CN108814600A - A kind of calibration method and system of radio-frequency power - Google Patents
A kind of calibration method and system of radio-frequency power Download PDFInfo
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/055—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
Abstract
The invention discloses a kind of calibration methods of radio-frequency power, including：Determine rf gain empirical value；Choose the rf gain of each equal difference near the rf gain empirical value；The corresponding amplitude of each rf gain is obtained, chooses maximum amplitude in each amplitude, using the corresponding rf gain of the maximum amplitude as target radio frequency gain；Radio-frequency power is calibrated according to the target radio frequency gain.Above-mentioned method, only choose the rf gain of each equal difference near the rf gain empirical value, target radio frequency gain is chosen in the rf gain of each equal difference, the radio-frequency power is calibrated according to the target radio frequency gain, it avoids the need for traversing entire section all rollovers angle and be scanned, the problem of homologous thread that just can determine that flip angle and radio-frequency power calibrates radio-frequency power according to the curve, causes calibration that can consume the long period.
Description
Technical field
The present invention relates to mr imaging technique field more particularly to the calibration methods and system of a kind of radio-frequency power.
Background technique
Need accurately to calculate the radio-frequency power of radio-frequency pulse during magnetic resonance imaging, radio-frequency power makes proton institute of spinning
The Net magnetic moment of formation can be with specific flip angle precession.Accurate flip angle in order to obtain, generally can be right before scanning
Radio-frequency power carries out calibration calculating.Common method is exactly to be continuously increased the rf gain of pulse using specific radio-frequency pulse
Amplitude, and corresponding FID signal is received, the flip angle and radio-frequency pulse power of all tests can be obtained by the method for traversal
Corresponding value, then draws homologous thread, calibrates according to the curve to radio-frequency power.
Inventor the calibration process of existing radio-frequency power is carried out the study found that above-mentioned calibration method need to be traversed for it is whole
A section all rollovers angle is scanned, and just can determine that the homologous thread of flip angle and radio-frequency power, according to the curve pair
Radio-frequency power is calibrated, and causes calibration that can consume the long period.
Summary of the invention
In view of this, the present invention provides a kind of calibration method of radio-frequency power and systems, to solve in the prior art
It needs to be traversed for entire section all rollovers angle to be scanned, just can determine that the homologous thread of flip angle and radio-frequency power, according to
The problem of radio-frequency power is calibrated according to the curve, causes calibration that can consume the long period.Concrete scheme is as follows：
A kind of calibration method of radio-frequency power, including：
Determine rf gain empirical value；
Choose the rf gain of each equal difference near the rf gain empirical value；
The corresponding amplitude of each rf gain is obtained, chooses maximum amplitude in each amplitude, by the maximum amplitude
Corresponding rf gain is as target radio frequency gain；
Radio-frequency power is calibrated according to the target radio frequency gain.
Above-mentioned method optionally determines that rf gain empirical value includes：
Determine each rf gain to be scanned；
Each rf gain is traversed, by each rf gain corresponding radio frequency reading to preset moisture film, is incited somebody to action
The corresponding rf gain of maximum reference amplitude in each reference amplitude is obtained as rf gain empirical value.
Above-mentioned method, optionally, the rf gain for choosing each equal difference near the rf gain empirical value includes：
Using the rf gain empirical value as starting point, preset step-length is chosen；
According to the preset step-length, the first preset quantity and second is chosen on the left side of the starting point and the right respectively
Preset quantity using the preset step-length as the rf gain of each equal difference of tolerance.
Above-mentioned method optionally further includes：
Judge the whether corresponding target gain of the gain interval range being made of the rf gain of each equal difference
Section matching；
When mismatching, first preset quantity and second preset quantity are adjusted.
Above-mentioned method, optionally, carrying out calibration to radio-frequency power according to the target radio frequency gain includes：
Radio frequency reference value is determined according to target radio frequency gain flip angle corresponding with its；
The radio frequency reference value is passed into the respective items in the capability correction formula, obtains rf gain and flip angle
The corresponding relationship of degree；
According to the corresponding relationship, the radio-frequency power is calibrated.
