CN106772157B - A kind of method and apparatus of magnetic resonance imaging - Google Patents
A kind of method and apparatus of magnetic resonance imaging Download PDFInfo
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- CN106772157B CN106772157B CN201510823697.7A CN201510823697A CN106772157B CN 106772157 B CN106772157 B CN 106772157B CN 201510823697 A CN201510823697 A CN 201510823697A CN 106772157 B CN106772157 B CN 106772157B
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Abstract
The invention discloses a kind of methods of magnetic resonance imaging, the following steps are included: the targeted scans position of scanned object is placed in a predetermined position, according to the relationship of the position of coil unit each in local coil and targeted scans position, choose coil unit, obtain magnetic resonance signal, Fourier transformation is carried out to magnetic resonance signal, obtains the magnetic resonance image at targeted scans position；The position acquisition step of each coil unit are as follows: obtain the initial position of each coil unit in local coil；Obtain the relative zero position of local coil；It is corrected according to initial position of the relative zero position to each coil unit, obtains the position of each coil unit.The present invention releases other coil unit positions with the highest location point of the accuracy obtained relative zero the most, according to loop construction, improves the Stability and veracity that local coil integrally positions.Meanwhile the present invention also proposes the device of magnetic resonance imaging.
Description
[technical field]
The present invention relates to magnetic resonance arts more particularly to a kind of method and apparatus of magnetic resonance imaging.
[background technique]
With the continuous improvement of medical level, Magnetic resonance imaging (Magnetic Resonance Imaging, MRI)
It is used in clinical diagnosis more and more.Magnetic resonance device is adopted by magnet system, gradient system, radio frequency system and data
The radio frequency system of collection, reconstructing system composition, multiple coil compositions is the important component of whole system, its common effect is
Emit radio-frequency pulse and receives signal.In workflow, needs access system that could be identified and operate normally.It is more when having
When a coil unit composition phased array local coil is used for image scanning, the corresponding specific effectively imaging of each coil unit
Region, selection are combined with the matched coil unit of scanning range, are the key that guarantee the optimal signal-to-noise ratio of magnetic resonance image.This is just needed
Local coil is identified and positioned, each coil is corresponded into respective imaging region and is shown on interface, with side
Just doctor selects suitable coil unit operation scanning.
In the prior art, magnetic resonance local coil is positioned and is identified and most widely used be mainly based upon coil unit
The method of sensitivity characteristic, by coil prescan collecting magnetic resonance signal to be positioned, according to coil unit in different location
When existing sensitivity characteristic positioned, the local coil unit of identification current system connection, and orient these coil lists
Position of the member relative to patient scan position.But the coil unit center that the above method identifies is independent from each other,
Positioning accuracy will receive the influence of many factors: on the one hand vulnerable to the influence of institutional framework；On the other hand, hospital bed is sent into magnetic
After body, it not can guarantee all coils unit and be at magnet center position or even some coil units outside effective imaging region,
The sensitivity signal of coil unit far from magnet center is influenced to generate sensitivity curve signal skew by the distortion of field, from
And reduce the precision of coil positioning.Therefore, it is necessary to which the local coil recognition methods to existing magnetic resonance device improves.
[summary of the invention]
The technical problem to be solved by the present invention is to propose a kind of high part for magnetic resonance device of positional accuracy
Coil recognition methods.
The technical scheme of the invention to solve the technical problem is: a kind of method of magnetic resonance imaging,
The following steps are included:
Scanned object is placed in magnetic resonance imaging equipment, and targeted scans position is placed in a predetermined position, and in mesh
Local coil is put at mark scanned position, the local coil includes several coil units, according to the position of each coil unit
The relationship with targeted scans position is set, one or more coil units are chosen, obtains the magnetic resonance signal at targeted scans position, it is right
Magnetic resonance signal carries out Fourier transformation, obtains the magnetic resonance image at targeted scans position；The position of each coil unit,
It obtains in the following manner:
Obtain the initial position of each coil unit in local coil；
Obtain the relative zero position of local coil；
It is corrected according to initial position of the relative zero position to each coil unit, obtains the position of each coil unit
It sets.
