CN104523274B - A kind of MR imaging method utilizing steady state free precession - Google Patents
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Abstract
The present invention provides a kind of MR imaging method utilizing steady state free precession, is applied to mr imaging technique field, comprising: apply excitation pulse simultaneously and the first level selects gradient A；Apply the second level selection gradient B, first phase coding gradient U and read pre-dephasing gradient J；Apply the first readout gradient G, gather echo translation signal simultaneously；Apply third layer face and select gradient D；Apply the second readout gradient H, the stable state precession signal of acquisition time reversion simultaneously；Apply to read rephasing gradient F, second phase coding gradient V, the 4th level selection gradient C；Wherein, gradient A, the square of B, C, D meet relation: MC=MA/ 2,2MB–MD=MA；Utilize the signal obtaining to fill k-space, and carry out Fourier transformation, obtain MRI.The present invention can gather echo translation signal and stable state precession time reversal signal simultaneously, shortens imaging time.
Description
Technical field
The present invention relates to mr imaging technique field, in particular it relates to a kind of magnetic resonance utilizing steady state free precession
Imaging method.
Background technology
Stable state precession time reversal (Time-reversed Fast Imaging with Steady-state Precession, time
Reversed FISP, or PSIF, or Contrast Enhanced Fourier Acquired Steady state, CE-FAST) signal
It is the gtadient echo signal of a kind of heavy T2 weighting.Compared to tradition based on FSE T2 weighted signal, it has collection
Speed is fast, the advantages such as selective absorbing rate is low.
Echo translation (Echo Shift, ES) signal is the gtadient echo signal of a kind of heavy T2* weighting, when it has long echo
Between the feature of (Echo Time, TE), also very sensitive for phase place change, be generally used for magnetic resonance temperature imaging etc. real
When monitoring field.
Both signals are typically to utilize corresponding sequence to be acquired respectively by current industry, and monitor neck in real time at some
Territory, needs to gather echo translation signal and stable state precession time reversal signal simultaneously, changes to obtain temperature information and tissue T 2
Information.
Content of the invention
The main purpose of the embodiment of the present invention is to provide a kind of MR imaging method utilizing steady state free precession, with
The problem solving can not simultaneously gather echo translation signal and stable state precession time reversal signal in prior art.
To achieve these goals, the embodiment of the present invention provides a kind of magnetic resonance imaging side utilizing steady state free precession
Method, comprising:
Circulation performs a steady state free precession；Wherein, the process performing this steady state free precession includes:
Step 1, applies excitation pulse, applies the first level simultaneously and selects gradient A；
Step 2, after applying described the first level and selecting gradient A, applies the second level selection gradient B, first phase
Encode gradient U and read pre-dephasing gradient J；
Step 3, is applying described second level selection gradient B, first phase coding gradient U and is reading pre-dephasing ladder
After degree J, apply the first readout gradient G；
Step 4, collecting magnetic resonance signal while applying described first readout gradient G, obtain echo translation signal；
Step 5, after collecting echo translation signal, applies third layer face and selects gradient D；
Step 6, after applying described third layer face and selecting gradient D, applies the second readout gradient H；
Step 7, collecting magnetic resonance signal while applying described second readout gradient H, obtain stable state time reversal and enter
Dynamic signal；
Step 8, after collecting stable state precession time reversal signal, applies to read rephasing gradient F, second phase volume
Code gradient V, the 4th level selection gradient C；
Wherein, described the first level select gradient A, the second level selection gradient B, the 4th level selection gradient C, the
Three level selection gradients D meet following relation:
MC=-MA/ 2,
2MB–MD=MA,
MAIt is the square that the first level selects gradient A,
MBIt is the square of the second level selection gradient B,
MCIt is the square of the 4th level selection gradient C,
MDIt is the square that third layer face selects gradient D；
Wherein, described first phase encodes gradient U, second phase coding gradient V meets following relation:
MU=-MV,
MUIt is the square of first phase coding gradient U,
MVIt is the square of second phase coding gradient V；
The echo utilizing the described steady state free precession of circulation execution to obtain translates signal and stable state precession time reversal signal
Fill k-space；
Fourier transformation is carried out to the data of described k-space, obtains MRI.
