CN110755072B - Magneto-acoustic magnetic particle concentration imaging device and imaging method - Google Patents
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Abstract
The invention discloses a magnetoacoustic magnetic particle concentration imaging device and an imaging method, wherein the device comprises the following steps: a gradient magnetic field excitation unit for generating a gradient magnetic field and acting on an imaging body containing superparamagnetic nanoparticles; the magneto-acoustic signal acquisition and display unit is used for acquiring magneto-acoustic signals and conditioning and displaying the acquired signals; the mechanical driving scanning unit is used for driving the magnetoacoustic signal acquisition and display unit to perform annular scanning to receive ultrasonic signals; the intelligent central control unit provides control signals for the gradient magnetic field excitation unit and the mechanical driving scanning unit and processes acquired data; and the data storage and imaging unit is used for further processing the acquired magneto-acoustic signals and reconstructing an image of the concentration of the magnetic particles. According to the invention, the superparamagnetic nanoparticle concentration matrix is calculated by utilizing sound pressure information, and ultrasonic information sent by each point sound source is recorded by circular scanning of an ultrasonic probe, so that the superparamagnetic nanoparticle concentrations at different positions are solved, and further the whole space imaging is realized.
Description
Technical Field
The invention belongs to the technical field of medical imaging technology, and particularly relates to a magnetoacoustic magnetic particle concentration imaging device and an imaging method, which are suitable for a superparamagnetic nanoparticle concentration imaging method based on electromagnetic pulse excitation and acoustic signal detection.
Background
The magnetic nanoparticles have been increasingly applied to relevant researches of biomedicine, clinical diagnosis and treatment in recent years, such as tumor magnetic hyperthermia, stem cell labeling, gene delivery, drug targeting treatment, disease diagnosis and the like, and have good application and development prospects.
Since 2005 b.gleich and j.weizenncker proposed magnetic particle imaging methods, the methods have been widely studied both at home and abroad. The magnetic particle imaging is used for imaging the concentration of magnetic nano particles, is an imaging mode based on a tracer agent, and has the advantages of no wound, no harm and high sensitivity. However, magnetic particle imaging measures induced voltages through an induction coil, and the excitation magnetic field is directly coupled into the measurement coil, and the resulting direct feed-through interference will reduce the spatial resolution and measurement sensitivity of the image. The resolution of magnetic particle imaging increases with increasing magnetic particles, and correspondingly the relaxation effect of magnetic nanoparticles increases, so that the higher the resolution, the more blurred the imaging.
The magnetization of magnetic nanoparticles is temperature dependent, and for this magnetic temperature characteristic, john b.weaver in 2009 first proposed a method for temperature estimation using magnetic nanoparticles, after which Liu Wenzhong teaches intensive research into this, and 2018 the team proposed an imaging method of magnetic nanoparticle alternating susceptibility.
As early as 2007, norton S.J et al proposed magnetic nanoparticle ultrasound imaging, which was imaged by detecting magnetic nanoparticle vibrational displacement. In 2014, research on magnetic induction nano sensing technology is performed by Nanjing university of education university house great, and a magnetic induction magnetic sonar rice sensing experimental system is established, experimental research is performed on a model with uniformly distributed magnetic nanoparticles, and magneto-acoustic signals are detected, but imaging research is not performed; in 2019, zhang Shuai et al propose a time-reversal-based magnetomotive ultrasonic imaging method, which obtains nanoparticle susceptibility imaging, but does not clearly determine the relationship between sound pressure and magnetic nanoparticle concentration.
Disclosure of Invention
Based on the defects of the prior art, the technical problem solved by the invention is to provide a magnetoacoustic magnetic particle concentration imaging device and an imaging method, and the invention provides a novel method for directly reconstructing the magnetic particle concentration based on the sound pressure amplitude generated by the magnetic force characteristics of superparamagnetic nanoparticles, which does not need an induction coil to receive signals, only needs to detect ultrasonic signals, and aims to realize biomedical imaging with higher resolution.
