a computer program to perform a magnetic resonance imaging method of an embodiment of the present application.
The scanner has a bore with an imaging field of view, which typically includes a magnetic resonance gantry within which is a main magnet 101, which main magnet 101 may be formed of superconducting coils for generating a main magnetic field, and in some cases permanent magnets may also be employed. The main magnet 101 may be used to produce a main magnetic field strength of 0.2 tesla, 0.5 tesla, 1.0 tesla, 1.5 tesla, 3.0 tesla, or higher. In magnetic resonance imaging, the imaging subject 150 is carried by the patient table 106, and the imaging subject 150 is moved into the region 105 where the main magnetic field is more uniformly distributed as the table moves. Typically for a magnetic resonance imaging system, as shown in fig. 1, the z-direction of the spatial coordinate system (i.e. the coordinate system of the magnetic resonance imaging system) is set to be the same as the axial direction of the gantry of the magnetic resonance imaging system, the patient's length direction is usually kept consistent with the z-direction for imaging, the horizontal plane of the magnetic resonance imaging system is set to be the xz-plane, the x-direction is perpendicular to the z-direction, and the y-direction is perpendicular to both the x-and z-directions.
In magnetic resonance imaging, the pulse control unit 111 controls the rf pulse generation unit 116 to generate rf pulses, and the rf pulses are amplified by the amplifier, passed through the switch control unit 117, and finally emitted by the body coil 103 or the local coil 104 to perform rf excitation on the imaging object 150. The imaging subject 150 generates corresponding radio frequency signals from resonance upon radio frequency excitation. When receiving the radio frequency signals generated by the imaging object 150 according to excitation, the body coil 103 or the local coil 104 can receive the radio frequency signals, and the radio frequency receiving links can have a plurality of radio frequency receiving links, and the radio frequency signals are further sent to the image reconstruction unit 121 for image reconstruction after being sent to the radio frequency receiving unit 118, so as to form a magnetic resonance image.
The magnetic resonance scanner also includes gradient coils 102 that may be used to spatially encode the radio frequency signals during magnetic resonance imaging. The pulse control unit 111 controls the gradient signal generating unit 112 to generate a gradient signal, which is generally divided into three mutually orthogonal direction signals: gradient signals in the x direction, the y direction and the z direction are amplified by gradient amplifiers (113, 114, 115), and then emitted by the gradient coil 102, so as to generate a gradient magnetic field in the region 105.
The pulse control unit 111, the image reconstruction unit 121, the processor 122, the display unit 123, the input/output device 124, the memory 125 and the communication port 126 can perform data transmission through the communication bus 127, so as to realize the control of the magnetic resonance imaging process.
Processor 122 may be comprised of one or more processors, may include a Central Processing Unit (CPU), or an application specific integrated circuit (Application Specific Integrated Circuit, abbreviated as ASIC), or may be configured to implement one or more integrated circuits of embodiments of the present application.
Among them, the display unit 123 may be a display provided to a user to display an image.
The input/output device 124 may be a keyboard, a mouse, a control box, etc., and supports input/output of corresponding data streams.
Memory 125 may include, among other things, mass storage for data or instructions. By way of example, and not limitation, memory 125 may include a Hard Disk Drive (HDD), floppy Disk Drive, flash memory, optical Disk, magneto-optical Disk, magnetic tape, or universal serial bus (Universal Serial Bus, USB) Drive, or a combination of two or more of these. The memory 125 may include removable or non-removable (or fixed) media, where appropriate. The memory 125 may be internal or external to the data processing apparatus, where appropriate. In a particular embodiment, the memory 125 is a non-volatile solid-state memory. In particular embodiments, memory 125 includes Read Only Memory (ROM). The ROM may be mask programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these, where appropriate. Memory 125 may be used to store various data files that need to be processed and/or used for communication, as well as possible program instructions for execution by processor 122. The processor 122 may perform the magnetic resonance imaging method proposed by the present application when the processor 122 executes a stored, specified program in the memory 125.
Among other things, the communication port 126 may enable, among other components, for example: and the external equipment, the image acquisition equipment, the database, the external storage, the image processing workstation and the like are used for data communication.
Wherein the communication bus 127 comprises hardware, software, or both, that couple the components of the magnetic resonance imaging system to each other. By way of example, and not limitation, the buses may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an infiniband interconnect, a Low Pin Count (LPC) bus, a memory bus, a micro channel architecture (MCa) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a video electronics standards association local (VLB) bus, or other suitable bus, or a combination of two or more of the above. Communication bus 127 may include one or more buses, where appropriate. Although embodiments of the application have been described and illustrated with respect to a particular bus, the application contemplates any suitable bus or interconnect.
