CN112823741A - Magnetic resonance scanning method and magnetic resonance system - Google Patents
Magnetic resonance scanning method and magnetic resonance system Download PDFInfo
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- CN112823741A CN112823741A CN201911140917.0A CN201911140917A CN112823741A CN 112823741 A CN112823741 A CN 112823741A CN 201911140917 A CN201911140917 A CN 201911140917A CN 112823741 A CN112823741 A CN 112823741A
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- 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
Abstract
The application relates to a magnetic resonance scanning method and a magnetic resonance system, wherein in the magnetic resonance scanning process, the process of acquiring images with different bias frequencies is added into the positioning scanning process, so that the optimal scanning frequency corresponding to a region to be scanned can be determined according to the positioning scanning images, and the accuracy of the magnetic resonance scanning result is ensured. Compared with the method that an additional scanning protocol needs to be added in the prior art, the scanning time can be effectively saved, and the scanning efficiency is improved; in addition, the shortening of the scanning time is also helpful for stabilizing the emotion of the patient, reducing the influence on the scanning result caused by the patient factors and further improving the accuracy of the scanning result.
Description
Technical Field
The present application relates to the field of magnetic resonance technology, and in particular, to a magnetic resonance scanning method and a magnetic resonance system.
Background
Magnetic Resonance Imaging (MRI) is an Imaging technique for medical examination using a nuclear Magnetic Resonance phenomenon, has advantages of safety, accuracy, and the like, and can be used for scanning key parts of a patient, such as a heart, and the like.
When scanning a patient's heart using magnetic resonance imaging techniques, cardiac scanning is typically performed using a balanced steady-state free precession (BSSFP) sequence. The B0 field at the heart is made more complex by the BSSFP sequence itself being sensitive to the homogeneity of the B0 field, and the heart having a flow of blood, itself beating. In high field situations, when BSSFP sequences are used for cardiac scanning, offset frequency scanning is typically required. The prior art typically additionally scans a protocol, scans images offset at different frequencies, and then manually determines to select an appropriate offset frequency for subsequent cardiac imaging scans. However, adding additional scanning protocols can result in lengthy scanning times, reduced scanning efficiency, and may also affect the mood of the patient, thereby reducing the accuracy of the scanning results.
Disclosure of Invention
In view of the above, it is necessary to provide a magnetic resonance scanning method and a magnetic resonance system with higher efficiency and accuracy.
A magnetic resonance scanning method, comprising:
determining a region to be scanned;
positioning and scanning the area to be scanned by adopting a plurality of scanning protocols to obtain a plurality of positioning images, wherein the plurality of scanning protocols and the system frequency have different frequency deviation values;
determining a proton spin frequency estimation value of the area to be scanned according to the plurality of positioning images;
determining the scanning frequency corresponding to the region to be scanned based on the proton spin frequency estimation value;
and determining an imaging sequence according to the scanning frequency, and performing magnetic resonance scanning on the region to be scanned through the imaging sequence to obtain a magnetic resonance scanning image corresponding to the region to be scanned.
A magnetic resonance system comprising:
the magnet surrounds the cavity and is used for forming a main magnetic field in the cavity;
the hospital bed is used for carrying an object and moving a region to be scanned of the object to a scanning visual field formed by the main magnetic field, and the main magnetic field at least comprises two system frequencies in the scanning visual field;
the transmitting coil is arranged inside the cavity and is used for applying radio frequency pulses to the area to be scanned;
the processor is used for controlling a radio frequency pulse of the transmitting coil, and the frequency of the radio frequency pulse is the same as the system frequency of the main magnetic field where the region to be scanned is located, or the frequency error between the frequency of the radio frequency pulse and the system frequency of the main magnetic field is within a preset range;
the region to be scanned comprises a plurality of slices, and the frequency of the radio frequency pulse applied by at least two slices is different.
The magnetic resonance scanning method and the magnetic resonance system determine the region to be scanned; positioning and scanning an area to be scanned by adopting a plurality of scanning protocols to obtain a plurality of positioning images, wherein the plurality of scanning protocols and the system frequency have different frequency deviation values; determining a proton spin frequency estimation value of a region to be scanned according to a plurality of positioning images; determining the scanning frequency corresponding to the region to be scanned based on the proton spin frequency estimation value; and determining an imaging sequence according to the scanning frequency, and performing magnetic resonance scanning on the region to be scanned through the imaging sequence to obtain a magnetic resonance scanning image corresponding to the region to be scanned. In the magnetic resonance scanning process, the process of acquiring images with different bias frequencies is added into the positioning scanning process, so that the optimal scanning frequency corresponding to the region to be scanned can be determined according to the positioning scanning images, and the accuracy of the magnetic resonance scanning result is ensured. Compared with the method that an additional scanning protocol needs to be added in the prior art, the scanning time can be effectively saved, and the scanning efficiency is improved; in addition, the shortening of the scanning time is also helpful for stabilizing the emotion of the patient, reducing the influence on the scanning result caused by the patient factors and further improving the accuracy of the scanning result.