By means of technique scheme, the present invention devises a kind of new steady state free precession, and perform this sequence can be simultaneously
Gathering echo translation signal and stable state precession time reversal signal, compared to prior art, the present invention disclosure satisfy that and gathers simultaneously
Echo translation signal and the needs of stable state precession time reversal signal, obtain temperature information and tissue T 2 change information, hence it is evident that contracting
The short magnetic resonance imaging time.
Brief description
In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, institute in embodiment being described below
The accompanying drawing using is needed to be briefly described, it should be apparent that, the accompanying drawing in describing below is only some enforcements of the present invention
Example, for those of ordinary skill in the art, on the premise of not paying creative work, can also be according to these accompanying drawings
Obtain other accompanying drawing.
Fig. 1 is the MR imaging method schematic flow sheet utilizing steady state free precession that the present invention provides；
Fig. 2 is a kind of steady state free precession example schematic for magnetic resonance two-dimensional imaging that the present invention provides；
Fig. 3 is the steady state free precession example schematic for magnetic resonance two-dimensional imaging for the another kind that provides of the present invention；
Fig. 4 is a kind of steady state free precession example schematic for magnetic resonance three-dimensional imaging that the present invention provides；
In Fig. 5, (a) is the echo displacement images that the present invention collects；B () is that stable state time reversal that the present invention collects enters cardon
Picture；C () is the echo displacement images collecting individually with echo translation sequence；D () is individually with stable state precession time reversal
Stable state time reversal of sequence scanning enters motion video.
Detailed description of the invention
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clearly and completely
Describe, it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.Based on this
Embodiment in invention, the every other reality that those of ordinary skill in the art are obtained under the premise of not making creative work
Execute example, broadly fall into the scope of protection of the invention.
The present invention provides a kind of MR imaging method utilizing steady state free precession, as it is shown in figure 1, the method includes:
Step S1, circulation performs a steady state free precession.
Steady state free precession includes excitation pulse, the gradient of level selection direction (Z-direction), phase-encoding direction (Y
Direction) gradient, the gradient of readout direction (X-direction).
Concrete, the cycle-index performing steady state free precession in step S1 is corresponding with the coded number of phase code, takes
Certainly in the resolution ratio (sweep parameter) of MRI.
In step S1, single performs steady state free precession and specifically includes as follows step by step:
Step S11, applies excitation pulse, applies the first level simultaneously and selects gradient A.
Concrete, excitation pulse is the pulse signal of one group of flip angle equidistant, identical.The first level selects gradient A to execute
It is added on level selection direction.
Step S12, after applying the first level and selecting gradient A, applies the second level selection gradient B, first phase coding
Gradient U and read pre-dephasing gradient J.
Concrete, the second level selection gradient B puts on level selection direction；First phase coding gradient U puts on phase place and compiles
Code direction；Read pre-dephasing gradient J and put on readout direction.
Step S13, is applying the second level selection gradient B, first phase coding gradient U and is reading pre-dephasing gradient J
Afterwards, the first readout gradient G is applied.
Concrete, the first readout gradient G puts on readout direction.
Step S14, collecting magnetic resonance signal while applying the first readout gradient G, obtain echo translation signal.
Step S15, after collecting echo translation signal, applies third layer face and selects gradient D.
Concrete, third layer face selects gradient D to put on level selection direction.
Step S16, after applying third layer face and selecting gradient D, applies the second readout gradient H.
Concrete, the second readout gradient H puts on readout direction.
Step S17, collecting magnetic resonance signal while applying the second readout gradient H, obtain stable state precession time reversal signal.
Step S18, after collecting stable state precession time reversal signal, applies to read rephasing gradient F, second phase coding
Gradient V, the 4th level selection gradient C.
Concrete, read rephasing gradient F and put on readout direction；Second phase coding gradient V puts on phase-encoding direction；
4th level selection gradient C puts on level selection direction.