In order to solve the technical problems, the invention is realized by the following technical scheme: the invention provides a magnetoacoustic magnetic particle concentration imaging device, comprising:
the gradient magnetic field excitation unit is used for generating a gradient magnetic field and acting on an imaging body containing superparamagnetic nano particles;
the magneto-acoustic signal acquisition and display unit is used for acquiring magneto-acoustic signals and conditioning and displaying the acquired signals;
the mechanical driving scanning unit is connected with the magnetoacoustic signal acquisition and display unit and is used for driving the magnetoacoustic signal acquisition and display unit to perform annular scanning to receive ultrasonic signals;
the intelligent central control unit is connected with the gradient magnetic field excitation unit and the mechanical driving scanning unit, and is used for providing control signals for the gradient magnetic field excitation unit and processing acquired data;
and the data storage and imaging unit is connected with the intelligent central control unit and is used for further processing the acquired magnetoacoustic signals and reconstructing the image of the concentration of the magnetic particles.
Further, the gradient magnetic field excitation unit comprises a signal generator, a power amplifier and a Maxwell coil;
the signal generator is controlled by the intelligent central control unit to send out a short pulse signal, and the short pulse signal is introduced into the Maxwell coil after passing through the power amplifier to generate a gradient magnetic field.
Further, the magnetoacoustic signal acquisition and display unit comprises a water immersion type ultrasonic transducer, a signal conditioning module and an oscilloscope which are symmetrically arranged, wherein the signal conditioning module comprises an amplifier and a filter;
the water immersion type ultrasonic transducer collects magneto-acoustic signals, and the collected signals are conditioned by the amplifier and the filter and then sent to the oscilloscope for display.
Optionally, the mechanical driving scanning unit comprises a motor driving module and a stepping motor, and the motor driving module is controlled by the intelligent central control unit and enables the stepping motor to act, so that the annular scanning work of the water immersion type ultrasonic transducer on the experimental object is realized.
Further, the intelligent central control unit comprises an intelligent controller and an AD acquisition module, and the intelligent controller is connected with the gradient magnetic field excitation unit and the mechanical driving scanning unit;
the AD acquisition module is connected with the filter and acquires the conditioned signals.
Optionally, the data storage and imaging unit comprises a data acquisition card and a computer, wherein the data acquisition card stores the processed data, the computer processes and calculates the stored data, and superparamagnetic nanoparticle concentration imaging is performed according to a reconstruction algorithm.
The invention also provides a magnetoacoustic magnetic particle concentration imaging method using the magnetoacoustic magnetic particle concentration imaging device, which comprises the following steps:
s10: initializing parameter setting, and setting signal acquisition times, a rotation step length of a stepping motor and rotation time;
s20: the method comprises the steps of starting a gradient magnetic field excitation unit, generating a pulse signal by a signal generator, amplifying the pulse signal by a power amplifier, introducing the pulse signal into Maxwell coils, generating a gradient magnetic field between the coils at the moment, and placing an imaging body containing superparamagnetic nano particles in the gradient magnetic field;
s30: the ultrasonic signals are received by symmetrically arranged water immersion type ultrasonic transducers in the magnetoacoustic signal acquisition and display unit, and the received ultrasonic signals are sent to an oscilloscope for display after being conditioned by signals of an amplifier and a filter; meanwhile, the AD acquisition module acquires the conditioned signals, and after multiple times of processing and calculation by the FPGA, the signals are transmitted to a data acquisition card in the data storage and imaging unit for storage;
s40: after the mechanical driving scanning unit receives the control signal, the stepping motor drives the ultrasonic transducer to perform annular scanning to receive ultrasonic signals, and after repeated acquisition is performed for set times, the intelligent central control unit sends an instruction to enable the rotating frame to rotate to enter the next acquisition until the circumference acquisition is finished;
s50: and after the circumference acquisition is finished, processing and calculating the acquired data by using a computer, and performing superparamagnetic nanoparticle concentration imaging according to a reconstruction algorithm.