Drawings
FIG. 1 is a diagram of an embodiment of an application of a magnetic resonance scanning method;
figure 2 is a flow chart of a magnetic resonance scanning method in one embodiment;
FIG. 3 is a schematic illustration of a scout scan performed in one embodiment;
FIG. 4 is a schematic illustration of a scout scan performed in another embodiment;
FIG. 5 is a schematic illustration of a scout scan performed in yet another embodiment;
FIG. 6 is a schematic illustration of longitudinal magnetization in one embodiment;
FIG. 7 is a sequence diagram used in one embodiment;
figure 8 is a schematic view of an embodiment of a magnetic resonance scanner;
figure 9 is a schematic diagram of the structure of a magnetic resonance system in one embodiment;
FIG. 10 is a diagram showing an internal structure of a computer device according to an embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
The embodiment of the application provides a magnetic resonance imaging method, which includes adjusting a radio frequency pulse of a transmitting coil to enable the frequency of the radio frequency pulse to be the same as the system frequency of a main magnetic field in a scanning area, or enabling the frequency error between the frequency of the radio frequency pulse and the system frequency of the main magnetic field to be within a preset range, enabling the system frequency of the main magnetic field to be different in different areas, and enabling the frequency of the radio frequency pulse to change along with the system frequency of the main magnetic field. Therefore, the proton spin frequency of the region to be scanned is consistent with the system frequency of the main magnetic field, the obtained magnetic resonance signal intensity is maximum, and the signal-to-noise ratio of the final imaging image is good. In some embodiments, the frequency of the rf pulses may be adjusted by:
acquiring a plurality of positioning images of an area to be scanned, wherein each of the plurality of positioning images corresponds to a scanning protocol, and each scanning protocol has a different frequency deviation value with a system frequency; determining a proton spin frequency estimation value of the area to be scanned according to a plurality of positioning images; the frequency of the radio frequency pulse is adjusted based on the proton spin frequency estimate.
In some embodiments, the above-described methods may perform multi-layer simultaneous imaging. For example, the transmitting coil is controlled to alternately transmit a first radio-frequency pulse and a second radio-frequency pulse, the first radio-frequency pulse is used for exciting a first slice of the region to be scanned, the second radio-frequency pulse is used for exciting a second slice of the region to be scanned, the frequencies of the first radio-frequency pulse and the second radio-frequency pulse are different, and the proton spin frequency of the slice excited by the two radio-frequency pulses is consistent with the system frequency of the main magnetic field.
In one embodiment, as shown in fig. 1, referring to fig. 1, the magnetic resonance scanning method of the present application is applied to a magnetic resonance scanning system including a magnetic resonance scanner 10, a processing device 20, a storage device 30, one or more terminals 40 (e.g., a mobile phone 40-1, a tablet 40-2, a laptop 40-3, etc.) and a network 50, wherein the magnetic resonance scanner 10 is configured to acquire scout scan data during a magnetic resonance scanning process based on a plurality of scanning protocols issued by the processing device 20 according to a region to be scanned, and send the scout scan data to the processing device 20, the processing device 20 is configured to perform image reconstruction according to the scout scan data to obtain a plurality of scout images, then determine proton spin frequency estimation values of the region to be scanned according to the plurality of scout images, determine a scanning frequency corresponding to the region to be scanned based on the proton spin frequency estimation values, the method includes the steps of determining an imaging sequence according to a scanning frequency, then issuing the imaging sequence to the magnetic resonance scanner 10, performing magnetic resonance scanning on a region to be scanned according to the imaging sequence to obtain magnetic resonance scanning data, and sending the magnetic resonance scanning data to the processing device 20, wherein the processing device 20 is configured to perform image reconstruction according to the magnetic resonance scanning data to obtain a magnetic resonance scanning image corresponding to the region to be scanned. The storage device 30 is used for storing the scout scan data, the scout image, the magnetic resonance scan data and the magnetic resonance image, and the terminal 40 is used for displaying the scout image and the magnetic resonance image so as to facilitate observation and analysis by a user. The components in the magnetic resonance scanning system may be connected in one or more ways. By way of example only, and with reference to figure 1, a magnetic resonance scanner 10 may be connected to the processing device 20 by a network 50. As another example, the magnetic resonance scanner 10 may be directly connected with the processing apparatus 20, as indicated by the double-headed arrow in the dashed line connecting the magnetic resonance scanner and the processing apparatus 20. As another example, storage device 30 may be connected directly to processing device 20 (not shown) or through network 50. As yet another example, terminal 40 may be connected directly to processing device 20 (as indicated by the double-headed arrow in the dashed line connecting terminal 40 and processing device 20) or through network 50.
In one embodiment, as shown in fig. 2, a magnetic resonance scanning method is provided, which is explained by taking the method as an example applied to the processing device in fig. 1, and the method mainly includes the following steps:
step S100, determining a region to be scanned.
The region to be scanned may be a specific body part (e.g., a head, a lower limb, etc.) of the target object to be scanned, or may be a specific organ tissue (e.g., a heart, a lung, etc.), which is not limited herein. The processing device may specifically extract relevant information of the region to be scanned by acquiring a medical scanning task.
Step S200, a plurality of scanning protocols are adopted to perform positioning scanning on the area to be scanned to obtain a plurality of positioning images, and the plurality of scanning protocols and the system frequency have different frequency deviation values.
Wherein, the system frequency is the frequency of the main magnetic field in the magnetic resonance scanning, the main magnetic field is the magnetic field formed by the main magnetic body of the magnetic resonance scanner, the magnet strength of the main magnetic body comprises 1.5T (Tesla) and 3.0T, the corresponding frequency is about 64MHz for the main magnetic body with the strength of 1.5T, and the corresponding frequency is about 128MHz for the main magnetic body with the strength of 3.0T. During the magnetic resonance scan, the excitation of the magnetic resonance signals is based on the premise that the resonance frequency of the tissue and organ is the same as the system frequency, and the proton signals are excited. However, due to the influence of physiological structures, the resonance frequency of the tissue and organ often differs from the system frequency, for example, for the cavity region, such as the junction region of the lung and the heart, where the lung is a gas, the corresponding resonance frequency often differs from the system frequency.