Further, the relative zero position obtains in the following manner:
The relative distance of the initial position of each coil unit and the magnet center position of magnetic resonance imaging equipment is calculated, with
The initial position of coil unit corresponding to relative distance reckling is the relative zero position；
Alternatively, calculating dead-center position according to the initial position of each coil unit, and obtain the dead-center position being calculated
Average value, enable the average value be the relative zero position.
Further, the initial position of the coil unit on the local coil by installing telltale mark or setting
Coil identification circuit obtains.
Further, the initial position of the coil unit can be by obtaining having for the coil unit sensitivity curve
Effect maximum value obtains.
Further, the relative zero position, can obtain in the following manner:
The sensitivity curve of the local coil middle line coil unit is obtained, the sensitivity curve at least two adjacent；
The position in the sensitivity curve crosspoint of adjacent coil units is obtained according to the sensitivity curve, and enables the friendship
The mean value of the position of crunode is the relative zero position.
Further, N number of crosspoint is obtained from the sensitivity curve of the local coil, a continuous crosspoint statistics M
The average value of position, and enabling the average value of the position in the crosspoint is the relative zero position, wherein 1≤M < N.
Further, the intensity value of sensitivity curve each position point be coil unit acquisition magnetic resonance signal with
The ratio of the magnetic resonance signal of body coil acquisition.
It further, further include determining the coil unit relative to described opposite according to the initial position of coil unit
The direction of dead-center position.
The present invention also provides a kind of devices of magnetic resonance imaging, comprising:
Chamber is scanned, for accommodating scanned object；
Local coil includes several coil units, is set to the position at the targeted scans position of scanned object, and institute
Coil unit is stated for receiving the magnetic resonance signal at corresponding targeted scans position；
Locating module corrects the office for obtaining the relative zero of the local coil, and according to the relative zero
The position of portion's coil neutralization coil unit；
Display module, for showing the corresponding position relationship of local coil middle line coil unit Yu targeted scans position；
Data acquisition module is connect with the local coil, for acquiring the magnetic resonance signal at targeted scans position；
Module is rebuild, is connect with the data acquisition module, for carrying out Fourier transformation to magnetic resonance signal, obtains mesh
Mark the magnetic resonance image of scanned position.
Further, the locating module includes:
Initial position acquiring unit, for obtaining the initial position of each coil unit in the local coil；
Relative zero acquiring unit is connect, for obtaining the Relative Zero of local coil with the initial position acquiring unit
Point, the relative zero position are the mean value or adjacent coil units of the dead-center position obtained according to the initial position of coil unit
Sensitivity curve crosspoint position mean value；
Position correction unit is connect with the relative zero acquiring unit, is used for according to relative zero position to each line
The initial position of coil unit is corrected, and obtains the position of each coil unit.
Compared with the prior art, the advantages of the present invention are as follows: the magnetic resonance signal and body collected according to coil unit
The magnetic resonance signal that coil collects is fitted to obtain sensitivity curve, only has one according to the sensitivity curve of adjacent coil units
The feature in crosspoint obtains the position in the sensitivity curve crosspoint of adjacent coil units, according to the position acquisition phase in crosspoint
To the position of zero point, the accuracy of calculated result is improved；According to the structure feature of local coil, the opposite position of each coil unit
The relationship of setting is fixed, by the higher relative zero position of accuracy can relative positional relationship correcting coil unit initial position, can keep away
Exempt from positioning result is influenced by institutional framework and magnetic field marginal distortion, further improves positioning accuracy and stability.
[Detailed description of the invention]
Fig. 1 is the method flow diagram of magnetic resonance imaging of the present invention；
Fig. 2 is that the local coil position of the embodiment of the present invention one positions schematic diagram；
Fig. 3 is that the local coil position of the embodiment of the present invention two positions schematic diagram；
Fig. 4 is that the local coil position of the embodiment of the present invention three positions schematic diagram；
Fig. 5 is that the local coil position of the embodiment of the present invention four positions schematic diagram.
