WO2021109348A1 - 一种便携式核磁共振器官弹性无创定量检测方法 - Google Patents
一种便携式核磁共振器官弹性无创定量检测方法 Download PDFInfo
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- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/055—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
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- the invention relates to the technical field of nuclear magnetic resonance medical detection, in particular to a portable non-invasive quantitative detection method for the elasticity of nuclear magnetic resonance organs.
- Elasticity is an important mechanical parameter of biological tissues, which characterizes the degree of difficulty of tissue deformation under the action of mechanical external forces.
- the change of tissue elasticity is closely related to its physiological and pathological state, which can distinguish normal and pathological tissues.
- detection methods based on tissue elasticity have been actively used in tumor diagnosis and liver fibrosis classification and rehabilitation assessment.
- doctors use palpation to qualitatively judge the elasticity of the tissue, and then diagnose the disease.
- the error of the diagnosis result is large, and it is subject to the operator's subjective influence.
- non-invasive elastic quantitative technology based on ultrasound/NMR has been in the ascendant.
- the elastic quantitative method based on ultrasound uses ultrasound to measure the propagation speed of shear waves in the tissue, and then estimate the elastic modulus of the tissue. However, the measurement process is easily affected by motion and is highly dependent on the operator.
- the elastic quantitative technology based on conventional nuclear magnetic resonance uses a phase contrast imaging pulse sequence to collect the strain distribution map in the biological tissue under the action of shearing force, and then process the image through a certain elastography algorithm to obtain the tissue elasticity. Quantitative distribution map. Due to the need for imaging, this method takes a long time, is also susceptible to movement, and has a high detection cost. It is generally not applicable in routine clinical detection.
- the purpose of the present invention is to provide a portable nuclear magnetic resonance organ elasticity non-invasive quantitative detection method, which reasonably and effectively solves the problem that the prior art ultrasonic elasticity detection is highly dependent on the operator, has a low sensitivity to motion, and uses magnetic resonance elasticity.
- the scanning time of imaging detection is too long, the price is high, equipment resources are scarce, and the problem of bedside detection and rapid screening cannot be applied.
- G is the shear elastic modulus
- ⁇ is the tissue density
- v is the wave velocity
- the density of soft tissue is close to the density of water, so ⁇ can be taken as the density of water.
- the speed of the shear wave propagating in the tissue and its wavelength satisfy the relationship:
- ⁇ is the wavelength and f is the frequency. From formulas (1) to (2), it can be seen that only the wavelength or wave velocity of the shear wave in the tissue propagation process is required to determine the shear elastic modulus of the tissue.
- the present invention is based on the principle of portable nuclear magnetic resonance. Its pulse sequence is shown in Figure 4. A shear wave is generated in the tissue through an external simple harmonic vibration excitation device, and then the static gradient generated by the portable magnet is used as the motion sensitive gradient to remove the tissue
- the vibration information is encoded into the phase of a one-dimensional image, and its phase can be expressed as:
- ⁇ is the magnetic rotation ratio
- N is the number of vibration cycles
- T is the period of simple harmonic vibration
- Is the motion sensitive gradient Is the amplitude
- Is the wave vector Is the particle position vector
- ⁇ is the initial phase of the simple harmonic vibration.
- a portable nuclear magnetic resonance organ elasticity non-invasive quantitative detection method which is characterized in that:
- the method for non-invasive quantitative detection of organ elasticity includes the following steps:
- Step 1 Construct the system: first construct a portable nuclear magnetic resonance organ elasticity non-invasive quantitative system.
- the measurement system adopts a portable nuclear magnetic resonance system, a mechanical vibration excitation device and a console construction system architecture.