Therefore, in this step, in the positioning scanning process, instead of performing the magnetic resonance scanning with a certain preset fixed frequency, the processing device may first perform the positioning scanning with a plurality of scanning protocols having different frequency offset values from the system frequency, and specifically, the processing device may first determine a plurality of corresponding scanning protocols according to the region to be scanned, then issue the plurality of scanning protocols to the magnetic resonance scanner in fig. 1, and obtain a plurality of positioning images according to the positioning scanning data sent by the magnetic resonance scanner after the magnetic resonance scanner completes the positioning scanning according to the plurality of scanning protocols.
And step S300, determining the proton spin frequency estimated value of the area to be scanned according to the plurality of scout images.
The proton spin frequency estimation value is an estimation value of the resonance frequency of the tissue and organ. After the processing device obtains the plurality of scout images, the processing device itself may perform image analysis processing according to the plurality of scout images, and then determine the proton spin frequency estimation value of the region to be scanned according to the image analysis processing result. The processing device may also send a plurality of positioning images to the terminal in fig. 1, and then the relevant person determines the proton spin frequency estimation value of the region to be scanned according to the positioning images displayed by the terminal, and sends the proton spin frequency estimation value to the processing device through the terminal.
And step S400, determining the scanning frequency corresponding to the area to be scanned based on the proton spin frequency estimated value.
After the proton spin frequency estimation value of the region to be scanned is determined, the processing equipment can determine the scanning frequency of the subsequent magnetic resonance scanning process according to the proton spin frequency estimation value, and the magnetic resonance scanning frequency is determined based on the proton spin frequency estimation value of the region to be scanned, so that the scanning effect can be improved.
Step S500, determining an imaging sequence according to the scanning frequency, and performing magnetic resonance scanning on the region to be scanned through the imaging sequence to obtain a magnetic resonance scanning image corresponding to the region to be scanned.
The imaging sequence of the magnetic resonance scanning refers to an organic combination of a radio frequency pulse and a gradient pulse with certain bandwidth and certain amplitude, different imaging sequences are formed by different combination modes of the radio frequency pulse and the gradient pulse, and images obtained by different imaging sequences have respective characteristics and also have corresponding application ranges. After the processing device determines the scanning frequency of the magnetic resonance, the adopted imaging sequence can be determined according to the scanning frequency, and then the magnetic resonance scanning is carried out on the region to be scanned based on the imaging sequence, so as to obtain a magnetic resonance scanning image corresponding to the region to be scanned.
Specifically, when determining the imaging sequence according to the scanning frequency, the processing device may determine the imaging sequence according to the scanning frequency, or the processing device may transmit the scanning frequency to the terminal and then manually determine the imaging sequence. And after the magnetic resonance scanner finishes magnetic resonance scanning according to the imaging sequence, obtaining a magnetic resonance scanning image corresponding to the region to be scanned according to the magnetic resonance scanning data sent by the magnetic resonance scanner.
In the magnetic resonance scanning process, the process of acquiring images with different bias frequencies is added to the positioning scanning process, so that the optimal scanning frequency corresponding to the region to be scanned can be determined according to the positioning scanning images, and the accuracy of the magnetic resonance scanning result is ensured. Compared with the method that an additional scanning protocol needs to be added in the prior art, the scanning time can be effectively saved, and the scanning efficiency is improved; in addition, the shortening of the scanning time is also helpful for stabilizing the emotion of the patient, reducing the influence on the scanning result caused by the patient factors and further improving the accuracy of the scanning result.
In one embodiment, performing positioning scanning on a region to be scanned by using a plurality of scanning protocols to obtain a plurality of positioning images includes: and based on the same scanning direction, performing positioning scanning on each layer surface in the region to be scanned by adopting the same type of scanning protocol to obtain a positioning image of each layer surface, wherein the corresponding positioning scanning frequencies of different layer surfaces are different.
In this embodiment, when performing positioning scanning on an area to be scanned, positioning scanning on different layers may be performed based on the same scanning direction and by using the same type of scanning protocol. The scanning direction may be specifically a coronary, sagittal, and transverse direction of the heart, and the same type of scanning protocol refers to a scanning protocol with the same scanning parameters except for different positioning and scanning frequencies. In addition, in practical application, because the clinical requirement on the image quality of the scout image is not high, only the basic image structure needs to be identified, so that the imaging sequence adopted in the scanning protocol can be a rapid imaging sequence to further shorten the scanning time.
Specifically, as shown in fig. 3, a schematic diagram of performing the scout scan in the present embodiment is shown, where Si represents the i-th layer image of the scout scan, f0 represents the system frequency, and x of f0 ± x represents the corresponding frequency offset value. For example, for the layer 1 image S1, the corresponding frequency offset value is Δ a, i.e., the layer 1 image S1 corresponds to the scout scan frequency of f0+ Δ a, and the scout scan frequencies of the other images are as shown in fig. 3.
In addition, each line segment in fig. 3 represents a scanning orientation, which is perpendicular to the centerline of the blood vessel during actual scanning. In this embodiment, the scanning orientations of the respective slices are the same, so that the line segments corresponding to the respective images are all along the horizontal direction.
In one embodiment, performing positioning scanning on a region to be scanned by using a plurality of scanning protocols to obtain a plurality of positioning images includes: based on different scanning orientations, different types of scanning protocols are adopted to perform positioning scanning on each layer surface in the region to be scanned, and positioning images of each layer surface are obtained, wherein the corresponding positioning scanning frequencies of different layer surfaces are different.