In some of these embodiments, the processor 122 is configured to modulate the radio frequency pulses into a first radio frequency pulse signal and a second radio frequency pulse signal of different center frequencies, wherein the first radio frequency pulse signal is used to excite the first substance signal and suppress the second substance signal, and the second radio frequency pulse signal is used to suppress the first substance signal and excite the second substance signal; the processor 122 is further configured to time-divisionally apply the first radio frequency pulse signal and the second radio frequency pulse signal into an imaging field of view of the magnetic resonance imaging system; the processor 122 is further configured to acquire first magnetic resonance data from the imaging field of view with the application of the first radio frequency pulse signals, reconstruct a first material signal image from the first magnetic resonance data; and the processor 122 is further configured to acquire second magnetic resonance data from the imaging field of view with the application of the second radio frequency pulse signal, reconstruct a second object signal image from the second magnetic resonance data.
In some of these embodiments, the excitation efficiency of the first rf pulse signal and the second rf pulse signal is the same; and a maximum excitation-to-suppression ratio of the first species signal intensity to the second species signal intensity with the application of the first radio frequency pulse is equal to a maximum suppression-to-excitation ratio of the first species signal intensity to the second species signal intensity with the application of the second radio frequency pulse.
In some of these embodiments, the radio frequency pulses include, but are not limited to, at least one of: a non-central resonant double rectangular pulse, a non-central non-resonant single rectangular pulse.
In some of these embodiments, the processor 122 is further configured to apply a first radio frequency pulse signal into the imaging field of view during a first scan period, acquire first magnetic resonance data from the imaging field of view, reconstruct a first material signal image from the first magnetic resonance data; the processor 122 is further configured to apply a second radio frequency pulse signal into the imaging field of view during a second scan period, acquire second magnetic resonance data from the imaging field of view, and reconstruct a second object signal image from the second magnetic resonance data.
In some of these embodiments, the processor 122 is further configured to cycle through the following steps to acquire each K-space signal line corresponding to the first and second substance signal images, respectively, until the first K-space corresponding to the first substance signal image and the second K-space corresponding to the second substance signal image are filled: applying a first radio frequency pulse signal to the imaging field of view during a scanning period, acquiring a K-space signal line from the imaging field of view and filling a first K-space; a second rf pulse signal is applied to the imaging field of view during a next scan period, and a K-space signal line is acquired from the imaging field of view and filled into a second K-space. The processor 122 is further configured to reconstruct a first substance signal image from the first K-space signal; and reconstructing a second object signal image according to the signal of the second K space.
In some embodiments, the first substance is chemically displaced from the second substance; wherein the chemically displaced material includes, but is not limited to, at least two of: water, fat, silica gel.
In some of these embodiments, the processor 122 is further configured to generate a material proportion image of the first material and the second material from the first material signal image and the second material signal image after reconstructing the first material signal image from the first magnetic resonance data and the second material signal image from the second magnetic resonance data.
A magnetic resonance imaging method is also provided in this embodiment. Figure 2 is a flow chart of a magnetic resonance imaging method according to an embodiment of the application, as shown in figure 2, the flow comprising the steps of:
step S201, modulating the radio frequency pulse into a first radio frequency pulse signal and a second radio frequency pulse signal with different center frequencies, where the first radio frequency pulse signal is used to excite the first material signal and suppress the second material signal, and the second radio frequency pulse signal is used to suppress the first material signal and excite the second material signal.
Step S202, applying the first radio frequency pulse signal and the second radio frequency pulse signal to an imaging field of view of the magnetic resonance imaging system in a time-sharing manner.
In step S203, first magnetic resonance data is acquired from the imaging field of view under the application of the first radio frequency pulse signal, and a first material signal image is reconstructed from the first magnetic resonance data.
Step S204, acquiring second magnetic resonance data from the imaging field under the condition of applying a second radio frequency pulse signal, and reconstructing a second object signal image according to the second magnetic resonance data.
In the above steps, the magnetic resonance imaging system applies radio frequency pulses in the imaging field of view during conventional 2D magnetic resonance imaging or conventional 3D magnetic resonance imaging, acquires magnetic resonance data during the application of the radio frequency pulses, and reconstructs corresponding substance signal images from the magnetic resonance data. The radio frequency pulse for exciting or suppressing the substance signal in this embodiment is a radio frequency pulse signal having the same intensity and the same waveform, which is modulated into a first radio frequency pulse signal and a second radio frequency pulse signal of different center frequencies, and wherein the first radio frequency pulse signal is capable of exciting the first substance signal and suppressing the second substance signal, and wherein the second radio frequency pulse signal is capable of exciting the second substance signal and suppressing the first substance signal.