In step S50, a linear acoustic pressure wave equation under a magnetic acoustic source in the fluid is establishedMagnetic force is solved by using processed magnetoacoustic signal data based on a time reversal algorithm, and the relation between the magnetic force and the concentration of superparamagnetic nano particles is adopted>Obtaining a superparamagnetic nanoparticle concentration distribution image;
wherein p is sound pressure, c s Is the propagation speed of sound wave in biological tissue, f is magnetic force, B is magnetic flux density, m 0 Is an atomic magnetic moment, L (a) is a Langmuir function,a＝μ 0 m 0 H/(kT), H is the magnetic field strength, mu 0 The magnetic permeability in vacuum, k is Boltzmann constant, and T is temperature.
The invention aims to change the signal receiving mode of magnetic particle imaging according to the specific characteristics of excitation measurement by referring to the concentration imaging principle of magnetic particle imaging and research results such as the measurement and reconstruction of images by using acoustic signals in magnetoacoustic imaging, and overcomes the defects of spatial resolution and measurement sensitivity caused by direct feed-through interference.
The magneto-acoustic magnetic particle concentration imaging device is different from the existing induction magneto-acoustic electric conductivity imaging device and injection magneto-acoustic electric conductivity imaging device, the detection device is an ultrasonic transducer, the defects of spatial resolution and measurement sensitivity of direct feed-through interference generated by receiving signals through an induction coil in magnetic particle imaging are overcome, and magnetic field and ultrasound are common detection means in the medical field, so that the magneto-acoustic magnetic particle concentration imaging device is safe and easy to realize. The magnetoacoustic magnetic particle concentration imaging method disclosed by the invention fuses the multi-physical field imaging technology of ultrasonic imaging and electric imaging, and has wide research and application values.
The foregoing description is only an overview of the present invention, and is intended to be implemented in accordance with the teachings of the present invention, as well as to provide further clarity and understanding of the above and other objects, features and advantages of the present invention, as described in the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings.
Drawings
In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings of the embodiments will be briefly described below.
FIG. 1 is a schematic diagram of a magnetoacoustic particle concentration imaging method according to a preferred embodiment of the present invention;
FIG. 2 is a block diagram of a magnetoacoustic particle concentration imaging apparatus in accordance with a preferred embodiment of the present invention;
FIG. 3 is a partial circuit diagram of an FPGA control system of the magnetoacoustic magnetic particle concentration imaging apparatus of the present invention;
FIG. 4 is a circuit diagram of an AD acquisition module of the magnetoacoustic magnetic particle concentration imaging device of the present invention;
FIG. 5 is a circuit diagram of the connection of the driver of the magnetoacoustic particle concentration imaging apparatus of the present invention to a stepper motor;
FIG. 6 is a schematic diagram of the relative positional relationship between an ultrasonic transducer and an experimental object of the magnetoacoustic magnetic particle concentration imaging apparatus of the present invention;
FIG. 7 is a schematic diagram of the structure of the magnetoacoustic magnetic particle concentration imaging apparatus of the present invention;
fig. 8 is a flow chart of a magnetoacoustic magnetic particle concentration imaging method of the present invention.
Detailed Description
The following detailed description of the invention, taken in conjunction with the accompanying drawings, illustrates the principles of the invention by way of example and by way of a further explanation of the principles of the invention, and its features and advantages will be apparent from the detailed description. In the drawings to which reference is made, the same or similar components in different drawings are denoted by the same reference numerals.
As shown in fig. 1 and 8, the main principle of the magnetoacoustic magnetic particle concentration imaging method of the present invention is as follows: the method comprises the steps of applying a pulse gradient magnetic field to biological tissues marked by superparamagnetic nanoparticles, enabling the superparamagnetic nanoparticles to interact with the gradient magnetic field after being magnetized so as to generate ultrasonic waves through magnetic vibration, and further enabling the superparamagnetic nanoparticles to be different in magnetic force due to different distribution concentrations in the biological tissues so as to generate different sound pressures. The change of sound pressure is detected by an ultrasonic probe, and then a superparamagnetic nanoparticle concentration distribution image is reconstructed according to a nonlinear relation determined between the sound pressure and the superparamagnetic nanoparticle concentration.
