CN1802123B - System of obtaining images and spectra of intracavity structures using 3.0 tesla magnetic resonance systems - Google Patents

System of obtaining images and spectra of intracavity structures using 3.0 tesla magnetic resonance systems Download PDF

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CN1802123B
CN1802123B CN03814486.7A CN03814486A CN1802123B CN 1802123 B CN1802123 B CN 1802123B CN 03814486 A CN03814486 A CN 03814486A CN 1802123 B CN1802123 B CN 1802123B
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endoprobe
coil loop
coil
balloon
dependence
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CN1802123A (en
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G·J·米西克
E·J·里尼哈特
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Bayer Pharmaceuticals Corp
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Medrad Inc
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Abstract

An MR system features an intracavity probe and associated interface device. The probe includes a shaft, a balloon at one end thereof, and a coil loop within the balloon. The loop has two drive capacitors and a tuning capacitor, all of which in series. A junction node between the drive capacitors serves as a ground for electrically balancing the loop. Diametrically opposite the node, the tuning capacitor enables the loop to resonate at the operating frequency of the MR system. The interface allows the MR system to couple the loop to a port of the MR system during a receive cycle thereof and decouple it from the port during a transmit cycle thereof. With its balloon inserted and inflated within a cavity of a patient, the probe allows the MR system to generate images and/or spectra of the region of interest using the MR signals received by the loop.

Description

Use the system that 3.0 tesla magnetic resonance systems obtain inner-cavity structure image and spectrogram
The cross reference of related application
The application enjoys the U.S. Provisional Application of submitting to respectively on November 26th, 2002 and on May 16th, 2,002 60/429 that is entitled as " System And Method of Obtaining Images And Spectra Of Intracavity StructuresUsing 3.0 Tesla Magnetic Resonance Systems " and " 3.0 Tesla Endorectal Coil AndInterface For Single Receiver And Phased Array MR Scanning Of The Prostate AndOther Pelvic Anatomy ", 257 and 60/318,727 interests.These provisional application have transferred following assignee of the present invention, and its content is included in this document through quoting.
Invention field
The present invention relates generally to and uses the System and method for that magnetic resonance (MR) system obtains inner-cavity structure image and spectrogram, relate in particular to a kind of endoprobe, it can insert various human body openings such as rectum, vagina, mouth etc., to obtain domain of dependence high-definition image and spectral results in the body, especially, the invention still further relates to some being designed to the interface arrangement of this endoprobe and 2.0～5.0 tesla MR system interfaces, so that these domain of dependences are obtained this high-definition image and spectral results.
Description of Related Art
The background information that provides below can help following content of the present invention and the typical environment for use thereof that discloses of reader understanding.All terms used herein are not limited to the explanation of any specific narrow sense, except as otherwise noted.
Nuclear magnetic resonance (MRI) is a kind of non-intruding method that produces the inside of human body high quality graphic, can allow medical personnel just can observe situation in the body without surgical operation or such as the X ray ionizing radiation.Image will have sufficiently high definition, can make a distinction with the soma of visual type with disease and other pathological forms and health usually.Mr techniques and system are also developed into can carry out spectrum analysis, can determine whereby to organize or the chemical content of other entity.
MRI uses strong magnets, radio wave and computer technology to the intravital soft tissue of people, muscle, neural and the detailed image of skeleton generation, has wherein utilized the i.e. fundamental characteristics of the interior competent a kind of atom of all cells in vivo of hydrogen atom.During no magnetic field, hydrogen nuclei spins or precession as gyro randomly along each direction.But during the experience high-intensity magnetic field, the spin axis of proton self aligned magnetic field direction, this is that brute force is tended to the aligned magnetic field direction because hydrogen nuclei has big magnetic moment.In a word, produced a magnetization by the proton of imaging area and point to the mean vector that is parallel to magnetic field.
Typical MRI system or scanner, comprise that main magnet, three gradient coils, radio frequency (RF) antenna (often being called whole coil) and operators can control the computer installation of whole M RI system, but the main element of MRI system is a main magnet, has superconducting property usually, is shaped as cylindrical.In its post thorax (when doing the MRI operation, patient enters in it), main magnet produces all even immobilized (not changing) high-intensity magnetic field, is commonly referred to the Bo field.This Bo magnetic field is called the z direction along thorax body longitudinal axis orientation, forces the magnetization vector of proton in the body oneself to aim at this direction.To on time, check and approve the RF energy that receives fully from the appropriate frequency of whole coil.This frequency is referred to as the Larmor frequency, is provided by formula ω=γ Bo, and ω is Laxmar frequency (hydrogen atom precession under this frequency), and γ is the magnetic rotation constant, and Bo is a magnetic field intensity.
RF antenna, or whole coil generally both be used for the transmitting RF energy pulse, also were used to receive magnetic resonance (MR) signal of proton internal induction.Specifically, in its emission cycle, body coil injects the post thorax to the RF energy, and this energy produces radio-frequency (RF) magnetic field, also is referred to as RFB 1, its magnetic field line aligned perpendicular is in the straight line of proton magnetization vector.RF pulse (or B 1) the proton spin axis is tilted to main field (Bo), cause the net magnetization vector to depart from a certain angle of Z direction.Yet the RF pulse only influences those protons around its precession under this RF pulse frequency.In other words, only the nuclear of " resonance " is just influenced under this frequency, and this resonance realizes in conjunction with three gradient coil one biconditional operations.
Gradient coil all is a solenoid, and each gradient coil produces the magnetostatic field of linear change along one of three kinds of direction in spaces (x, y, z) in the post thorax, be referred to as gradient B1 field.Gradient coil in being positioned at main magnet as quick as thought during connecting and disconnecting, just can change main field by extremely narrow grade with ad hoc fashion.Like this,, can make when applying the RF pulse of relevant frequency that the proton in arbitrary set point or any given bar, sheet or elementary volume, volume element can resonate by various imaging techniques operation gradient coils in conjunction with main magnet.In response to the RF pulse, the RF energy of can the absorber coil being launched at the precession hydrogen atom of selecting in the district, thus force its magnetization vector to tilt and depart from the direction of main field (Bo).When body coil disconnected, proton began to discharge the RF energy with the form of MR signal, repeats below.
A kind of less known technology that can obtain image is called the spin-echo imaging art.During this technical operation, the MRI system at first activates a gradient coil, to set up magnetic field gradient along the z axle, be called " gradient is selected in section ", it is set up when adding the RF pulse, and when disconnecting the RF pulse, close, only allow to be positioned at and occur resonating in those protons of imaging area section, do not produce resonance at any tissue that is positioned at relevant plane either side.After the RF pulse-break, all nuclears in being excited to cut into slices are " homophase " all, and promptly their magnetization vector is all pointed to same direction.On its oneself the utensil left side, the net magnetization vector of all protons is with loose, so aim at the z direction again in the section.But second gradient coil activates immediately and produce magnetic field gradient along the y axle, and this is called " phase encoding gradient ", when between weak and the strongest two ends of people in gradient when mobile, makes the progressively different direction of magnetization vector sensing of tangent plane kernel.Then, after the RF pulse, after section selection gradient and phase encoding gradient had disconnected, the 3rd gradient coil was excited immediately and is produced a gradient along the x axle, Here it is so-called " frequency coding gradient " or " readout gradient " is because it only applies when measuring the MR signal final.This makes loose magnetization vector irregularly be excited again, thereby begins with the faster rate precession near the nuclear of gradient lower end, and the speed of high-end nuclear is also wanted soon.When these nuclears are loose again, the fastest nuclear (it is high-end the to be positioned at gradient) radio wave that tranmitting frequency is the highest.
In a word, gradient coil allows the MR signal by space encoding, makes the frequency of its resonance signal and the various piece that phase place can limit imaging area uniquely.Especially, when proton is loose, become a microminiature transmitting set separately, according to the local microenvironment at its place, provide time dependent characteristic pulse, for example, the proton in the fat has the microenvironment different with the proton in the water, launches different pulses.Because these differences, in conjunction with the different water/fat ratio of different tissues, different tissues can be launched the radio signal of different frequency.In its receiving cycle, body coil detects these microminiature wireless radio transmission that often is referred to as the MR signal.These unique resonance signals are transferred to the receiver of MR system from body coil, and they convert correspondingly mathematics data at this.For forming the signal to noise ratio (snr) preferable image, whole operation must repeat repeatedly.Use multidimensional Fourier transformation, the MR system can become two dimension or even three-dimensional image with the mathematics data transaction.
When the human body specific part is required more detailed image, to use local coil toward contact, or replace whole coil with it.Local coil can be tried to please and be amassed the form of coil or surface coils.Volume coil can be used to surround or sealing imaging volume (as head, arm, wrist, the cheek, knee joint or other domain of dependence), but surface coils only is fit to pasting or be positioned over patient's particular surface, makes the following domain of dependence can imaging (as abdominal part, chest and/or pelvic region).In addition, local coil both can also be designed to and can only also can be used as transmitting-receiving (T/R) coil working as receiving only coil working, receives only the MR signal that coil can only human body produces (when scan operation in response to the B of MR system generation 1Magnetic field), but the T/R coil can receive the MR signal, again can the transmitting RF pulse, and be created in and cause the necessary RFB of resonance in the domain of dependence tissue 1Magnetic field.
As everyone knows, in the MRI field, can use single local coil (no matter being surperficial, still volumetrical) to detect the MR signal.According to this unicoil method, can hide or seal whole domain of dependence with bigger local coil.Early stage receiving coil is a linearity coil, can only detect that two quadrature components (are vertical M in the MR signal that domain of dependence produces x' and horizontal M r') in one.But the receiving coil in later stage has been used the detection method of orthogonal modes, can intercept and capture two kinds of components of vertical and horizontal.Compare with linear receiving coil, the quadrature receiving coil makes the image that the MRI system can provide SNR to be greatly improved, and is typically SNR and has improved nearly 41%.Even the orthogonal mode detection method has had significant improvement, but the image that the unicoil method provides, its quality also is significantly improved.The inherent shortcoming of unicoil method is only to adopt a loop construction to obtain the MR signal of whole domain of dependence.
For overcoming the shortcoming of unicoil method, developed phased-array coil.Phase array method replaces a large-scale local coil with a plurality of less local coils, and every coil only covers or seal a part of domain of dependence.For example, in the system that two this coils are arranged, each coil almost covers or seals half domain of dependence, and two coils generally just partly overlap to realize the magnetic isolation.Two coils obtain simultaneously from its separately the part the MR signal, because of overlapping mutually unfriendly the effect.Because of each coil only covers half domain of dependence, so each coil can receive the MR signal of the interior domain of dependence part of its area of coverage than higher SNR ratio.Therefore, the less local coil of phased array provides to the MRI system together and produces the required signal data of whole domain of dependence image, and resolution is higher than the resolution that derives from single large-scale local coil.