- the portable nuclear magnetic resonance system mainly includes an NMR spectrometer, Power amplifier, preamplifier, transceiver switching module, portable magnet module and probe, the NMR spectrum analyzer is equipped with transmission (Tx) and gate control (GATE) unidirectional signal paths connected with a power amplifier, and is equipped with a transceiver conversion gate
- T/R GATE is connected to the transceiver switching module, the power amplifier amplifies the transmitted signal and then connects to the transceiver switching module, the transceiver switching module is connected to the probe, and the transceiver switching module is used to switch the portable
- the nuclear magnetic resonance system is in the transmitting state or the receiving state, the portable magnet module is provided with a unilateral magnet, and the unilateral magnet is set as an ergonomic curved surface that fits the body surface adjacent
- Step 2 Connect the detection part: fix the passive driver, the portable magnet module and the probe on the surface of the human body corresponding to the target organ for sample;
- Step 2 Start the detection system: click the system start button to run the portable nuclear magnetic resonance elasticity measurement system;
- Step 3 Collect sample data: The NMR spectrometer generates and transmits vibration to the passive driver through the active driver of the mechanical vibration excitation device to generate a shear wave inside the tissue after the vibration is generated. After the tissue vibration state is stabilized, the The NMR spectrometer transmits a 90-degree radio frequency pulse according to the timing specified by the elasticity measurement pulse sequence through the probe. Due to the existence of the magnetic field gradient, the spin within a certain slice thickness in the ROI range will be excited.
- the echo time will be shortened by partial motion coding or multiple signal accumulation Or a combination of the two to improve SNR; in order to improve phase sensitivity, in at least one setting, multiple 180-degree radio frequency pulses will be applied;
- Step 4 Sample inspection data analysis: In order to analyze the wavelength or velocity of the shear wave in the tissue, Fourier transform is performed on the collected echo data to obtain the one-dimensional tissue profile in the spatial domain.
- the phase of the one-dimensional profile is Is the spatial phase curve organized in the shear wave propagation direction, and its distribution satisfies the formula
- ⁇ is usually taken as the density value of water, that is, the elastic modulus value of the tissue is calculated, which constitutes the portable MRI organ elasticity non-invasive quantitative detection method.
- the portable magnet module is made of rare earth permanent magnetic materials, is small in size and light in weight, supports handheld or bracket mounting, and is convenient to adjust to a supine, prone, sitting or standing posture suitable for the subject.
- the excited thin layer is moved in the AP direction of the shear wave propagation, and the phases of the echo center points at multiple slice positions are collected, and the spatial phase distribution also satisfies the formula
- the expressed sine curve can also be used to estimate the wavelength or wave speed of the shear wave, and then determine the shear elastic modulus value.
- the AP (A-P) direction is the shear wave propagation direction
- the LR (L-R) direction is the displacement direction of the simple harmonic motion of the particles in the tissue
- the AP (A-P) direction and the LR (L-R) direction are perpendicular to each other.
- the invention discloses a portable nuclear magnetic resonance organ elasticity non-invasive quantitative detection method, which reasonably and effectively solves the problem that the prior art ultrasonic elasticity detection is highly dependent on the operator, has a low sensitivity to motion, and uses magnetic resonance elasticity imaging detection.
- the scanning time is too long, the price is high, the equipment resources are tight, and the bedside detection and rapid screening cannot be applied.
- the invention adopts a portable nuclear magnetic resonance system, a mechanical vibration excitation device and a console to construct a system architecture.
- the portable nuclear magnetic resonance system mainly includes an NMR spectrometer, a power amplifier, a preamplifier, a transceiver switching module, a portable magnet module and a probe;
- the portable nuclear magnetic resonance system has no damage to organs and tissues when it acts on the human body, and it can realize safe, accurate, quantitative and non-invasive organ elasticity detection.
- the system is streamlined, scientific and reasonable, equipment is simple and optimized, light weight, small size, easy to carry; one-key operation, no operator dependence, high repeatability; widely applicable to bedside detection and rapid screening; no imaging required, short measurement time ,
- the motion sensitive gradient has certain motion frequency selectivity, the measurement process is not easily affected by motion, and the accuracy is high. Overcome the shortcomings of the existing technology.
- Fig. 1 is a schematic diagram of the system architecture adopted by the present invention.
- Figure 2 is a schematic diagram of the portable magnet structure of the present invention.