[specific embodiment]
To make the above purposes, features and advantages of the invention more obvious and understandable, with reference to the accompanying drawings and examples
Specific embodiments of the present invention will be described in detail.
MR imaging apparatus of the present invention mainly includes the superconducting magnet being arranged in around scanning chamber, gradient system, penetrates
Display system.Wherein, the inside of chamber is scanned for accommodating scanned object；The superconducting magnet outside scanning chamber is arranged in open in superconduction
The lower main field for generating uniform and stable magnetostatic field B0 of control is closed, the intensity homogeneity in magnetic field, the size for scanning chamber etc. all can shadows
Ring the signal-to-noise ratio and image resolution ratio of magnetic resonance signal；Gradient system is by gradient coil, gradient controller, digital analog converter, ladder
Spend amplifier and gradient cooling system etc. composition, provide it is that system linear degree is met the requirements, can high-speed switch gradient fields, master
It determines the size of imaging region, the space orientation of voxel is imaged, be one of core component of magnetic resonance system, gradient magnetic position
In in imaging region, the gradient of the orthogonal three-dimensional space linear change of X, Y, a Z is added in main field dynamically as needed
Magnetic field, the gradient in a direction are used for the spin of one level inner proton of excitation of radio-frequency pulse selectivity, second gradient pair
The MR signal in direction carries out frequency coding along level, third gradient to the MR signal in another direction along level into
Row phase space coding, makes subject have different resonant frequencies in different location, is implemented as choosing layer and the space of voxel
The function of coding.Above three gradient fields are generated by three orthogonal gradient AC coils respectively, and each group of coil requires have one
A independent current drive amplifiers power supply, every group of coil is made of two opposite coaxial coils of current direction, to generate it
Axial greatest gradient magnetic field；Radio frequency system is then to implement RF excited in magnetic resonance system and receive and handle radiofrequency signal
Functional unit, mainly includes rf transmitter unit and signal receiving unit, and rf transmitter unit is the work in sequence controller
Under, the various radio-frequency pulses for meeting sequence requirements are generated, rf receiver unit receives human body and produce under sequence controller effect
Raw magnetic resonance signal；When the local radio frequency coil array formed with multiple coil units is used for MRI scan,
Each coil unit has specific effective imaging region, and selection is combined with the coil unit that scanning range matches to be imaged
Scanning, is the premise that magnetic resonance image obtains optimal signal-to-noise ratio.In the present invention, the local coil of radio frequency system includes several
Coil unit is set to the position at the targeted scans position of scanned object, and each coil unit is for corresponding to targeted scans
The magnetic resonance imaging at position.In order to be accurately positioned the position of each coil unit, MR imaging apparatus of the invention includes fixed
Position module corrects local coil middle line coil unit for obtaining the relative zero of local coil, and according to the relative zero
Position.Data collecting module collected connects local coil, and acquires the magnetic resonance letter at the received targeted scans position of local coil
Number, above-mentioned magnetic resonance signal can obtain target by Fourier transformation in the connected reconstruction module of data acquisition module by being
The magnetic resonance image of scanned position.In order to achieve the above object, it is single to specifically include that initial position obtains to locating module of the invention
Member, for obtaining the initial position of each coil unit in local coil；Relative zero acquiring unit obtains single with initial position
Member connection, for obtaining the relative zero of local coil, the position of relative zero is to be obtained according to the initial position of coil unit
Dead-center position mean value or adjacent coil units sensitivity curve crosspoint position mean value, can also be magnetic resonance at
As the initial position of coil unit nearest with magnet center in device；Position correction unit connects with relative zero acquiring unit
It connects, for being corrected according to initial position of the relative zero position to each coil unit, obtains the position of each coil unit
It sets.The device of magnetic resonance imaging of the invention is connected with display module, display local coil middle line coil unit and targeted scans portion
The corresponding position relationship of position, by the way that locating module is arranged, so that coil unit is corresponding with targeted scans position more accurate.It needs
Illustrate, the local coil in the present invention is not limited to head coil, spine coil or lower main pole winding etc., can also refer to
Enter the coil sections structure of the coil unit composition in effective imaging region in above-mentioned local coil.