In order to reach to gather the purpose of echo translation signal and stable state precession time reversal signal, in the present invention, ground floor simultaneously
Face selects gradient A, the second level selection gradient B, the 4th level selection gradient C, third layer face to select gradient D should meet such as
Lower relation:
MC=-MA/ 2,
2MB–MD=MA,
MAIt is the square that the first level selects gradient A,
MBIt is the square of the second level selection gradient B,
MCIt is the square of the 4th level selection gradient C,
MDIt is the square that third layer face selects gradient D.
Concrete, the first level selects gradient A to be to cooperate with excitation pulse for exciting the ladder required for a certain layer of acquisition target
Degree, it is determined by parameters such as the bandwidth exciting thickness and excitation pulse.
The present invention is applicable to magnetic resonance two-dimensional imaging and magnetic resonance three-dimensional imaging.
In magnetic resonance two-dimensional imaging, in each repetition period, only apply the first phase at phase-encoding direction (Y-direction)
Position coding gradient U and second phase coding gradient V.Wherein, the purpose applying first phase coding gradient U is to make from copper plate tool
Standby different initial phase, to distinguish the position of corresponding voxel, is used for magnetic resonance two-dimensional imaging, but in the next repetition period
Before arriving, all phase places from copper plate need to be made to return poly-, pole identical with first phase coding gradient U intensity will be applied for this
Property contrary second phase coding gradient V (i.e. rephasing gradient).It is to say, first phase coding gradient U, second phase
Coding gradient V should meet relation: MU=-MV, MUIt is the square of first phase coding gradient U, MVIt is second phase coding
The square of gradient V.
In magnetic resonance three-dimensional imaging, in each repetition period, except applying first phase coding ladder at phase-encoding direction
Outside degree U and second phase coding gradient V, in addition it is also necessary to apply third phase coding gradient in level selection direction (Z-direction)
S and the 4th phase encoding gradient T.Wherein, applying third phase coding gradient S is after applying the first level and selecting gradient A,
Before applying the first readout gradient G；Apply the 4th phase encoding gradient T be collect stable state precession time reversal signal it
After；Further, third phase coding gradient S, the 4th phase encoding gradient T should meet relation: MS=-MT, MSIt is the 3rd
The square of phase encoding gradient S, MTIt is the square of the 4th phase encoding gradient T.
Step S2, the echo utilizing circulation execution steady state free precession to obtain translates signal and stable state precession time reversal letter
Number fill k-space.
The data of k-space are carried out Fourier transformation, obtain MRI by step S3.
Perform this steady state free precession, apply different phase encoding gradients in each repetition period empty to cover whole k
Between, the signal of k-space is done Fourier transformation and i.e. can get corresponding image information.
If the free induction decay of excitation pulse (Free Induction Decay, FID) signal is not decayed completely, and enters
Arrive in the acquisition window of echo translation signal, will interfere to gathering echo translation signal.In consideration of it, this
In invention so that the FID signal of excitation pulse do not affect collection echo translation signal, level selection gradient A, B, C,
D also should meet relation: MA/2+MB∣≧MA/ 2, so that the FID signal of excitation pulse is quickly decayed completely.
In a kind of preferred embodiment, make MB=MA, MD=MA, above-mentioned relation M can be metA/2+MB∣
≧MA/2。
The present invention provide a kind of as shown in Figure 2 can be applicable to the steady-state free that method shown in Fig. 1 carries out magnetic resonance two-dimensional imaging
Precession example series, this sequence includes excitation pulse, the gradient in level selection direction, the gradient of phase-encoding direction, reading
The gradient in direction.
In Fig. 2, excitation pulse is the pulse signal of one group of flip angle α equidistant, identical.ADC#1 represents in applying first
Echo translation signal is gathered while readout gradient G.ADC#2 represents acquisition time while applying the second readout gradient H
Reversion stable state precession signal.
Based on Fig. 2, in each repetition period, after applying the first readout gradient G, and apply the second readout gradient H
Before, also include: apply to read back poly-pre-dephasing gradient E, and, pre-dephasing gradient J of the reading in Fig. 2, the first reading
Gradient G, read back poly-pre-dephasing gradient E, the second readout gradient H, read rephasing gradient F and meet following relation:
MJ=-MG/ 2,
ME=-(MG+MH)/2,
MF=-MH/ 2,
MJIt is the square reading pre-dephasing gradient J,
MGIt is the square of the first readout gradient G,
MEIt is the square reading back poly-pre-dephasing gradient E,
MHIt is the square of the second readout gradient H,
MFIt is the square reading rephasing gradient F.