- Fig. 3 is a schematic diagram of the magnetic field of the portable magnet of the present invention.
- Fig. 4 is a schematic diagram of a pulse sequence for elasticity measurement of the present invention.
- a portable MRI organ elasticity non-invasive quantitative detection method is characterized by:
- the method for non-invasive quantitative detection of organ elasticity includes the following steps:
- Step 1 Construct the system: first construct a portable nuclear magnetic resonance organ elasticity non-invasive quantitative system.
- the measurement system adopts a portable nuclear magnetic resonance system, a mechanical vibration excitation device and a console construction system architecture.
- the portable nuclear magnetic resonance system mainly includes an NMR spectrometer, Power amplifier, preamplifier, transceiver switching module, portable magnet module and probe, the NMR spectrum analyzer is equipped with transmission (Tx) and gate control (GATE) unidirectional signal paths connected with a power amplifier, and is equipped with a transceiver conversion gate
- T/R GATE is connected to the transceiver switching module, the power amplifier amplifies the transmitted signal and then connects to the transceiver switching module, the transceiver switching module is connected to the probe, and the transceiver switching module is used to switch the portable
- the nuclear magnetic resonance system is in the transmitting state or the receiving state, the portable magnet module is provided with a unilateral magnet, and the unilateral magnet is set as an ergonomic curved surface that fits the body surface adjacent
- Step 2 Connect the detection part: fix the passive driver, the portable magnet module and the probe on the surface of the human body corresponding to the target organ for sample;
- Step 2 Start the detection system: click the system start button to run the portable nuclear magnetic resonance elasticity measurement system;
- Step 3 Collect sample data: The NMR spectrometer generates and transmits vibration to the passive driver through the active driver of the mechanical vibration excitation device to generate a shear wave inside the tissue after the vibration is generated. After the tissue vibration state is stabilized, the The NMR spectrometer transmits a 90-degree radio frequency pulse according to the timing specified by the elasticity measurement pulse sequence through the probe. Due to the existence of the magnetic field gradient, the spin within a certain slice thickness in the ROI range will be excited.
- the echo time will be shortened by partial motion coding or multiple signal accumulation Or a combination of the two to improve SNR; in order to improve phase sensitivity, in at least one setting, multiple 180-degree radio frequency pulses will be applied;
- Step 4 Sample inspection data analysis: In order to analyze the wavelength or velocity of the shear wave in the tissue, Fourier transform is performed on the collected echo data to obtain the one-dimensional tissue profile in the spatial domain.
- the phase of the one-dimensional profile is Is the spatial phase curve organized in the shear wave propagation direction, and its distribution satisfies the formula
- ⁇ is usually taken as the density value of water, that is, the elastic modulus value of the tissue is calculated, which constitutes the portable MRI organ elasticity non-invasive quantitative detection method.
- the portable magnet module is made of rare earth permanent magnetic materials, is small in size and light in weight, supports handheld or bracket mounting, and is convenient to adjust to a supine, prone, sitting or standing posture suitable for the subject.
- the excited thin layer is moved in the AP direction of the shear wave propagation, and the phases of the echo center points at multiple slice positions are collected, and the spatial phase distribution also satisfies the formula
- the expressed sine curve can also be used to estimate the wavelength or wave speed of the shear wave, and then determine the shear elastic modulus value.
- the AP (A-P) direction is the shear wave propagation direction
- the LR (L-R) direction is the displacement direction of the simple harmonic motion of the particles in the tissue
- the AP (A-P) direction and the LR (L-R) direction are perpendicular to each other.