In this embodiment, the excitation efficiency of the first rf pulse signal and the second rf pulse signal on different substances is the same; and a maximum excitation-to-suppression ratio of the first species signal intensity to the second species signal intensity with the application of the first radio frequency pulse is equal to a maximum suppression-to-excitation ratio of the first species signal intensity to the second species signal intensity with the application of the second radio frequency pulse. Wherein the maximum excitation-suppression ratio refers to the maximum ratio of the signal intensity when the first substance is excited to the signal intensity when the second substance is suppressed in the frequency response of the first substance and the second substance to the first radio frequency pulse signal; the maximum suppression-excitation ratio refers to the maximum ratio of the signal intensity when the first substance is suppressed to the signal intensity when the second substance is excited in the frequency response of the first substance and the second substance to the second radio frequency pulse signal.
There are various kinds of radio frequency pulse signals capable of satisfying the above requirements. In the embodiment of the application, a non-central resonance double rectangular (BORR) pulse or a non-central non-resonance single rectangular pulse can be selected.
Fig. 3 is a schematic diagram of a BORR pulse according to an embodiment of the application. As shown in fig. 3, the waveform of the BORR pulse is composed of two square radio frequency pulses, which have the same length and intensity, and are 180 ° out of phase. TE refers to the separation between the breakpoint of the second rf pulse and the center of the echo.
Fig. 4 is a graph of the frequency response of water and fat after application of a BORR pulse according to an embodiment of the application. In fig. 4, the abscissa indicates the frequency offset from the center frequency of the magnetic resonance system (equal to the resonance frequency of water), and the ordinate indicates the signal strength in units a.u (arbitrary units). From FIG. 4, it can be seen that the resonance frequencies of water and fat are 0 and-460 Hz, respectively. When applying the BORR pulse, for example, when selecting the radio frequency offset of the BORR pulse to be-780 Hz, the fat signal can be excited and the water signal can be restrained; and when the radio frequency offset of the BORR pulse is selected to be +320Hz, the water signal can be excited and the fat signal can be restrained. It can be seen from fig. 4 that the water signal has a flatter frequency band region near the +320Hz frequency offset or the fat signal has been excited near the-780 Hz frequency offset, indicating that the frequency response of water and fat under the BORR pulse has a wider excitation bandwidth. Similarly, near the +320Hz or-780 Hz frequency offset, the fat signal is suppressed to have a flatter frequency band, which indicates that the frequency response of water and fat under the BORR pulse has a wider suppression bandwidth (also called suppression bandwidth). The excitation bandwidth and the suppression bandwidth in the embodiment are both above 200Hz, and the signal excitation bandwidth and the signal suppression bandwidth which are wide enough can ensure that the influence of the magnetic field inhomogeneity on the excitation and suppression efficiency of the signal is minimized.
In this embodiment, the frequency band in which the excited signal remains above 95% of the maximum and the suppressed signal remains below 5% of the maximum is defined as the frequency passband of the acquired magnetic resonance signal. In other words, in the frequency passband, the signal to be suppressed can reach the suppression efficiency of more than 95%, and the excitation signal collected in the frequency passband can obtain the optimal signal-to-noise ratio, so that the selectively excited signal is prevented from being polluted by the suppressed signal, and the accuracy of the subsequent possible quantitative analysis of the substance components is ensured.
Taking the BORR pulse as an example, the frequency shift range of the center frequency of the first radio frequency pulse signal for exciting the water signal relative to the resonance frequency of water includes +210Hz to +440Hz. The frequency shift range of the center frequency of the second radio frequency pulse signal for exciting the fat signal with respect to the resonance frequency of water includes-920 Hz to-670 Hz.
With continued reference to fig. 4, under the action of the BORR pulse, the water and fat have the same response mode (but different center frequencies) and excitation efficiency (same maximum intensity value of the excitation signal). The same response mode and excitation efficiency avoid the introduction of different and unknown weighting factors in the excited signals of water and fat, ensure that the relative signals of the two signals can be linked through a physical model of a magnetic resonance signal, and ensure the accuracy of quantitative analysis. In addition, the excitation efficiency equivalent to 90 degrees (namely 100 percent) can be obtained at most in the range of the signal excitation bandwidth, so that the radio frequency pulse excitation efficiency is ensured, and the signal-to-noise ratio level of the signal is improved.
In the above examples, the two substances having chemical shifts, namely, water and fat, were described and illustrated. However, the magnetic resonance imaging method provided in this embodiment is not limited to the magnetic resonance imaging of the two substances, and may be applied to imaging of any other substance having a distinguishable chemical shift or quantitative analysis of the proportion of the substance. For example, silica gel has chemical shift with water or fat, so that the embodiment can also be used for magnetic resonance imaging of any at least two substances among silica gel, water and fat and quantitative analysis of the proportion of the substances.
