• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Viscosity is included in the quantification by an ultrasound imaging system. The logarithm of a motion spectrum as a function of time is determined (36, 38) for each of the various locations subjected to a shear wave or the like. The resolution (40) using the logarithm as a location function gives the complex wave number. Various viscoelasticity parameters, such as a loss module and a storage module, are determined (34) from the complex wave number.
    公开号:FR3034975A1
    申请号:FR1653349
    申请日:2016-04-15
    公开日:2016-10-21
    发明作者:Liexiang Fan；Yassin Labyed
    申请人:Siemens Medical Solutions USA Inc；
    IPC主号:
    专利说明:

    [0001] BACKGROUND The present embodiments relate to ultrasound imaging. In particular, ultrasound imaging of viscoelasticity is improved.
    [0002] Several commercial ultrasound systems provide quantitative values or tissue stiffness images, such as measured rigidity using shear wave imaging. Rigidity is estimated by assuming that the fabric is purely elastic (ie assuming that the viscosity is negligible). Different approaches are used to measure stiffness. These different approaches can focus on different bands of the shear wave frequency spectrum even assuming that the tissue is purely elastic. For example, some approaches find a displacement peak caused by the shear wave, while others find a peak in a derivative of shifts. The derivative function modifies the measured frequency band. As a result, different ultrasound systems give different values for rigidity or shear wave parameter, even for the same fabric. In addition, human tissue is viscoelastic, so that a shear wave dispersion is present. Different shear wave frequencies move at different speeds. The dispersion is governed by the storage module pi and the loss module p2 dependent on the frequency. BRIEF SUMMARY As an introduction, the preferred embodiments described below include methods, instructions, and systems for quantification in ultrasonic viscoelasticity imaging. Viscosity is included in the quantification by an ultrasound imaging system. The logarithm of a displacement spectrum as a function of time is determined for each of the various locations subjected to a shear wave or the like.
    [0003] The resolution using the logarithm as a location function gives the complex wave number. Various viscoelasticity parameters, such as a loss module and a storage module, are determined from the complex wave number. In a first aspect, a method is proposed for quantification in ultrasound imaging of viscoelasticity. An ultrasound system measures a time displacement at first and second tissue locations within a patient in response to pulse excitation. A processor applies a Fourier transform in the time of travel in time for each of the first and second locations. The processor calculates a logarithm of transformation results, and resolves for a complex wave number from the logarithm of the results. A value for a frequency dependent viscoelastic parameter is determined with the complex wave number. The value for the fabric is outputted to a display. In embodiments, the method may include transmitting acoustic excitation in a patient, the pulse excitation including acoustic excitation; wherein the measurement of displacements comprises repetitive scanning of the first and second locations with ultrasound. The step of measuring displacements at the first and second locations may include transmitting ultrasound to the tissue and receiving the reflections from the transmission, the ultrasound transmission and reception being performed a multiple number of times, and the detection of the displacement from the reflections of the multiple reception. In embodiments, the measurement comprises measuring the displacements at the first and second locations caused by a shear wave resulting from the pulse excitation. In embodiments, the measurement of time displacements at the first and second locations comprises measuring the displacements after the pulse excitation.
    [0004] In embodiments, the determination of the value comprises determining a storage module, a loss module, a shear modulus, a viscosity, or combinations thereof.
    [0005] In embodiments, determining the value for the frequency dependent viscoelastic parameter includes determining as a function of a range of different frequencies. In embodiments, the determination comprises the determination with both an amplitude and a phase of the displacements in time. In a second aspect, a computer-readable nonvolatile storage medium has, stored therein, data representing instructions executable by a processor programmed for quantification in viscoelastic ultrasound imaging. The storage medium includes instructions for determining tissue displacements as a function of time in a patient, estimating a loss module, a storage module, or both, as a function of the frequency of tissue displacements, and delivering at the output the loss module, the storage module, or both.
    [0006] In embodiments, the determining step includes determining the tissue displacements as a function of time for each of a plurality of locations, and wherein the estimation comprises estimating from logarithms of spectra. tissue displacements as a function of time for locations.
    [0007] In embodiments, the determining step includes determining tissue displacements as a function of time for each of a plurality of locations, and wherein the estimate comprises the estimate as a phase function and amplitude of tissue displacements for locations.
    [0008] In a third aspect, a system is proposed for quantification in ultrasound imaging of viscoelasticity. A transducer is configured to transmit pulsed acoustic excitation to a patient and configured to scan a region of the patient with ultrasound. A receive beam former is configured to generate data representing the region at different times after the pulse acoustic excitation. The data is generated from the scan with ultrasound. A processor is configured to estimate a pulse induced acoustic excitation induced tissue displacement and to calculate a viscoelasticity property from an amplitude and a phase of tissue displacements at different locations in the region. A display is configured to display an image representing the property of viscoelasticity. In embodiments, the processor is configured to compute as log logarithms tissue displacements over time for locations. Other aspects and advantages of the invention are discussed below in conjunction with the preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS The components and figures are not necessarily to scale, the emphasis being rather placed on the illustration of the principles of the invention. In addition, in the figures, like reference numerals designate corresponding parts in all the different views. Figure 1 is a process diagram of an embodiment of a method for quantification in ultrasonic viscoelasticity imaging; Figure 2 shows examples of viscoelasticity parameter graphs in a phantom of elasticity. Figure 3 shows examples of viscoelasticity parameter graphs in a viscoelastic phantom, and Figure 4 shows examples of viscoelasticity parameter graphs in a patient's liver; Figure 5 is an example of quantification in ultrasonic viscoelasticity imaging with quantities determined as a function of frequency; and Figure 6 is a block diagram of an embodiment of a system for quantification in viscoelastic imaging.