Match with the device of above-mentioned magnetic resonance imaging, a kind of method that the present invention proposes magnetic resonance imaging, specific steps
Scanned object is placed in magnetic resonance imaging equipment as shown in Figure 1:, and targeted scans position is placed in a predetermined position, and
Targeted scans put local coil at position, wherein local coil includes several coil units, according to each coil unit
The relationship of position and targeted scans position chooses one or more coil units, obtains the magnetic resonance signal at targeted scans position,
Fourier transformation is carried out to magnetic resonance signal, obtains the magnetic resonance image at targeted scans position.The position of each coil unit leads to
Cross following manner acquisition: the initial position of each coil unit first in acquisition local coil；Then, the phase of local coil is obtained
To dead-center position；It is finally corrected according to initial position of the relative zero position to each coil unit, obtains each coil
The position of unit.
According to the method described above, in the method for one magnetic resonance imaging of the embodiment of the present invention, the position positioning of local coil can lead to
Following process is crossed to realize:
S10, the initial position for obtaining each coil unit in local coil, specific steps are as follows:
(a) prescan sequence is excited, the magnetic for obtaining several coil units acquisition in body coil and local coil respectively is total
Shake signal, and the frequency coding direction of magnetic resonance signal is along main field direction.It should be noted that in the present embodiment, body coil and
The magnetic resonance signal of coil unit acquisition be it is one-dimensional, main field direction is the Z-direction along subject's axial direction, wherein Iv(x) table
Show body coil in the intensity value of the position x magnetic resonance signal obtained, middle Il(x) indicate the coil unit in local coil in position
The intensity value for the magnetic resonance signal that x is obtained.
(b) using the magnetic resonance signal of body coil acquisition as reference signal, the magnetic that fitting obtains each coil unit acquisition is total
The sensitivity curve of vibration signal, wherein the intensity value of each coordinate points of sensitivity curve is that the magnetic of coil unit acquisition is total
The ratio for the signal strength indication and reference signal strength value of shaking, in the present embodiment sensitive the writing music of the corresponding coil unit of position x
Intensity value of the line at x beThe magnetic resonance signal for using body coil to acquire is as with reference to calculating coil unit
Sensitivity characteristic can remove the influence of scanned object institutional framework or contrast to coil feature to the greatest extent.Coil spirit
Acuity curve embodies the ability that coil unit receives signal on main field direction, and receives the ability and coil unit of signal
Position be closely related.In the position closer to coil unit center, the ability for receiving signal is stronger, the intensity of sensitivity curve
It is worth bigger；And far from coil unit center, the ability for receiving signal is weaker, and the intensity value of sensitivity curve is smaller.
(c) effective maximum value on sensitivity curve is obtained, which is the initial alignment of coil unit
Information, wherein local coil may include N number of coil unit (N >=2).
It should be noted that being not necessarily to obtain the initial positioning information of each coil unit in aforesaid operations, it can be only obtained
The location information of the middle higher coil unit of confidence level or the only coil unit in effective scanning region, as confidence level is higher
Close to the coil unit position of magnet center.The initial positioning information that coil unit is obtained in the present invention can also use its other party
Formula.The adjustment notch object such as on each coil unit detects marker simultaneously by the detection device being located in local coil device
Detection signal is generated, finally according to the position of detection signal judge mark object, to obtain the position of each coil unit.This
Outside, the initial positioning information for coil unit being obtained in the present invention can also use interpole coil identification circuit.