In the steps S202 to S204, the first rf pulse signal and one of the second rf pulse signals are applied in a time-sharing manner, and the corresponding magnetic resonance data are acquired to reconstruct a magnetic resonance image, and the obtained magnetic resonance images are the first material magnetic resonance image and the second material magnetic resonance image, respectively.
The method for time-sharing application and collection of the radio frequency pulse signals comprises the following two modes:
in the first mode, after a first radio frequency pulse signal is applied to an imaging field of view in one scanning period to perform complete first material signal acquisition, a second radio frequency pulse signal is applied to the imaging field of view in another scanning period to perform complete second material signal acquisition.
For example, in the case of applying a first radio frequency pulse signal into the imaging field of view within a first scan period, acquiring first magnetic resonance data from the imaging field of view, reconstructing a first material signal image from the first magnetic resonance data; under the condition that a second radio frequency pulse signal is applied to the imaging visual field in a second scanning time period, second magnetic resonance data are acquired from the imaging visual field, and a second object signal image is obtained through reconstruction according to the second magnetic resonance data.
The acquisition mode does not need to frequently modulate the radio frequency pulse signals to different center frequencies, and the acquisition of the two substance magnetic resonance signals for reconstructing the two magnetic resonance images can be completed through the twice radio frequency pulse modulation.
In a second mode, a scanning process is divided into a plurality of continuous K space signal line acquisition time periods, and in two adjacent acquisition time periods, one acquisition time period applies a first radio frequency pulse signal to an imaging visual field to acquire a K space signal line corresponding to a first substance, and the other acquisition time period applies a second radio frequency pulse signal to the imaging visual field to acquire a K space signal line corresponding to a second substance.
For example, first, the following steps are cyclically performed to acquire each K-space signal line corresponding to the first substance signal image and the second substance signal image, respectively, until the first K-space corresponding to the first substance signal image and the second K-space corresponding to the second substance signal image are filled: acquiring a K space signal line from the imaging field of view and filling a first K space under the condition that a first radio frequency pulse signal is applied to the imaging field of view in a scanning time period; in the case where a second radio frequency pulse signal is applied to the imaging field of view in the next scanning period, one K-space signal line is acquired from the imaging field of view and filled into the second K-space. Then, a first substance signal image is reconstructed according to the first K space signal, and a second substance signal image is reconstructed according to the second K space signal.
The second mode has the advantage that the acquisition of magnetic resonance signals of two substances can be respectively completed by one magnetic resonance scanning, and compared with the first mode, the magnetic resonance scanning process is reduced.
In this embodiment, the imaging sequence used for magnetic resonance imaging may be any imaging sequence, including, but not limited to, fast Spin Echo (FSE) sequences, gradient Echo (Gradient Recalled Echo GRE) sequences, echo planar imaging (Echo Planer Imaging, EPI) sequences, and any Non-Cartesian coordinate system (Non-Cartesian) acquisition, for example. Furthermore, magnetic resonance imaging also allows the use of downsampling techniques, i.e. reconstruction of magnetic resonance images based on partial K-space data without acquisition of complete K-space data, resulting in the above-mentioned images.
In some embodiments, a material proportion image of the first material and the second material may also be generated from the first material signal image and the second material signal image after the first material signal image is reconstructed from the first magnetic resonance data and the second material signal image is reconstructed from the second magnetic resonance data.
For example, taking a magnetic resonance image of the fat acquired and reconstructed in the above-described manner and generating a fat ratio image, a fat ratio image may be generated using a procedure comprising the steps of:
And step 1, setting the center frequency of the BORR pulse as the water excitation frequency, and obtaining an independent water excitation image A by single scanning.
And 2, setting the center frequency of the BORR pulse as the fat excitation frequency, and obtaining an independent fat excitation image B through single scanning.
Step 3, on a per pixel basis, a fat content calculation, that is, ff=sb/(sa+sb) ×100% is performed. Wherein FF is the pixel value in the fat proportion image, and SA and SB are the pixel values of the pixels at the same position in the water-excited magnetic resonance image and the fat-excited magnetic resonance image, respectively.
As another example, taking the second acquisition and reconstruction of magnetic resonance images of water and fat and the generation of fat ratio images in the manner described above, a procedure comprising the steps of:
repeating the step 1 and the step 2 until the k-space signals of the image A and the image B are acquired, and then executing the step 3:
and step 1, setting the center frequency of the BORR pulse as the water excitation frequency, and collecting a k-space signal line corresponding to the water excitation image A.