One routine phased-array coil is that W.L.Gore and Associates company produces
Figure G038144867D00041
The trunk array, it has four surface coils, and two are positioned at preceding backing plate, and two are positioned at the back backing plate in addition.Two backing plates are designed to touch respectively the front and rear surfaces of patient's abdomen, breast and pelvic region.This trunk array design becomes the MR system coupling that a plurality of receivers are arranged with data collecting system.Four lead-in wires of trunk array, promptly two front coils and two back coils are each one, connect independently receiver, and each receiver is kept straight on to its received signal and is amplified and digitized.Then, the MR system will be combined into image from the digitalized data of independent receivers, and its total SNR is better than by single the local coil that only covers whole domain of dependence or even two resulting total SNR of bigger front and back local coil.
As everyone knows, can obtain body inner structure image with endoprobe.The endoprobe of one routine prior art can be at United States Patent (USP) 5,476, finds in 095 and 5,355,087, and these patents have also transferred the assignee of the present invention, comprise therewith by reference.The prior art probe that these patents disclose can insert human body openings such as rectum, vagina and mouth.These patents have also disclosed interface arrangement, are designed so that prior art endoprobe and MR imaging spectrum system join.United States Patent (USP) 5,348,010 has disclosed the using method of this endoprobe, and this patent also transfers the assignee of the present invention, comprises therewith by reference.
Prior art probe with relevant interface arrangement is operated together allows the MR system produce various body inner structures such as prostate, colon or Cervical image and spectral composition.The example of this class probe comprises BPX-15 prostate/interior rectum coil (E coil), PCC-15 colorectum coil and BCR-15 cervix uteri coil, all is to put coil
Figure G038144867D00042
The part of system, by Indianola, the Medrad company of Pennsylvania makes.The example of interface arrangement comprises ATD-II and the ATD-Torso device that Medrad company produces.
The ATD-II device is provided at the receiver interface of prior art probe with the MR system to close the zone, for example, and prostate, colon or Cervical image or spectrogram.The ATD-Torso device not only can be used as the prior art probe, and is Many interface message processor (IMP) interfaces of trunk array and MR system.When this probe was connected with the trunk array, the ATD-Torso device made the MR system that prostate, colon or Cervical image or spectrogram not only can be provided, and structure also can be provided on every side, for example, the image or the spectrogram of breast and pelvis area.
Although these prior art endoprobes and interface arrangement command a ready sale in the market and enjoy a good reputation, still have some shortcomings.At first, prior art probe and relevant interface arrangement (being ATD-II and ATD-Torso device) thereof are designed to only operate with 1.0 or 1.5 tesla MR systems, therefore be not suitable for MR system with more high field intensity work, such as 2.0～5.0 MR systems of 3.0 teslas especially, these MR systems can produce higher-quality image and spectral results.Secondly, result as design limitations, the coil loop of prior art endoprobe design presents 750～1000 ohm output impedance, thereby the interface arrangement of probe must be complementary the required low input impedance (as 50 ohm) of the high output impedance of coil loop and various MR system with π network or similar circuit.Once more, the design of prior art probe allows its coil loop is tuned to the operation frequency that departs from the MR system, and departure degree depends on the specified conditions (as patient) that use probe, therefore, the prior art interface arrangement that is used for the prior art probe generally all must comprise tuning circuit, can both be transferred to the operation frequency of MR system to guarantee endoprobe under all operations condition.
Goal of the invention
Therefore, an object of the present invention is to provide a kind of endoprobe, it can be used in the MR system of especially operating with 3.0 tesla field intensity with 2.0～5.0 teslas at least.
Another purpose of the present invention provides a kind of Frequency Response endoprobe wideer than prior art endoprobe of its coil loop, seldom or not even sacrifice signal to noise ratio, thereby needn't need be to each patient or every coil tuning coil loop as prior art probe.
Another purpose provides a kind of interface arrangement that makes this endoprobe and this MR system interface, need not tuningly pop one's head in to obtain domain of dependence high-definition image and spectral results.
Another purpose provides a kind of interface arrangement, and it makes this MR system not only can connect this endoprobe, can also connect the phased-array coil system as The trunk array.
Another purpose of the present invention provides a kind of method that this endoprobe, interface arrangement and MR system obtain interior domain of dependence image of patient's body cavity and/or spectrogram of using.
Another purpose of the present invention provides a kind of manufacture method that is applicable to this endoprobe of this MR system, with image and/or the spectrogram that obtains domain of dependence in patient's cavity.
Another purpose provides a kind of disposable endoprobe, and it does not contain can allocate the expensive decoupling component that re-uses that connects probe into.
Another purpose provides a kind of endoprobe as the interior transrectal probe that inserts rectum, to obtain male prostate image and/or spectrogram.
Another purpose provides a kind of endoprobe that can insert various trunk openings such as rectum, vagina, mouth etc., with high-definition picture and the spectral results of obtaining domain of dependence.
Except that above all purposes and advantage, after relevant technologies personnel have read the detailed description part of presents, understand other purpose of the present invention and advantage easilier.Detailed description and accompanying drawing with following combine research as claim, it is more clear that other purpose and advantage will become.
Summary of the invention
Related fields by following generalized all embodiment and invention can realize above-mentioned all purposes and advantage.
Aspect an of preferred embodiment, the invention provides the endoprobe of a kind of MR of being used in system, with image or the spectrogram that obtains domain of dependence in patient's cavity.This probe comprises coil loop and output cable.The coil loop that is designed to receive domain of dependence MR signal has many capacitors, comprises that first and second drives capacitor and tuning capacitor.First and second drives capacitor series in coil loop, forms a virtual earth at its abutment, and coil loop is made electric balance and impedance matching.Two drive capacitor has approaching equivalence.Tuning capacitor is serially connected in the coil loop, is connected with another abutment that drives capacitor, and its value is hanked and made the operation frequency low-resonance of coil loop in the MR system.Output cable is connected to the interface arrangement of endoprobe in succession with coil loop, and the one end connects a driving capacitor that intersects, and the other end has the plug of a connecting interface device.The electrical length of output cable is n (λ/2)+S L, wherein: n is an integer, λ is the wavelength of MR system operation frequency, S LFor augmenting length, its reactance equates with the reactance of a driving capacitor.
In using widely, MR provided by the present invention system comprises MR scanner, endoprobe and interface arrangement.Be designed to insert the intravital endoprobe in patient chamber, comprise rotating shaft, inflatable ball and coil loop, balloon switches through a far-end, and coil loop is fixed on the interior bottom near its front of balloon.The balloon front adapts to profile in the cavity, and the balloon back is used for balloon is positioned in the cavity.During balloon inflation, cavity and its interior another wall of domain of dependence are pushed down in the back, force the balloon front to prop up profile in the cavity, make coil loop near domain of dependence, receive the MR signal to optimize.Coil loop has many capacitors, comprises that first and second drives capacitor and tuning capacitor.First and second drives capacitor series in coil loop, forms the virtual earth of coil loop being made electric balance and impedance matching at its abutment.Two drive capacitor is approximately equivalent.Tuning capacitor is serially connected in the coil loop and is connected with another abutment that drives capacitor, and its value is hanked and made the operation frequency low-resonance of coil loop in the MR system.The MR signal that the MR scanner utilizes coil loop to be received from domain of dependence produces the image or the spectrogram of domain of dependence.The probe interface circuit of interface arrangement is used for endoprobe and MR system are made electric interconnection.The feature of probe interface circuit is that the PIN diode that can only be setovered by the MR system, a coil loop energy thus arranged: (i) in receiving cycle, be coupled with the probe input port of MR system and (ii) in the emission cycle, disconnect with the probe input port.
Aspect another, interface arrangement provided by the present invention can be used for endoprobe is connected with (probe) input port of the MR system of the preamplifier that is not equipped with self in this example.Probe has output cable, is used for its coil loop is connected to interface arrangement.Interface arrangement comprises PIN diode and preamplifier.The MR system PIN diode of setovering makes coil loop (i) in the receiving cycle of MR system, is coupled with connecing the probe input port, and (ii) in the emission cycle of MR system, disconnects with the probe input port.Preamplifier provides gain and impedance matching between the probe input port of PIN diode anode and MR system, the MR signal that coil loop is received can be transferred to the probe input port of MR system with enhanced signal to noise ratio.
Aspect another, the two all links to each other with the MR system interface arrangement provided by the present invention endoprobe and coil system in this example.Endoprobe is characterised in that the output cable that the coil loop of probe is connected to interface arrangement.Interface arrangement allows probe be connected with (probe) input port of the MR system that is furnished with own preamplifier by its output cable.Interface arrangement comprises PIN diode and array interface circuit.The MR system PIN diode of setovering makes coil loop: (i) in the receiving cycle of MR system, be coupled with the probe input port, and (ii) in the emission cycle of MR system, disconnect with the probe input port.The array interface circuit is interconnection coil system and MR system on electric, and it comprises first and second resonance series network, a pair of 1/4 wavelength network and 1/4 wavelength combiner.The first series resonance network is transferred to the first coil input port of MR system to the MR signal from first coil of coil system, and the second string vibrating network is transferred to the MR signal the second coil input port of MR system from second coil of coil system.One of 1/4 wavelength network receives the MR signal from the coil system tertiary coil, and another 1/4 wavelength network receives the signal from the MR of coil system the 4th coil.1/4 wavelength combiner makes up from the received MR signal of a pair of 1/4 wavelength network, and the MR signal of combination is transferred to the tertiary coil input port.
The present invention also provides and has used the preferred approach that the MR system obtains interior domain of dependence image of patient's cavity or spectrogram, and this method comprises the step that endoprobe and output cable are provided.Endoprobe should have (i) Flexible Rotating, (ii) is connected on the inflatable ball of Flexible Rotating end and (iii) is fixed in the balloon near the following coil loop that can receive from the MR signal of domain of dependence in its front.The balloon front adapts to the cavity profile, and the back has a pair of undulate fold layer at least.Coil loop has many capacitors, comprises that first and second drives capacitor and tuning capacitor.First and second drives capacitor series in coil loop, forms the virtual earth of coil loop being made electric balance and impedance matching at its abutment, and two drive capacitor is approximately equivalent.Tuning capacitor is serially connected in the coil loop, is connected with another abutment that drives capacitor, and its value is hanked and made the operation frequency low-resonance of coil in the MR system.This method also comprises the step that an output cable is provided, and be used for coil loop is connected in external circuit, and described endoprobe utilizes this external circuit to be connected in the MR system.Another step is that endoprobe is inserted a certain position in patient's cavity, makes the balloon front be adjacent to domain of dependence.Next step forces the undulate fold layer that the wall of the relative domain of dependence of cavity is launched to balloon inflation, and this just forces the balloon front to touch the cavity profile, and coil loop is fixed near domain of dependence, receives the MR signal to optimize.Follow-up step comprises makes domain of dependence emission MR signal, and detects the MR signal that the domain of dependence internal induction goes out with coil loop.This method comprises that also the therefrom received MR signal of use produces the step of the image and the spectrogram of domain of dependence.