S20, the relative zero position for obtaining local coil, can be according to the mutual pass between coil unit each in local coil
The initial positioning information of system and several coil units obtains relative zero position.Specifically: according to the pendulum position drawn game of subject
The inherent structure of portion's coil determines the correlation obtained in local coil between each coil unit, the mutual pass in the present embodiment
System is that the arragement direction of each coil unit is fixed, and spacing is fixed；On fixed arrangement direction, according to the first of each coil unit
Beginning location information, the distance of comparator coil cell distance magnet center, and according to apart from the smallest coil unit of magnet center
Initial position is relative zero position.
The common certain coils such as lower limb local coil of magnetic resonance system, clinical use more specification is single, each coil list
Member is often fixed relative to the direction at local coil center.As shown in Fig. 2, lower limb local coil includes 6 coil units,
First coil unit LEC1 is at patient feet direction (F), and corresponding in shank side, the 6th coil unit LEC6 is in patient's head
Portion direction (H), corresponding in thigh side, (LEC-LEC6 respectively corresponds Coil1-Coil6, from foot sequentially arrangement and main magnetic to the end
Field direction is identical, and each coil unit can be given value according to local coil structure determination relative to the distance of zero point, respectively
For D1, D2, D3, D4, D5, D6, the placing direction of lower main pole winding each unit and the pendulum position relationship of patient are fixed, and pass through patient
Pendulum position can determine the positive direction that coil position is shown.At this point, each coil in lower limb local coil can be obtained based on aforementioned process
The initial positioning information of unit, the initial position of LEC1, LEC2, LEC3, LEC4, LEC5, LEC6 be expressed as P1, P2,
P3,P4,P5,P6.One of them result the most believable is filtered out in above- mentioned information as a reference to estimating other coil lists
The position of member, and abandon the relatively low result of other confidence levels.Screening most believable judgment criteria is near magnet center
Coil unit position, by comparing distance of each coil unit relative to zero point in the present embodiment, it is known that LEC5 is apart from magnetic
Body center is nearest, then P5 is the position of relative zero.
S30, according to the correction position of each coil unit of relative zero position acquisition.It is obtained according to step S20 opposite
Distance D1, D2, D3, D4, D5, the D6 of zero point and each coil unit relative to zero point, and coupling coil position is shown just
Mutual spacing can be obtained in direction, thus obtain the correction position P1' of LEC1, LEC2, LEC3, LEC4, LEC5, LEC6,
P2'、P3'、P4'、P5'、P6'。
The positioning of two local coil position of the embodiment of the present invention can be realized by following process:
The initial positioning information for obtaining several coil units in local coil first, specifically uses and is based in embodiment one
The method of coil unit sensitivity characteristic.It should be noted that local coil includes at least two coil units, and at least obtain
The initial position of two coil units.Local line in the method for two magnetic resonance imaging of the embodiment of the present invention is illustrated in figure 3 to draw a circle to approve
Position schematic diagram, in the present embodiment, local coil includes 3 coil units, respectively Coil1, Coil2 and Coil3, relative to
The distance of zero point is respectively D1, D2 and D3, corresponding, excitation available three coil units of prescanned data sequence
Sensitivity curve Pr1, Pr2 and Pr3, according to sensitivity curve can obtain on every coil unit sensitivity curve effectively most
Position P1, P2 and P3 where big value, P1, P2 and P3 then respectively correspond the initial of Coil1, Coil2 and Coil3 coil unit
Position location.Since the spacing between coil unit center is fixed, the distance between coil unit be can measure, and may be used as
Priori knowledge.It is with previous embodiment difference: according to the initial position location information of each coil and relative to zero point
Distance can calculate separately to obtain three dead-center positions.In the present embodiment, according to the initial position location P1 of Coil1 and relatively
Zero point P0 can be calculated in the distance D1 of zero point1, according to the initial position location P2 of Coil2 and relative to the distance D2 of zero point
Zero point P0 can be calculated2, zero point can be calculated according to the initial position location P3 of Coil3 and the distance D3 relative to zero point
P03, seek three relative zero P01、P02、P03The average value of position is the position of relative zero P0.According to the above process
Obtained suppressed zero P0 and each coil unit relative to zero point distance D1, D2, D3 (according to the independent line of any two
The position of coil unit determines direction of each coil unit relative to zero distance), Coil1, Coil2 and Coil3 can be obtained
Correction position P1', P2' and P3'.