In this embodiment, when performing positioning scanning on the region to be scanned, positioning scanning on different layers may be performed based on different scanning orientations and by using different types of scanning protocols. The scanning direction may be three directions of coronary heart, sagittal heart and transverse heart, and the different types of scanning protocols refer to scanning protocols in which the positioning scanning frequency and other scanning parameters are different. In addition, in practical application, because the clinical requirement on the image quality of the scout image is not high, only the basic image structure needs to be identified, so that the imaging sequence adopted in the scanning protocol can be a rapid imaging sequence to further shorten the scanning time.
Specifically, as shown in fig. 4, it is a schematic diagram of performing positioning scanning in the present embodiment, where Pi represents an image of the ith scanning protocol, f0 represents a system frequency, and x of f0 ± x represents a corresponding frequency offset value. For example, for the image P1 of the 1 st scan protocol, the corresponding frequency offset value is Δ a, i.e., the scout scan frequency for the image P1 of the 1 st scan protocol is f0+ Δ a, and the scout scan frequencies of the other images are as shown in fig. 4.
In addition, each line segment in fig. 4 represents a scanning orientation, which is perpendicular to the centerline of the blood vessel during actual scanning. In this embodiment, the scanning orientations of the respective slices are different, and therefore, the line segment corresponding to each image is along the horizontal direction or along the oblique direction intersecting the horizontal direction.
In one embodiment, performing positioning scanning on a region to be scanned by using a plurality of scanning protocols to obtain a plurality of positioning images includes: based on different scanning orientations, the same type of scanning protocol is adopted to perform positioning scanning on each layer in the region to be scanned to obtain positioning images of each layer, wherein the corresponding positioning scanning frequencies of different layers are different.
In this embodiment, when performing positioning scanning on an area to be scanned, positioning scanning on different layers may be performed based on different scanning orientations and by using the same type of scanning protocol. The scanning direction may be specifically a coronary, sagittal, and transverse direction of the heart, and the same type of scanning protocol refers to a scanning protocol with the same scanning parameters except for different positioning and scanning frequencies. In addition, in practical application, because the clinical requirement on the image quality of the scout image is not high, only the basic image structure needs to be identified, so that the imaging sequence adopted in the scanning protocol can be a rapid imaging sequence to further shorten the scanning time.
Specifically, as shown in fig. 5, a schematic diagram of performing the scout scan in the present embodiment is shown, where Si represents the i-th layer image of the scout scan, f0 represents the system frequency, and x of f0 ± x represents the corresponding frequency offset value. For example, for the layer 1 image S1, the corresponding frequency offset value is Δ a, i.e., the layer 1 image S1 corresponds to the scout scan frequency of f0+ Δ a, and the scout scan frequencies of the other images are as shown in fig. 5.
In addition, each line segment in fig. 5 represents a scanning orientation, which is perpendicular to the centerline of the blood vessel during actual scanning. In this embodiment, the scanning orientations of the respective slices are different, and therefore, the line segment corresponding to each image is along the horizontal direction or along the oblique direction intersecting the horizontal direction.
In one embodiment, determining an estimate of proton spin frequency for a region to be scanned from a plurality of scout images comprises: screening a target positioning image with the best imaging quality from all positioning images; and taking the positioning scanning frequency corresponding to the target positioning image as an estimated proton spin frequency value.
The substance is composed of molecules, the molecules are composed of atoms, the atoms are composed of a nucleus and electrons with different numbers, and the nucleus is composed of protons with positive charges and neutrons without showing electric property. Under normal conditions, the nuclei are not stationary, but rotate around their own axes without stopping, called "spins".
When no external magnetic field exists, the spin of the atomic nucleus can take any direction; when the substance is placed in a strong external magnetic field B0 (the external magnetic field B0 is along the z-axis direction), the magnetic field of the proton itself is regulated by the strong external magnetic field, the south pole and the north pole of the proton are forced to be arranged along the external magnetic field, and the process of generating magnetism in the magnetic field direction is called magnetization, and the magnitude of the magnetization is the magnetization intensity. All the protons in the external magnetic field are arranged in the direction parallel to or antiparallel to the external magnetic field, so that the magnetic forces thereof are cancelled out, and only the protons in the weak difference part of the number of protons in the two energy levels are kept without being cancelled out. Because the protons are aligned in the same direction, the magnetic moment vectors that exist can be superimposed to form a corresponding net macroscopic magnetization vector. Because the atomic nucleus has a magnetic moment, when it is in the external magnetic field B0, it is subjected to the magnetic moment, and as a result, the atomic nucleus rotates around its own axis and precesses around the direction of the external magnetic field, which is called lamor precession. When the spinning top rotates, the rotating shaft deviates from the gravity direction, and the spinning top can spin around the self axis and rotate around the gravity direction. This precession of the gyroscope is due to the earth's gravity, while the precession of the nuclear magnetic moments is due to the external magnetic field B0. The magnetic moments of nuclei in an external magnetic field precess around the external field is the main mechanism for producing nuclear magnetic resonance.
The area to be scanned in this application is understood to be the area in the external magnetic field B0, as shown in fig. 6, for the substance in the area to be scanned, there is a longitudinal magnetization M0, when a radio frequency pulse B1 is applied in the X-axis direction and perpendicular to M0, i.e. perpendicular to the Z-axis or the external magnetic field B0, and the angular frequency of B1 is equal to the angular frequency at which all protons in the proton system make a ramjet around the external magnetic field B0, then the protons absorb the energy of the radio frequency pulse and nuclear magnetic resonance occurs. The principle of magnetic resonance scanning is that nuclear spins of a scanned object in a region to be scanned are magnetically excited by radio frequency pulses, and then a corresponding image is obtained according to a nuclear magnetic resonance signal generated by the excitation.