The present invention also provides the preferred approach of the endoprobe making that is used in the MR system, and this endoprobe can obtain the image or the spectrogram of domain of dependence in patient's cavity.The method comprising the steps of: select the size of probe coil ring, make probe be suitable for inserting intracavity, and insert a variable condenser that is serially connected in the coil loop temporarily.This method also comprises step: allow coil loop bear the operation frequency of MR system, and subsequently variable condenser is transferred to the resonance value that resonates with coil loop.On this operation frequency, the capacitive reactance of coil loop will equal the induction reactance of coil loop.Correlation step comprises measures the quality factor of coil loop when loading, and the induction reactance when quality factor that reuse records and coil loop load is determined the series resistance of coil loop.Then, calculate the matching value of matching capacitor, make the output impedance and the used required impedance phase coupling of external circuit of endoprobe interface of probe.This method also comprises step: two driving capacitors with matching value are inserted coil loop in the mode of mutual serial connection, connecting the formation abutment, place that drives capacitor.This abutment can connect the shielded conductor of output cable, and another contact that drives the corresponding point of one of capacitor can connect the center conductor of output cable.Then, the selecting tuning capacitor makes the total capacitance of coil loop equal resonance value, and the reuse tuning capacitor replaces variable condenser.This tuning capacitor is serially connected in the coil loop, is connected with two another contacts that drive the abutment of capacitor.So the abutment forms the virtual earth of electric balance coil ring.
It should be understood that the present invention be not limited to above-mentioned preferred embodiment as and related fields.
Brief description
With reference to following detailed description and accompanying drawing, will understand the present invention and proposition thereof and alternate all preferred embodiments better, wherein:
Fig. 1 is the coil loop and the output cable sketch map of the endoprobe of an aspect of preferred embodiment according to the present invention;
Fig. 2 is that the endoprobe of presentation graphs 1 is in assembling fully and the perspective view that is equipped with state fully;
Fig. 3 is with the endoprobe sectional view of straight line 3-3 intercepting shown in Figure 2, shows distal probe and the inflatable ball that it is connected;
Fig. 4 is the endoprobe partial section with straight line 4-4 shown in Figure 2 intercepting, and its rotating shaft cross section and two tube chambers and anti-the move disk of snap-on in rotating shaft that limit within it are shown;
Fig. 5 is with the sectional view of the endoprobe far-end of straight line 5-5 intercepting shown in Figure 3, its extraluminal balloon is shown, is positioned at coil loop and two tube chamber qualification rotating shafts within it between balloon;
Fig. 6 is the sectional view with the endoprobe far-end of straight line 6-6 intercepting shown in Figure 3, it is shown is positioned at the coil loop that push up the balloon front;
Fig. 7 is the sectional view of endoprobe rotating shaft shown in Figure 2, and the flexible pivot of two qualifications tube chamber within it and its far-end is shown;
Fig. 8 is preferred embodiment interface arrangement sketch map on the other hand according to the present invention, in its single-receiver pattern, interface arrangement has the probe interface circuit, is used for the endoprobe of Fig. 1-7 (probe) input port with the MR system that is not equipped with self preamplifier is connected;
Fig. 9 is the interface arrangement sketch map of the another aspect of preferred embodiment according to the present invention, in its multi-receiver pattern, interface arrangement have (i) be connected the endoprobe of Fig. 1-7 with (probe) input port of the MR system that is furnished with self preamplifier probe interface circuit and (ii) the phased-array coil system such as
Figure G038144867D00091
The array interface circuit that the trunk array is connected with (coil) input port of MR system;
Figure 10 is the interface arrangement perspective view of single-receiver pattern shown in Figure 8, is designed to endoprobe is connected by its (probe) input port with the MR system that is not equipped with preamplifier;
Figure 11 is the interface arrangement perspective view of multi-receiver pattern shown in Figure 9, be designed to endoprobe and phased array coil system such as The trunk array is connected with the phased array mouth of MR system;
Figure 12 is the coil loop of the endoprobe of first alternate embodiment according to the present invention and output cable and the interface arrangement sketch map of corresponding decoupling diode with it;
Figure 13 is the coil loop of the endoprobe of second alternate embodiment according to the present invention and output cable and the interface arrangement sketch map of corresponding decoupling diode with it; With
Figure 14 is the coil loop of endoprobe of the present invention's the 3rd alternate embodiment and output cable and the interface arrangement sketch map of corresponding decoupling diode with it.
The detailed description of invention
In all embodiment and the parties concerned, below disclosed the present invention can be used in MR system ideally with 3.0 tesla field intensity work, although also be applicable to the MR system that can work in 2.0～5.0T.For ease of explanation, the present invention discusses with the content of the 3.0T system that General Electric Medical Systems (GEMS) company produces.
Fig. 1-7 illustrates an aspect of preferred embodiment of the present invention, promptly is often referred to be decided to be 1 endoprobe.This probe is used in the MR system, with the image or the spectrogram of domain of dependence in the cavity that obtains disease.Here describe an implementation-specific and excute a law, promptly interior transrectal probe is designed to insert rectum and obtains male prostate image and/or spectrogram.Though show interior transrectal probe here, it should be understood that the present invention can be suitable for obtaining image and/or spectrogram by other approaching domain of dependence such as endoprobe by mouth, vagina or other opening equally.Here the principle that is proposed also can be applicable to MR imaging or spectral technique, is fit to tremulous pulse, vein and other structure of human body.Which kind of occasion no matter, all will pack the receiving coil in the endoprobe into or allocate into be designed to meet in the packaging part of target formation.
Shown in Figure 1 up-to-date aspect in, endoprobe 1 comprises coil loop 2 and output cable 3.Coil loop 2 the most handy flexible conducting materials are made, and are preferably the single-turn circular coil that can pick up radio frequency (RF) signal.The coil loop 2 that is designed to receive from the magnetic resonance RF signal of domain of dependence has many capacitors, comprises that first and second drives capacitor 21 and 23 and tuning capacitor 24, and first and second drives capacitor and is connected in series in coil loop 2.As described below, connect the abutment 22 that drives capacitor 21 and 23, form the virtual earth of coil loop 2 being made electric balance and impedance matching.Tuning capacitor 24 also is serially connected in the coil loop 2, but another contact relative with capacitor 21 and 23 abutment 22 is connected.Tuning capacitor 24 is hanked and is made the operation frequency low-resonance of coil loop 2 in the MR system, and for the 3.0Telsa scanner, its vibration frequency is about 128MHz.
Output cable 3 is designed to coil loop 2 is being connected the interface arrangement of endoprobe 1.This interface arrangement such as following any, its other end is connecting the probe input port of MR system 10, shown in Fig. 8 and 9.The output cable 3 that wraps in the insulation crust has shielded conductor 31 and the center conductor 32 that insulation sets within it, and the former is connecting abutment 22, and the latter is connecting and drives connect another node of chalaza 22 of one of capacitor 21 and 23, as shown in Figure 1.In addition, for following reason, the electrical length of output cable 3 is preferably n (λ/2)+S L, wherein n is an integer, λ is the wavelength of the operation frequency of MR system 10, S LFor augmenting length.
Fig. 2 illustrates the endoprobe 1 that the present invention assembles form entirely, and Fig. 3-7 illustrates its each several part sectional view.Endoprobe 1 comprises Flexible Rotating 40 and extraluminal balloon 50 and 60.Rotating shaft 40 has a far-end, and its pivot 41 is preferably much flexible than the rotating shaft remainder, in fact with axle remainder bonding mutually, as shown in the reference numeral 15.Use this flexible pivot 41, not only reduced patient's discomfort, also reduced near the probability of tissue wearing out when probe uses.
Interior balloon 50 is connecting the far-end of rotating shaft 40 and is sealing its pivot 41, preferably as shown in Figure 3.Interior balloon 50 is generally cylindrical, but its front 51 is essentially smooth section, it be fixed in rotating shaft 40 with anchor clamps 16 and utilize blockage and rotating shaft 40 far-ends adaptive.Use above coil loop 2 preferably is encapsulated in itself in the 5K volt insulator that shrinks involucrum or similar tubing, thereby double hyer insulation is provided.The front 51 of balloon 50 is fixed on coil loop 2 between extraluminal balloon 50 and 60 in the best non-telescopic material of being made up of sticky cloth 55 coil loop 2 being connected to then.
Another balloon 60 also switches through the far-end of axle 40, encapsulated coil ring 2 and interior balloon 50, and available anchor clamps 17 are fixed in rotating shaft 40 and adaptive by blockage and far-end to it.Outer balloon 60 has front-back 61 and 62.Front 61 is preferably the shape of a saddle, touch the inner face/profile of cavity respective shapes, under the situation of prostate probe, will be the rectum prostate projection below the ampulla of rectum.Next 62 characteristics are to have at least a pair of undulate fold layer 63 that therefrom stretches out.As described below, when interior balloon 50 was inflated, these plicated layers 63 can make outer balloon 60 that coil loop 2 correctly is positioned adjacent to patient's rectum prostate projection when operating, and this has just optimized the coupling between coil loop 2 and target formation.In addition, as shown in Figure 5, preferably balloon 60 interior front-back 61 and 62 centres are provided with transverse concave grooves 64 outside, and these grooves formed the shelf of positioned coil ring 2 sides thereon at 1 o'clock at the assembling probe, when balloon 50 and 60 is not inflated coil loop were not positioned between these surfaces.Balloon 50 and 60 is preferably made of medical grade rubber or other suitable elastic materials separately, and this class material is non-paramagnetism certainly, and dielectric loss is very little.
Flexible Rotating 40 limits two tube chambers 42 and 44, shown in Fig. 3,4,5 and 7.In its cylindrical wall near far-end, rotating shaft 40 also defines the hole 43 with tube chamber 42 UNICOMs, as shown in Figure 7.Tube chamber 42 with hole 43 as passage, balloon 50 in when charging and discharging gas, respectively air or other gas being pumped into and discharges.Far away again from far-end, rotating shaft 40 limits another hole 45 in its cylindrical wall, and tube chamber 44 is drawn the pipeline that passes through with hole 45 as output cable 3 from coil loop 2.As shown in Figure 2, output cable 3 joins endoprobe 1 at the plug 35 of its near-end with relevant interface arrangement.