There are certain characteristic information between adjacent coil unit, i.e. the sensitivity curve of adjacent coil units has only
One crosspoint.According to this feature information, three local coil location positioning method of the embodiment of the present invention can be realized by following process:
The initial positioning information for obtaining several coil units in local coil first, specifically uses and is based in embodiment one
The method of coil unit sensitivity characteristic.It should be noted that local coil includes at least two groups of adjacent coil units, and every
Group coil unit includes the public domain of collecting magnetic resonance signal.Two sensitivity curves of adjacent coil units have and have only
One crosspoint, and the relative position in sensitivity curve crosspoint not will receive the influence of institutional framework, by magnetic field marginal distortion
Influence it is also smaller.Along main field direction, adjacent coil unit is centrosymmetric to be distributed in crosspoint two sides.Each list of coil
When fixed range L between member, crosspoint is L/2 at a distance of the distance of coil unit, and the distance is with directionality.Based on spirit
Acuity curve information, can calculating the cross-point locations of every two adjacent sensitivity curves, (two adjacent sensitivity curves differences are most
At small position), the crosspoint CP being denoted as between adjacent coil units.Local coil comprising N+1 coil unit can get N number of
Continuous crosspoint (N >=1) remembers that the position in each crosspoint is CP respectively1、 CP2、···、CPx、···、CPN-1、CPN。
Then, these cross-point locations are averaging, it can be seen that the center of entire coil namely suppressed zero position P0,It should be noted that can only unite at this time when crosspoints certain in local coil are outside effective areas imaging
Meter is in the interior sensitivity crosspoint effective scanning region (FOV), and the number in the continuous crosspoint of local coil sensitivity curve is at this time
M (1≤M < N), is denoted as CP respectively1、CP2、···、CPx、···、CPM.Using the continuous crosspoints M and they relative to
The distance at whole coil center calculates the position of suppressed zero P0,It is further possible to only obtain
The crosspoint that partial sensitivity curve in imaging region is formed, the average value of the position by calculating these sensitivity crosspoints
Obtain the position of suppressed zero.
In the present embodiment, local coil includes 3 coil units, respectively Coil1, Coil2 and Coil3, Coil1
It is adjacent with Coil2, Coil2 (coil distribution arrangement is from Coil1 to Coil3 along main field direction) adjacent with Coil3, relative to
The distance of zero point is respectively D1, D2 and D3, and corresponding, available three coil units of prescanned data analysis are sensitive to write music
Line Pr1, Pr2 and Pr3, and the place of effective maximum value on every coil unit sensitivity curve can be obtained by sensitivity curve
Position P1, P2 and P3, P1, P2 and P3 respectively correspond the initial position location of Coil1, Coil2 and Coil3 coil unit.This
Outside, Coil1 and Coil2, Coil2 and Coil3 include the public domain of collecting magnetic resonance signal, Pr1 and Pr2, Pr2 with
There are intersection regions by Pr3, and in the crosspoint of intersection region existence anduniquess.As shown in figure 4, Pr2 is adjacent with Pr1 and Pr3 respectively,
Pr2 and Pr1 form unique crosspoint A, Pr2 and Pr3 and form unique crosspoint B, two intersection coil unit centers away from
From all be L/2.The average value of crosspoint A and B location are obtained, which is relative zero position P0.In specific embodiment
In, the position of relative zero P0 is also the correction position P2' of Coil2, obtains Coil1 and Coil3 correction position P1' and P3'
Method can be respectively D1, D2 and D3 relative to the distance of zero point using priori knowledge Coil1, Coil2 and Coil3, wherein each
Coil unit is obtained relative to the direction of the distance of zero point by the initial position message of any two coil unit；Also it can use
The distance of two adjacent intersections be L (direction of L also according to any two coil unit initial position message obtain) this
Prior information, according to each coil unit position of relative zero position acquisition.Pass through the coil unit of crosspoint information acquisition
Correction position can effectively exclude influence of the initial alignment error of individual coil unit greatly to whole positioning result.