As shown in fig. 2, the magnetoacoustic magnetic particle concentration imaging device of the invention consists of a gradient magnetic field excitation unit, a mechanical driving scanning unit, a magnetoacoustic signal acquisition and display unit, an intelligent central control unit and a data storage and imaging unit. The gradient magnetic field excitation unit comprises a signal generator, a power amplifier and a Maxwell coil; the mechanical driving scanning unit comprises a motor driving module and a stepping motor; the magneto-acoustic signal acquisition and display unit comprises a water immersion type ultrasonic transducer, a signal conditioning module and an oscilloscope which are symmetrically arranged; the intelligent central control unit comprises an intelligent controller and an AD acquisition module; the data storage and imaging unit comprises a data acquisition card and a computer.
In the experiment, a signal generator is used for being cascaded with a power amplifier, mu s-level pulse with the period of 20-200Hz is generated and is introduced into a Maxwell coil to generate a gradient magnetic field, and the output voltage range is 0-1kV.
The intelligent controller in the intelligent central control unit adopts a Cyclone IV series FPGA of ALTERA company, the model is EP4CE6F17C8, the intelligent controller also comprises JTAG interface circuits, power supply, active crystal oscillator, SPI Flash and the like, and the specific circuit principle is shown in figure 3. In addition, the intelligent controller also comprises an eight-channel AD acquisition module, the module chip adopts an AD7606, a circuit is shown in fig. 4, and when the intelligent controller works, the filter is only connected with four-channel ADIN1-ADIN4 pins in the diagram to be used as an input signal for AD acquisition; the pins of the OS0-OS2 in FIG. 4 are respectively connected with the pins R13, T14 and R12 of the FPGA, and the functions of the pins are oversampling selection; the CONVSTAB pin is connected with a T13 pin of the FPGA, and the pin function is data conversion; the RD, RESET, BUSY, CS, FIRSTDATA pins are respectively connected with the T12, R11, T11, R10 and R9 pins of the FPGA, and the functions of the pins are respectively divided into data reading, resetting, busy data conversion, chip selection for data reading and first data; the DB0-DB15 pins are connected with T8, R7, T7, R6, T6, R5, T5, R4, T4, R3, T3, P3, T2, M9, L10 and L9 of the FPGA, and the functions of the pins are all AD data buses.
A motor driving module of the mechanical driving scanning unit adopts a TB6600 driver, when the mechanical driving scanning unit works, the TB6600 driver is connected by adopting a common anode connection method as shown in figure 5, ENA+, DIR+ and PUL+ of the TB6600 driver are connected with VCC+5V, ENA-is connected with a B3 pin of the FPGA, DIR-is connected with a B4 pin of the FPGA, PUL-is connected with a B5 pin of the FPGA, the driver is enabled through the B3 pin, the B4 pin is a direction signal, and the B5 pin is a pulse signal. The A+ and A-of the driver are connected with the positive and negative ends of the A phase winding of the stepping motor; b+ and B-of the driver are connected with the positive and negative ends of the B-phase winding of the stepping motor.
As shown in fig. 7, the intelligent central control unit controls the stepping motor to enable the 4 ultrasonic transducers to move simultaneously, so that annular scanning of an experimental object is achieved, the scanning step length is 1-3 degrees, the scanning range is 360 degrees, and the arrangement mode of the ultrasonic transducers and the position relation of the experimental object are shown schematically in fig. 6.