    [0009] DETAILED DESCRIPTION OF THE DRAWINGS AND EMBODIMENTS TODAY PREFERRED In quantitative imaging of viscoelasticity, the shear wave equation is solved in the frequency domain. The viscoelasticity wave equation is given by: ## EQU1 ## y, z) μiv2s (t, x, y, z) = W p VS = (3) 3p where s (txyz) is the particle displacement (m), pi is the shear modulus (kPa), p2 is the shear viscosity (Pa-s), E is the Young's modulus (kPa), vs is the shear wave velocity, and p is the density (kg / m3). The shear modulus has a known relationship with the storage module, and the shear viscosity has a known relationship with the loss module. Equation 1 assumes that the stress components are linear functions of the deformation components and their first derivatives in time. The second term of Equation 1 is a viscosity term, frequently ignored when measuring rigidity with ultrasound. Equation 1 can be used to estimate any of the viscoelasticity parameters. Using the displacement spectrum, the viscosity term is not ignored to obtain a stable solution. The shear storage modulus, the shear loss modulus, the shear attenuation, and / or the phase velocity are estimated over a bandwidth of the propagating shear wave. Estimates of viscoelasticity parameters can improve the diagnostic capability of ultrasound.
    [0010] Figure 1 shows a method for quantification in ultrasound imaging of viscoelasticity. The method uses the spectrum of displacements in time. By taking the logarithm of the spectra of different locations, the viscoelasticity parameters can be solved as a function of the frequency without using a second derivative, which can result in noisy measurements. (2) The method is implemented by the system of Figure 6 or a different system. An ultrasound system, such as a system with a transducer and a beamformer, performs the transmission and detection actions 30 and 32. An ultrasound system processor or a different computer performs the action estimation. 34 and the output output of the action 42 to a display, a speaker or other device. Different components can perform any one or more actions. Additional, different or fewer actions may be planned. For example, actions 36, 38, and 40 represent an example for an estimate, but other actions may be used. In another example, the action 30 is not executed and the source of stress is provided by the body, manually, using a striker, or by some other mechanism. Action 42 is optional. The actions are executed in the order described or shown, but can be executed in other orders.
    [0011] In action 30 of Figure 1, acoustic excitation is transmitted in a patient. Acoustic excitation acts as pulse excitation. For example, a 400 cycle transmission waveform with power levels or amplitude peaks similar to or greater than mode B transmissions for tissue imaging is transmitted. In one embodiment, the transmission is a radiation force sequence applied to the field of view. Any acoustic radiation force imaging (ARFI) sequence may be used. The transmission is configured by power, amplitude, timing, or other characteristic to cause stress on a tissue sufficient to move the tissue in one or more locations. For example, a transmission focus is positioned near a bottom, center of the field of view to cause movement throughout the field of view. Transmission can be repeated for different subregions.
    [0012] The excitation is transmitted from an ultrasound transducer. Excitement is an acoustic energy. The acoustic energy is focused, resulting in a three-dimensional beam profile. The excitation is focused using phase and / or mechanical control. The excitation can be de-focused in one dimension, such as the elevation dimension. The excitation is transmitted in a tissue of a patient. At action 32, a movement response profile in the patient is determined. For example, the displacement profiles as a function of time are determined for each of the various locations spaced from the shear wave origin, xo (i.e. the shear wave origin at the focus). The excitation causes a displacement of the tissue. A shear wave is generated and propagates from the focal region. As the shear wave moves through the tissue, the tissue is displaced. Longitudinal waves or other causes of displacement may be used. The tissue is forced to move in the patient. Displacement caused by force or strain is measured. Displacement is measured over time in different locations. The displacement measurement can begin before the constraint or pulse is complete, such as using a different frequency or coding. As an alternative, the displacement measurement begins after the pulse is complete. Since the shear wave causing movement in the tissue spaced from the constraint point or region takes time to move, moving from a rest state or partially forced to a maximum displacement and then to a state of rest can be measured. Upon cessation of the pulse, the shear wave generated moves from the focus region. As the shear wave passes through each location, displacement increases, reaches a peak, and then falls. Alternatively, the displacement is measured only when the tissue returns to rest. The measure is that of the quantity or size of the displacement. The fabric is moved in any direction. The measurement can be along the direction of the most important movement. The size of the motion vector is determined. Alternatively, the measurement is along a given direction, such as perpendicular to the scan line, whether the tissue is more or less displaced in other directions.