Concrete, the first readout gradient G, the second readout gradient H need mating die number converter to perform the work of collecting magnetic resonance signal
Making, their size is determined by parameters such as the visual field sizes of sampling number, acquisition bandwidth and readout direction.
Below for performing the course of work and the principle of steady state free precession shown in Fig. 2:
In each repetition period:
(1) excitation pulse is applied on acquisition target by radio-frequency coil, coordinates the first level to select gradient A simultaneously so that
It all of in certain plane in space is excited from copper plate；
(2) first phase coding gradient U is applied so that possess certain different initial phase from copper plate, be used for magnetic resonance
Two-dimensional imaging；
(3) apply to read pre-dephasing J；
(4) apply the first readout gradient G, open analog-digital converter, collecting magnetic resonance signal, the magnetic now collecting simultaneously
Resonance signal is echo translation signal；
(5) apply to read back poly-pre-dephasing gradient E；
(6) apply the second readout gradient H, open analog-digital converter, collecting magnetic resonance signal, the letter now collecting simultaneously
Number be stable state precession time reversal signal.
Based on the sequence shown in Fig. 2, the present invention can be combined with partial echo (asymmetric) technology and reduces repetition period, contracting
The time of short magnetic resonance imaging.Due to partial echo technology make echo center not readout gradient G the magnetic resonance of H and collection
The center of signal (echo-signal stable state precession time reversal signal), decreases the duration of readout gradient G and H, from
And the repetition period can be shortened.In this case, the gradient of readout direction only needs to meet: MJ+ME+MF+MG+MH=
0；Wherein gradient J, E, F polarity identical；Gradient G, H and gradient J, the opposite polarity of E, F.
The present invention provides the another kind of method shown in Fig. 1 that can be applicable to as shown in Figure 3 to carry out the stable state of magnetic resonance two-dimensional imaging certainly
By precession example series, this sequence includes excitation pulse, the gradient in level selection direction, the gradient of phase-encoding direction, reading
The gradient of outgoing direction.Wherein, gradient J, G, H, F meet relation: MJ+MF+MG+MH=0；Further, first reads
Go out gradient G and the opposite polarity of the second readout gradient H.
Compared with the steady state free precession shown in Fig. 2, in the sequence shown in Fig. 3, after applying the first readout gradient G,
And before applying the second readout gradient H, do not apply to read back poly-pre-dephasing gradient E.This is because the sequence shown in Fig. 3 is
The mode using ambipolar reading is removed and is read back poly-pre-dephasing gradient E, to reach to reduce the effect of repetition period, shortens magnetic
The time of resonance image-forming.
The present invention provide a kind of as shown in Figure 4 can be applicable to the steady-state free that method shown in Fig. 1 carries out magnetic resonance three-dimensional imaging
Precession example series, this sequence includes excitation pulse, the gradient in level selection direction, the gradient of phase-encoding direction, reading
The gradient in direction.
In Fig. 4, excitation pulse is the pulse signal of one group of flip angle α equidistant, identical.ADC#1 represents in applying first
Echo translation signal is gathered while readout gradient G.ADC#2 represents acquisition time while applying the second readout gradient H
Reversion stable state precession signal.
Based on Fig. 4, in each repetition period, after applying described the first level and selecting gradient A, apply the first reading ladder
Before degree G, also include: apply third phase coding gradient S in level selection direction；And, collecting time reversal
After stable state precession signal, also include: apply the 4th phase encoding gradient T in level selection direction.
In a kind of preferred embodiment, third phase coding gradient S of Fig. 4 can merge with the second level selection gradient B,
4th phase encoding gradient T can merge with the 4th level selection gradient C.
In Fig. 5, (a) is the two-dimentional echo displacement images that the present invention collects；B two-dimensional time reversion that () present invention collects is steady
State enters motion video；C () is the echo displacement images collecting individually with echo translation sequence；D () is individually with time reversal
Stable state time reversal of stable state precession sequence scanning enters motion video.