Therefore, it can be understood that, after the positioning scanning is performed by adopting a plurality of scanning protocols, the better the quality of the obtained positioning image is, the better the effect of the radio-frequency pulse in the scanning protocol for exciting the protons of the scanning object to do larmor precession is, and therefore, the closer the frequency of the radio-frequency pulse is to the spin frequency of the protons is, and thus, according to the principle, the target positioning image with the best imaging quality can be screened from the positioning images; and taking the positioning scanning frequency corresponding to the target positioning image as an estimated proton spin frequency value.
In one embodiment, determining the scanning frequency corresponding to the region to be scanned based on the proton spin frequency estimation value comprises: and taking the proton spin frequency estimation value as the scanning frequency corresponding to the area to be scanned.
Specifically, when determining the proton spin frequency estimation value, the positioning scanning frequency corresponding to the target positioning image with the best imaging quality is used as the proton spin frequency estimation value, and the effect of larmor precession of the proton of the scanning object excited by the radio frequency pulse under the frequency is the best, so that when performing subsequent magnetic resonance scanning, the proton spin frequency estimation value can be directly used as the scanning frequency corresponding to the region to be scanned, thereby ensuring that the magnetic resonance scanning imaging result is the best.
In one embodiment, determining an imaging sequence from a scan frequency comprises: and comparing the scanning frequency with the transmitting frequency of each sequence, and selecting the sequence with the transmitting frequency consistent with the scanning frequency as an imaging sequence.
The aim of magnetic resonance imaging is to provide a gray scale image satisfying the diagnosis requirement for clinic, and under the condition that the hardware condition of the system is not changed, the contrast between different tissues on the image is only related to the application of radio frequency pulse and gradient magnetic field during scanning. The radio frequency pulse emission frequencies of different pulse sequences are different to a certain extent, so that in order to ensure the imaging quality, the pulse sequence with the radio frequency pulse emission frequency consistent with the scanning frequency can be selected as the imaging sequence to carry out magnetic resonance scanning, and a magnetic resonance image with better image quality is obtained.
In an embodiment, as shown in fig. 7, which is a sequence diagram used in the present application, the present application may specifically adopt a GRE-BssP sequence, refer to fig. 7, where RF is Radio Frequency (Radio Frequency) and α is an applied flip angle (not shown in the Frequency diagram); GS is the slice selection gradient; GP is the phase encoding gradient; GR is the readout frequency encoding gradient; the last row is the actually acquired magnetic resonance signal.
It should be understood that, under reasonable circumstances, although the steps in the flowcharts referred to in the foregoing embodiments are shown in sequence as indicated by the arrows, the steps are not necessarily executed in sequence as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in each flowchart may include multiple sub-steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of performing the sub-steps or stages is not necessarily sequential, but may be performed alternately or alternately with other steps or at least a portion of the sub-steps or stages of other steps.
In one embodiment, as shown in figure 8, there is provided a magnetic resonance scanning apparatus, the apparatus essentially comprising the following modules:
an area determination module 100, configured to determine an area to be scanned;
the positioning and scanning module 200 is configured to perform positioning and scanning on a region to be scanned by using a plurality of scanning protocols to obtain a plurality of positioning images, where the plurality of scanning protocols and the system frequency have different frequency offset values;
a spin frequency determining module 300, configured to determine a proton spin frequency estimation value of the region to be scanned according to the multiple scout images;
a scanning frequency determining module 400, configured to determine a scanning frequency corresponding to a region to be scanned based on the proton spin frequency estimation value;
the magnetic resonance scanning module 500 is configured to determine an imaging sequence according to the scanning frequency, and perform magnetic resonance scanning on a region to be scanned through the imaging sequence to obtain a magnetic resonance scanning image corresponding to the region to be scanned.
In the magnetic resonance scanning process, the process of acquiring images with different bias frequencies is added to the positioning scanning process, so that the optimal scanning frequency corresponding to the region to be scanned can be determined according to the positioning scanning images, and the accuracy of the magnetic resonance scanning result is ensured. Compared with the method that an additional scanning protocol needs to be added in the prior art, the scanning time can be effectively saved, and the scanning efficiency is improved; in addition, the shortening of the scanning time is also helpful for stabilizing the emotion of the patient, reducing the influence on the scanning result caused by the patient factors and further improving the accuracy of the scanning result.
In one embodiment, the scout scan module 200 is further configured to: and based on the same scanning direction, performing positioning scanning on each layer surface in the region to be scanned by adopting the same type of scanning protocol to obtain a positioning image of each layer surface, wherein the corresponding positioning scanning frequencies of different layer surfaces are different.
In one embodiment, the scout scan module 200 is further configured to: based on different scanning orientations, different types of scanning protocols are adopted to perform positioning scanning on each layer surface in the region to be scanned, and positioning images of each layer surface are obtained, wherein the corresponding positioning scanning frequencies of different layer surfaces are different.
In one embodiment, the scout scan module 200 is further configured to: based on different scanning orientations, the same type of scanning protocol is adopted to perform positioning scanning on each layer in the region to be scanned to obtain positioning images of each layer, wherein the corresponding positioning scanning frequencies of different layers are different.
In one embodiment, the spin frequency determination module 300 is further configured to: screening a target positioning image with the best imaging quality from all positioning images; and taking the positioning scanning frequency corresponding to the target positioning image as an estimated proton spin frequency value.
In one embodiment, the scan frequency determination module 400 is further configured to: and taking the proton spin frequency estimation value as the scanning frequency corresponding to the area to be scanned.
In one embodiment, the magnetic resonance scanning module 500 is further configured to: and comparing the scanning frequency with the transmitting frequency of each sequence, and selecting the sequence with the transmitting frequency consistent with the scanning frequency as an imaging sequence.