    [0013] Displacement is detected with ultrasound scanning. A region, such as a region of interest, an entire field of view, or a subregion of interest, is scanned with ultrasound. Over a given duration, ultrasound is transmitted to the tissue or region of interest. Any motion imagery known today or developed later may be used. For example, pulses with durations of 1 to 5 cycle (s) are used with an intensity of less than 720 mW / cm2. Pulses with other intensities can be used. Echoes or reflections of the transmission are received. the echoes are formed into bundles, and the data formed into bundles represent one or more locations. Multibeam reception (eg, 4, 8, 16, 32, or other number of lines in response to each measurement transmission) may be used. To detect displacement, ultrasonic energy is transmitted to the tissue undergoing movement and energy reflections are received. Any sequence of transmissions and receptions can be used. By executing the transmission and reception a multiple number of times, data representing a region in one, two or three dimensions at different times are received. Transmission and reception are performed multiple times to determine a shift due to displacement. By repeatedly scanning with ultrasound, the position of the tissue at different times is determined. Echoes are detected using B-mode or Doppler detection. Displacement is detected from the differences for each spatial location. For example, the speed, variance, intensity pattern shift (eg tracking tracking), or other information is detected from the received data as the displacement. In one embodiment using mode B data, the data of different scans are correlated. For example, a current data set is correlated with a set of reference data. Different translations and / or relative rotations between the two sets of data are executed. The location of a subset of data 3034975 9 centered at a given location in the reference set is identified in the current set. The reference is a first set of data or data from another scan. The same reference is used for all motion detection or reference data changes in a continuous or moving window. The correlation is in one, two or three dimensions. For example, a correlation along a scan line away from and to the transducer is used. For two-dimensional scanning, translation is along two axes with or without rotation. For a three-dimensional scan, the translation is along three axes with or without rotation around three axes or less. The level of similarity or correlation of the data at each of the different offset positions is calculated. The translation and / or rotation with the greatest correlation represents the motion vector or offset for the moment associated with the current data compared to the reference. Any correlation known today or developed later can be used, such as cross-correlation, pattern matching, or a minimum sum of absolute differences. A tissue structure and / or shimmer are correlated. Using Doppler detection, a clutter filter passes information associated with a moving tissue. The velocity of the tissue is derived from multiple echoes. The speed is used to determine the displacement to or away from the transducer. Alternatively, the relative difference between speeds in different locations may indicate a constraint or displacement.
    [0014] The distance magnitude of the motion vector over time relative to reference data gives the displacement as a function of time. the analysis period is greater than about 10 milliseconds, but may be longer or shorter. At action 34, one or more viscoelasticity parameter (s) are estimated. For example, the loss module, the storage module, or both are estimated. The loss module and the storage module correspond to the viscosity and the shear modulus, respectively. In other embodiments, the known relationships between the storage module and the shear modulus and / or between the loss modulus and the viscosity are used to derive one from the others. In yet other embodiments, the shear modulus and / or viscosity are estimated instead of the storage module and the loss module. A value for the viscoelasticity parameter is estimated for a location. For example, a user selects a location on an ultrasound image. In response, the value for the viscoelasticity parameter is output. Values for different locations may be estimated, such as the estimate for locations in a region of interest and the display of an image where pixel values are modulated as a function of the values. The viscoelasticity parameter is estimated as a function of frequency from tissue displacements as a function of time.
    [0015] Rather than using spatial derivatives, the estimate is based on logarithms of spectra of tissue displacements as a function of time for each of the locations. The value for the viscoelasticity parameter is determined from the logarithms of spectra at the different locations. The estimate uses both the phase and the amplitude of the tissue displacements for the locations. By analyzing the amplitude and phase information of the displacement spectrum, the complex wave number is estimated. The various frequency dependent viscoelastic parameters can be obtained from the complex wave number. The estimate makes use of all available spectrum of displacement data rather than just amplitude. Actions 36, 38 and 40 represent an exemplary embodiment for performing the estimate of action 34. In other embodiments, additional, different or fewer actions are provided. For example, action 36 is executed, but actions 38 and / or 40 are not executed. At action 36, a processor applies a Fourier transform over time. Any transform to the frequency domain may be used, such as fast Fourier transform (FFT). Displacements as a function of time for a given location are transformed. The displacement profile is transformed into a profile as a function of the frequency. The processor calculates a spectrum of displacements in time. Separate spectra are calculated for separate spatial locations. For each space location, the displacements as a function of time are transformed by a Fourier transform. The Fourier transform is applied at each location independently of the displacements of the other locations. The transform gives a set of spectra for a respective set of locations. Any number of locations can be used, such as two or more. In other embodiments, a given spectrum is calculated from the displacements in more than one location.