Endoprobe 1 also comprises anti-move disk 46, conductor 48 and handle 49.Handle 49 is fixed in the near-end of rotating shaft 40, when its far-end is inserted in rectum and the cavity correctly on time together with outer balloon 60 fixed thereon, makes probe 1 be convenient to handle, and is as described below.Conductor 48 is also referred to as expansion member, is designed to be convenient to slide in the overall length of rotating shaft 40.Preferably with the bucket-shaped conductor 48 manual expansion anal sphincters of drain electrode, so that outer balloon 60 is located in cavity.Without conductor 48, then anal sphincter can tighten up rotating shaft 40, hinders endoprobe 1 to make rotation and longitudinal register in cavity.The anti-disk 46 that moves by semirigid plastic or other suitable polymers constitute is preferably hemispherical.Shown in Fig. 2 and 4, disk 46 defines groove 47, and this groove makes disk 46 snap-ons to rotating shaft 40.When the anti-disk 46 that moves when probe inserts the rectum postadhesion in the rotating shaft 40 of contiguous anal sphincter, can prevent to pop one's head in 1 occurs obviously moving because of the normal creeping effect of colon.
Endoprobe 1 also comprises the device of balloon 50 inflations in the control, is preferably the form of compressive charge ring set 70, pipe 71 and pipe close 72.The syringe that the ring set useful size is suitable replaces, and pipe 71 is received the tube chamber 42 of rotating shaft 40 near-ends inflating ring set 70 or syringe, and pipe close 72 is connected in series with pipe 71 and is used to control air and pumps into or emit interior balloon 50.Another feature of probe 1 is the scale 14 that is imprinted on rotating shaft 40 outer surfaces, and this scale not only indicates rotating shaft 40 to insert the distance of cavity, but also turning to of indicating remote makes the shape of a saddle front 61 of outer balloon 60 aim at prostate.
During operation, the far-end per rectum of endoprobe 1 inserts cavity, and interior balloon 50 and ring are wrapping its outer balloon 60 and all be in and do not inflate attitude.Far-end one inserts, and just keeps the anal sphincter expansion with conductor 48, and the far-end that rotating shaft 40 and balloon thereof are sealed is convenient to operate in cavity.Far-end insert and conductor 48 in place after, the scale 14 in the rotating shaft 40 is just as guide rail, makes the doctor can be more accurately rotate in will near the cavity of probe domain of dependence and longitudinally locate.The in a single day correct location of endoprobe 1, conductor 48 just can be pulled out downwards along rotating shaft, allows sphincter tighten up rotating shaft 40, and this helps to keep endoprobe 1 in place.Move disk 46 snap-ons near the rotating shaft the sphincter 40 anti-then, guarantee that endoprobe 1 keeps original position when MR scans.
Before the balloon inflation, pipe close 72 must switch to open mode.By the pump fortune inflation collar 70, the tube chamber 42 of interior balloon in pipe 71, pipe close 72 and rotating shaft 40 and hole 43 inflations.During interior balloon inflation, the inflation of balloon in the non-telescopic material 55 of balloon 50 fronts 51 was also assembled in the back in coil loop 2 was fastened to charges into gas on the undulate fold layer 63 of outer balloon 60.During undulate fold layer 63 inflation, force the back 62 (being plicated layer 63) of outer balloon 60 to touch the wall of the relative domain of dependence of cavity immediately.When interior balloon 50 continues inflation, the bottom of the outer balloon of expansive force guiding 60 fronts 61.So the front 51 that interior balloon 50 connects coil loop 2 forces outer balloon 60 saddle-shaped fronts 61 to touch the in-profile of cavity respective shapes, that is, and the prostate region of rectum.In case the balloon of far-end is inflated entirely, coil loop 2 is accepted the MR signal just near prostate so that can optimize when MR scans.Then pipe close 72 is switched to make position, allow the doctor disconnect and inflate the collar 70 and do not make balloon 50 and 60 venting.Then, endoprobe 1 is connecting relevant interface arrangement through the plug 35 of output cable 3.
During the end of scan, whether the doctor allows extraluminal balloon 50 and 60 venting no matter prevent moving disk 46 and takes out from rotating shaft 40 as long as pipe close 72 is switched to open position, as long as draw endoprobe 1 handle 49, just can take out the far-end that balloon is sealed from rectum.
Perhaps, endoprobe 1 can replace above-mentioned two balloons with single balloon, and balloon is made of monolayer medical grade rubber or other suitable elastic materials.In this structure, balloon is still received the far-end of Flexible Rotating 40, and balloon is preferable has the front and back, and is analogous to the structure that two balloon-type can be discussed.Yet coil loop 2 is preferably bonding or be fastened to the bottom of balloon front 61.When making balloon, coil loop 2 also can be encapsulated in the front 61, for example earlier coil loop 2 is placed balloon surface, then balloon is sunk, and places another layer material on its outer surface, thereby covers coil loop 2 and form above-mentioned front 61.But when inflatable ball is inserted the cavity inflation, the undulate fold layer 63 of making will be pushed down the wall of the relative domain of dependence of cavity.In case when balloon is sufficient, just forces its front 61 to touch the in-profile that cavity equates formation, thereby make coil loop 2 be close to domain of dependence (being prostate), from receiving the MR signal best here.
The present invention also provides preferable endoprobe 1 method for designing.The masterful technique personage has read this document will make the contemplated various variations of the present invention become apparent.This preferred approach first step is to select the conductor loop size on the basis of formation coil loop 2.Be used for the endoprobe to the prostate imaging, the size of conductor loop can make distal probe have two balloons of coil loop 2 can insert rectum, patient's discomfort minimum in the middle of comprising.Next step is interim plug in variable condenser in conductor loop, makes ring stand the operation frequency of MR system again.The present invention is particularly suitable for the scanner of 3.0 teslas, and its operation frequency approaches 128MHz, for GEMS3.0T's
Figure G038144867D00131
Scanner, operation frequency in fact more approach 127.74MHz, and for the Siemens3.0T scanner, operation frequency approaches 123.2MHz.
When conductor loop bears the RF energy under specified operation frequency, variable condenser is transferred to the value that conductor loop resonates, calls C in the following text RVIn case resonance, the capacitive reactance at this operation frequency lower wire ring is to equate with induction reactance certainly.For following calculating,, in conductor loop, set up the desirable C of resonance according to this preferable endoprobe 1 design method RVValue is 10pF.
C RVAfter the foundation, can work at ring and measure its factor of merit under the loading environment.The known technology that some kinds of measurement factors of merit are arranged, a kind of technology is made S with two test probes and Network Analyzer 21Response measurement, two test probes connect the port one and 2 of Network Analyzer respectively.Use two test probes to be positioned to mutual rectangular ring, conductor loop of the present invention is placed therebetween, this structure allows to go out to be added at the conductor loop internal induction RF energy of the first test probe ring, goes out the RF signal at the second test probe ring internal induction successively.Then.Two test probes pass to Network Analyzer with RF signal separately, and the latter's the amplitude and the graph of a relation of frequency illustrate the frequency response curve that obtains.Utilize shown signal, the mid frequency by finding out frequency response curve and with it divided by three dB bandwidth (that is, the frequency band between high go side of curve and low go side 3dB (half-power) point), just can determine factor of merit.To 3.0 tesla scanneies, the factor of merit of ring is 10～20.More typical is that under loading environment, the factor of merit of ring is generally:
Q loads=15 (measured values)
Next step is the series resistance Rs that measures ring for this method.This series resistance representative ring is because of appearing at the equivalent resistance loss that presents in patient's cavity, thereby Rs is not a physical component, the just effect of patient to encircling, and it leads to part dissipation energy in coil loop 2 and has reduced the quality of coil loop.It can be calculated as:
Rs＝X L/Q
Q is the factor of merit of measuring above in the formula, X LInduction reactance when being the conductor loop loading.As mentioned above, the capacitive reactance of ring equates when resonating with induction reactance:
X L＝X P
X L=2 π fL CoILAnd X P=1/ (2 π fC RV)
In the formula: f is the operation frequency of MR system 10, thereby the induction reactance X of ring LBe calculated as:
X L＝1/(2πfC RV)＝1/(2π×128×106×10×10 -12)＝124.34Ω.
Therefore, the series resistance of ring is:
R S=X L/ Q Load=124.34 Ω/15=8.29 Ω
This method also requires to make the output impedance and the used required impedance phase coupling of external circuit of endoprobe interface of endoprobe 1.External circuit can be got the form of one of interface arrangement of announcement here, and generally requiring impedance is 50 Ω.Therefore, this step of this method comprises design-impedance matching network, and the required impedance Rp of external circuit and the series resistance Rs of ring are complementary.In this impedance matching network, the quality of matching network connection in series-parallel branch road is identical, is expressed as Qp=Rp/Xp and Qs=Xs/Rs.Therefore, Rs is relevant by following formula with Rp:
R P＝(Q 2+1)R S
In the formula: Rp is also referred to as equivalent parallel resistance.The quality of supposing matching network connection in series-parallel branch road is the same, and then the quality of matching network is called:
Q＝Q S，P＝(R P/R S-1) 1/2＝(50Ω/8.29Ω-1) 1/2＝2.24.
So, calculate the parallel reactance Xp relevant by following formula with Rp in the impedance matching network:
X P＝R P/Q＝50Ω/2.24＝22.32Ω.
Determine the value of matching capacitor again according to parallel reactance:
C P＝1/(2πfX P)＝1/(2π×128×10 6×22.32)＝55.7pF
Another step is that two capacitors that will have matching value in series insert conductor loop mutually.This is two driving capacitor C D1With C D2, be denoted as 21 and 23 among Fig. 1.Utilization is above calculates, and the total virtual value that drives capacitor 21 and 23 is 27.85Pf.The formation abutment 22, position that connects and drive capacitor 21 and 23.The shielded conductor 31 of output cable 3 is connecting abutment 22, and center conductor 32 is connecting the opposite side node that drives capacitor 21 or 23.Thereby, drive the value C of capacitor 21 according to above calculating D1Can make coil loop 2 docking port devices or other external circuit be rendered as the source of 50 Ω, the coaxial cable of such 50 Ω is used as output cable 3.