However in magnetic resonance, after hospital bed is sent into magnet, generally require to determine that magnetic resonance system connects all coils
The position of unit not can guarantee the center that all coils unit is at magnet, some coil units are in effective scanning
Outside region, the sensitivity curve of the coil unit far from magnet center is easy to be influenced by the distortion of field in this case.This
A little factors frequently can lead to the accuracy of positioning result.Local coil determines in the method for four magnetic resonance imaging of the embodiment of the present invention
It is realized by following process position:
In local coil include at least two coil units, and wherein coil unit Coil1 be fully located at effective scanning at
As region, adjacent coil unit Coil2 only has part and is located at effective scanning imaging region, and the sensitivity curve formed is as schemed
Shown in 5.The sensitivity curve that wherein Coil1 is formed is Pr1, and the partial sensitivity curve that Coil2 is formed is (the dotted line position Pr2
It is overseas that corresponding coil is in active scanning interval, and without magnetic resonance signal), two curve existence anduniquess crosspoint C (intersections
With at a distance from Coil1 be L/2).The initial position message P1 of Coil1 can be acquired according to aforementioned process, two curve distances are nearest
Point is the location information of crosspoint C, then the position in the crosspoint can be used as the position of relative zero, and according to P1's and C
Positional relationship can get the direction of coil unit arrangement.Combine and each coil unit in local coil can be obtained using above- mentioned information
Correction position.
Local coil method for correcting position of the present invention, using between each absolute coil cell position and each coil unit
Feature, realize the correction of the position of coil unit, and it is inclined to can reduce system not vulnerable to the influence of institutional framework for positioning result
The distortion effects generated from central magnetic field improve the Stability and veracity of positioning result.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Within mind and principle, any modification, equivalent substitution, improvement and etc. done be should all be included in the protection scope of the present invention.
Claims (10)
1. a kind of method of magnetic resonance imaging, comprising the following steps:
Scanned object is placed in magnetic resonance imaging equipment, and targeted scans position is placed in a predetermined position, and is swept in target
Retouch and put local coil at position, the local coil includes several coil units, according to the position of each coil unit with
The relationship at targeted scans position chooses one or more coil units, obtains the magnetic resonance signal at targeted scans position, total to magnetic
The signal that shakes carries out Fourier transformation, obtains the magnetic resonance image at targeted scans position；The position of each coil unit, passes through
Following manner obtains:
Obtain the initial position of each coil unit in local coil；
The relative zero position of local coil is obtained, the position of relative zero is obtain according to the initial position of coil unit zero
The point mean value of position, the mean value of position in the sensitivity curve crosspoint of adjacent coil units, in MR imaging apparatus with magnetic
Nearest one of the initial position of coil unit in body center, and enabling the magnet center position of magnetic resonance imaging equipment is zero point
Position；
It is corrected according to initial position of the relative zero position to each coil unit, obtains the position of each coil unit.
2. the method for magnetic resonance imaging according to claim 1, which is characterized in that the relative zero position passes through following
Mode obtains:
The relative distance of the initial position of each coil unit and the magnet center position of magnetic resonance imaging equipment is calculated, with opposite
The initial position of the coil unit corresponding to the reckling is the relative zero position；
Alternatively, calculating dead-center position according to the initial position of each coil unit, and obtain the flat of the dead-center position being calculated
Mean value, enabling the average value is the relative zero position.
3. the method for magnetic resonance imaging according to claim 2, which is characterized in that the initial position of the coil unit is logical
It crosses that telltale mark is installed on the local coil or coil identification circuit is arranged and obtains.
4. the method for magnetic resonance imaging according to claim 2, which is characterized in that the initial position of the coil unit is logical
It crosses and obtains effective maximum value of the coil unit sensitivity curve and obtain.