The ultrasonic signals generated when the symmetrically arranged water immersed ultrasonic transducers of the magneto-acoustic signal acquisition and display unit receive the vibration of the superparamagnetic nano particles are sent to the oscilloscope for display after passing through the preamplifier and the filter, wherein the amplification factor of the preamplifier can be automatically selected and amplified by 40dB or 60dB, and the passband parameters of the filter can be adjusted according to the experimental design parameters.
The data storage and imaging unit comprises a data acquisition card and a computer, wherein the upper computer is used together with the data acquisition card to store conditioned signals, when the acquisition of the circular scanning is finished, the upper computer can be used for exporting data and transferring the data into a TXT file or an excel file, and finally, a reconstruction algorithm is used for processing the data to reconstruct the concentration image of the superparamagnetic nanoparticles.
In addition, the method for imaging the magnetoacoustic magnetic particle concentration comprises the following specific implementation steps:
(1) Initializing parameter setting, and setting signal acquisition times, a rotation step length of a stepping motor and rotation time;
(2) Starting an excitation source device, generating a mu s-level pulse signal by a signal generator, amplifying the mu s-level pulse signal by a power amplifier, introducing the mu s-level pulse signal into Maxwell coils, generating a gradient magnetic field between the coils at the moment, and placing an imaging body containing superparamagnetic nano particles in the gradient magnetic field;
(3) The ultrasonic signals are received by symmetrically arranged water immersion ultrasonic transducers, and the received ultrasonic signals are sent to an oscilloscope for display after being conditioned by signals of a preamplifier and a filter. And meanwhile, the AD acquisition module acquires the conditioned signals, and after the signals are processed and calculated for many times by the FPGA, the data are transmitted to the data acquisition card for storage.
(4) After the mechanical driving scanning unit receives the control signal, the stepping motor drives the ultrasonic transducer to conduct annular scanning to receive ultrasonic signals, and after repeated collection for set times, the intelligent central control unit sends an instruction to enable the rotating frame to rotate to enter next collection until circumference collection is finished.
(5) And after the circumference acquisition is finished, processing and calculating the acquired data by using a computer, and performing superparamagnetic nanoparticle concentration imaging according to a reconstruction algorithm.
Further, the theory of the data processing and reconstruction process in the step (5) is that:
when applying current density J to Maxwell coil s When the space magnetic field vector magnetic potential of the target area meets the poisson equation, the space magnetic field vector magnetic potential of the target area meets the poisson equation:
solving equation (1) to obtain vector magnetic potential A according to the relationship between B and A and the relationship between B and H
The magnetic flux density B and the magnetic field strength H at each position in the target region can be solved.
Assuming that the number of superparamagnetic nanoparticles in a unit volume is N, when a magnetic field B is applied to the superparamagnetic nanoparticles, the magnetization M of the superparamagnetic nanoparticles under the Langevin paramagnetic classical theory satisfies the following conditions:
M＝Nm 0 L(a)e H (4)
m is in 0 Is an atomic magnetic moment, L (a) is a Langmuir function,wherein a=μ 0 m 0 H/(kT), H is the magnetic field strength, mu 0 Is magnetic permeability in vacuum, k is Boltzmann constant, T is temperature, and the unit is Kelvin, e H The unit vector is shown to coincide with the direction of the magnetic field strength H.
Superparamagnetic nanoparticles of number N per unit volume are subjected to a magnetic volume force of
In medicine, biological tissues marked by superparamagnetic nano particles can be approximated to be uniform acoustic media, and ultrasonic waves excited by magnetic vibration of the superparamagnetic nano particles under a gradient magnetic field meet a sound pressure wave equation:
wherein p is sound pressure, c s For propagation of acoustic waves in biological tissueSpeed.