Next step is selecting tuning capacitor C TUN, make the conductor loop total capacitance equal resonance value C RVCan determine conductor loop total capacitance C by following formula RV:
1/C RV＝1/C TUN+1/C D1+1/C D2.＝1/C TUN+2/C D
In the formula: C D=C D1=C D2, then, calculate tuning capacitor value C with following formula TUN:
C TUN＝(C RV*C D)/(C D-2C RV)
＝(10×10 -12F×55.7×10 -12F)/(55.7×10 -12F-2×10×10 -12F)
＝15.6pF
Then, from conductor loop, remove variable condenser, change tuning capacitor C TUNBe designated as C among Fig. 1 T Tuning capacitor 24 be serially connected in the opposite side at abutment 22 in the conductor loop, thereby abutment 22 constitutes the virtual earth of electric balance coil ring because electric field is actually zero, each voltage drop that drives the capacitor two ends equates but opposite in sign.This structure produces in MR system 10 receiving cycles and is symmetric electric field with respect to patient, making 2 pairs of these magnetic fields of coil loop rather than electric field is that the component of MR signal of domain of dependence emission is especially responsive, thereby coil loop 2 receives the MR signal with the signal to noise ratio bigger than the prior art probe.And safety is also bigger, because the voltage of coil loop internal induction half when to be coil loop fully uneven.
Owing to operation frequency height (is 128MHz as the 3.0T MR system) Q-value of working of coil loop 2 extremely low (promptly 10～20), needn't or press coil tuning coil loop 2 by patient, this and United States Patent (USP) 5,476,095 and 5,355,08) the probe difference that discloses.According to above calculating, comprise the factor of merit of loading coil ring, the bandwidth of coil loop 2 is nominally ± 4.25MHz.Therefore, suppose coil loop ± 2% element body plan, the tuning deviation between each probe is to the maximum ± 1.85MHz, and this is far smaller than the 3dB broadband of coil loop, even does not have the influence of following low input impedance preamplifier.Tuningly in fact be fixed, and do not need to take into account material, because of the Q-value of coil loop 2 very low under loading environment.
The electrical length of output cable 3 is preferably n (λ/2)+S L, wherein n is an integer, λ is the wavelength of MR system 10 operation frequencies, S LFor augmenting length.As shown in Figure 1, the total length of output cable 3 extends to its plug 35 from coil loop 2, and on behalf of output cable, plug 35 connect the point of PIN diode 33, and diode 33 is also referred to as the decoupling diode of interface arrangement or other external circuit.N (λ/2) part draws long for half part of operative wavelength, in fact is rendered as zero electrical length.The n value need only be 1 usually, because the in fact always very close circuit that will connect of coil loop 2.S LRepresent the extention of output cable 3, its induction reactance preferably equals the capacitive reactance at first capacitor 21 of the terminal of its two terminations cable 3.Its net effect is that the overall length of output cable 3 presents the induction reactance that equates with the capacitive reactance of first capacitor 21.
Thereby, augment length S LItself can be used as inducer, calls L in the following text D, it affects the work of endoprobe 1.In the MR system in 10 emission cycles, the MR system is with 200mA current forward biases PIN diode 33, and the coil loop 2 of endoprobe 1 is withdrawed from MR system (as seeing Fig. 8), in fact short circuit PIN diode 33, make the natural inductance device L of output cable 3 DWith first to drive capacitor 21 be C D1Become tank circuit.The high impedance of this tank circuit is similar to and opens circuit, and has in fact disconnected coil loop 2, thereby makes endoprobe 1 withdraw from the probe input port of main MR system 10.Otherwise in receiving cycle, the MR system makes endoprobe 1 couple the MR system with-5 volts of DC reverse bias decoupling diodes 33, in fact allows output cable 3 as 50 Ω transmission lines rather than inducer L DThereby coil loop 2 utilizes the resonance induced RF pulse of body coil (or other the external coil) emission of MR system 10 to detect the MR signal that produces in the domain of dependence.The MR signal is passed to interface arrangement through the conductor of cable 3 again.
Drive capacitor C D1With C D2Value be generally 62～82pF, similarly, tuning capacitor 24 is C TUNBe preferably 12～15pF.C D1Use the value of this scope lower end, can in the emission cycle, realize preferable decoupling (open-circuit impedance is higher).Drive capacitor 21 this lower values and also increased coil loop 2 is presented to interface arrangement in receiving cycle source impedance.In addition, S LLength depends on the certain coil ring that uses in the endoprobe 1 accurately.The slight coil loop that loads during for use, such as the driving capacitor of use 120pF, S like this LWill be shorter.Otherwise,, may use the driving capacitor of 40pF, then S to the coil loop that reloads LCan be longer.
Above-mentioned endoprobe 1 especially is fit to be used in the 3.0TMS system that GEMS generates pops one's head in as interior rectum coil, also can be used for other occasion certainly.
Fig. 8 and 9 illustrates two aspects in addition of this embodiment of the invention, and the two all is designed so that the MR system interface of endoprobe 1 and GEMS.In its first aspect, interface arrangement links to each other endoprobe with a receiver of MR system, so be called the single-receiver type.In its second aspect, interface arrangement all links to each other endoprobe 1 with external coil with the MR system that uses many receivers, be called the multi-receiver type.As everyone knows, typical GEMS
Figure G038144867D00161
The characteristics of system are that four receivers and eight input ports are arranged, and receiver 0 is connecting port one or 5, and receiver 1 is connecting port 2 or 6, and receiver 2 is connecting port 3 or 7, and receiver 3 is connecting port 4 or 8.In standard configuration, except connecting port one and 8, each input port of GEMS MR system all has a preamplifier.
Fig. 8 and 10 illustrates the interface arrangement of its single-receiver type, generally is designated as 100.Interface arrangement 100 is designed to by output cable 3 endoprobe 1 is interconnected to the port one of the master control MR system 10 that is not equipped with self preamplifier with its adapter 102, so interface arrangement 100 comprises PIN diode 33 and preamplifier 101.PIN diode 33 is connected across the input socket 103 that the inside is inserted with the interface arrangement 100 of output cable 3 plugs 35, this design alternative allows PIN diode 33 physically away from endoprobe 1, but make it probe 1 is processed fall after still reuse make the parts of interface arrangement.Preamplifier comprises GASFEA110 and the string input circuit 130 that shakes, and the latter comprises input capacitor Cp and input inductor Lp, is also connecting the grid of GASFET110 at its abutment.The source electrode of GASFET110 connects bias resistor R B, drain coupled capacitor Cc and RF choke coil RFC 2According to known circuit design principle, resistor R BHank and make the electric current that flows through GASFET110 produce suitable gain and low noise figure.RFC 2Allow the feed drain electrode of GASFET110 of DC electricity, MR RF signal that needn't 101 outputs of short circuit preamplifier in MR system 10 receiving cycles.Preferably block undesirable cable current at capacitor Cc opposite side with cable snare 115.
When interface arrangement 100 when probe cable 150 is connected the MR system with adapter 102, drain electrode connects the port one of MR systems 10 by coupling capacitor Cc and cable snare 115, RF choke coil RFC is also passed through in drain electrode 2The DC power supply that connects MR system 10.Bypass capacitor C B2Be connected between this RF choke coil and the ground, any non-DC component ground connection.Interface arrangement 100 also comprises bypass capacitor C B1With RF choke coil RFC 1, the former be connected on and MR system 10 can be setovered between the bias line 121 of PIN diode 33, make any non-DC component leave bias line and decoupling diode 33.RFC 1Be connected the anode and the bypass capacitor C of PIN diode 33 B1Between, the RF frequency is presented high impedance and the flowing of not obvious restriction bias current.Interface arrangement 100 also comprises preamplifier protection diode Dpp and bypass capacitor C B3, the former is at the emission period protection preamplifier 101 of MR system, and the latter is connected between the anode and ground of diode Dpp.RFC 3Prevent to flow into MR system 10, allow bias current on bias line 121, flow from any RF electric current of preamplifier 101.
MR system 10 passes through bias line 121 forward bias diode D in the emission cycle DWith Dpp.As mentioned above, PIN diode D DBe positioned at the two ends that device 100 is inserted with the adapter 103 of output cable 3 plugs 35, make endoprobe 1 decoupling.Simultaneously, preamplifier protection diode Dpp is the grid of short circuit GASFET 110 effectively, prevents that the RF pulse signal of launching from damaging preamplifier 101.At receiving cycle, MR system 10 anti-these diodes partially make them disconnect effectively.When coil loop 2 was operated under loading environment, string the 130 couples of GASFET 110 of circuit that shake provided the optimization impedance.The string circuit 130 that shakes couples the grid of GASFET 110, provide lower input impedance to preamplifier 101, widened the Frequency Response of coil loop 2, thereby remedied fixed tuning scheme, with United States Patent (USP) 5,476,095 and 5,355,087 probes that disclose are compared, coil loop 2 tuning much looser.More particularly, as 50 Ω inputs, the string circuit 130 that shakes will provide high impedance (～1000～2000 Ω) to GASFET110, and coil loop 2 is presented utmost point Low ESR (～1～5 Ω) coil loop 2.Make coil loop 2 decoupling to some extent so effectively, widened its Frequency Response and do not sacrifice signal to noise ratio.Therefore, preamplifier 101 provides gain and impedance matching together with its string input circuit 130 that shakes between the anode of decoupling diode 33 and port one, and the MR signal that coil loop 2 is detected is transferred to the port one of MR system with enhanced signal to noise ratio.
Interface arrangement 100 preferably also is furnished with circuit 160, when endoprobe 1 is provided with the connecting interface device, can prevent 10 scannings of MR system.This circuit 160 can make the drives fail in the MR system 10 when disconnecting probe, prevent its scanning.Also available audio alert or display 161 are pointed out this fault by it to the medical worker as the part of circuit 160.
Fig. 9 and 11 illustrates the interface arrangement of its multi-receiver type, is designated as 200.Interface arrangement 200 be designed to its adapter 202 not only endoprobe 1 but also with phased-array coil system 80 together with GEMS3.0T
Figure G038144867D00181
The phased array port of MD system links to each other.This phased array port generally has four ports (as port 2,4,5 and 7), can both enter by single adapter.Prior art The trunk array is a kind of such phased-array coil system 80, and itself can insert the phased array port by its single adapter 81.If
Figure G038144867D00183
The trunk array is as coil system 80, and then the coil part P1 of Fig. 9 and P2 are two surface coils in the preceding backing plate 82, and coil part P1 and P2 are two surface coils in the backing plate 83 of back.Two backing plates each have two coil parts, and its lead-in wire is guided to single adapter 81 by two cables 84,85. Trunk array 80 utilizes the phased array port of adapter 81 insertion master control MR systems, its four coil parts and four systems port interconnection just.But interface arrangement 200 and endoprobe 1 He During trunk array adapted, will link to each other five coil parts (being coil loop 2 and coil part A1, A2, P1 and P2) with four receiver phased array ports of MR system 10.Interface arrangement 200 combines the trunk array of four coils and the interior rectum coil 1 that only receives only, with phased array imaging pelvis area high-resolution ground imaging prostate.