For specific definitions of the magnetic resonance scanner, reference may be made to the above definitions of the magnetic resonance scanning method, which are not further described here. The modules in the magnetic resonance scanning apparatus can be implemented in whole or in part by software, hardware, and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
In one embodiment, as shown in figure 9, a magnetic resonance system 600 is provided comprising a magnetic resonance scanning device and a computer, wherein the computer comprises a processor 622, a display unit 623, an input/output device 624, a memory 625, a communication port 626 and a computer program stored on the memory 625 and executable on the processor 622.
The magnetic resonance system 600 generally includes a magnetic resonance housing having a main magnet 601 disposed therein, the main magnet 601 surrounding a bore and configured to form a main magnetic field within the bore, the main magnet 601 may be formed of superconducting coils, and in some cases, permanent magnets may be used. The main magnet 601 may be used to generate main magnetic field strengths of 0.2 tesla, 0.5 tesla, 1.0 tesla, 1.5 tesla, 3.0 tesla, or higher.
In magnetic resonance imaging, an imaging subject 650 is carried by the patient bed 606, and as the patient bed moves, a region to be scanned of the imaging subject 650 is moved into a scanning field of view 605 in which the magnetic field distribution of the main magnetic field is uniform.
Generally, for a magnetic resonance system, the z-direction of a spatial coordinate system (i.e. a coordinate system of the apparatus) is set to be the same as the axial direction of a gantry of the magnetic resonance system, the length direction of a patient is generally kept consistent with the z-direction for imaging, a horizontal plane of the magnetic resonance system is set to be an xz-plane, the x-direction is perpendicular to the z-direction, and the y-direction is perpendicular to both the x-direction and the z-direction.
The transmitting coil includes a body coil 603 and a local coil 604, and during magnetic resonance imaging, the pulse control unit 611 controls the radio frequency pulse generating unit 616 to generate a radio frequency pulse, and the radio frequency pulse is amplified by the amplifier, passes through the switch control unit 617, and is finally emitted by the body coil 603 or the local coil 604 to perform radio frequency excitation on the imaging object 650. The imaging subject 650 generates corresponding radio frequency signals from resonance upon radio frequency excitation. When receiving the radio frequency signals generated by the imaging subject 650 according to the excitation, the radio frequency signals may be received by the body coil 603 or the local coil 604, there may be a plurality of radio frequency receiving links, and after the radio frequency signals are sent to the radio frequency receiving unit 618, the radio frequency signals are further sent to the image reconstruction unit 621 for image reconstruction, so as to form a magnetic resonance image.
The magnetic resonance system 600 also includes gradient coils 602 that can be used to spatially encode radio frequency signals in magnetic resonance imaging. The pulse control unit 611 controls the gradient signal generating unit 612 to generate gradient signals, which are generally divided into three signals in mutually orthogonal directions: gradient signals in the x, y and z directions, which are different from each other, are amplified by gradient amplifiers (613, 614, 615) and emitted from the gradient coil 602, thereby generating a gradient magnetic field in the region 605.
The pulse control unit 611, the image reconstruction unit 621, the processor 622, the display unit 623, the input/output device 624, the memory 625 and the communication port 626 can perform data transmission via the communication bus 627, so as to control the magnetic resonance imaging process. The processor 622 may be composed of one or more processors. The display unit 623 may be a display provided to a user to display an image. The input/output device 624 may be a keyboard, a mouse, a control box, or other related devices, and supports input/output of corresponding data streams. Memory 625 may be Read Only Memory (ROM), Random Access Memory (RAM), hard disk, etc., and memory 625 may be used to store various data files for processing and/or communication use, as well as possible program instructions for execution by processor 622. When the processor 622 executes the designated program stored in the memory 625, the processor 622 can execute the magnetic resonance scanning method proposed by the present application. The communication port 626 may enable communication with other components such as: and the external equipment, the image acquisition equipment, the database, the external storage, the image processing workstation and the like are in data communication.
In one embodiment, the processor 622 is configured to control the rf pulses of the transmitting coil, and the frequency of the rf pulses is the same as the system frequency of the main magnetic field of the region to be scanned, or the frequency error between the frequency of the rf pulses and the system frequency of the main magnetic field is within a preset range, the region to be scanned includes multiple slices, and the frequency of the rf pulses applied to at least two slices is different.
In one embodiment, the processor 622 is further configured to perform: acquiring a plurality of positioning images of an area to be scanned, wherein each of the plurality of positioning images corresponds to a scanning protocol, and each scanning protocol has a different frequency deviation value with a system frequency; determining a proton spin frequency estimation value of the area to be scanned according to a plurality of positioning images; adjusting the frequency of the radio frequency pulse based on the proton spin frequency estimate. For example: the main magnetic field of the region to be scanned comprises two or more system frequencies, in the embodiment of the application, the transmitting coil is controlled to alternately transmit a first radio frequency pulse and a second radio frequency pulse, the first radio frequency pulse is used for exciting a first slice layer of the region to be scanned, the second radio frequency pulse is used for exciting a second slice layer of the region to be scanned, the frequencies of the first radio frequency pulse and the second radio frequency pulse are different, and multi-layer simultaneous imaging is achieved through the method.
In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having a computer program stored therein, the processor implementing the following steps when executing the computer program: determining a region to be scanned; positioning and scanning an area to be scanned by adopting a plurality of scanning protocols to obtain a plurality of positioning images, wherein the plurality of scanning protocols and the system frequency have different frequency deviation values; determining a proton spin frequency estimation value of a region to be scanned according to a plurality of positioning images; determining the scanning frequency corresponding to the region to be scanned based on the proton spin frequency estimation value; and determining an imaging sequence according to the scanning frequency, and performing magnetic resonance scanning on the region to be scanned through the imaging sequence to obtain a magnetic resonance scanning image corresponding to the region to be scanned.