    [0016] The complex wave number and the resulting viscoelasticity parameters can be calculated from the frequency domain displacements. To estimate the frequency dependent viscoelastic parameters, the frequency domain viscoelasticity wave equation is given by: ## EQU1 ## where S (w, x) is the spectrum of displacement s (t, x) at the lateral position x, w is the angular frequency, and h is the complex wave number. The complex wave number is given by:, 2 1 h = () i iii (c0) + iti2 ((o) where p is the density of the fabric, i is the imaginary component, and pi (w) and p2 (w) are the storage module and the loss module, respectively Density can be assumed or treated as a constant Any density can be used, such as 1000 kg / m3 Equation (4) is a generalization of Equation (1) in the frequency domain (i.e. the deformation components are linear functions of the stress components and their first-order or higher temporal derivatives.) This generalization (5) results in modules frequency-dependent storage and loss Equation 5 is a second-order differential equation and its solution is given by: S (co, = So (co, xo) eih (OE)) x (6 ) = So (u), xo) e (w) x ea (co) x where So (w, xo) is the spectrum of displacement at lateral position xo (i.e. shear wave rigidity), k (w) is the wave number, and a (w) is the attenuation coefficient. The parameters k (w) and a (w) are given by: k (co) = -9i (h (w)) (7) 10 a (co) = Zs (h (w)) (8) where 9 is the real part and Z's is the imaginary part of the complex wave number. At action 38, the processor calculates a logarithm of the results of the transformation. The logarithm is determined for each spectrum. For each location, the logarithm of the frequency response of the displacements as a function of time is calculated. Any logarithm can be used. In one embodiment, the natural logarithm is used. To determine the complex wave number, the natural logarithm of Equation 6 is represented as: ln (S (co, x)) = ln So (w, xo) + ihx (9) Equation 9 defines a line for each frequency as a function of the location, x. At action 40, the processor resolves for the complex wave number. The logarithm of the spectra as a function of the location defines a slope. The resolution of Equation 9 for the complex wave number, h, gives h = 1. n (S (co, x)) Sx Any solution finding the slope for a given frequency can be used. The slope between the first and second locations of the spectral logarithm indicates the complex wave number. The slope is that of an imaginary component. (10) In one embodiment, the processor applies a linear least squares adjustment to the logarithms. The least squares linear fit of the logarithm of the spectra as a function of location indicates the slope of the complex wave number. In other embodiments, a spatial derivative is used to calculate the number. complex wave. Other slope determinations may be used. To return to action 34, the value for one or more frequency dependent viscoelastic parameter (s) is estimated from the complex wave number. Since the parameters depend on the frequency, values for the parameters at different frequencies are determined, or a value for a desired or representative frequency is determined. Any viscoelasticity parameter can be estimated from the complex wave number, such as a storage modulus, a loss modulus, a shear modulus, a viscosity, a phase velocity (i.e. frequency), attenuation, or combinations thereof. Using Equation 5, the processor estimates the storage module and the frequency-dependent loss module as: (to) = Pw29 (1 *) (11) μ2 (w) = P (02Z-5 (1 * ) (12) Using Equations 7 and 8, the processor estimates phase velocity and frequency dependent shear wave attenuation as: C (W) = ci) = k (co) 9i ( co) a (w) = 53 (h) Further calculations for deriving values as a function of the frequency for any of the parameters may be used. Equations 11 to 14 show that the frequency-dependent viscoelastic parameters simply follow from the complex wave number, h, calculated in Equation 10. Figures 2 to 4 show examples of parameter estimation of 30 viscoelasticity. Figure 2 shows the parameters calculated from a phantom of elasticity. Figure 3 shows the parameters calculated from a phantom of (13) (14) viscoelasticity. Figure 4 shows the parameters calculated from a liver of a patient. Figures 2 to 4 each show an example of the shear modulus (e.g. storage module) (Equation 11), shear viscosity (e.g. loss modulus) (Equation 12), velocity phase (Equation 13), and shear wave attenuation (Equation 14). Phase velocity graphs show a phase velocity processing as viscoelastic. The values of the parameters are shown as a function of the frequency, which itself may assist in a diagnosis. Group values can be determined. A group value is for the parameter over a range of frequencies. For example, an average over a frequency range is calculated. As another example, a derivative over a frequency range is calculated. Other functions, such as an integral, a difference, a variance, or other statistics can be calculated from the values for different frequencies. The viscoelasticity parameter at specific frequencies and / or a frequency range can be determined. The viscoelasticity parameter is determined with both amplitude and phase of displacements in time. The assumption that shear modulus and shear viscosity are independent of frequency is not used. An adjustment to a model is not used. The viscoelasticity parameter is resolved as a function of the frequency. Only one pulse excitation is required, so that the values are estimated without information in response to additional pulsed excitations. A single ARFI thrust pulse is sufficient to estimate the viscoelasticity parameters as a function of frequency. In other embodiments, information in response to more than one pulse excitation is used to estimate a value of one or more viscoelasticity parameter (s). The calculation of the value is performed without a spatial derivative (for example without a second-order spatial derivative) of the measurement of the displacements at the output of the value. All viscoelasticity parameters can be computed without a second-order spatial derivative, resulting in a more stable solution in a low signal-to-noise ratio shear wave imaging environment. In other embodiments, a spatial derivative is used. At action 42, the value or values are / are outputted to the display. The value for the loss module, storage module, shear modulus, viscosity, phase velocity, attenuation or combinations thereof is outputted. The value or values is / are 10 for a given frequency. Multiple values can be output for a given parameter at different frequencies. A group value, such as a combination of values for a parameter at different frequencies, may be output. The output may be text, such as text on or adjacent to an ultrasound image. The text can be alphanumeric. Figure 5 shows an example of an ultrasound image. In response to a user placing a grid at a location, a graph of phase velocity, loss module, storage module, and frequency attenuation is created for that grid location. . Graph 20 is a chart or spreadsheet of the values of viscoelasticity parameters at different frequencies. Additional, different or fewer information may be given. In one embodiment, a graph or graphics is / are outputted. For example, one or more of the graphs shown in Figure 4 are / are outputted. The graphics can cover any range of frequencies, such as frequencies in the transducer bandwidth. In other embodiments, an image is generated from the value or values. For example, a value is calculated for each of a plurality of locations. The solution for the value of a given location is based on spectra in a kernel centered at the location. The kernel defines a spatial (e.g. unidimensional) window around the location of interest. By adjusting the kernel at other locations, values for the parameter are calculated for different locations. Any parameter or combination of parameters may be used. any frequency or group value can be used.