Interface arrangement comprises probe interface circuit 210 and array interface circuit 240, and the former comprises PIN diode 33 and cable snare 211,200 li input sockets 203 that are inserted with the plug 35 of output cable 3 of PIN diode 33 crossover assemblies.Probe cable 213 also claims circuit length 213, is used for first port (being port 7) of decoupling diode 33 and coil loop 2 with MR system 10 by its endoprobe 1 is connected.Cable snare 211 prevents that undesirable electric current from flowing on the shielded conductor of probe cable.As shown in Figure 9, the electrical length of circuit length 213 is preferably n (λ/2), and wherein n is an integer, and λ is the wavelength of MR system operation frequency, and this makes circuit length 213 be actually zero electrical length.
Array interface circuit 240 is phased-array coil system 80 and MR system 10 electric interconnections, and it comprises first and second string battle array network 242 and 252, two 1/4 wavelength networks 261 and 261 and 1/4 wavelength combiner 271.Suppose that coil system 80 gets The trunk array format, string vibrating network 242 just is transferred to the MR signal second port (being port 4) of MR system 10 from the coil part A1 of front.Similarly, another string vibrating network 252 is transferred to the 3rd port (being port 2) with the MR signal from the coil part A2 of front.As shown in Figure 9, the MR signal that one 1/4 wavelength network 261 receives from rear wires coil element P1, the MR signal that another 1/4 wavelength network 262 receives from rear wires coil element P2.Preferably 1/4 wavelength combiner 271 of Wilkinsou type is connected on the outfan of 1/4 wavelength network 261 and 262, and its combined reception is transferred to the MR signal that draws the 4th port (being port 5) of MR system 10 from the MR signal of these two networks.
The first string vibrating 242 comprises capacitor C R1With RF choke coil RFC 5, similarly, the second string vibrating 252 comprises capacitor C R2With RF choke coil RFC 6, C R1With C R2Value hank and each capacitor transferred remove inherent inductance in its individual circuits path.Like this, first and second network 242 and 252 is gone here and there under MR system 10 operation frequencies and is shaken and (is that length is to work in n (λ/2) time, n=0), makes the work on electric of coil system 80 and MR system 10 as network 240 and 252 is not had length.In addition, RF choke coil RFC 5Be set to and capacitor C R1Parallel connection is as choke coil RFC 6With capacitor C R2In parallel the same, because along the circuit pathways of string vibrating 242 and 252, MR system 10 is transferred to offset signal for the coil part A1 of front and A2 the decoupling diode of coil system 80.Choke coil RFC 5With RFC 6Allow these offset signals be transferred to these decoupling diodes from port 4 and 2.
For another shown in Figure 9, circuit pathways to the length of port 5, it is desirable to half (being n λ/2) of operative wavelength from the input (by net 261 and combiner 271) of coil part P1.Extend to the circuit pathways of port 5 from the input of coil part P2, length is the same.Therefore, in fact these circuit pathways are rendered as zero electrical length, make their inputs separately of advantageous effect reflected back of the anti-preamplifier of port 5 medium or low resistances.In addition, MR system 10 is transferred to the decoupling diode to offset signal for the coil part P1 of back and P2.RF choke coil and interlock circuit in combiner 271 and the net 261 allow offset signal to be transferred to the decoupling diode of coil part P2 from port 5.RF choke coil RFC 7Allow offset signal to be transferred to the decoupling diode of coil part P1 from port 8 with interlock circuit.The offset signal of coil part P1 is derived from port 8, and is irrelevant with the offset signal of coil part P2.
In the emission cycle, MR system 10 utilizes the preferably decoupling voltage forward bias decoupling diode D of superposition on cable signal line 213 D, thereby be inserted with the PIN diode D of the adapter 203 of output cable 3 plugs 35 in cross-over connection and the device 200 DTo make endoprobe 1 decoupling, as mentioned above.MR system 10 goes back the decoupling diode of four coil part A1, A2, P1 and P2 in the while forward bias coil system 80, make these decoupling diode short circuits, form the tank circuit of high impedance thus, four coil parts of coil system 80 are opened circuit.Like this, master control MR system 10 will make endoprobe 1 and trunk array 80 all withdraw from the phased array port of MR system.Otherwise, at receiving cycle, the PIN diode D of MR system 10 reverse bias probe 1 DDecoupling diode with coil system 80, in fact they are disconnected, so just endoprobe 1 and trunk array 80 are coupled the phased array port, make coil loop 2 and coil part A1, A2, P1 and P2 in response to the induced RF pulse of resonance, detect its MR signal of domain of dependence (as prostate and abdominal part, chest and pelvis area on every side) emission separately.Then, with said method this MR signal is transmitted by interface arrangement 200, and pass to the phased array port of master control MR system 10 through adapter 202.
Interface arrangement 200 preferably also is furnished with circuit 280, prevents that the MR system from scanning when endoprobe 1 is provided with the connecting interface device.Sort circuit 280 comprises that also the connection the inside is inserted with the probe detection line of the socket 203 of endoprobe 1 plug 35.When popping one's head in 1 connecting interface device 200 (plug 35 inserts socket 203), the probe detection line so circuit 280 detects this ground, is transferred to port one to relevant signal with regard to ground connection, makes the MR system begin scanning.If endoprobe is provided with the connecting interface device, then circuit 280 detects opening circuit of causing, and makes answer by changing the port one state, in case the MR system scan.Also available audio alert or display 281 are pointed out this fault by it to the doctor as the part of circuit 280.Certainly, the present invention also dreams up other various judgements method of connection interface device of whether popping one's head in.
Figure 12 illustrates the endoprobe and the corresponding with it relative section of interface arrangement of the present invention's first alternate embodiment.Particularly, Figure 12 does not show and is connecting interface arrangement decoupling diode D by output cable 3a DCoil loop 2a.Output cable 3a imbalance, its shielded conductor 31a is connecting abutment 22a, and center conductor 32a connects and drives capacitor C D1The node of opposite side.But unlike aforesaid embodiment, the electrical length of output cable 3a only is n (λ/2), because augment length S LFit in the interface arrangement.As shown in figure 12, for example its implementation is to guarantee to make the input socket to decoupling diode D DElectric length equal S LWhen the output cable 3a of probe inserted interface arrangement, coil loop 2a was to PIN diode D DTotal electrical length equal n (λ/2)+S LThough should example S LPlace interface arrangement rather than output cable 3a, but, still can make endoprobe and corresponding interface device thereof with the same method work of preferred embodiment of the present invention in emission and two cycles of reception of MR system.
Figure 13 illustrates the endoprobe and the corresponding with it relative section of interface arrangement of the present invention's second alternate embodiment.Specifically, Figure 13 illustrates by balanced type output cable 3b and is connected to interface arrangement decoupling diode D D1With D D2Coil loop 2b.At output cable 3b one end, first and second center conductor 32b and 34b connect respectively and drive capacitor C D1With C D2The node of opposite side.When inserting the input socket of the corresponding interface device, output cable 3b is electrically connected diode D respectively at first and second center conductor 32b and the 34b of its near-end D1With D D2Anode, the minus earth of its shielded conductor 31b and two decoupling diodes.Different with aforesaid embodiment, the electrical length of output cable 3b only is n (λ/2), because of S LStill fit in the interface arrangement.So use balanced type output cable 3b, the uneven formula output cable 3a that comparable first alternate embodiment is used is decoupling (drive the capacitor two ends is 2 * 1500 Ω as each) better.
Figure 14 illustrates the endoprobe and the corresponding with it relative section of interface arrangement of the present invention's the 3rd alternate embodiment.The coil loop 2c of probe is by the decoupling diode D of balanced type output cable 3c connecting interface device DDifferent with aforesaid embodiment, coil loop 2c only uses a driving capacitor C DBody plan, tuning capacitor C TBe positioned at the intra-annular opposite side of lead.Drive capacitor C DWith tuning capacitor C TValue generally press preceding method and calculate, make coil loop 2c not only the docking port device be rendered as 50 Ω sources, and at the operation frequency low-resonance of MR system.At output cable 3c one end, first and second center conductor 32c and 34c cross-over connection drive capacitor C DTwo ends.When inserting the input socket of interface arrangement, output cable 3c is electrically connected decoupling diode D respectively at first and second conductor 32c and the 34c of its near-end DAnode and negative electrode, its shielded conductor 31c and interface arrangement ground connection.Different with aforesaid embodiment, the electrical length of output cable 3c has only n (λ/2), because S LStill fit in the interface arrangement.
The technical staff in nuclear magnetic resonance and spectrum field should understand, the endoprobe of above-mentioned arbitrary embodiment can constitute with lining up two of the phased array structure or more coil loop.In addition, in the single intra-cavity probe two or more coil loop are directed jointly, so that quadrature covers domain of dependence.The output cable of this endoprobe must correspondingly be revised, so that coil loop correctly is connected to interface arrangement.
Proposed to implement preferable and alternate all embodiment at present of the present invention in detail by Patent Law, those skilled in the art in the invention know other various enforcements approach of the present invention and without prejudice to following spirit as claim.Therefore, drop on as claim implication and all changes and modification in the equal scope and be included in its scope.The technical staff also will understand, the scope of the invention is indicated as claim rather than aforementioned arbitrary instantiation or embodiment by following.
Therefore, be to promote development in science and technology, we comprise that in the time of patent statute all are following as content that claim comprised with the patent rights of " letters patent ".

Claims (64)

1. a magnetic resonance (MR) system is characterized in that, comprising:
(a) can be inserted in the intravital endoprobe in patient chamber, described endoprobe has (i) rotating shaft, the inflatable ball that is (ii) connecting described rotating shaft one end, (iii) be fixed in the described inflatable ball coil loop near its front bottom, the described front of described inflatable ball is fit to the profile of described cavity, its back is used for described inflatable ball is positioned in the described cavity, when described inflatable ball is inflated, described cavity is pushed down usually with respect to the wall of domain of dependence in the described cavity in described back, force the described front of described inflatable ball to touch the profile of described cavity, make described coil loop near described domain of dependence, therefrom optimize and receive the MR signal, described coil loop has many capacitors, comprising:
(A) approximately equivalent is serially connected in described coil intra-annular first and second and drives capacitor, forms the virtual earth of described coil loop being made electric balance and impedance matching at its abutment; With
(B) be serially connected in the described coil loop tuning capacitor with the described abutment opposite side of described driving capacitor, its value is hanked and is made the operation frequency low-resonance of described coil loop in described MR system;
(b) MR scanner, available described coil loop produces the image of described domain of dependence and at least one in the spectrogram from the described MR signal that described domain of dependence receives; With
(c) has interface arrangement with the probe interface circuit of described endoprobe and described MR system electrical interconnection, described probe interface circuit has one can only be by the PIN diode of described MR system biasing, make the described coil loop of described endoprobe can (i) at the receiving cycle of described MR system, be coupled with the probe input port of described MR system, and (ii) disconnect in the emission cycle and the described probe input port of described MR system.