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Abstract
一种便携式核磁共振器官弹性无创定量检测方法,采用便携式核磁共振系统、机械振动激励装置和控制台建构系统架构,便携式核磁共振系统主要包括NMR频谱仪、功率放大器、前置放大器、收发切换模块、便携式磁体模块和探头。便携式核磁共振系统作用于人体时对器官、组织无损伤、无创口,实现安全准确、定量、非侵入性器官弹性检测。系统精简、科学合理、设备简便优化、重量轻、体积小、携带方便;一键操作、无操作者依赖性、可重复性高;广泛适用床旁检测和快速筛查;无需成像,测量时间短,运动敏感梯度具有一定的运动频率选择性,测量过程不易受运动影响,准确性高。
Description
本发明涉及一种核磁共振医学检测技术领域,尤其涉及一种便携式核磁共振器官弹性无创定量检测方法。
弹性是生物组织的一个重要的机械力学参数,它表征了组织在机械外力作用下的形变难易程度。组织弹性的变化与其生理病理状态密切相关,据此可以区分正常与病理组织。目前,基于组织弹性的检测方法已经在肿瘤诊断以及肝脏纤维化的分级和康复评估中得到了积极的应用。在传统医学上,医生通过触诊来定性地判断组织弹性大小,进而诊断病变,诊断结果误差大,受操作者主观影响大。近年来,基于超声/核磁共振的非侵入式弹性定量技术方兴未艾。基于超声的弹性定量方法利用超声波测量剪切波在组织内传播的速度,进而组织的弹性模量估算值,但测量过程易受运动影响,对操作者依赖性强。而基于常规核磁共振的弹性定量技术则是利用一个相位对比度成像脉冲序列,采集得到在剪切力的作用下生物组织内的应变分布图,再经过一定的弹性成像算法进行图像处理,得到组织弹性定量分布图。由于需要成像,这种方法耗时较长,也易受运动影响,且检测成本高,在常规临床检测中普遍适用性不强。
发明内容
本发明的目的在于提供一种便携式核磁共振器官弹性无创定量检测方法,合理有效地解决了现有技术的超声波弹性检测对操作者依赖性大、对运动敏感的区分率低和采用磁共振的弹性成像检测的扫描时间太长、且价格高昂、设备资源紧张、不能适用床旁检测和快速筛查的问题。
本发明的技术原理:
剪切波在组织传播过程中,其波速与剪切弹性模量近似满足如下关系:
G=ρv
2 (1)
其中,G是剪切弹性模量,ρ是组织密度,v是波速。
在实际中,通常认为软组织密度接近水密度,因此ρ可取水的密度值。同时,所述剪切波在组织中传播的速度与其波长满足关系:
v=λf (2)
其中,λ是波长,f是频率。由式(1)~(2)可知,只要求得剪切波在组织传播过程中的波长或波速,即可确定组织的剪切弹性模量。
本发明基于便携式核磁共振原理,其脉冲序列如图4所示,通过外部的简谐振动激励装置,在组织内产生一个剪切波,然后以便携式磁体产生的静态梯度作为运动敏感梯度将组织的振动信息编码到一维图像的相位中,其相位可以表示为:
其中,γ是磁旋比,N是振动周期数,T是简谐振动周期,
为运动敏感梯度,
为振幅,
是波矢量,
是质点位置矢量,α是简谐振动的初始相位。从式(3)可以看出,一维图像的相位与组织振动造成的位移成简单的线性关系。因此,通过一维图像的相位曲线即可估算剪切波在组织中的波长,再由式(2)计算出剪切波传播速度,最终通过式(1),即可获得组织的剪切弹性模量。
本发明采用如下技术方案:
一种便携式核磁共振器官弹性无创定量检测方法,其特征在于:
所述器官弹性无创定量检测方法包括以下步骤:
步骤一、建构系统:首先建构便携式核磁共振器官弹性无创定量系统,所述测量系统采用便携式核磁共振系统、机械振动激励装置和控制台建构系统架构,所述便携式核磁共振系统主要包括NMR频谱仪、功率放大器、前置放大器、收发切换模块、便携式磁体模块和探头,所述NMR频谱仪设有发射(Tx)和门控(GATE)单向信号通路与一台功率放大器连接,设有收发转换门控(T/R GATE)与收发切换模块连接,所述功率放大器将发射信号放大后与收发切换模块连接,所述收发切换模块与所述探头连接,所述收发切换模块用于切换所述便携式核磁共振系统处于发射状态或接收状态,所述便携式磁体模块设有单边磁体,所述单边磁体设置为与目标检样器官相邻的身体表面贴合的人体工程学弧曲面,背面连接设有磁轭,背面磁场强度迅速衰减;所述机械振动激励装置设有主动驱动器和被动驱动器,所述被动驱动器与主动驱动器通过气动方式连接并贴合安放在目标检样器官相邻的身体表面,且在组织内部产生剪切波,所述控制台与所述NMR频谱仪连接,控制运行核磁共振脉冲序列指令,并接收NMR频谱仪采集到的核磁共振信号,完成实时数据处理;
步骤二、连接检测部位:将所述被动驱动器、便携式磁体模块和探头固定贴合在目标检样器官对应的人体表面;
步骤二、启动检测系统:点击系统启动键,运行所述便携式核磁共振弹性测量系统;
步骤三、采集检样数据:所述NMR频谱仪通过所述机械振动激励装置的主动驱动器产生并传送振动到被动驱动器产生振动后在组织内部产生剪切波,在组织振动状态稳定后,所述NMR频谱仪通过所述探头按照弹性测量脉冲序列规定的时序发射一个90度射频脉冲,由于磁场梯度的存在,ROI范围内一定层面厚度内的自旋将被激发,经过一定的振动周期 后,施加180度脉冲,在所述180度脉冲之后,自旋聚相,检测回波信号并传输回控制台完成计算;在至少一种设置中,将通过部分运动编码缩短回波时间或多次信号累加或二者的组合来提高SNR;为了提高相位敏感度,在至少一种设置中,将施加多个180度射频脉冲;
步骤四、检样数据分析:为分析组织内剪切波的波长或波速,对采集到的回波数据做傅里叶变换,得到空间域内的一维组织轮廓,所述一维轮廓的相位即是在剪切波传播方向上组织的空间相位曲线,其分布满足式
所表达的正弦曲线,式中,
为运动敏感梯度,
为振幅,由此即可确定剪切波在组织内传播的波长或波速,再由波速与剪切弹性模量的关系式G=ρv
2,式中,G是剪切弹性模量,v是波速,ρ是组织密度,对于软组织,ρ通常取为水的密度值,即运算出组织的弹性模量值,构成所述一种便携式核磁共振器官弹性无创定量检测方法。
进一步地,所述便携式磁体模块由稀土永久磁性材料构成,体积小、重量轻,支持手持或支架挂载,便于调整到适合受检者的仰卧、俯卧、坐姿或站姿体位。
进一步地,通过改变射频脉冲激发频率,使激发的一个薄层在剪切波传播的AP方向上移动,采集多个层面位置处的回波中心点相位,其空间相位分布也满足式
所表达的正弦曲线,也可以用以估算剪切波的波长或波速,进而确定剪切弹性模量值。
进一步地,所述AP(A-P)方向为剪切波传播方向,LR(L-R)方向为组织内质点做简谐振动的位移方向,所述AP(A-P)方向和LR(L-R)方向相互垂直。
本发明的有益技术效果是:
本发明公开了一种便携式核磁共振器官弹性无创定量检测方法,合理有效地解决了现有技术的超声波弹性检测对操作者依赖性大、对运动敏感的区分率低和采用磁共振的弹性成像检测的扫描时间太长、且价格高昂、设备资源紧张、不能适用床旁检测和快速筛查的问题。
本发明采用便携式核磁共振系统、机械振动激励装置和控制台建构系统架构,所述便携式核磁共振系统主要包括NMR频谱仪、功率放大器、前置放大器、收发切换模块、便携式磁体模块和探头;所述便携式核磁共振系统作用于人体时对器官、组织无损伤、无创口,实现安全准确、定量、非侵入性器官弹性检测。系统精简、科学合理、设备简便优化、重量轻、体积小、携带方便;一键操作、无操作者依赖性、可重复性高;广泛适用床旁检测和快速筛查;无需成像,测量时间短,运动敏感梯度具有一定的运动频率选择性,测量过程不易受运动影响,准确性高。克服了现有技术的不足。