    [0017] The spatial distribution of the value is mapped to pixel values. The pixels are modulated, at least in part, by the values of viscoelasticity parameters. Other outputs can be used. By outputting the value for the tissue of a patient, diagnostically useful information can be outputted. By measuring movements with ultrasound, viscoelasticity information relating to the tissue of interest of a patient can be measured and output. Viscoelasticity imaging provides more information on the mechanical properties of tissues than shear wave imaging assuming an operation on elastic tissue. The value for the viscoelasticity parameter is output alone or with other information. For example, a mode B image is also outputted. A shear velocity and / or other electrographic tissue stiffness imaging may be outputted with the values of viscoelasticity parameters. Figure 6 shows an embodiment of a system for quantification in ultrasound imaging of viscoelasticity. The system 10 implements the method of Figure 1 or other methods. The system 10 includes a transmission beamformer 12, a transducer 14, a receiver beamformer 16, an image processor 18, a display 20, and a memory 22. Additional, different or lesser components may be provided. For example, a user input is provided for user interaction with the system. As another example, a separate processor, such as a general or control processor, is provided to derive displacements and compute viscoelasticity parameters.
    [0018] The system 10 is an ultrasound imaging system for medical diagnosis. In other embodiments, the image processor 18, the display 20, and / or the memory 22 are part of a personal computer, a workstation, a PACS station, or the like. arrangement at a single location or distributed over a network for real-time or post-acquisition imaging with an ultrasound scanner. Transmission beamformer 12 is an ultrasonic transmitter, memory, blower, analog circuit, digital circuit, or combinations thereof. The transmission beamformer 12 is configured to generate waveforms for a plurality of channels with different or relative amplitudes, delays, and / or phasing. At the transmission of acoustic waves from the transducer 14 in response to the generated waveforms, one or more beams (x) is / are generated. A transmission beam sequence is generated to scan a region in two or three dimensions. Vector, vector®, linear or other sector scan formats can be used. The same region is scanned a multiple number of times. For flow or Doppler imaging and for shear imaging, a sequence of scans is used. In Doppler imaging, the sequence may include multiple beams on the same scan line before scanning an adjacent scan line. For shear imaging, an interlace of scans or frames may be used (ie scan the entire region before scanning again). In other embodiments, the transmission beamformer 12 generates a plane wave or a diverging wave for faster scanning. The same transmission beamformer 12 generates pulsed excitations or electric waveforms to generate acoustic energy to cause displacement. In other embodiments, a different transmission beamformer is provided to generate the pulse excitation. The transmission beamformer 12 causes the transducer 14 to generate high intensity focused ultrasound waveforms.
    [0019] Transducer 14 is a network for generating acoustic energy from electric waveforms. For a network, relative delays focus the acoustic energy. A given transmission event corresponds to acoustic energy transmission by different elements substantially at the same time given the delays. The transmission event creates a pulse of ultrasonic energy to move the tissue. The pulse is a pulse excitation. Pulse excitation includes waveforms with many cycles (eg, 500 cycles), but this over a relatively short time to cause tissue movement over a longer period of time. Transducer 14 is a 1, 1.25, 1.5, 1.75 or 2 dimensional array of piezoelectric or capacitive membrane elements. The transducer 14 includes a plurality of elements for transduction between acoustic and electrical energies. Receiving signals are generated in response to ultrasonic energy (echoes) impinging on the transducer elements 14. The elements connect with the channels of the transmit and receive beam formers 12, 16. Alternatively, only one mechanically focused element is used. The receiver beamformer 16 includes a plurality of channels 20 with amplifiers, delays, and / or phase rotators, and one or more summers. Each channel connects with one or more transducer elements. The receive beamformer 16 is hardware or software configured to apply relative delays, phases, and / or apodization to form one or more receive beams in response to each imaging transmission. A receive operation may not occur for echoes from the pulse excitation used to move a tissue. The receive beamformer 16 outputs data representing spatial locations using the receive signals. Relative delays and / or phasing and summation of signals from different elements results in beam formation. In other embodiments, the receive beamformer 16 is a processor for generating samples using a Fourier transform or the like. The receiver beamformer 16 may include a filter, such as a filter, for isolating information at a second harmonic or other frequency band with respect to the transmission frequency band. Such information may more likely include a desired tissue, a contrast agent, and or flow information. In another embodiment, the receive beamformer 16 includes a memory or buffer and a filter or adder. Two or more receive beams are combined to isolate information at a desired frequency band, such as a second harmonic, a cubic fundamental, or other band. In coordination with the transmission beamformer 12, the receive beamformer 16 generates data representing the region at different times. After the pulsed acoustic excitation, the receive beamformer 16 generates beams representing different lines or different locations in time. By scanning the region of interest with ultrasound, data (eg, beamformed samples) is generated. The receiver beamformer 16 outputs beamed data 20 representing spatial locations. Data for a single location, locations along a line, locations for a zone, or locations for a volume are outputted. A dynamic focus can be provided. The data can have different purposes. For example, different scans are run for mode B or tissue data and for motion. Alternatively, mode B data is also used to determine a displacement. As another example, data for viscoelastic parameter calculation and shear imaging are performed with a series of shared scans, and a B-mode or