Basic common acquisition parameter is:
Field range: 384mm*384mm
Thickness: 5mm
Resolution ratio: 384*384
Pulse flip angle: 20degree
The sequence that the present invention proposes:
Repetition time/echo time: 8ms/2.4ms, acquisition bandwidth: 610Hz/pixel
Echo translation sequence:
Repetition time/echo time: 5ms/2.5ms, acquisition bandwidth: 592Hz/pixel
Stable state precession time reversal sequence:
Repetition time/echo time: 5ms/2.5ms, acquisition bandwidth: 592Hz/pixel
Comparison diagram 5 (a)～(d) understands, the image of collection of the present invention enters with individually with echo translation sequence and stable state time reversal
The image that dynamic sequence collects respectively has similar contrast.But the present invention disclosure satisfy that simultaneously gather echo translation signal and
The needs of stable state precession time reversal signal, obtain temperature information and tissue T 2 change information, hence it is evident that when shortening magnetic resonance imaging
Between.
Particular embodiments described above, has been carried out further specifically to the purpose of the present invention, technical scheme and beneficial effect
Bright, be it should be understood that the specific embodiment that the foregoing is only the present invention, the protection being not intended to limit the present invention
Scope, all within the spirit and principles in the present invention, any modification, equivalent substitution and improvement etc. done, should be included in
Within protection scope of the present invention.
Those skilled in the art are it will also be appreciated that the various illustrative components, blocks (illustrative that list of the embodiment of the present invention
Logical block), unit, and step can pass through electronic hardware, computer software, or both combination realize.For
Clearly show that the replaceability (interchangeability) of hardware and software, above-mentioned various illustrative components (illustrative
Components), unit and step have universally described their function.Such function is by hardware or soft
Part realizes depending on specifically applying the design with whole system to require.Those skilled in the art can be specific for every kind
Application, it is possible to use various methods realize described function, but this realization is understood not to protect beyond the embodiment of the present invention
The scope protected.
Various illustrative logical block described in the embodiment of the present invention, or unit, or device can pass through general procedure
Device, digital signal processor, special IC (ASIC), field programmable gate array or other programmable logic devices,
Discrete gate or transistor logic, discrete hardware components, or the design of any of the above described combination realize or operate described function.
General processor can be microprocessor, alternatively, this general processor also can for any traditional processor, controller,
Microcontroller or state machine.Processor also can be realized by the combination of computing device, for example digital signal processor and micro-
Processor, multi-microprocessor, one or more microprocessors combine a Digital Signal Processor Core, or any other class
As configure and realize.
The software mould that the step of the method described in the embodiment of the present invention or algorithm can be directly embedded into hardware, processor performs
Block or the combination of both.Software module can be stored in RAM memory, flash memory, ROM memory, EPROM
Other arbitrary shapes in memory, eeprom memory, register, hard disk, moveable magnetic disc, CD-ROM or this area
In the storage medium of formula.Exemplarily, store medium to be connected with processor, so that processor can be from storage medium
Middle reading information, it is possible to deposit write information to storage medium.Alternatively, store medium can also be integrated in processor.Place
Reason device and storage medium can be arranged in ASIC, and ASIC can be arranged in user terminal.Alternatively, processor and depositing
Storage medium also can be arranged in the different parts in user terminal.
In one or more exemplary designs, the above-mentioned functions described by the embodiment of the present invention can hardware, software,
Any combination of firmware or this three realizes.If realized in software, these functions can store the matchmaker with computer-readable
It on Jie, or is transmitted on the medium of computer-readable with one or more instructions or code form.Computer readable medium includes computer
Storage medium and being easy to so that allow computer program transfer to the telecommunication media in other places from place.Storage medium can be
Any general or special computer can be with the useable medium of access.For example, such computer readable media can include but not
It is limited to RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices,
Other any may be used for carrying or storage with instruct or data structure and other can by general or special computer or general or
Special processor reads the medium of the program code of form.Additionally, any connection can be properly termed computer-readable
Medium, for example, if software is to pass through coaxial cable, a light from web-site, server or other remote resources
Fiber-optic cable, twisted-pair feeder, Digital Subscriber Line (DSL) or with the wireless way for transmittings such as example infrared, wireless and microwave also by
It is included in defined computer readable medium.Described video disc (disk) and disk (disc) include Zip disk, radium-shine
Dish, CD, DVD, floppy disk and Blu-ray Disc, disk is generally with magnetic duplication data, and video disc generally carries out light with laser
Learn and replicate data.Combinations of the above also may be embodied in computer readable medium.