And 2, setting the center frequency of the BORR pulse as the fat excitation frequency, and collecting a k-space signal line corresponding to the fat excitation image B.
And 3, reconstructing an image A and an image B according to the k-space signal, namely acquiring a water excitation image and a fat excitation image at the same time by single scanning.
Step 4, on a per pixel basis, performing calculation of fat content, that is, ff=sb/(sa+sb) ×100%; wherein FF is the pixel value in the fat proportion image, and SA and SB are the pixel values of the pixels at the same position in the water-excited magnetic resonance image and the fat-excited magnetic resonance image, respectively.
Figure 5 is a magnetic resonance image of a knee image in accordance with an embodiment of the present application. As shown in fig. 5, where (a) is a water-excited magnetic resonance image, (b) is a fat-excited magnetic resonance image, and (c) is a fat proportion image.
Since the two substances having chemical shifts are excited and suppressed by the radio frequency pulse signal of the same intensity and waveform in the present embodiment, and the two substances having chemical shifts have the same excitation efficiency and response pattern under the radio frequency pulse signal, the substance ratio image can be generated with the same weighting factor from the first substance signal image and the second substance signal image in the present embodiment, excluding the influence of the different weighting factors on the quantitative analysis of the substance ratio.
The present embodiment also provides an electronic device comprising a memory 604 and a processor 602, the memory 604 having stored therein a computer program, the processor 602 being arranged to run the computer program to perform the steps of any of the method embodiments described above.
In particular, the processor 602 may include a Central Processing Unit (CPU), or an application specific integrated circuit (Application Specific Integrated Circuit, abbreviated as ASIC), or may be configured as one or more integrated circuits that implement embodiments of the present application.
Wherein the memory 604 may include mass storage 604 for data or instructions. By way of example, and not limitation, memory 604 may comprise a Hard Disk Drive (HDD), a floppy Disk Drive, a solid state Drive (Solid State Drive, SSD), flash memory, an optical Disk, a magneto-optical Disk, a tape, or a universal serial bus (Universal Serial Bus, USB) Drive, or a combination of two or more of these. Memory 604 may include removable or non-removable (or fixed) media, where appropriate. The memory 604 may be internal or external to the data processing apparatus, where appropriate. In a particular embodiment, the memory 604 is a Non-Volatile (Non-Volatile) memory. In a particular embodiment, the Memory 604 includes Read-Only Memory (ROM) and random access Memory (Random Access Memory, RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (Programmable Read-Only Memory, abbreviated PROM), an erasable PROM (Erasable Programmable Read-Only Memory, abbreviated EPROM), an electrically erasable PROM (Electrically Erasable Programmable Read-Only Memory, abbreviated EEPROM), an electrically rewritable ROM (Electrically Alterable Read-Only Memory, abbreviated EAROM), or a FLASH Memory (FLASH), or a combination of two or more of these. The RAM may be Static Random-Access Memory (SRAM) or dynamic Random-Access Memory (Dynamic Random Access Memory DRAM), where the DRAM may be a fast page mode dynamic Random-Access Memory 604 (Fast Page Mode Dynamic Random Access Memory FPMDRAM), extended data output dynamic Random-Access Memory (Extended Date Out Dynamic Random Access Memory EDODRAM), synchronous dynamic Random-Access Memory (Synchronous Dynamic Random-Access Memory SDRAM), etc., as appropriate.
Memory 604 may be used to store or cache various data files that are required for processing and/or communication, as well as possible computer program instructions for execution by processor 602.
The processor 602 implements any of the magnetic resonance imaging methods of the above embodiments by reading and executing computer program instructions stored in the memory 604.
Optionally, the electronic apparatus may further include a transmission device 606 and an input/output device 608, where the transmission device 606 is connected to the processor 602 and the input/output device 608 is connected to the processor 602.
Alternatively, in the present embodiment, the above-mentioned processor 602 may be configured to execute the following steps by a computer program:
s1, modulating radio frequency pulses into a first radio frequency pulse signal and a second radio frequency pulse signal with different center frequencies, wherein the first radio frequency pulse signal is used for exciting a first substance signal and inhibiting a second substance signal, and the second radio frequency pulse signal is used for inhibiting the first substance signal and exciting the second substance signal.
S2, the first radio frequency pulse signal and the second radio frequency pulse signal are applied to an imaging field of view of the magnetic resonance imaging system in a time sharing mode.
And S3, acquiring first magnetic resonance data from an imaging field under the condition of applying a first radio frequency pulse signal, and reconstructing according to the first magnetic resonance data to obtain a first substance signal image.