Doppler scan is performed separately or using some of the same data. The image processor 18 is a B-mode detector, a Doppler detector, a pulsed-wave Doppler detector, a correlation processor, a Fourier transform process, a specific integrated circuit, a general processor, a processor, and a processor. control, an image processor, a user programmable gate array, a digital signal processor, an analog circuit, a digital circuit, combinations thereof, or other device known today or later developed for detecting and processing information for display from ultrasound samples formed into bundles. In one embodiment, the processor 18 includes one or more detector (s) and a separate processor. The separate processor is a control processor, a general processor, a digital signal processor, a specific integrated circuit, a user-programmable gate array, a network, a server, a group of processors, a data path, combinations thereof or other device known today or later developed to determine displacements and calculate viscoelasticity properties. For example, the processor is configured by hardware and / or software to perform any combination of one or more of the actions 34 to 42 shown in Figure 1. The processor 18 is configured to estimate a tissue displacement induced by the pulsed acoustic excitation. By using correlation, tracking, motion detection, or other displacement measurement, the amount of positional shift of the tissue is estimated. The estimate is performed a multiple number of times over a period, such as before the tissue is displaced by the impulse, until after the tissue has substantially or fully returned to a state of rest (eg recovered from the stress caused by the pulse excitation). The processor 18 estimates tissue displacement as a function of time for each of a plurality of locations. The processor 18 is configured to calculate a viscoelasticity property. The amplitude and phase of tissue displacements at different locations in the region are used. By computing spectral logarithms of the tissue displacements in time for the locations, the processor 18 determines the complex wave number. The value or values 3034975 for one or more viscoelasticity parameter (s) is / are calculated from the complex wave number. The complex wave number represents the shear wave as a function of frequency, allowing a determination of the viscoelasticity parameters as a function of the frequency. The processor 18 operates according to instructions stored in the memory 22 or other memory for quantification in ultrasonic viscoelasticity imaging. The memory 22 is a non-transitory storage medium readable by computer. The instructions for carrying out the processes, methods and / or techniques discussed herein are provided on the computer readable storage medium OR memories, such as a cache, a buffer, a RAM, a removable medium, a hard disk or other computer readable storage medium. A computer readable storage medium includes various types of volatile and nonvolatile storage media. The functions, actions, or tasks illustrated in the figures or described herein are performed in response to one or more instruction sets stored in or on a computer readable storage medium. Functions, actions, or tasks are independent of the particular type of instruction set, storage medium, processor, or processing strategy and may be implemented by software, hardware, integrated circuits, firmware. , a microcode and the like, operating alone or in combination. Similarly, treatment strategies may include multiprocessing, multitasking or parallel processing, and the like. In one embodiment, the instructions are stored on a removable media device for playback by local or remote systems. In other embodiments, the instructions are stored at a remote location for transfer over a computer network or over telephone lines. In still other embodiments, the instructions are stored in a given computer, CPU, graphics processing unit or system. Display 20 is a CRT display, LCD display, projector, plasma display, or other display for displaying two-dimensional images or three-dimensional representations. The display 20 is configured by the processor 18 or other device by inputting the signals to be displayed as an image. The display 20 displays an image representing the viscoelasticity property for one or more location (s). image 5 represents the property of viscoelasticity in any way, such as a text, a graph or a modulation of pixels in a region of interest or a complete image. If the invention has been described above with reference to various embodiments, it should be understood that many changes and modifications can be made without departing from the scope of the invention. It is therefore intended that the foregoing detailed description be considered illustrative rather than limiting.
    权利要求:
    Claims (13)
    [0001]
    REVENDICATIONS1. A method for quantification in ultrasound imaging of viscoelasticity, the method comprising: measuring (30, 32), with an ultrasound system, a time displacement at a first tissue location in a patient in response to a pulse excitation; measuring (30, 32), with the ultrasound system, a time shift at a second tissue location in a patient in response to the pulse excitation; the Fourier transform (36), by a processor (18), in the time of travel in time for each of the first and second locations; computing (38), by the processor (18), a result logarithm of the transformation (36); the resolution (40), by the processor (18), of a complex wave number from the logarithm of the results; determining (34) a value for a frequency dependent viscoelastic parameter with the complex wave number; and outputting (42) up to a display the value for the fabric.
    [0002]
    The method of claim 1 further comprising: transmitting (30) acoustic excitation in a patient, the pulse driving comprising acoustic excitation; wherein the measurement (30, 32) of the displacements comprises repetitive scanning of the first and second locations with ultrasound.
    [0003]
    The method of claim 1 wherein measuring (30, 32) displacements at the first and second locations comprises transmitting ultrasound (30) to the tissue and receiving reflections from the transmission (30), the ultrasound transmission (30) and the reception being performed a multiple number of times, and detecting (32) the displacement from the reflections from the multiple reception.
    [0004]
    The method of claim 1 wherein the measurement (30, 32) comprises measuring (30, 32) displacements at the first and second locations caused by a shear wave resulting from the pulse excitation.
    [0005]
    The method of claim 1 wherein measuring (30,32) the time displacements at the first and second locations comprises measuring (30,32) the displacements after the pulse excitation.
    [0006]
    The method of claim 1 wherein determining (34) the value comprises determining (34) a storage module, a loss module, a shear modulus, a viscosity, or combinations thereof.
    [0007]
    The method of claim 1 wherein determining (34) the value for the frequency dependent viscoelastic parameter comprises determining (34) as a function of a range of different frequencies.
    [0008]
    The method of claim 1 wherein the determination (34) comprises determining (34) with both an amplitude and a phase of the displacements in time.
    [0009]
    A computer-readable non-transitory storage medium having, stored therein, data representing executable instructions by a processor (18) programmed for quantification in ultrasonic viscoelastic imaging, the storage medium including instructions for : 3034975 determine (32) tissue displacements as a function of time in a patient; estimating (34) a loss module, a storage module, or both as a frequency function from the tissue displacements; and outputting (42) the loss module, the storage module, or both.
    [0010]
    The computer-readable non-transit storage medium of claim 9 wherein the determination (32) comprises determining (32) tissue displacements as a function of time for each of a plurality of locations, and wherein the estimate (34) comprises estimating (34) from logarithms of spectra of tissue displacements as a function of time for locations. 15
    [0011]
    The computer-readable non-transit storage medium of claim 9 wherein the determination (32) comprises determining (32) tissue displacements as a function of time for each of a plurality of locations, and wherein estimate (34) includes estimation (34) as a function of phase and amplitude of tissue displacements for locations.
    [0012]
    A system for quantification in ultrasonic viscoelastic imaging, the system comprising: a transducer (14) configured to transmit pulsed acoustic excitation into a patient and configured to scan a region of the patient with ultrasound; a receive beamformer (16) configured to generate data representing the region at different times after the pulse acoustic excitation, the data generated from the ultrasound scan; a processor (18) configured to estimate pulsed acoustic excitation-induced tissue displacement and to calculate a viscoelasticity property from an amplitude and a phase of tissue displacements at different locations in the region ; and a display (20) configured to display an image representing the viscoelasticity property.
    [0013]
    The system of claim 12 wherein the processor (18) is configured to calculate as spectral logarithms tissue displacements over time for the locations. 5 10
    类似技术:
    公开号 | 公开日 | 专利标题
    FR3034975A1|2016-10-21|
    FR3005563B1|2019-10-11|CLEAR MEASUREMENTS OF TISSUE PROPERTIES IN ULTRASONIC MEDICAL IMAGING
    KR101868381B1|2018-06-18|Solving for shear wave information in medical ultrasound imaging
    FR2982475A1|2013-05-17|ADAPTIVE IMAGE OPTIMIZATION IN INDUCED WAVE ULTRASONIC IMAGING
    KR102170630B1|2020-10-27|Measuring acoustic absorption or attenuation of ultrasound
    FR3003153A1|2014-09-19|ULTRASONIC ARFI DISPLACEMENT IMAGING USING AN ADAPTIVE TIMING INSTANCE
    FR3003154A1|2014-09-19|ESTIMATING THE FAT FRACTION USING ULTRASONICS FROM SHEAR WAVE PROPAGATION
    KR102051293B1|2019-12-03|Classification preprocessing in medical ultrasound shear wave imaging
    FR2986701A1|2013-08-16|SHEAR WAVE CHARACTERIZATION ON AXIS WITH ULTRASOUND
    CN104510499B|2019-12-20|Shear wave detection in medical ultrasound imaging
    FR2971695A1|2012-08-24|VISCOELASTICITY MEASUREMENT USING PHASE AMPLITUDE MODULATED ULTRASONIC WAVE
    FR3031448A1|2016-07-15|
    KR102332464B1|2021-11-26|Shear wave estimation from analytic data
    JP2005152648A|2005-06-16|Method and system for motion-adaptive type spatial synthesis
    FR3039981A1|2017-02-17|
    FR3047405A1|2017-08-11|
    US10799208B2|2020-10-13|Compressional sound speed imaging using ultrasound
    FR3053882A1|2018-01-19|CHARACTERIZATION OF TISSUE BY MEDICAL DIAGNOSTIC ULTRASOUND
    FR2986960A1|2013-08-23|METHOD AND SYSTEM FOR VISUALIZATION OF ASSOCIATED INFORMATION IN ULTRASONIC SHEAR WAVE IMAGING AND COMPUTER-READABLE STORAGE MEDIUM
    FR3049845A1|2017-10-13|
    FR3072870A1|2019-05-03|VISCOELASTIC ESTIMATION OF A FABRIC FROM SHEAR SPEED IN ULTRASONIC MEDICAL IMAGING
    FR3050104A1|2017-10-20|
    FR3085760A1|2020-03-13|Angles for ultrasonic shear wave imaging