2. MR as claimed in claim 1 system, it is characterized in that, described endoprobe also comprises the output cable that described coil loop is connected to described probe interface circuit, described output cable connects one of described driving capacitor at the one end span, the described PIN diode of the described interface arrangement of its other end cross-over connection.
3. MR as claimed in claim 2 system is characterized in that the electrical length of described output cable is n (λ/2)+S L, wherein n is an integer, λ is the wavelength of the described operation frequency of described MR system, S LBe to augment length, its reactance is identical with the reactance of one of described driving capacitor.
4. MR as claimed in claim 1 system is characterized in that, it is 62～82Pf that described first and second drives capacitor value separately, and the value of described tuning capacitor is 12～15pF.
5. MR as claimed in claim 1 system is characterized in that, described first and second drive in capacitor at least one also be used to make the output impedance of described coil loop and the impedance phase that described interface arrangement requires to mate.
6. MR as claimed in claim 1 system, it is characterized in that, described probe interface circuit also comprises a preamplifier, be used between the described probe input port of the anode of described PIN diode and described MR system, providing gain and impedance matching, make described MR signal be transferred to the described probe input port of described MR system with enhanced signal to noise ratio.
7. MR as claimed in claim 6 system is characterized in that described preamplifier comprises:
(a) has the GASFET of grid, source electrode and drain electrode; With
(b) the string input circuit that shakes, be used for described endoprobe coupled the described grid of described GASFET and expand the Frequency Response of described line chart ring, the described string input circuit that shakes comprises input capacitor and input inductor, connecting the described grid that described GASFET is arranged at its contact, when described coil loop loaded, the described string input circuit that shakes provided the impedance of optimization to described GASFET at the described receiving cycle of described MR system.
8. MR as claimed in claim 7 system, it is characterized in that, described GASFET connects a bias resistor at its described source electrode, connect coupling capacitor and RF choke coil in its described drain electrode, thereby when described interface arrangement is connected in described MR system, described drain electrode is connecting described probe input port through described coupling capacitor, and is connecting DC power supply in the described MR system through described RF choke coil.
9. MR as claimed in claim 1 system is characterized in that described probe interface circuit also comprises:
(a) output of described probe interface circuit is connected to the probe cable of the described probe input port of described MR system; With
(b) prevent undesirable electric current mobile cable snare on the shielded conductor of described probe cable.
10. MR as claimed in claim 1 system is characterized in that described probe interface circuit also comprises:
(a) its interior probe cable that is provided with shielded conductor and center conductor with insulating, end at described probe cable, described shielded conductor is connecting the negative electrode of described PIN diode, described center conductor is connecting the anode of described PIN diode, the electrical length of described probe cable is n (λ/2), wherein n is an integer, and λ is the wavelength of the described operation frequency of described MR system; With
(b) prevent undesirable electric current mobile cable snare on the described shielded conductor of described probe cable.
11. MR as claimed in claim 1 system is characterized in that, described interface arrangement comprises that also described array interface circuit comprises with the array interface circuit of phased-array coil system and the interconnection of described MR system electrical:
(a) the first string vibrating network is used for the MR signal is transferred to from first coil of described phased-array coil system the first coil input port of described MR system;
(b) the second string vibrating network is used for the MR signal is transferred to from second coil of described phased-array coil system the second coil input port of described MR system;
(c) a pair of 1/4 wavelength network, of described centering is used to receive the MR signal from described phased-array coil system tertiary coil, and another is used to receive the MR signal from described phased-array coil system the 4th coil; With
(d) 1/4 wavelength combiner is used for the sort signal of combined reception from described paired 1/4 wavelength network, and the MR signal of this combination is transferred to the tertiary coil input port of described MR system.
12. MR as claimed in claim 11 system is characterized in that described 1/4 wavelength combiner is the Wilkinson combiner.
13. MR as claimed in claim 11 system is characterized in that, the described first and second string vibrating networks all go here and theres under the described operation frequency of described MR system and are shaken, and it is zero that its electrical length is actually.
14. MR as claimed in claim 11 system, it is characterized in that described 1/4 wavelength combiner and the described 1/4 wavelength network that it is connected can provide this MR signal by its transmission and be actually zero electrical length under the described operation frequency of described MR system.
15. one kind is used in magnetic resonance (MR) system and is used to obtain the image of domain of dependence in patient's cavity or the endoprobe of spectrogram, it is characterized in that described endoprobe comprises:
(a) reception is from the coil loop of the MR signal of described domain of dependence, have many capacitors in the described coil, described many capacitors comprise: (i) approximately equivalent is serially connected in described coil intra-annular first and second and drives capacitor, form the virtual earth of described coil loop being made electric balance and impedance matching at its abutment, (ii) be serially connected in the described coil loop tuning capacitor with the described abutment opposite side of described driving capacitor, its value is hanked and is made the operation frequency low-resonance of described coil loop in described MR system; With
(b) be the output cable that described endoprobe is connected to described coil loop interface arrangement, described output cable connects one of described driving capacitor at the one end span, the plug of its other end connects described interface arrangement, and the electrical length of described output cable is n (λ/2)+S L, wherein n is an integer, λ is the wavelength of the described operation frequency of described MR system, S LFor augmenting length, its reactance is identical with the reactance of one of described driving capacitor.
16. endoprobe as claimed in claim 15 is characterized in that, also comprises:
(a) pivot is in the Flexible Rotating of its far-end, and described pivot is much more flexible than the remainder of described Flexible Rotating;
(b) connect the described far-end of described Flexible Rotating and seal the interior balloon of its described pivot;
(c) described coil loop be fixed in described in the non-telescopic material of balloon front; With
(d) the described far-end that connects described rotating shaft seal described in balloon and to the two outer balloon of its fixed described coil loop, described outer balloon is used for described interior balloon is positioned in described patient's the described cavity;
Make described non-telescopic material affect described interior balloon expansion in the balloon outside described, make the described coil loop of the inside can be positioned adjacent to described domain of dependence, therefrom optimize the described MR signal of reception.
17. endoprobe as claimed in claim 16, it is characterized in that, described non-telescopic material is assembled the expansion of described interior balloon, force the back of described outer balloon to touch the wall of described cavity, so force the front of described outer balloon to touch the in-profile of described cavity respective shapes, make described coil loop near described domain of dependence, therefrom optimize the described MR signal of reception.
18. endoprobe as claimed in claim 16 is characterized in that, the front of described outer balloon adapts to the in-profile of described cavity respective shapes.
19. endoprobe as claimed in claim 18 is characterized in that, described outer balloon has a back relative with its described front, comprises at least one pair of undulate fold layer.
20. endoprobe as claimed in claim 19 is characterized in that, also comprises the device of the described interior balloon inflation of a control, described ventilating control device is connecting the described Flexible Rotating that can supply gas, so that balloon in described is charged and discharged gas.
21. endoprobe as claimed in claim 20 is characterized in that, described ventilating control device comprises a pipe close, be used to control described balloon from its by with therefrom discharge described balloon.
22. endoprobe as claimed in claim 20 is characterized in that, described Flexible Rotating comprises:
(a) first tube chamber that described ventilating control device and described interior balloon are interconnected; With
(b) described output cable can be from second tube chamber of described coil loop laying, so that described endoprobe is connected described interface arrangement by it.
23. endoprobe as claimed in claim 22, it is characterized in that, described ventilating control device comprises the pipe of compressible inflation mantle and described first tube chamber that is used for being connected described Flexible Rotating, in case when compressing the described inflator collar just in described balloon described gas is provided.
24. endoprobe as claimed in claim 19, it is characterized in that, described non-telescopic material is assembled the expansion of described interior balloon, force the described undulate fold layer of described outer balloon to touch the wall of described cavity in the back, so force the described front of described outer balloon to touch the in-profile of described cavity respective shapes in front, make described coil loop near described domain of dependence, therefrom optimize the described MR signal of reception.
25. endoprobe as claimed in claim 24 is characterized in that, the described front of described outer balloon is the shape of a saddle, and the in-profile of the described respective shapes of described cavity is described patient's a rectum prostate projection.
26. endoprobe as claimed in claim 16 is characterized in that, described Flexible Rotating comprises seal scale on its outer surface.
27. endoprobe as claimed in claim 16 is characterized in that, described extraluminal balloon all comprises a kind of non-paramagnetism of low-dielectric loss characteristic, anti-burning, biocompatible medical grade material.
28. endoprobe as claimed in claim 16 is characterized in that, also comprises an anti-disk that moves that can connect described Flexible Rotating, can prevent that described endoprobe from doing undesirable move with respect to described patient's described cavity.
29. endoprobe as claimed in claim 28 is characterized in that, described anti-moving device is a hemispherical disk, and described disk limits one and allows the groove of described disk snap-on on the described Flexible Rotating.
30. endoprobe as claimed in claim 16 is characterized in that, comprises that also one is contained in the dilator element on the described Flexible Rotating slidably, is used to expand the opening that imports described cavity, is convenient to described endoprobe and locatees in described cavity.
31. endoprobe as claimed in claim 16 is characterized in that, described outer balloon also comprises the groove of the inside to groove, and described coil loop balloon outside described is not inflated up to small part placed on it.
32. endoprobe as claimed in claim 15 is characterized in that, also comprises:
(a) Flexible Rotating;
(b) connect the inflatable ball of described Flexible Rotating far-end, described inflatable ball has: (i) adapt to described cavity respective shapes in-profile the front and (ii) comprise the back of at least one pair of undulate fold layer; With
(c) be fixed on the bottom of the interior described coil loop of described inflatable ball near its described front, when described inflatable ball is inserted the inflation of described cavity, its described undulate fold layer is just pushed down the described cavity wall relative with described domain of dependence usually, force the described front of described inflatable ball to touch the in-profile of the described respective shapes of described cavity, thereby make described coil loop near described domain of dependence, therefrom optimize the described MR signal of reception.
33. endoprobe as claimed in claim 15 is characterized in that, the described value that first and second drives capacitor all is 62～82pF, and the value of described tuning capacitor is 12～15pF.
34. endoprobe as claimed in claim 15, it is characterized in that, described interface arrangement comprises that one can only be by the PIN diode of described MR system biasing, described coil loop (i) is coupled at the signal processing port of the receiving cycle of described MR system and described MR system by described output cable, and (ii) emission cycle and the described signal processing port in described MR system disconnects.
35. endoprobe as claimed in claim 15, it is characterized in that, forward bias is worth described PIN diode causes that thereby the capacitive resonance of one of the inductance of described output cable and described driving capacitor disconnects described coil loop effectively, and described endoprobe is disconnected at the described signal processing mouth of described emission cycle and described MR system.