And S4, acquiring second magnetic resonance data from the imaging visual field under the condition of applying a second radio frequency pulse signal, and reconstructing according to the second magnetic resonance data to obtain a second object signal image.
It should be noted that, specific examples in this embodiment may refer to examples described in the foregoing embodiments and alternative implementations, and this embodiment is not repeated herein.
In addition, in combination with the magnetic resonance imaging method in the above embodiment, the embodiment of the present application may be implemented by providing a storage medium. The storage medium having stored thereon computer program instructions; the computer program instructions, when executed by a processor, implement a magnetic resonance imaging method of any of the above embodiments.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.
Claims (9)
1. A method of magnetic resonance imaging comprising:
modulating radio frequency pulses into a first radio frequency pulse signal and a second radio frequency pulse signal with different center frequencies, wherein the first radio frequency pulse signal is used for exciting a first substance signal and inhibiting a second substance signal, the second radio frequency pulse signal is used for inhibiting the first substance signal and exciting the second substance signal, and the excitation efficiency of the first radio frequency pulse signal is the same as that of the second radio frequency pulse signal;
applying the first radio frequency pulse signal and the second radio frequency pulse signal to an imaging field of view of a magnetic resonance imaging system in a time-sharing manner;
acquiring first magnetic resonance data from the imaging field of view under the condition of applying the first radio frequency pulse signals, and reconstructing a first substance signal image according to the first magnetic resonance data; and
Acquiring second magnetic resonance data from the imaging field of view under the condition of applying the second radio frequency pulse signals, and reconstructing a second object signal image according to the second magnetic resonance data;
and generating a substance ratio image of the first substance and the second substance according to the first substance signal image and the second substance signal image.
2. The method of magnetic resonance imaging according to claim 1, characterized in that the maximum excitation-to-suppression ratio of the first substance signal intensity to the second substance signal intensity with the application of the first radio frequency pulse is equal to the maximum suppression-to-excitation ratio of the first substance signal intensity to the second substance signal intensity with the application of the second radio frequency pulse.
3. The method of magnetic resonance imaging according to claim 1, characterized in that the radio frequency pulses comprise at least one of the following: a non-center resonant double rectangular pulse, a non-center resonant single rectangular pulse.
4. The magnetic resonance imaging method as set forth in claim 1, characterized in that the first and second radio frequency pulse signals are applied time-divisionally into an imaging field of view of a magnetic resonance imaging system; acquiring first magnetic resonance data from the imaging field of view under the condition of applying the first radio frequency pulse signals, and reconstructing a first substance signal image according to the first magnetic resonance data; and acquiring second magnetic resonance data from the imaging field of view with the application of the second radio frequency pulse signal, reconstructing a second object signal image from the second magnetic resonance data comprising:
Applying the first radio frequency pulse signal to the imaging field of view in a first scanning period, acquiring the first magnetic resonance data from the imaging field of view, and reconstructing the first substance signal image according to the first magnetic resonance data;
and applying the second radio frequency pulse signal to the imaging field of view in a second scanning period, acquiring the second magnetic resonance data from the imaging field of view, and reconstructing the second object signal image according to the second magnetic resonance data.
5. The magnetic resonance imaging method as set forth in claim 1, characterized in that the first and second radio frequency pulse signals are applied time-divisionally into an imaging field of view of a magnetic resonance imaging system; acquiring first magnetic resonance data from the imaging field of view under the condition of applying the first radio frequency pulse signals, and reconstructing a first substance signal image according to the first magnetic resonance data; and acquiring second magnetic resonance data from the imaging field of view with the application of the second radio frequency pulse signal, reconstructing a second object signal image from the second magnetic resonance data comprising:
the following steps are circularly executed to acquire each K-space signal line corresponding to the first substance signal image and the second substance signal image respectively until the first K-space corresponding to the first substance signal image and the second K-space corresponding to the second substance signal image are filled: applying the first radio frequency pulse signal to the imaging field of view during a scanning period, acquiring a K-space signal line from the imaging field of view and filling the first K-space; applying the second radio frequency pulse signal to the imaging field of view in the next scanning period, acquiring a K space signal line from the imaging field of view and filling the K space;
Reconstructing the first substance signal image according to the signal of the first K space; and reconstructing the second object signal image according to the signal of the second K space.
6. The method of magnetic resonance imaging according to claim 1, characterized in that the first substance has a chemical shift with the second substance; wherein the chemically displaced material comprises at least two of: water, fat, silica gel.
7. A magnetic resonance imaging system, characterized in that the magnetic resonance imaging system comprises: a magnetic resonance scanner having a bore with an imaging field of view; and a processor configured to operate the magnetic resonance scanner when the subject is located in the magnetic resonance scanner, perform a diagnostic scan by acquiring magnetic resonance signals from a region of interest of the subject, and a memory storing a computer program; wherein the processor is further configured to run the computer program to perform the magnetic resonance imaging method of any one of claims 1 to 6.