5. the method for magnetic resonance imaging according to claim 1, which is characterized in that the relative zero position, by with
Under type obtains:
The sensitivity curve of the local coil middle line coil unit is obtained, the sensitivity curve at least two adjacent；
The position in the sensitivity curve crosspoint of adjacent coil units is obtained according to the sensitivity curve, and enables the crosspoint
Position mean value be the relative zero position.
6. the method for magnetic resonance imaging according to claim 5, which is characterized in that sensitive from the local coil is write music
Line obtains N number of crosspoint, the average value of the position in statistics M continuous crosspoints, and enables the average value of the position in the crosspoint
For the relative zero position, wherein 1≤M < N.
7. the method for magnetic resonance imaging according to claim 4, which is characterized in that sensitivity curve each position point
Intensity value be coil unit acquisition magnetic resonance signal and body coil acquisition magnetic resonance signal ratio.
8. the method for magnetic resonance imaging according to claim 1, which is characterized in that further include, according to the first of coil unit
Beginning position determines direction of the coil unit relative to the relative zero position.
9. a kind of device of magnetic resonance imaging, comprising:
Chamber is scanned, for accommodating scanned object；
Local coil includes several coil units, is set to the position at the targeted scans position of scanned object, and the line
Coil unit is used to receive the magnetic resonance signal at corresponding targeted scans position；
Locating module corrects the local line for obtaining the relative zero of the local coil, and according to the relative zero
The position of middle line coil unit is enclosed, the position of the relative zero is the dead-center position obtained according to the initial position of coil unit
The mean value of the position in the sensitivity curve crosspoint of mean value or adjacent coil units, and enable the magnet center of magnetic resonance imaging equipment
Position is dead-center position；
Display module, for showing the corresponding position relationship of local coil middle line coil unit Yu targeted scans position；
Data acquisition module is connect with the local coil, for acquiring the magnetic resonance signal at targeted scans position；
Module is rebuild, is connect with the data acquisition module, for carrying out Fourier transformation to magnetic resonance signal, target is obtained and sweeps
Retouch the magnetic resonance image at position.
10. the device of magnetic resonance imaging according to claim 9, which is characterized in that the locating module includes:
Initial position acquiring unit, for obtaining the initial position of each coil unit in the local coil；
Relative zero acquiring unit is connect, for obtaining the relative zero of local coil with the initial position acquiring unit；
Position correction unit is connect with the relative zero acquiring unit, is used for according to relative zero position to each coil list
The initial position of member is corrected, and obtains the position of each coil unit.
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| CN108378852A (en) * | 2018-02-08 | 2018-08-10 | 上海联影医疗科技有限公司 | The method and terminal, scanning system, computer readable storage medium of positioning scanning bed |
| US11534068B2 (en) | 2017-08-11 | 2022-12-27 | Shanghai United Imaging Healthcare Co., Ltd. | Systems and methods for determining a target position of a scanning table |
| CN107589387B (en) * | 2017-10-23 | 2020-01-07 | 东软医疗系统股份有限公司 | Magnetic resonance imaging method and apparatus |
| CN107861079B (en) * | 2017-11-03 | 2020-04-24 | 上海联影医疗科技有限公司 | Method for local coil localization, magnetic resonance system and computer-readable storage medium |
| CN108344960B (en) * | 2018-02-09 | 2020-09-25 | 上海东软医疗科技有限公司 | Coil unit gating method and device for magnetic resonance imaging system |
| CN108663640B (en) * | 2018-05-09 | 2021-07-13 | 上海东软医疗科技有限公司 | Method and device for determining position of magnetic resonance coil |
| CN110095741B (en) * | 2019-04-30 | 2021-09-28 | 上海东软医疗科技有限公司 | Magnetic resonance coil position determining method and device and magnetic resonance imaging system |
| CN110286343B (en) * | 2019-07-10 | 2021-06-25 | 苏州众志医疗科技有限公司 | Magnetic resonance radio frequency receiving coil and image post-processing method |
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