A kind of calibration system of radio-frequency power, including：
Determining module, for determining rf gain empirical value；
First chooses module, for choosing the rf gain of each equal difference near the rf gain empirical value；
Second selection module is chosen most substantially for obtaining the corresponding amplitude of each rf gain in each amplitude
Value, using the corresponding rf gain of the maximum amplitude as target radio frequency gain；
Calibration module, for being calibrated according to the target radio frequency gain to radio-frequency power.
Above-mentioned system, optionally, the determining module includes：
First determination unit, for determining each rf gain to be scanned；
Second determination unit, for traversing each rf gain, by the corresponding radio frequency reading of each rf gain
Onto preset moisture film, using the corresponding rf gain of maximum reference amplitude obtained in each reference amplitude as rf gain
Empirical value.
Above-mentioned system, optionally, the first selection module includes：
First selection unit, for choosing preset step-length using the rf gain empirical value as starting point；
Second selection unit, for being chosen on the left side of the starting point and the right respectively according to the preset step-length
First preset quantity and the second preset quantity using the preset step-length as the rf gain of each equal difference of tolerance.
Above-mentioned system optionally further includes：
Whether judging unit, the gain interval range for judging to be made of the rf gain of each equal difference are right with it
The target gain section matching answered；
Adjustment unit, for being adjusted to first preset quantity and second preset quantity when mismatching.
Above-mentioned system, optionally, the calibration module includes：
Third determination unit, for determining radio frequency reference value according to target radio frequency gain flip angle corresponding with its；
4th determination unit is obtained for the radio frequency reference value to be passed to the respective items in the capability correction formula
To the corresponding relationship of rf gain and flip angle；
Calibration unit, for being calibrated to the radio-frequency power according to the corresponding relationship.
Compared with prior art, the present invention includes the following advantages：
The invention discloses a kind of calibration methods of radio-frequency power, including：Rf gain empirical value is determined first, chooses institute
The rf gain for stating each equal difference near rf gain empirical value obtains the corresponding amplitude of each rf gain, each
Maximum amplitude is chosen in amplitude, using the corresponding rf gain of the maximum amplitude as target radio frequency gain, according to the target
Rf gain calibrates radio-frequency power.Above-mentioned method avoids the need for traversing entire section all rollovers angle progress
Scanning, just can determine that the homologous thread of flip angle and radio-frequency power, calibrates according to the curve to radio-frequency power, lead to school
The problem of long period will definitely be consumed.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with
It obtains other drawings based on these drawings.
Fig. 1 is a kind of calibration method flow chart of radio-frequency power disclosed in the embodiment of the present application；
Fig. 2 is a kind of another method flow diagram of the calibration method of radio-frequency power disclosed in the embodiment of the present application；
Fig. 3 is a kind of calibration system structural block diagram of radio-frequency power disclosed in the embodiment of the present application.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other
Embodiment shall fall within the protection scope of the present invention.
The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention.
Various modifications to these embodiments will be readily apparent to those skilled in the art, as defined herein
General Principle can be realized in other embodiments without departing from the spirit or scope of the present invention.Therefore, of the invention
It is not intended to be limited to the embodiments shown herein, and is to fit to and the principles and novel features disclosed herein phase one
The widest scope of cause.
The invention discloses a kind of calibration method of radio-frequency power, the calibration method is applied in Magnetic resonance imaging process
In, wherein Magnetic resonance imaging is to make the proton of precession in tissue that precession generation occur with radio-frequency pulse using magnetic field to penetrate
Frequency signal is imaged through computer processing.Atomic nucleus absorbs RF pulse-to-pulse identical with atomic nucleus precession frequency in precession
Punching, i.e., the frequency of additional alternating magnetic field are equal to Rameau frequency, and RESONANCE ABSORPTION just occurs for atomic nucleus so that remove radio-frequency pulse it
Afterwards, nuclear moments in the form of an electromagnetic wave emit a part in the energy absorbed again, referred to as ejection values.Altogether
Vibration absorbs and the process of ejection values is called " nuclear magnetic resonance " and needs accurately to calculate radio-frequency pulse function during magnetic resonance imaging
Rate enables spin proton to be formed by Net magnetic moment with specific flip angle precession.If radio-frequency pulse power inaccuracy, that
The flip angle of radio-frequency drive will have error, and so as to cause received signal strength reduction, signal noise ratio (snr) of image decline etc. is asked
Topic.In the embodiment of the present invention, the execution process of the calibration method is as shown in Figure 1, include step：
S101, rf gain empirical value is determined；
In the embodiment of the present invention, in a nuclear magnetic resonance equipment, it is first determined each rf gain to be scanned, traversal
Each rf gain will obtain each reference on each rf gain corresponding radio frequency reading to preset moisture film
The corresponding rf gain of maximum reference amplitude in amplitude is as rf gain empirical value.
The rf gain of each equal difference near S102, the selection rf gain empirical value；
In the embodiment of the present invention, using the rf gain empirical value as starting point, respectively in the rf gain empirical value
The right and left choose that multiple there are the rf gains of equal difference relationship.
S103, the corresponding amplitude of each rf gain is obtained, chooses maximum amplitude in each amplitude, by the maximum
The corresponding rf gain of amplitude is as target radio frequency gain；
In the embodiment of the present invention, the radio-frequency pulse that each rf gain generates is energized into can on the object that is excited
An amplitude is generated, the corresponding amplitude of each rf gain is obtained, increases the corresponding radio frequency of maximum amplitude in each amplitude
Benefit is used as target radio frequency gain.
S104, radio-frequency power is calibrated according to the target radio frequency gain.
In the embodiment of the present invention, according to the target radio frequency gain, determine radio frequency reference value, determine radio frequency reference value with
Afterwards, by adjusting rf gain and excitation angle, the radio-frequency power is calibrated.Wherein, wherein rf gain is to penetrate
The amplification factor of frequency power output, can be equivalent at a concept, and the calibration to radio-frequency power can be equivalent to rf gain
Calibration.
Wherein, nuclear magnetic resonance equipment is typically necessary maintenance correction system etc. and operates, such as Magnetic field inhomogeneity, gradient system
The problems such as error of uniting, will lead to image inaccuracy, just need this when through magnetic resonance imaging picture collection feedback information come school
Just, scanning human body can not directly be removed this when, human body is more troublesome and tissue is because people is different because scanning, at this time
It will be scanned with a regular shape and with moisture film as tissue class signal, here it is the origin of moisture film, so this
In scanning moisture film as reference value.In scanning moisture film before radio frequency empirical value, we are inexperienced value on hand, so the
It is primary just to find out this empirical value with the method for traversal, after having empirical value, any material no matter is scanned all with this value
Centered on a certain range be scanned, there is no need to all traverse.
The invention discloses a kind of calibration methods of radio-frequency power, including：Rf gain empirical value is determined first, chooses institute
The rf gain for stating each equal difference near rf gain empirical value obtains the corresponding amplitude of each rf gain, each
Maximum amplitude is chosen in amplitude, using the corresponding rf gain of the maximum amplitude as target radio frequency gain, according to the target
Rf gain calibrates radio-frequency power.Above-mentioned method avoids the need for traversing entire section all rollovers angle progress
Scanning, just can determine that the homologous thread of flip angle and radio-frequency power, calibrates according to the curve to radio-frequency power, lead to school
The problem of long period will definitely be consumed.
In the embodiment of the present invention, it is preferred that the corresponding pulse excitation angle of maximum value in each amplitude is 90 °,
Because in the embodiment of the present invention, being excited using three continuous pulses (in a TR), generating the signal of a stimulated echo,
Wherein it is by the amplitude of energizing signal：
M=(M0/2)*sin(θ1)*sin(θ2)*sin(θ3) (1)
When three continuous pulse excitation angles are all ɑ angles, the amplitude of stimulated echo is：
M=(M0/2)*sin3(α) (2)
Therefore, amplitude and radio-frequency pulse angle value have specific curved line relation, corresponding when 90 ° of radio-frequency drive to be excited back
Wave-amplitude is maximum.
In the embodiment of the present invention, the method stream of the rf gain of each equal difference near the rf gain empirical value is chosen
Journey is as shown in Fig. 2, include step：
S201, using the rf gain empirical value as starting point, choose preset step-length；
In the embodiment of the present invention, using the rf gain empirical value as starting point, preset step-length is chosen, it is described preset
Step-length with actual alignment during it is related to the selection of calibration accuracy, the required precision of calibration is higher, the preset step-length
That chooses is smaller.
S202, according to the preset step-length, choose the first preset quantity on the left side of the starting point and the right respectively
With the second preset quantity using the preset step-length as the rf gain of each equal difference of tolerance.
In the embodiment of the present invention, preset first quantity and preset second quantity can identical not yet
Together, such as：Present rf gain empirical value is 10.Preferably, precision controlling is 0.5, then step-length is just arranged to 0.5, so
A point is respectively arranged in step number or so afterwards, such as：8-12, then being finally exactly to run 8；8.5；9；9.5；10；10.5；11；
11.5；12 this 9 numbers look for maximum value.Finally also a step should be added to prevent from crossing the border.If peak-peak is not in 8-12, then mesh
Preceding maximum value is in hithermost marginal position, for example is 12 this point, then peak value is likely to be 12.5,13 equal numerical value.
So be exactly in next step run 12.5 the right point, as operation how far also select on one's own account, above-mentioned process can be divided into as
Lower two kinds of situations：
If situation A：Peak value (i.e. some point is all bigger than its two point in left and right) is run out, then it is exactly accurate that this peak is corresponding
It is worth (90 °), off-test, wherein the first preset quantity is 4, and the second preset quantity is 4.
If situation B：Peak value (some endpoint of left and right is in maximum value) can not be run, then next time, operation was just to this endpoint
Direction extend, if there is situation A, terminate, if there is situation B, continue, wherein the first preset quantity is 4, and second is pre-
If quantity is to be adjusted.
Wherein, each material properties is according to more to that can correspond to a target gain section, the target gain section
What the empirical value of secondary calculating determined, it is set according to the target gain section, it is possible to reduce calculation amount realizes school faster
It is quasi-.Preferably, target gain section corresponding after gain interval range has been determined is matched, and judges the gain
Whether the corresponding target gain section of interval range is fluctuated in the same range that error allows, when the two gap is larger and
When mismatch, first preset quantity and second preset quantity are adjusted according to the target gain interval range
It is whole.
In the embodiment of the present invention, the method calibrated according to the target radio frequency gain to radio-frequency power is as follows：First
Assuming that：Rf gain：RFA0, radio frequency reference value：REF, radio frequency angle：ɑ, radio frequency duration：T, radio frequency waveform parameter：B, often
Number：c.
According to formula (3)：
RFA0=REF* (ɑ/90) * (1/t)/b (, 3)
Know rf gain and radio frequency angle, radio frequency reference value, the radio frequency duration, radio frequency waveform parameter has relationship.
In actual operation, if we want that the object that is excited is excited ɑ angle with some radio frequency, this radio frequency
Duration t, radio frequency waveform parameter b, when we select radio frequency waveform be all it is known, in radio frequency duration t and
In the case that radio frequency waveform b is constant, formula be can simplify into：
RFA0=REF* (ɑ/90) * c (4)
If we want 90 ° of the object excitation that is excited described in, rf gain is only needed to be arranged to RFA0=
REF*c；If we want object to excite 45 °, rf gain is only needed to be arranged to RFA0=REF*0.5*c.
Wherein, it is related among all parameters of rf gain calculating, radio frequency angle is known.The radio frequency duration,
Radio frequency waveform parameter, is also known.
And radio frequency reference value, it is unknown, because exciting different materials in different systems, necessarily this is caused to penetrate
The difference of frequency reference value.Such as we are with a duration t, waveform b, radio frequency on A magnet, excite 90 ° of B object,
The rf gain used is (RFA0)=10.It will be apparent that if changed a magnet, or an object has been changed, then wanting
90 ° of excitation is just inaccurate with rf gain (RFA0)=10.
So to sum up, seek the process of rf gain, exactly seeking the process of radio frequency reference value REF, (wherein REF is one
A variable with changes in environmental conditions).It can use formula (5)：
RFA0=REF* (ɑ/90) * c (5)
Wherein, c is known constant,
If radio-frequency power is arranged to RFA0=10 by we, object has deflected 1 angle of ɑ.If we are radio-frequency power
It is arranged to RFA0=15, object has deflected 2 angle of ɑ.Due to the deflection angle ɑ 1 of object, we can not be directly observed ɑ 2, institute
Using angle and by the formula of energizing signal：M=(M0/2) * sin3 (ɑ), carrys out indirect observation.When ɑ=90 °, M is maximum.It is i.e. defeated
Enter the pulsed RF A1, RFA2, RFA3, RFA4, RFA5...... of a series of rf gains.It obtains a series of being excited signal amplitude
It is M1, M2, M3, M4, M5.......Wherein, it is preferred that a series of selection of rf gains can be chosen at the object that is excited
Near the empirical value of rf gain.
If M3 be this it is a series of be excited signal amplitude maximum value if, it is clear that according to formula it is found that deflection at this time
Angle is 90 °, then corresponding rf gain is RFA3.
So RFA3=REF* (90/90) * c, substitution can find out REF.
After finding out REF, it can be obtained according to formula (3)：
RFA0=REF* (ɑ/90) * (1/t)/b.
Based on above-mentioned calculating process, if certain material magnetic resonance signal is want to overturn 90 °, REF=20 is found out, has been determined
Radio frequency time t=3, radio frequency waveform parameter b=4, then rf gain is only needed to be adjusted to：RFA0=20* (90/
90) * (1/3)/4. may be reversed 90 °.If I wants material magnetic resonance signal to overturn 45 °, RFA0=20* (45/90) * (1/
3)/4..If having changed a magnetic resonance system certainly, or if having changed a material, REF is recalculated again.
It illustrates, it is known that last time using A as material, obtains REF=20.Now using B as material, then REF can be attached 20
Closely.Because on any one fixed system, the difference for scanning material will lead to REF variation, but the range generally changed is not
It can be too big.So REF is arranged to 11,12,13,14,15 by we ..., 20,21,22,23 ... 29,30, wherein
First preset quantity is 10, and the second preset quantity is 9.It is such a series of to be worth corresponding rf gain RFA11, RFA12,
RFA13 ..., RFA30.A series of M11, M12, M13 are obtained ..., M30.If wherein M22 is maximum, then M22 is corresponding
Be ɑ=90, target radio frequency gain RFA=22.It is possible thereby to calculate new REF=22.It can be obtained according to formula (3)：
RFA0=REF* (ɑ/90) * (1/t)/b
Wherein, all variables may be implemented all it is known that according to rf gain and the corresponding relationship for exciting angle to radio frequency function
The calibration of rate.
In the embodiment of the present invention, corresponding with the radio frequency power calibration method the present invention provides a kind of rf gains
Calibration system, the structural block diagram of the calibration system is as shown in figure 3, include：
Determining module 301, first chooses module 302, and second chooses module 303 and calibration module 304.
Wherein,
The determining module 301, for determining rf gain empirical value；
Described first chooses module 302, and the radio frequency for choosing each equal difference near the rf gain empirical value increases
Benefit；
The second selection module 303 is chosen in each amplitude for obtaining the corresponding amplitude of each rf gain
Maximum amplitude, using the corresponding rf gain of the maximum amplitude as target radio frequency gain；
The calibration module 304, for being calibrated according to the target radio frequency gain to radio-frequency power.
The invention discloses a kind of calibration systems of radio-frequency power, including：Determine rf gain empirical value；It is penetrated described in selection
The rf gain of each equal difference near frequency gain empirical value；The corresponding amplitude of each rf gain is obtained, in each amplitude
Middle selection maximum amplitude, using the corresponding rf gain of the maximum amplitude as target radio frequency gain；According to the target radio frequency
Radio-frequency power is calibrated in gain.Above-mentioned system only chooses penetrating for each equal difference near the rf gain empirical value
Frequency gain chooses target radio frequency gain, according to the target radio frequency gain to the radio frequency in the rf gain of each equal difference
Power is calibrated, and is avoided the need for traversing entire section all rollovers angle and is scanned, and just be can determine that flip angle and is penetrated
The problem of homologous thread of frequency power calibrates radio-frequency power according to the curve, causes calibration that can consume the long period.
In the embodiment of the present invention, the determining module 301 includes：First determination unit 305 and the second determination unit 306.
Wherein,
First determination unit, for determining each rf gain to be scanned；
Second determination unit, for traversing each rf gain, by the corresponding radio frequency reading of each rf gain
Onto preset moisture film, using the corresponding rf gain of maximum reference amplitude obtained in each reference amplitude as rf gain
Empirical value.
In the embodiment of the present invention, the first selection module 302 includes：First selection unit 307 and the second selection unit
308。
Wherein,
First selection unit 307, for choosing preset step-length using the rf gain empirical value as starting point；
Second selection unit 308 is used for according to the preset step-length, respectively on the left side and the right side of the starting point
Side choose the first preset quantity and the second preset quantity using the preset step-length as the rf gain of each equal difference of tolerance.
In the embodiment of the present invention, the calibration system further includes：Judging unit 309 and adjustment unit 310.
Wherein,
The judging unit 309, for judging that the gain interval range being made of the rf gain of each equal difference is
No corresponding target gain section matching；
The adjustment unit 310, for when mismatching, to first preset quantity and second preset quantity into
Row adjustment.
In the embodiment of the present invention, the calibration module 304 includes：Third determination unit 311,312 He of the 4th determination unit
Calibration unit 313.
Wherein,
The third determination unit 311, for determining radio frequency according to target radio frequency gain flip angle corresponding with its
Reference value；
4th determination unit 312, for the radio frequency reference value to be passed to pair in the capability correction formula
Ying Xiang obtains the corresponding relationship of rf gain and flip angle；
The calibration unit 313, for being calibrated to the radio-frequency power according to the corresponding relationship.
It should be noted that all the embodiments in this specification are described in a progressive manner, each embodiment weight
Point explanation is the difference from other embodiments, and the same or similar parts between the embodiments can be referred to each other.
For device class embodiment, since it is basically similar to the method embodiment, so being described relatively simple, related place ginseng
See the part explanation of embodiment of the method.
Finally, it is to be noted that, herein, relational terms such as first and second and the like be used merely to by
One entity or operation are distinguished with another entity or operation, without necessarily requiring or implying these entities or operation
Between there are any actual relationship or orders.Moreover, the terms "include", "comprise" or its any other variant meaning
Covering non-exclusive inclusion, so that the process, method, article or equipment for including a series of elements not only includes that
A little elements, but also including other elements that are not explicitly listed, or further include for this process, method, article or
The intrinsic element of equipment.In the absence of more restrictions, the element limited by sentence "including a ...", is not arranged
Except there is also other identical elements in the process, method, article or apparatus that includes the element.
For convenience of description, it is divided into various units when description apparatus above with function to describe respectively.Certainly, implementing this
The function of each unit can be realized in the same or multiple software and or hardware when invention.
As seen through the above description of the embodiments, those skilled in the art can be understood that the present invention can
It realizes by means of software and necessary general hardware platform.Based on this understanding, technical solution of the present invention essence
On in other words the part that contributes to existing technology can be embodied in the form of software products, the computer software product
It can store in storage medium, such as ROM/RAM, magnetic disk, CD, including some instructions are used so that a computer equipment
(can be personal computer, server or the network equipment etc.) executes the certain of each embodiment or embodiment of the invention
Method described in part.
The calibration method and system of a kind of radio-frequency power provided by the present invention are described in detail above, herein
Apply that a specific example illustrates the principle and implementation of the invention, the explanation of above example is only intended to help
Understand method and its core concept of the invention；At the same time, for those skilled in the art, according to the thought of the present invention,
There will be changes in the specific implementation manner and application range, in conclusion the content of the present specification should not be construed as to this
The limitation of invention.
Claims (10)
1. a kind of calibration method of radio-frequency power, which is characterized in that including：
Determine rf gain empirical value；
Choose the rf gain of each equal difference near the rf gain empirical value；
The corresponding amplitude of each rf gain is obtained, chooses maximum amplitude in each amplitude, the maximum amplitude is corresponding
Rf gain as target radio frequency gain；
Radio-frequency power is calibrated according to the target radio frequency gain.
2. the method according to claim 1, wherein determining that rf gain empirical value includes：
Determine each rf gain to be scanned；
Each rf gain is traversed, by each rf gain corresponding radio frequency reading to preset moisture film, will be obtained
The corresponding rf gain of maximum reference amplitude in each reference amplitude is as rf gain empirical value.
3. the method according to claim 1, wherein choosing each equal difference near the rf gain empirical value
Rf gain include：
Using the rf gain empirical value as starting point, preset step-length is chosen；
According to the preset step-length, the first preset quantity and second is chosen on the left side of the starting point and the right respectively and is preset
Quantity using the preset step-length as the rf gain of each equal difference of tolerance.
4. according to the method described in claim 3, it is characterized in that, further including：
Judge the whether corresponding target gain section of the gain interval range being made of the rf gain of each equal difference
Matching；
When mismatching, first preset quantity and second preset quantity are adjusted.
5. the method according to claim 1, wherein carrying out school to radio-frequency power according to the target radio frequency gain
Standard includes：
Radio frequency reference value is determined according to target radio frequency gain flip angle corresponding with its；
The radio frequency reference value is passed into the respective items in the capability correction formula, obtains rf gain and flip angle
Corresponding relationship；
According to the corresponding relationship, the radio-frequency power is calibrated.
6. a kind of calibration system of radio-frequency power, which is characterized in that including：
Determining module, for determining rf gain empirical value；
First chooses module, for choosing the rf gain of each equal difference near the rf gain empirical value；
Second chooses module, for obtaining the corresponding amplitude of each rf gain, maximum amplitude is chosen in each amplitude, is incited somebody to action
The corresponding rf gain of the maximum amplitude is as target radio frequency gain；
Calibration module, for being calibrated according to the target radio frequency gain to radio-frequency power.
7. system according to claim 6, which is characterized in that the determining module includes：
First determination unit, for determining each rf gain to be scanned；
Second determination unit, for traversing each rf gain, by the corresponding radio frequency reading of each rf gain in advance
If moisture film on, using the corresponding rf gain of maximum reference amplitude obtained in each reference amplitude as rf gain experience
Value.
8. system according to claim 6, which is characterized in that described first, which chooses module, includes：
First selection unit, for choosing preset step-length using the rf gain empirical value as starting point；
Second selection unit, for choosing first on the left side of the starting point and the right respectively according to the preset step-length
Preset quantity and the second preset quantity using the preset step-length as the rf gain of each equal difference of tolerance.
9. system according to claim 8, which is characterized in that further include：
Whether judging unit, the gain interval range for judging to be made of the rf gain of each equal difference are corresponding
The matching of target gain section；
Adjustment unit, for being adjusted to first preset quantity and second preset quantity when mismatching.
10. system according to claim 6, which is characterized in that the calibration module includes：
Third determination unit, for determining radio frequency reference value according to target radio frequency gain flip angle corresponding with its；
4th determination unit is penetrated for the radio frequency reference value to be passed to the respective items in the capability correction formula
The corresponding relationship of frequency gain and flip angle；
Calibration unit, for being calibrated to the radio-frequency power according to the corresponding relationship.
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