8. An electronic device comprising a memory and a processor, wherein the memory has stored therein a computer program, the processor being arranged to run the computer program to perform the magnetic resonance imaging method of any one of claims 1 to 6.
9. A storage medium having stored thereon computer program instructions, which when executed by a processor, implement the magnetic resonance imaging method of any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011117988.1A CN112244812B (en) | 2020-10-19 | 2020-10-19 | Magnetic resonance imaging method, magnetic resonance imaging system and electronic device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011117988.1A CN112244812B (en) | 2020-10-19 | 2020-10-19 | Magnetic resonance imaging method, magnetic resonance imaging system and electronic device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112244812A CN112244812A (en) | 2021-01-22 |
| CN112244812B true CN112244812B (en) | 2023-08-22 |
Family
ID=74244693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011117988.1A Active CN112244812B (en) | 2020-10-19 | 2020-10-19 | Magnetic resonance imaging method, magnetic resonance imaging system and electronic device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112244812B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114089240B (en) * | 2021-11-05 | 2024-08-23 | 深圳市联影高端医疗装备创新研究院 | Magnetic resonance detection method and device, magnetic resonance imaging system and storage medium |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09154831A (en) * | 1995-12-12 | 1997-06-17 | Toshiba Corp | Magnetic resonance imaging method and device |
| JP2004024902A (en) * | 1994-04-15 | 2004-01-29 | Toshiba Corp | Magnetic resonance imaging apparatus |
| JP2005192700A (en) * | 2004-01-05 | 2005-07-21 | Hitachi Medical Corp | Magnetic resonance imaging equipment |
| US8115485B1 (en) * | 2006-03-10 | 2012-02-14 | General Electric Company | Method and apparatus for interactively setting parameters of an MR imaging sequence through inspection of frequency spectrum |
| CN103167829A (en) * | 2011-10-13 | 2013-06-19 | 株式会社东芝 | Magnetic resonance imaging device and magnetic resonance imaging method |
| CN104545914A (en) * | 2013-10-21 | 2015-04-29 | 深圳先进技术研究院 | Water and fat separation imaging method and water and fat separation imaging system |
| CN107367703A (en) * | 2017-08-29 | 2017-11-21 | 上海联影医疗科技有限公司 | Magnetic resonance scanning method, system, device and storage medium |
| CA3168472A1 (en) * | 2018-09-14 | 2020-03-19 | 10250929 Canada Inc. | Method and system for in-vivo, and non-invasive measurement of metabolite levels |
| CN111257810A (en) * | 2020-01-19 | 2020-06-09 | 上海联影医疗科技有限公司 | Magnetic resonance signal acquisition system and method |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6147492A (en) * | 1998-10-28 | 2000-11-14 | Toshiba America Mri, Inc. | Quantitative MR imaging of water and fat using a quadruple-echo sequence |
| AU2002223111A1 (en) * | 2000-12-27 | 2002-07-08 | Ramot University Authority For Applied Research And Industrial Development Ltd. | Method of selective excitation for improving contrast in magnetic resonance imaging |
| US7574248B2 (en) * | 2002-05-17 | 2009-08-11 | General Hospital Corporation | Method and apparatus for quantitative bone matrix imaging by magnetic resonance imaging |
| JP3971726B2 (en) * | 2003-09-16 | 2007-09-05 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Magnetic resonance imaging device |
| WO2006084125A2 (en) * | 2005-02-03 | 2006-08-10 | The Johns Hopkins University | Mri method of selective visualization with on-resonant water suppression |
| US7795867B2 (en) * | 2006-02-02 | 2010-09-14 | Ramot At Tel-Aviv University Ltd. | Method, apparatus and system for magnetic resonance analysis based on water magnetization transferred from other molecules |
| JP5072250B2 (en) * | 2006-04-04 | 2012-11-14 | 株式会社東芝 | Magnetic resonance imaging system |
| WO2008004324A1 (en) * | 2006-07-07 | 2008-01-10 | Hitachi Medical Corporation | Magnetic resonance imaging device |
| JP5398149B2 (en) * | 2007-03-27 | 2014-01-29 | 株式会社東芝 | Magnetic resonance imaging system |
| EP3236277B1 (en) * | 2016-04-18 | 2021-12-01 | Centre Hospitalier Universitaire Vaudois (CHUV) | Differentiated tissue excitation by mri using binomial off-resonance 1-1 rf pulses |