Claims (7)
1. the MR imaging method utilizing steady state free precession, it is characterised in that include:
Circulation performs a steady state free precession；Wherein, the process performing this steady state free precession includes:
Step 1, applies excitation pulse, applies the first level simultaneously and selects gradient A；
Step 2, after applying described the first level and selecting gradient A, applies the second level selection gradient B, first phase
Encode gradient U and read pre-dephasing gradient J；
Step 3, is applying described second level selection gradient B, first phase coding gradient U and is reading pre-dephasing ladder
After degree J, apply the first readout gradient G；
Step 4, collecting magnetic resonance signal while applying described first readout gradient G, obtain echo translation signal；
Step 5, after collecting echo translation signal, applies third layer face and selects gradient D；
Step 6, after applying described third layer face and selecting gradient D, applies the second readout gradient H；
Step 7, collecting magnetic resonance signal while applying described second readout gradient H, obtain stable state time reversal and enter
Dynamic signal；
Step 8, after collecting stable state precession time reversal signal, applies to read rephasing gradient F, second phase volume
Code gradient V, the 4th level selection gradient C；
Wherein, described the first level select gradient A, the second level selection gradient B, the 4th level selection gradient C, the
Three level selection gradients D meet following relation:
MC=-MA/ 2,
2MB–MD=MA,
MAIt is the square that the first level selects gradient A,
MBIt is the square of the second level selection gradient B,
MCIt is the square of the 4th level selection gradient C,
MDIt is the square that third layer face selects gradient D；
Wherein, described first phase encodes gradient U, second phase coding gradient V meets following relation:
MU=-MV,
MUIt is the square of first phase coding gradient U,
MVIt is the square of second phase coding gradient V；
The echo utilizing the described steady state free precession of circulation execution to obtain translates signal and stable state precession time reversal signal
Fill k-space；
Fourier transformation is carried out to the data of described k-space, obtains MRI.
2. method according to claim 1, it is characterised in that described the first level selects gradient A, the second aspect choosing
Select gradient B, the 4th level selection gradient C, third layer face select gradient D also meet relation: MA/2+MB∣≧MA/2。
3. method according to claim 2, it is characterised in that described the first level selects gradient A, the second aspect choosing
Select gradient B, third layer face selection gradient D meets relation:
MB=MA,
MD=MA。
4. method according to claim 1, it is characterised in that after applying described first readout gradient G, applies
Before described second readout gradient H, the process of described this steady state free precession of execution also includes: applying reads back poly-
Pre-dephasing gradient E；
Wherein, described read pre-dephasing gradient J, the first readout gradient G, to read back poly-pre-dephasing gradient E, the second reading terraced
Spend H, reading rephasing gradient F meets following relation:
MJ=-MG/ 2,
ME=-(MG+MH)/2,
MF=-MH/ 2,
Further, described first readout gradient G, the second readout gradient H polarity identical；
MJIt is the square reading pre-dephasing gradient J,
MGIt is the square of the first readout gradient G,
MEIt is the square reading back poly-pre-dephasing gradient E,
MHIt is the square of the second readout gradient H,
MFIt is the square reading rephasing gradient F.
5. method according to claim 4, it is characterised in that described reading pre-dephasing gradient J, the first readout gradient G,
Read back poly-pre-dephasing gradient E, the second readout gradient H, reading rephasing gradient F also meet relation: MJ+ME+MF+MG
+MH=0；
Further, described read pre-dephasing gradient J, reads back poly-pre-dephasing gradient E, reading rephasing gradient F polarity identical；
Described first readout gradient G, the second readout gradient H with described read pre-dephasing gradient J, read back poly-pre-dephasing gradient E,
Read the opposite polarity of rephasing gradient F.