    FR3079059A1|2019-09-20|Adaptive Filtering of Clutter in Ultrasonic Imaging Based on Acoustic Radiation Force
    FR3046693A1|2017-07-14|
    同族专利:
    公开号 | 公开日
    DE102016106998A1|2016-10-20|
    US10376242B2|2019-08-13|
    FR3034975B1|2020-02-21|
    KR20160124019A|2016-10-26|
    US20160302769A1|2016-10-20|
    KR101881876B1|2018-07-25|
    CN106037796A|2016-10-26|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US5625146A|1995-12-18|1997-04-29|The United States Of America As Represented By The Secretary Of The Navy|Method and system for determining axial modulus|
    US20040034304A1|2001-12-21|2004-02-19|Chikayoshi Sumi|Displacement measurement method and apparatus, strain measurement method and apparatus elasticity and visco-elasticity constants measurement apparatus, and the elasticity and visco-elasticity constants measurement apparatus-based treatment apparatus|
    CA2457376C|2003-10-14|2015-09-15|The University Of British Columbia|Method for imaging the mechanical properties of tissue|
    US8052602B2|2005-11-30|2011-11-08|Panasonic Corporation|Ultrasonic diagnostic apparatus|
    US8137275B2|2007-06-28|2012-03-20|Siemens Medical Solutions Usa, Inc.|Tissue complex modulus and/or viscosity ultrasound imaging|
    US8197408B2|2008-02-27|2012-06-12|Siemens Medical Solutions Usa, Inc.|Sparse tissue property measurements in medical ultrasound imaging|
    US8394026B2|2008-11-03|2013-03-12|University Of British Columbia|Method and apparatus for determining viscoelastic parameters in tissue|
    US8398550B2|2008-12-01|2013-03-19|The Board Of Trustees Of The University Of Illinois|Techniques to evaluate mechanical properties of a biologic material|
    CN101699280B|2009-10-15|2011-08-17|北京索瑞特医学技术有限公司|Method and device for ultrasonic and nondestructive detection of elasticity of viscoelastic medium|
    WO2011132014A1|2010-04-20|2011-10-27|Super Sonic Imagine|Imaging method and apparatus using shear waves|
    US8961418B2|2010-10-06|2015-02-24|Siemens Medical Solutions Usa, Inc.|Solving for shear wave information in medical ultrasound imaging|
    US8469891B2|2011-02-17|2013-06-25|Siemens Medical Solutions Usa, Inc.|Viscoelasticity measurement using amplitude-phase modulated ultrasound wave|
    CN102078205A|2011-03-04|2011-06-01|深圳市一体医疗科技股份有限公司|Displacement estimating method for measuring elasticity of viscoelastic medium and application method|
    US10357226B2|2012-03-12|2019-07-23|Mayo Foundation For Medical Education And Research|System and method for model-independent quantification of tissue viscoelastic properties using ultrasound|
    EP2903530B1|2012-10-01|2019-08-07|Mayo Foundation For Medical Education And Research|Shear wave attenuation from k-space analysis system|
    JP6002970B2|2013-02-25|2016-10-05|コーニンクレッカ フィリップス エヌ ヴェＫｏｎｉｎｋｌｉｊｋｅ Ｐｈｉｌｉｐｓ Ｎ．Ｖ．|Determination of the concentration distribution of acoustic dispersive elements|
    US9332962B2|2013-03-13|2016-05-10|Siemens Medical Solutions Usa, Inc.|Ultrasound ARFI displacement imaging using an adaptive time instance|
    US20140358447A1|2013-05-03|2014-12-04|Timothy Edwin Doyle|Instant, in-situ, nondestructive material differentiation apparatus and method|
    WO2015009339A1|2013-07-19|2015-01-22|Mayo Foundation For Medical Education And Research|System and method for measurement of shear wave speed from multi-directional wave fields|US9814446B2|2015-04-22|2017-11-14|Siemens Medical Solutions Usa, Inc.|Method and system for automatic estimation of shear modulus and viscosity from shear wave imaging|
    KR20210116268A|2020-03-12|2021-09-27|지멘스 메디컬 솔루션즈 유에스에이, 인크.|Liver disease activity estimation with ultrasound medical imaging|
    CN107505232B|2017-07-21|2019-09-03|无锡海斯凯尔医学技术有限公司|Motion information acquisition methods and device|
    EP3453336B1|2017-09-08|2020-11-04|Samsung Medison Co., Ltd.|Ultrasound imaging apparatus and control method thereof|
    US11154277B2|2017-10-31|2021-10-26|Siemens Medical Solutions Usa, Inc.|Tissue viscoelastic estimation from shear velocity in ultrasound medical imaging|
    WO2021212494A1|2020-04-24|2021-10-28|深圳迈瑞生物医疗电子股份有限公司|Viscosity and elasticity measurement method and ultrasonic measurement system|
    法律状态:
    2017-04-25| PLFP| Fee payment|Year of fee payment: 2 |
    2018-04-06| PLSC| Search report ready|Effective date: 20180406 |
    2018-04-12| PLFP| Fee payment|Year of fee payment: 3 |
    2019-04-25| PLFP| Fee payment|Year of fee payment: 4 |
    2020-04-10| PLFP| Fee payment|Year of fee payment: 5 |
    2021-04-19| PLFP| Fee payment|Year of fee payment: 6 |
    优先权:
    申请号 | 申请日 | 专利标题
    US14/688,965|US10376242B2|2015-04-16|2015-04-16|Quantitative viscoelastic ultrasound imaging|
    US14688965|2015-04-16|
    [返回顶部]