36. a making is used in the method for the endoprobe of magnetic resonance (MR) system, described MR system is used to obtain the image or the spectrogram of domain of dependence in patient's cavity, it is characterized in that described method comprises step:
(a) select described endoprobe coil loop size, make described endoprobe be suitable for inserting described cavity;
(b) be inserted in the variable condenser that is connected in series in the described coil loop temporarily;
(c) make described coil loop bear the operation frequency of described MR system;
(d) described variable condenser is transferred to the resonance value of described coil loop at described operation frequency low-resonance, so the capacitive reactance of described coil loop equals its induction reactance;
Measure the factor of merit Q of described coil loop when (e) loading described coil loop;
Induction reactance when (f) loading with the described factor of merit Q that so records and described coil loop is measured the series resistance Rs of described coil loop;
(g) calculate the matching value of described coil loop coupling, the output impedance that makes described endoprobe with allow the required impedance phase coupling of external circuit of described endoprobe interface;
(h) two driving capacitors with described matching value are in series inserted described coil loop mutually, form the abutment that connects described driving capacitor, described abutment can connect the shielded conductor of output cable, and the opposite side node of one of described driving capacitor connects the center conductor of described output cable;
(i) select a tuning capacitor, make the total capacitance of described coil loop equal described resonance value; With
(J) replace described variable condenser with described tuning capacitor, described tuning capacitor is serially connected in the described coil loop and the opposite side at the described abutment of described driving capacitor, thereby described abutment constitutes the virtual earth of the described coil loop of electric balance.
37. method as claimed in claim 36 is characterized in that, also comprises step:
(a) prepare the Flexible Rotating that far-end has pivot, described pivot is much more flexible than the remainder of described Flexible Rotating;
(b) interior balloon is received the described far-end of described Flexible Rotating and sealed described pivot;
(c) described coil loop is fixed to the front of described balloon with non-telescopic material; With
(d) the described far-end that outer balloon is received described rotating shaft seal described in balloon and to its fixed described coil loop the two, described outer balloon is used for described interior balloon is positioned in described patient's the described cavity; Thereby described non-telescopic material affects described interior balloon inflation in the balloon outside described, makes the described coil loop of the inside be positioned proximate to described domain of dependence, therefrom optimizes to receive the MR signal.
38. method as claimed in claim 37 is characterized in that, the front of described outer balloon adapts to the in-profile of described cavity respective shapes.
39. method as claimed in claim 39 is characterized in that, described outer ball has the rear surface with respect to its described front, comprises at least one pair of undulate fold layer.
40. the method as claim 39 is characterized in that, also comprise provide control described in the step of device of balloon inflation, described ventilating control device is connecting the described Flexible Rotating that can transmit gas, with to balloon inflation in described and venting.
41. method as claimed in claim 40 is characterized in that, described ventilating control device comprises a pipe close, is used to control the passage of described gas and therefrom discharges described gas.
42. method as claimed in claim 40 is characterized in that, described Flexible Rotating comprises:
(a) first tube chamber that described ventilating control device and described interior balloon are interconnected; With
(b) described output cable is set as second tube chamber of the described external circuit that is connecting described endoprobe by its cloth from described coil loop.
43. method as claimed in claim 46 is characterized in that, also is included in the step that the geosynclinal concave groove is set in the described outer balloon, when balloon was not inflated outside described, described coil loop to small part was shelved on it.
44. method as claimed in claim 36 is characterized in that, described operation frequency is applicable to the described MR system of 3 tesla main magnets, and the described value that first and second drives capacitor is 62～82pF, and the value of tuning capacitor is 12～15pF.
45. method as claimed in claim 36 is characterized in that, described external circuit is the interface arrangement of described endoprobe.
46. method as claimed in claim 36 is characterized in that, also comprises preparing that one one end span connects one of described driving capacitor and the other end has the output cable of the plug that connects described external circuit, the electrical length of described output cable is n (λ/2)+S L, wherein n is an integer, λ is the wavelength of described operation frequency, S LFor augmenting length, its reactance is identical with the reactance of one of described driving capacitor.
47. one kind is used in magnetic resonance (MR) system with the image that obtains domain of dependence in patient's cavity or the endoprobe of spectrogram, it is characterized in that described endoprobe comprises:
(a) reception is from the coil loop of the MR signal of described domain of dependence, have many capacitors in the described coil loop, described many capacitors comprise: (i) be serially connected in intra-annular first and second of described coil near equivalence and drive capacitor, form the virtual earth of described coil loop being made electric balance and impedance matching at its abutment, (ii) be serially connected in the described coil loop tuning capacitor with the described abutment opposite side of described driving capacitor, its value is hanked and is made the operation frequency low-resonance of described coil loop in described MR system; With
(b) be the output cable that described endoprobe is received described coil loop interface arrangement, one end span of described output cable connects one of described driving capacitor, its near-end can connect described interface arrangement, the electrical length of described output cable is n (λ/2), wherein n is an integer, and λ is the wavelength of the described operation frequency of described MR system.
48. endoprobe as claimed in claim 47 is characterized in that, the described electrical length of described output cable also comprises augments length S L, its reactance is identical with the reactance of one of described driving capacitor.
49. endoprobe as claimed in claim 48 is characterized in that, at least two described coil loop are lined up the phased array structure on described domain of dependence.
50. endoprobe as claimed in claim 49 is characterized in that, the collaborative orientation of described at least two described coil loop covers described domain of dependence with quadrature.
51. endoprobe as claimed in claim 48 is characterized in that, at least two collaborative orientations of described coil loop cover described domain of dependence with quadrature.
52. endoprobe as claimed in claim 47, it is characterized in that, described output cable is a balanced type, first and second center conductor of described output cable described first and second of the described coil loop of cross-over connection respectively drives capacitor, and the shielded conductor of described output cable connects the described abutment of described coil loop.
53. endoprobe as claimed in claim 47 is characterized in that, at least two described coil loop are lined up the phased array structure on described domain of dependence.
54. endoprobe as claimed in claim 53 is characterized in that, at least two collaborative orientations of described coil loop cover described domain of dependence with quadrature.
55. endoprobe as claimed in claim 47 is characterized in that, at least two collaborative orientations of described coil loop cover described domain of dependence with quadrature.
56. one kind is used in magnetic resonance (MR) system with the image that obtains domain of dependence in patient's cavity or the endoprobe of spectrogram, it is characterized in that described endoprobe comprises:
(a) reception is from the coil loop of the MR signal of described domain of dependence, many serial connection capacitors are arranged in the described coil loop, described many capacitors comprise: (i) the driving capacitor of electric balance and the described coil loop of impedance matching, (ii) with the relative tuning capacitor of described driving capacitor, its value is hanked and is made the operation frequency low-resonance of described coil loop in described MR system; With
(b) be the output cable that described endoprobe is received described coil loop interface arrangement, the described driving capacitor of described output cable cross-over connection at one end, its near-end can connect described interface arrangement, the electrical length of described output cable is n (λ/2), wherein n is an integer, and λ is the wavelength of the described operation frequency of described MR system.
57. endoprobe as claimed in claim 56 is characterized in that, the described electrical length of described output cable also comprises augments length S L, make its reactance identical with the reactance of described driving capacitor.
58. endoprobe as claimed in claim 57 is characterized in that, at least two described coil loop are lined up the phased array structure on described domain of dependence.
59. endoprobe as claimed in claim 58 is characterized in that, at least two collaborative orientations of described coil loop cover described domain of dependence with quadrature.
60. endoprobe as claimed in claim 57 is characterized in that, at least two collaborative orientations of described coil loop cover described domain of dependence with quadrature.
61. endoprobe as claimed in claim 56 is characterized in that, described output cable is a balanced type, the described driving capacitor of first and second center conductor cross-over connection two ends of described output cable, the shielded conductor ground connection of described output cable.
62. endoprobe as claimed in claim 56 is characterized in that, at least two described coil loop are lined up the phased array structure on described domain of dependence.
63. endoprobe as claimed in claim 62 is characterized in that, at least two collaborative orientations of described coil loop cover described domain of dependence with quadrature.
64. endoprobe as claimed in claim 56 is characterized in that, at least two collaborative orientations of described coil loop cover described domain of dependence with quadrature.
CN03814486.7A 2002-05-16 2003-03-13 System of obtaining images and spectra of intracavity structures using 3.0 tesla magnetic resonance systems Expired - Fee Related CN1802123B (en)

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Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2620783A1 (en) * 2007-02-26 2013-07-31 Koninklijke Philips Electronics N.V. Doubly resonant high field radio frequency surface coils for magnetic resonance
JP2012239723A (en) 2011-05-20 2012-12-10 Toshiba Corp Magnetic resonance imaging apparatus
CN103959603B (en) * 2011-12-07 2016-07-06 株式会社Ihi Electrical power transmission system
EP2814047B1 (en) 2012-02-06 2021-08-04 IHI Corporation Non-contact power supply system
RU2639020C2 (en) * 2012-08-08 2017-12-19 Конинклейке Филипс Н.В. Endorectal coil for prostate gland with open access for surgical instruments
CN103969609B (en) * 2013-01-30 2016-12-28 西门子(深圳)磁共振有限公司 A kind of local coil and magnetic resonance imaging system
CN104076305B (en) * 2013-03-29 2018-02-13 西门子(深圳)磁共振有限公司 A kind of debugging apparatus of the body coil of magnetic resonance imaging system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5348010A (en) * 1989-02-24 1994-09-20 Medrea, Inc., Pennsylvania Corp., Pa. Intracavity probe and interface device for MRI imaging and spectroscopy
US5355087A (en) * 1989-02-27 1994-10-11 Medrad, Inc. Intracavity probe and interface device for MRI imaging and spectroscopy
CN1291873A (en) * 1998-03-04 2001-04-18 株式会社日立医药 Magnetic resonance imaging device
US6263229B1 (en) * 1998-11-13 2001-07-17 Johns Hopkins University School Of Medicine Miniature magnetic resonance catheter coils and related methods

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5348010A (en) * 1989-02-24 1994-09-20 Medrea, Inc., Pennsylvania Corp., Pa. Intracavity probe and interface device for MRI imaging and spectroscopy
US5476095A (en) * 1989-02-24 1995-12-19 Medrad, Inc. Intracavity probe and interface device for MRI imaging and spectroscopy
US5355087A (en) * 1989-02-27 1994-10-11 Medrad, Inc. Intracavity probe and interface device for MRI imaging and spectroscopy
CN1291873A (en) * 1998-03-04 2001-04-18 株式会社日立医药 Magnetic resonance imaging device
US6263229B1 (en) * 1998-11-13 2001-07-17 Johns Hopkins University School Of Medicine Miniature magnetic resonance catheter coils and related methods

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