图1是本发明所采用的系统架构示意图。
图2是本发明便携式磁体结构示意图。
图3是本发明便携式磁体磁场示意图。
图4是本发明弹性测量的脉冲序列示意图。
图中所示:1-单边磁体、2-人体工程学弧曲面、3-磁轭、4-手柄、5-感兴趣区域(ROI)。
通过下面对实施例的描述,将更加有助于公众理解本发明,但不能也不应当将申请人所给出的具体的实施例视为对本发明技术方案的限制,任何对部件或技术特征的定义进行改变和/或对整体结构作形式的而非实质的变换都应视为本发明的技术方案所限定的保护范围。
实施例
如图1-4所示一种便携式核磁共振器官弹性无创定量检测方法,其特征在于:
所述器官弹性无创定量检测方法包括以下步骤:
步骤一、建构系统:首先建构便携式核磁共振器官弹性无创定量系统,所述测量系统采用便携式核磁共振系统、机械振动激励装置和控制台建构系统架构,所述便携式核磁共振系统主要包括NMR频谱仪、功率放大器、前置放大器、收发切换模块、便携式磁体模块和探头,所述NMR频谱仪设有发射(Tx)和门控(GATE)单向信号通路与一台功率放大器连接,设有收发转换门控(T/R GATE)与收发切换模块连接,所述功率放大器将发射信号放大后与收发切换模块连接,所述收发切换模块与所述探头连接,所述收发切换模块用于切换所述便携式核磁共振系统处于发射状态或接收状态,所述便携式磁体模块设有单边磁体,所述单边磁体设置为与目标检样器官相邻的身体表面贴合的人体工程学弧曲面,背面连接设有磁轭,背面磁场强度迅速衰减;所述机械振动激励装置设有主动驱动器和被动驱动器,所述被动驱动器与主动驱动器通过气动方式连接并贴合安放在目标检样器官相邻的身体表面,且在组织内部产生剪切波,所述控制台与所述NMR频谱仪连接,控制运行核磁共振脉冲序列指令,并接收NMR频谱仪采集到的核磁共振信号,完成实时数据处理;
步骤二、连接检测部位:将所述被动驱动器、便携式磁体模块和探头固定贴合在目标检样器官对应的人体表面;
步骤二、启动检测系统:点击系统启动键,运行所述便携式核磁共振弹性测量系统;
步骤三、采集检样数据:所述NMR频谱仪通过所述机械振动激励装置的主动驱动器产生并传送振动到被动驱动器产生振动后在组织内部产 生剪切波,在组织振动状态稳定后,所述NMR频谱仪通过所述探头按照弹性测量脉冲序列规定的时序发射一个90度射频脉冲,由于磁场梯度的存在,ROI范围内一定层面厚度内的自旋将被激发,经过一定的振动周期后,施加180度脉冲,在所述180度脉冲之后,自旋聚相,检测回波信号并传输回控制台完成计算;在至少一种设置中,将通过部分运动编码缩短回波时间或多次信号累加或二者的组合来提高SNR;为了提高相位敏感度,在至少一种设置中,将施加多个180度射频脉冲;
步骤四、检样数据分析:为分析组织内剪切波的波长或波速,对采集到的回波数据做傅里叶变换,得到空间域内的一维组织轮廓,所述一维轮廓的相位即是在剪切波传播方向上组织的空间相位曲线,其分布满足式
所表达的正弦曲线,式中,
为运动敏感梯度,
为振幅,由此即可确定剪切波在组织内传播的波长或波速,再由波速与剪切弹性模量的关系式G=ρv
2,式中,G是剪切弹性模量,v是波速,ρ是组织密度,对于软组织,ρ通常取为水的密度值,即运算出组织的弹性模量值,构成所述一种便携式核磁共振器官弹性无创定量检测方法。