In one embodiment, the processor, when executing the computer program, further performs the steps of: and based on the same scanning direction, performing positioning scanning on each layer surface in the region to be scanned by adopting the same type of scanning protocol to obtain a positioning image of each layer surface, wherein the corresponding positioning scanning frequencies of different layer surfaces are different.
In one embodiment, the processor, when executing the computer program, further performs the steps of: based on different scanning orientations, different types of scanning protocols are adopted to perform positioning scanning on each layer surface in the region to be scanned, and positioning images of each layer surface are obtained, wherein the corresponding positioning scanning frequencies of different layer surfaces are different.
In one embodiment, the processor, when executing the computer program, further performs the steps of: based on different scanning orientations, the same type of scanning protocol is adopted to perform positioning scanning on each layer in the region to be scanned to obtain positioning images of each layer, wherein the corresponding positioning scanning frequencies of different layers are different.
In one embodiment, the processor, when executing the computer program, further performs the steps of: screening a target positioning image with the best imaging quality from all positioning images; and taking the positioning scanning frequency corresponding to the target positioning image as an estimated proton spin frequency value.
In one embodiment, the processor, when executing the computer program, further performs the steps of: and taking the proton spin frequency estimation value as the scanning frequency corresponding to the area to be scanned.
In one embodiment, the processor, when executing the computer program, further performs the steps of: and comparing the scanning frequency with the transmitting frequency of each sequence, and selecting the sequence with the transmitting frequency consistent with the scanning frequency as an imaging sequence.
FIG. 10 is a diagram showing an internal structure of a computer device according to an embodiment. The computer device may specifically be a terminal (or server). As shown in fig. 10, the computer apparatus includes a processor, a memory, a network interface, an input device, and a display screen connected through a system bus. Wherein the memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program which, when executed by the processor, causes the processor to carry out the magnetic resonance scanning method. The internal memory may also have stored therein a computer program that, when executed by the processor, causes the processor to perform a magnetic resonance scanning method. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on the shell of the computer equipment, an external keyboard, a touch pad or a mouse and the like.
Those skilled in the art will appreciate that the architecture shown in fig. 10 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.
In one embodiment, a computer-readable storage medium is provided, having a computer program stored thereon, which when executed by a processor, performs the steps of: determining a region to be scanned; positioning and scanning an area to be scanned by adopting a plurality of scanning protocols to obtain a plurality of positioning images, wherein the plurality of scanning protocols and the system frequency have different frequency deviation values; determining a proton spin frequency estimation value of a region to be scanned according to a plurality of positioning images; determining the scanning frequency corresponding to the region to be scanned based on the proton spin frequency estimation value; and determining an imaging sequence according to the scanning frequency, and performing magnetic resonance scanning on the region to be scanned through the imaging sequence to obtain a magnetic resonance scanning image corresponding to the region to be scanned.
In one embodiment, the computer program when executed by the processor further performs the steps of: and based on the same scanning direction, performing positioning scanning on each layer surface in the region to be scanned by adopting the same type of scanning protocol to obtain a positioning image of each layer surface, wherein the corresponding positioning scanning frequencies of different layer surfaces are different.
In one embodiment, the computer program when executed by the processor further performs the steps of: based on different scanning orientations, different types of scanning protocols are adopted to perform positioning scanning on each layer surface in the region to be scanned, and positioning images of each layer surface are obtained, wherein the corresponding positioning scanning frequencies of different layer surfaces are different.
In one embodiment, the computer program when executed by the processor further performs the steps of: based on different scanning orientations, the same type of scanning protocol is adopted to perform positioning scanning on each layer in the region to be scanned to obtain positioning images of each layer, wherein the corresponding positioning scanning frequencies of different layers are different.
In one embodiment, the computer program when executed by the processor further performs the steps of: screening a target positioning image with the best imaging quality from all positioning images; and taking the positioning scanning frequency corresponding to the target positioning image as an estimated proton spin frequency value.
In one embodiment, the computer program when executed by the processor further performs the steps of: and taking the proton spin frequency estimation value as the scanning frequency corresponding to the area to be scanned.
In one embodiment, the computer program when executed by the processor further performs the steps of: and comparing the scanning frequency with the transmitting frequency of each sequence, and selecting the sequence with the transmitting frequency consistent with the scanning frequency as an imaging sequence.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware related to instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, the computer program can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A magnetic resonance scanning method, comprising:
determining a region to be scanned;
positioning and scanning the area to be scanned by adopting a plurality of scanning protocols to obtain a plurality of positioning images, wherein the plurality of scanning protocols and the system frequency have different frequency deviation values;
determining a proton spin frequency estimation value of the area to be scanned according to the plurality of positioning images;
determining the scanning frequency corresponding to the region to be scanned based on the proton spin frequency estimation value;
and determining an imaging sequence according to the scanning frequency, and performing magnetic resonance scanning on the region to be scanned through the imaging sequence to obtain a magnetic resonance scanning image corresponding to the region to be scanned.
2. The method of claim 1, wherein performing a scout scan on the region to be scanned using a plurality of scan protocols to obtain a plurality of scout images comprises:
and based on the same scanning direction, performing positioning scanning on each layer surface in the area to be scanned by adopting the same type of scanning protocol to obtain a positioning image of each layer surface, wherein the positioning scanning frequencies corresponding to different layer surfaces are different.