When the image is reconstructed, firstly, the magnetic divergence of a sound source in a sound pressure wave equation is solved according to the collected sound pressure signal pFurther, the distribution of the magnetic force f is calculated, and since the magnetic flux density and the magnetic force are functions of time and position, the concentration at a certain position can be calculated by the following equation
From the above deduction, the superparamagnetic nanoparticles with different concentrations under the gradient magnetic field are magnetized to different degrees, so that the superparamagnetic nanoparticles are subjected to magnetic forces with different magnitudes, and the ultrasonic sound pressures generated by vibration are different, so that the concentration distribution of the superparamagnetic nanoparticles and the magnetic forces are in a clear nonlinear relation, and the concentration imaging of the superparamagnetic nanoparticles in the whole space is realized by detecting the sound pressures generated by point sound sources at different positions.
The main innovation of the invention is that the method for detecting the magnetoacoustic signals is adopted to carry out concentration imaging on the superparamagnetic nanoparticles, thereby effectively improving the spatial resolution of the superparamagnetic nanoparticle imaging. And applying a gradient magnetic field to the biological tissue marked by the superparamagnetic nanoparticles, detecting the amplitude and the phase of sound pressure, calculating a superparamagnetic nanoparticle concentration matrix by utilizing sound pressure information, and recording ultrasonic information emitted by each point sound source through circular scanning of an ultrasonic probe, so that the superparamagnetic nanoparticle concentrations at different positions are solved, and further, the whole space imaging is realized. The magnetoacoustic magnetic particle concentration imaging method is a multi-physical field imaging technology which is used for fusing ultrasonic imaging and magnetic characteristic imaging of superparamagnetic nanoparticles, and can well improve the spatial resolution of the superparamagnetic nanoparticle imaging.
While the invention has been described with respect to the preferred embodiments, it will be understood that the invention is not limited thereto, but is capable of modification and variation without departing from the spirit of the invention, as will be apparent to those skilled in the art.
Claims (6)
1. A magnetoacoustic magnetic particle concentration imaging method, the imaging method being implemented by a magnetoacoustic magnetic particle concentration imaging apparatus comprising:
the gradient magnetic field excitation unit is used for generating a gradient magnetic field and acting on an imaging body containing superparamagnetic nano particles;
the magneto-acoustic signal acquisition and display unit is used for acquiring magneto-acoustic signals and conditioning and displaying the acquired signals;
the mechanical driving scanning unit is connected with the magnetoacoustic signal acquisition and display unit and is used for driving the magnetoacoustic signal acquisition and display unit to perform annular scanning to receive ultrasonic signals;
the intelligent central control unit is connected with the gradient magnetic field excitation unit and the mechanical driving scanning unit, and is used for providing control signals for the gradient magnetic field excitation unit and processing acquired data;
the data storage and imaging unit is connected with the intelligent central control unit and is used for further processing the acquired magneto-acoustic signals and reconstructing the image of the concentration of the magnetic particles;
the method comprises the following steps:
s10: initializing parameter setting, and setting signal acquisition times, a rotation step length of a stepping motor and rotation time;
s20: the method comprises the steps of starting a gradient magnetic field excitation unit, generating a pulse signal by a signal generator, amplifying the pulse signal by a power amplifier, introducing the pulse signal into Maxwell coils, generating a gradient magnetic field between the coils at the moment, and placing an imaging body containing superparamagnetic nano particles in the gradient magnetic field;
s30: the ultrasonic signals are received by symmetrically arranged water immersion type ultrasonic transducers in the magnetoacoustic signal acquisition and display unit, and the received ultrasonic signals are sent to an oscilloscope for display after being conditioned by signals of an amplifier and a filter; meanwhile, the AD acquisition module acquires the conditioned signals, and after multiple times of processing and calculation by the FPGA, the signals are transmitted to a data acquisition card in the data storage and imaging unit for storage; the number of the water immersion type ultrasonic transducers is 4, and the ultrasonic transducers move simultaneously during the acquisition of the magnetoacoustic signals, so that the annular scanning of an experimental object is realized, the scanning step length is 1-3 degrees, and the scanning range is 360 degrees;
s40: after the mechanical driving scanning unit receives the control signal, the stepping motor drives the ultrasonic transducer to perform annular scanning to receive ultrasonic signals, and after repeated acquisition is performed for set times, the intelligent central control unit sends an instruction to enable the rotating frame to rotate to enter the next acquisition until the circumference acquisition is finished;
s50: after the circumference acquisition is finished, processing and calculating the acquired data by using a computer, and imaging the concentration of the superparamagnetic nanoparticles according to a reconstruction algorithm;
in step S50, a linear acoustic pressure wave equation under a magnetic acoustic source in the fluid is established Magnetic force is solved by using processed magnetoacoustic signal data based on time reversal algorithm, and the relationship between the magnetic force and the concentration of superparamagnetic nano particles is utilizedObtaining a superparamagnetic nanoparticle concentration distribution image;
wherein p is sound pressure, c s Is the propagation speed of sound wave in biological tissue, f is magnetic force, B is magnetic flux density, m 0 Is an atomic magnetic moment, L (a) is a Langmuir function,a＝μ 0 m 0 H/(kT), H is the magnetic field strength, mu 0 The magnetic permeability in vacuum, k is Boltzmann constant, and T is temperature.