6. method according to claim 1, it is characterised in that described reading pre-dephasing gradient J, the first readout gradient G,
Second readout gradient H, read rephasing gradient F and meet relation:
MJ+MF+MG+MH=0；
Further, described first readout gradient G, the opposite polarity of the second readout gradient H；
MJIt is the square reading pre-dephasing gradient J,
MGIt is the square of the first readout gradient G,
MHIt is the square of the second readout gradient H,
MFIt is the square reading rephasing gradient F.
7. method according to claim 1, it is characterised in that after applying described the first level and selecting gradient A,
Before applying the first readout gradient G, the process of described this steady state free precession of execution also includes: in level selection side
Encode gradient S to applying third phase；
After collecting stable state precession time reversal signal, the process of described this steady state free precession of execution is also wrapped
Include: apply the 4th phase encoding gradient T in level selection direction；
Wherein, described third phase encodes gradient S, the 4th phase encoding gradient T meets following relation:
MS=-MT,
MSIt is the square of third phase coding gradient S,
MTIt is the square of the 4th phase encoding gradient T.
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| CN108020796B (en) * | 2016-10-31 | 2021-10-29 | 西门子(深圳)磁共振有限公司 | Magnetic resonance diffusion weighted imaging method and device |
| KR20180067442A (en) * | 2016-12-12 | 2018-06-20 | 지멘스 헬스케어 게엠베하 | Accelerated magnetic resonance imaging |
| CN108245158B (en) * | 2016-12-29 | 2021-05-11 | 中国科学院深圳先进技术研究院 | Magnetic resonance temperature measuring method and device |
| WO2019041123A1 (en) * | 2017-08-29 | 2019-03-07 | 深圳先进技术研究院 | Method and apparatus for optimizing balanced steady state free precession sequence |
| CN107728090B (en) * | 2017-08-29 | 2019-10-18 | 深圳先进技术研究院 | A kind of method and apparatus of optimization balance steady state free precession |
| CN108514415B (en) * | 2018-02-09 | 2021-09-10 | 奥泰医疗系统有限责任公司 | Rapid magnetic sensitivity weighted imaging scanning sequence improvement method and imaging method |
| CN111310529A (en) * | 2018-12-12 | 2020-06-19 | 深圳先进技术研究院 | Target area identification and necrotic tissue assessment method, device, medium and system |
| CN113917378B (en) * | 2020-07-09 | 2023-06-27 | 上海联影医疗科技股份有限公司 | Magnetic resonance imaging method and magnetic resonance imaging system |
| CN116299108A (en) * | 2023-03-27 | 2023-06-23 | 广东省人民医院 | MR imaging method and system based on 3D-BUDA acquisition and combined low-rank constraint reconstruction |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5270654A (en) * | 1991-07-05 | 1993-12-14 | Feinberg David A | Ultra-fast multi-section MRI using gradient and spin echo (grase) imaging |
| CN102680930A (en) * | 2011-03-17 | 2012-09-19 | 西门子公司 | Method to adjust shim current and RF center frequency and magnetic resonance apparatus |
| CN103327891A (en) * | 2011-01-17 | 2013-09-25 | 株式会社日立医疗器械 | Magnetic resonance imaging apparatus and fluid-enhanced image acquisition method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9513358B2 (en) * | 2013-03-12 | 2016-12-06 | Vaposun Inc. | Method and apparatus for magnetic resonance imaging |
-
2014
- 2014-12-25 CN CN201410826073.6A patent/CN104523274B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5270654A (en) * | 1991-07-05 | 1993-12-14 | Feinberg David A | Ultra-fast multi-section MRI using gradient and spin echo (grase) imaging |
| CN103327891A (en) * | 2011-01-17 | 2013-09-25 | 株式会社日立医疗器械 | Magnetic resonance imaging apparatus and fluid-enhanced image acquisition method |
| CN102680930A (en) * | 2011-03-17 | 2012-09-19 | 西门子公司 | Method to adjust shim current and RF center frequency and magnetic resonance apparatus |
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