3. The method of claim 1, wherein performing a scout scan on the region to be scanned using a plurality of scan protocols to obtain a plurality of scout images comprises:
and based on different scanning orientations, adopting different types of scanning protocols to perform positioning scanning on each layer surface in the area to be scanned to obtain positioning images of each layer surface, wherein the positioning scanning frequencies corresponding to different layer surfaces are different.
4. The method of claim 1, wherein performing a scout scan on the region to be scanned using a plurality of scan protocols to obtain a plurality of scout images comprises:
and based on different scanning orientations, performing positioning scanning on each layer surface in the region to be scanned by adopting the same type of scanning protocol to obtain positioning images of each layer surface, wherein the positioning scanning frequencies corresponding to different layer surfaces are different.
5. The method of claim 1, wherein determining an estimate of proton spin frequency of the region to be scanned from the plurality of scout images comprises:
screening a target positioning image with the best imaging quality from all the positioning images;
and taking the positioning scanning frequency corresponding to the target positioning image as the proton spin frequency estimated value.
6. The method of claim 1, wherein determining a scanning frequency corresponding to the region to be scanned based on the proton spin frequency estimate comprises:
and taking the proton spin frequency estimation value as the scanning frequency corresponding to the area to be scanned.
7. The method of claim 1, wherein determining an imaging sequence from the scan frequency comprises:
and comparing the scanning frequency with the transmitting frequency of each sequence, and selecting the sequence with the transmitting frequency consistent with the scanning frequency as the imaging sequence.
8. A magnetic resonance system, comprising:
a main magnet surrounding a bore and configured to form a main magnetic field within the bore;
the hospital bed is used for carrying an object and moving a region to be scanned of the object to a scanning visual field formed by the main magnetic field, and the main magnetic field at least comprises two system frequencies in the scanning visual field;
the transmitting coil is arranged inside the cavity and is used for applying radio frequency pulses to the area to be scanned;
the processor is used for controlling a radio frequency pulse of the transmitting coil, and the frequency of the radio frequency pulse is the same as the system frequency of the main magnetic field where the region to be scanned is located, or the frequency error between the frequency of the radio frequency pulse and the system frequency of the main magnetic field is within a preset range;
the region to be scanned comprises a plurality of slices, and the frequency of the radio frequency pulse applied by at least two slices is different.
9. The magnetic resonance system of claim 8, wherein the processor is further configured to perform:
acquiring a plurality of positioning images of the area to be scanned, wherein each of the plurality of positioning images corresponds to a scanning protocol, and each scanning protocol and the system frequency have different frequency deviation values;
determining a proton spin frequency estimation value of the area to be scanned according to the plurality of positioning images;
adjusting a frequency of the radio frequency pulse based on the proton spin frequency estimate.
10. The system of claim 8, wherein the processor is further configured to:
and controlling the transmitting coil to alternately transmit a first radio frequency pulse and a second radio frequency pulse, wherein the first radio frequency pulse is used for exciting a first slice of the area to be scanned, the second radio frequency pulse is used for exciting a second slice of the area to be scanned, and the frequencies of the first radio frequency pulse and the second radio frequency pulse are different.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116172543A (en) * | 2023-04-23 | 2023-05-30 | 安徽硕金医疗设备有限公司 | Magnetic resonance rapid imaging method and system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1618398A (en) * | 2003-10-30 | 2005-05-25 | Ge医药系统环球科技公司 | Method and system for optimized pre-saturation in mr with corrected transmitter frequency of pre-pulses |
| CN101744616A (en) * | 2008-12-19 | 2010-06-23 | Ge医疗系统环球技术有限公司 | Transmitting frequency calibration method for chemical saturation in MRI and MRI system |
| US20130293230A1 (en) * | 2012-04-19 | 2013-11-07 | Bruker Biospin Mri Gmbh | Method for magnetic resonance imaging with optimized background phase distribution |
| CN103529412A (en) * | 2013-10-18 | 2014-01-22 | 吴仁华 | Experiment method based on pH value-sensitive magnetization transfer on 1.5T magnetic resonance imaging |
| CN107669273A (en) * | 2017-11-07 | 2018-02-09 | 上海联影医疗科技有限公司 | Magnetic resonance equipment scanning system, scan method and computer-readable recording medium |
| CN107997763A (en) * | 2017-12-26 | 2018-05-08 | 中国科学院生物物理研究所 | A kind of water fat separates MR imaging method |
-
2019
- 2019-11-20 CN CN201911140917.0A patent/CN112823741A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1618398A (en) * | 2003-10-30 | 2005-05-25 | Ge医药系统环球科技公司 | Method and system for optimized pre-saturation in mr with corrected transmitter frequency of pre-pulses |
| CN101744616A (en) * | 2008-12-19 | 2010-06-23 | Ge医疗系统环球技术有限公司 | Transmitting frequency calibration method for chemical saturation in MRI and MRI system |
| US20130293230A1 (en) * | 2012-04-19 | 2013-11-07 | Bruker Biospin Mri Gmbh | Method for magnetic resonance imaging with optimized background phase distribution |
| CN103529412A (en) * | 2013-10-18 | 2014-01-22 | 吴仁华 | Experiment method based on pH value-sensitive magnetization transfer on 1.5T magnetic resonance imaging |
| CN107669273A (en) * | 2017-11-07 | 2018-02-09 | 上海联影医疗科技有限公司 | Magnetic resonance equipment scanning system, scan method and computer-readable recording medium |
| CN107997763A (en) * | 2017-12-26 | 2018-05-08 | 中国科学院生物物理研究所 | A kind of water fat separates MR imaging method |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116172543A (en) * | 2023-04-23 | 2023-05-30 | 安徽硕金医疗设备有限公司 | Magnetic resonance rapid imaging method and system |
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