2. A magnetoacoustic magnetic particle concentration imaging method as claimed in claim 1 wherein the gradient magnetic field excitation unit includes a signal generator, a power amplifier and maxwell's coil;
the signal generator is controlled by the intelligent central control unit to send out a short pulse signal, and the short pulse signal is introduced into the Maxwell coil after passing through the power amplifier to generate a gradient magnetic field.
3. The magnetoacoustic magnetic particle concentration imaging method of claim 1, wherein the magnetoacoustic signal acquisition and display unit comprises a symmetrically arranged water immersed ultrasonic transducer, a signal conditioning module and an oscilloscope, the signal conditioning module comprising an amplifier and a filter;
the water immersion type ultrasonic transducer collects magneto-acoustic signals, and the collected signals are conditioned by the amplifier and the filter and then sent to the oscilloscope for display.
4. A magnetoacoustic magnetic particle concentration imaging method as claimed in claim 3 wherein the mechanically driven scanning unit comprises a motor drive module and a stepper motor, the motor drive module being controlled by the intelligent central control unit and causing the stepper motor to act to effect annular scanning of the test object by the water immersed ultrasonic transducer.
5. A magnetoacoustic magnetic particle concentration imaging method as claimed in claim 3 wherein the intelligent central control unit comprises an intelligent controller and an AD acquisition module, the intelligent controller being connected to the gradient magnetic field excitation unit and the mechanical drive scanning unit;
the AD acquisition module is connected with the filter and acquires the conditioned signals.
6. The magnetoacoustic magnetic particle concentration imaging method of claim 1, wherein the data storage and imaging unit comprises a data acquisition card and a computer, the data acquisition card stores processed data, the computer processes and calculates the stored data, and superparamagnetic nanoparticle concentration imaging is performed according to a reconstruction algorithm.
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| CN1774210A (en) * | 2003-04-15 | 2006-05-17 | 皇家飞利浦电子股份有限公司 | Elastography device and method for determining and imaging of mechanical and elastic parameters of an examination object |
| CN102788836A (en) * | 2012-07-26 | 2012-11-21 | 中国科学院电工研究所 | Magneto-acoustic microscopic imaging method and imaging system |
| CN108294751A (en) * | 2018-01-15 | 2018-07-20 | 中国科学院电工研究所 | A kind of magnetosonic electricity-supersonic detection device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1774210A (en) * | 2003-04-15 | 2006-05-17 | 皇家飞利浦电子股份有限公司 | Elastography device and method for determining and imaging of mechanical and elastic parameters of an examination object |
| CN102788836A (en) * | 2012-07-26 | 2012-11-21 | 中国科学院电工研究所 | Magneto-acoustic microscopic imaging method and imaging system |
| CN108294751A (en) * | 2018-01-15 | 2018-07-20 | 中国科学院电工研究所 | A kind of magnetosonic electricity-supersonic detection device |
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