进一步地,所述便携式磁体模块由稀土永久磁性材料构成,体积小、重量轻,支持手持或支架挂载,便于调整到适合受检者的仰卧、俯卧、坐姿或站姿体位。
进一步地,通过改变射频脉冲激发频率,使激发的一个薄层在剪切波传播的AP方向上移动,采集多个层面位置处的回波中心点相位,其空间相位分布也满足式
所表达的正弦曲线,也可以用以估算剪切波的波长或波速,进而确定剪切弹性模量值。
进一步地,所述AP(A-P)方向为剪切波传播方向,LR(L-R)方向为组织内质点做简谐振动的位移方向,所述AP(A-P)方向和LR(L-R)方向相互垂直。完成所述一种便携式核磁共振器官弹性无创定量检测方法的实施。
当然,本发明还可以有其他多种实施例,在不背离本发明精神及其实质的情况下,熟悉本领域的技术人员可以根据本发明做出各种相应的改变和变形,但这些相应的改变和变形都应属于本发明所附的权利要求的保护范围。
Claims (4)
- 一种便携式核磁共振器官弹性无创定量检测方法,其特征在于:所述器官弹性无创定量检测方法包括以下步骤:步骤一、建构系统:首先建构便携式核磁共振器官弹性无创定量系统,所述测量系统采用便携式核磁共振系统、机械振动激励装置和控制台建构系统架构,所述便携式核磁共振系统主要包括NMR频谱仪、功率放大器、前置放大器、收发切换模块、便携式磁体模块和探头,所述NMR频谱仪设有发射(Tx)和门控(GATE)单向信号通路与一台功率放大器连接,设有收发转换门控(T/R GATE)与收发切换模块连接,所述功率放大器将发射信号放大后与收发切换模块连接,所述收发切换模块与所述探头连接,所述收发切换模块用于切换所述便携式核磁共振系统处于发射状态或接收状态,所述便携式磁体模块设有单边磁体,所述单边磁体设置为与目标检样器官相邻的身体表面贴合的人体工程学弧曲面,背面连接设有磁轭,背面磁场强度迅速衰减;所述机械振动激励装置设有主动驱动器和被动驱动器,所述被动驱动器与主动驱动器通过气动方式连接并贴合安放在目标检样器官相邻的身体表面,且在组织内部产生剪切波,所述控制台与所述NMR频谱仪连接,控制运行核磁共振脉冲序列指令,并接收NMR频谱仪采集到的核磁共振信号,完成实时数据处理;步骤二、连接检测部位:将所述被动驱动器、便携式磁体模块和探头固定贴合在目标检样器官对应的人体表面;步骤三、启动检测系统:点击系统启动键,运行所述便携式核磁共振弹性测量系统;步骤四、采集检样数据:所述NMR频谱仪通过所述机械振动激励装置的主动驱动器产生并传送振动到被动驱动器产生振动后在组织内部产生剪切波,在组织振动状态稳定后,所述NMR频谱仪通过所述探头按照弹性测量脉冲序列规定的时序发射一个90度射频脉冲,由于磁场梯度的 存在,ROI范围内一定层面厚度内的自旋将被激发,经过一定的振动周期后,施加180度脉冲,在所述180度脉冲之后,自旋聚相,检测回波信号并传输回控制台完成计算;在至少一种设置中,将通过部分运动编码缩短回波时间或多次信号累加或二者的组合来提高SNR;为了提高相位敏感度,在至少一种设置中,将施加多个180度射频脉冲;
- 根据权利要求1所述一种便携式核磁共振器官弹性无创定量检测方法,其特征在于,所述便携式磁体模块由稀土永久磁性材料构成,体积小、重量轻,支持手持或支架挂载,便于调整到适合受检者的仰卧、俯卧、坐姿或站姿体位。
- 根据权利要求1所述一种便携式核磁共振器官弹性无创定量检测方法,其特征在于,所述AP(A-P)方向为剪切波传播方向,LR(L-R)方向为组织内质点做简谐振动的位移方向,所述AP(A-P)方向和LR(L-R)方向相互垂直。
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