| EP3511728A1 (en) * | 2018-01-12 | 2019-07-17 | Koninklijke Philips N.V. | Single-point dixon method for fat-water separation in chemical exchange saturation transfer magnetic resonance imaging |
| DE102018208569A1 (en) * | 2018-05-30 | 2019-12-05 | Siemens Healthcare Gmbh | Recording two magnetic resonance images |
-
2020
- 2020-10-19 CN CN202011117988.1A patent/CN112244812B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004024902A (en) * | 1994-04-15 | 2004-01-29 | Toshiba Corp | Magnetic resonance imaging apparatus |
| JPH09154831A (en) * | 1995-12-12 | 1997-06-17 | Toshiba Corp | Magnetic resonance imaging method and device |
| JP2005192700A (en) * | 2004-01-05 | 2005-07-21 | Hitachi Medical Corp | Magnetic resonance imaging equipment |
| US8115485B1 (en) * | 2006-03-10 | 2012-02-14 | General Electric Company | Method and apparatus for interactively setting parameters of an MR imaging sequence through inspection of frequency spectrum |
| CN103167829A (en) * | 2011-10-13 | 2013-06-19 | 株式会社东芝 | Magnetic resonance imaging device and magnetic resonance imaging method |
| CN104545914A (en) * | 2013-10-21 | 2015-04-29 | 深圳先进技术研究院 | Water and fat separation imaging method and water and fat separation imaging system |
| CN107367703A (en) * | 2017-08-29 | 2017-11-21 | 上海联影医疗科技有限公司 | Magnetic resonance scanning method, system, device and storage medium |
| CA3168472A1 (en) * | 2018-09-14 | 2020-03-19 | 10250929 Canada Inc. | Method and system for in-vivo, and non-invasive measurement of metabolite levels |
| CN111257810A (en) * | 2020-01-19 | 2020-06-09 | 上海联影医疗科技有限公司 | Magnetic resonance signal acquisition system and method |
Non-Patent Citations (1)
| Title |
|---|
| 磁共振脂肪抑制技术在骨与关节病变中的应用;吴婧;卢铃铨;顾建平;;医学影像学杂志(第01期);第146-150页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112244812A (en) | 2021-01-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0086306B1 (en) | Selective material projection imaging system using nuclear magnetic resonance | |
| JP5127841B2 (en) | Magnetic resonance imaging apparatus and magnetic susceptibility weighted imaging method | |
| JP5848713B2 (en) | Magnetic resonance imaging apparatus and contrast-enhanced image acquisition method | |
| US10120053B2 (en) | Magnetic resonance imaging method and apparatus | |
| RU2702859C2 (en) | Parallel multi-slice mr-imaging with suppression of side band artefacts | |
| JP2014083445A (en) | Magnetic resonance imaging system, and magnetic resonance imaging method | |
| US10247798B2 (en) | Simultaneous multi-slice MRI measurement | |
| JP6005948B2 (en) | Magnetic resonance imaging system and method | |
| US10203387B2 (en) | MR imaging with enhanced susceptibility contrast | |
| CN105005011A (en) | MRI method of hybrid acquisition in 3D TSE | |
| US10481232B2 (en) | Magnetic resonance imaging apparatus and magnetic resonance imaging method | |
| KR101625715B1 (en) | Method and control device to control a magnetic resonance system | |
| KR101743163B1 (en) | Method and magnetic resonance system for reconstructing an mr image taking into account the chemical shift | |
| US7479782B2 (en) | System and method for MRI using MR signals from different resonant species in different regions of k-space | |
| CN112630713A (en) | Magnetic resonance imaging method, system, electronic device, and storage medium | |
| US10073156B2 (en) | Methods and systems for improved magnetic resonance acquisition | |
| US9274197B2 (en) | Magnetic resonance imaging data sampling methods and systems | |
| CN112244812B (en) | Magnetic resonance imaging method, magnetic resonance imaging system and electronic device | |
| JP5278914B2 (en) | Magnetic resonance imaging apparatus and magnetic susceptibility weighted imaging method | |
| US10534054B2 (en) | Magnetic resonance imaging apparatus and magnetic resonance imaging method | |
| US9618595B2 (en) | Magnetic resonance imaging system, data processing apparatus, and method for generating magnetic resonance image | |
| CN111044957B (en) | Magnetic resonance imaging method, magnetic resonance imaging device, storage medium and magnetic resonance imaging system | |
| JP2020151108A (en) | Magnetic resonance imaging apparatus | |
| CN114089240B (en) | Magnetic resonance detection method and device, magnetic resonance imaging system and storage medium | |
| CN103354908A (en) | Broad bandwidth magnetic resonance spectroscopy at high static (B0) magnetic field using polarization transfer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |