Additional diagnostic data in parametric ultrasonic medical imaging

Abstract

For parametric ultrasound imaging with an ultrasound scanner, values of a plurality of parameters are determined (12) for a patient's tissue using ultrasound. The determination (12) can be in response to a single activation (10), avoiding the user having to reconfigure and activate separately for each parameter. To aid diagnosis, one or more indicators of parameter measurement quality are computed and displayed (16) to the user. To further aid diagnosis, the patient's measured values are displayed (18) relative to published or population values.

Description

BACKGROUND

[0001] This embodiment relates to parametric ultrasound imaging. Parametric ultrasound measures a characteristic of the scanned tissue. The characteristic of the tissue is calculated using the scanned or detected data, rather than B-mode or flow-mode imaging. Parametric imaging provides quantitative values of tissue physical properties. Parametric imaging can be biomarker features derived from one or more parameters as an indicator of normal biological processes, pathogenic processes, or response to therapeutic intervention. Example types of parametric ultrasound imaging include quantitative imaging (e.g., nonlinear coefficient, frequency-dependent attenuation coefficient, frequency-dependent backscatter coefficient, or derived parameters such as fat fraction) and / or acoustic radiation force impulse (ARFI) imaging (e.g., shear wave velocity, complex storage modulus, complex loss modulus, or derived parameters such as inflammation index).

[0002] In many tissues, disease states are characterized by the presence of many conditions with varying degrees. For example, a liver can have steatosis, inflammation, and fibrosis simultaneously. Using medical ultrasound to obtain a comprehensive assessment of the tissue requires multi-parameter measurements of physical properties. The quality of the calculated parameters can vary from patient to patient and / or from different sonographer operators, so the calculated parameter values can have variable reliability. Diagnoses can rely on an ambiguous relationship of the calculated values to disease states. Parametric imaging can be difficult to interpret even for skilled physicians or sonographers. Diagnoses from multiple parameters can be even more difficult. SUMMARY

[0003] By way of introduction, the preferred embodiments described below include methods, instructions, and systems for parametric ultrasound imaging with an ultrasound scanner. Values of multiple parameters are determined for a patient's tissue using ultrasound. The determination can be in response to a single activation, avoiding the user having to reconfigure and individually activate each parameter. To aid in diagnosis, one or more indicators of parameter measurement quality are calculated and displayed to the user. To further aid in diagnosis, the patient's measured values are displayed relative to published values or population values.

[0004] In a first aspect, a method of parametric ultrasound imaging with an ultrasound scanner is provided. Multi-parameter ultrasound imaging of a patient is activated. The ultrasound scanner measures two or more parameters of the multi-parameter ultrasound imaging in response to one activation instance. An image of values of the two or more parameters is generated. A quality indicator for the measurement is displayed along with one or more of the values relative to a population.

[0005] In a second aspect, a system for parametric ultrasound medical imaging is provided. A beamformer is configured to scan tissue in a patient with a transducer. The scan is for a first and a second type of parametric ultrasound medical imaging. An image processor is configured to estimate a first value of the first type and a second value of the second type from the scan, to determine a first and a second quality indicator of the estimates of the first and second values, respectively, and to generate a first and a second panel showing the first and second values, respectively, relative to a published value of a disease state level. A display is configured to display the first and second values, the first and second indicators, and the first and second panels.

[0006] In a third aspect, a method of parametric ultrasound imaging with an ultrasound scanner is provided. The ultrasound scanner measures a first tissue property and a second tissue property of a patient. An image is generated showing the first and second tissue properties. A first and a second indicator of a measurement reliability of the first and second tissue properties, respectively, is displayed. A first and a second indicator of a measurement population statistic of the first and second tissue properties, respectively, is displayed.

[0007] The present invention is defined by the following claims, and no contents of this section should be taken as limiting those claims in any way. Further aspects and advantages of the present invention are discussed below in conjunction with preferred embodiments, and can be claimed independently or in combination later. BRIEF DESCRIPTION OF DRAWINGS

[0008] The components and various diagrams are not necessarily drawn to scale, emphasis instead being placed upon illustrating the principles of the invention. In addition, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0009] Figure 1 is a flowchart of one embodiment of a method of parametric ultrasound imaging with an ultrasound scanner;

[0010] Figure 2 illustrates an example image of multi-parametric ultrasound imaging;

[0011] Figure 3 illustrates an example display of quality indicators;

[0012] Figure 4 illustrates one embodiment of a display of a relationship to a population;

[0013] Figure 5 illustrates another embodiment of a display of a relationship to a population; and

[0014] Figure 6 is a block diagram of one embodiment of a multi-parametric ultrasound medical imaging system. DETAILED DESCRIPTION

[0015] Diagnosis based on multi-parameter ultrasound imaging can benefit from determination and visualization of associated information. For simultaneous multi-parameter ultrasound imaging, different tissue properties are measured based on a single button press. An indicator of the quality of each tissue property measurement is displayed. A panel of measurement values is displayed that indicates published values relative to different levels of disease state.

[0016] Figure 1 An embodiment of a method of parametric ultrasound imaging with an ultrasound medical scanner is shown. Multiple types of parameters based on ultrasound imaging are used for diagnosis. Due to variability of parametric imaging, one or more indicators of measurement quality are provided. To help understand the results of the measurement, which can be an absolute number, the results can be provided to a population or other research-based information. Indications of quality and relationships to other patients aid in diagnosis.

[0017] The method is implemented by Figure 6 a system or a different system. A medical diagnostic ultrasound scanner performs measurements by acoustically generating waves and measuring responses with a beamformer and transducer. An image processor of the scanner, computer, server, or other device estimates values of the parameters, indicators of quality, and population relationships. A display device is used to output images of the parameters, indicators of quality, and / or population relationships.

[0018] Additional, different, or fewer actions can be provided. For example, one of actions 14, 16, or 18 is not provided. As another example, action 10 is not provided, or is provided separately for each parameter being measured.

[0019] Actions are performed in the order described or shown (e.g., top to bottom or in numerical order). Other orders can be used. For example, actions 16 and 18 are performed simultaneously, such as by including the indicators of quality and population relationships in the same image or display. Actions 14, 16, and 18 can be performed simultaneously or in any order. Action 14 can be performed simultaneously with, before, or after actions 16 and / or 18.

[0020] In action 10, a user (e.g., sonographer operator) activates multi-parameter ultrasound imaging of a patient. In alternative embodiments, the ultrasound scanner is activated, such as in response to detection of a tissue of interest in a scan. A transducer is positioned at a window on or in the patient for scanning the tissue of interest. For example, a handheld transducer probe is positioned against the skin of a patient's abdomen for imaging the liver. Any tissue of the patient can be imaged.

[0021] An ultrasound scanner is configured for multi-parameter imaging. For example, an application of liver imaging is selected. Default or preset values configure the ultrasound scanner to scan a patient for measurement of multiple parameters. Alternatively, a user manually configures various programmable settings, such as beamformer or scan settings, to perform each, some, or all scans for multiple types of parameters.

[0022] An input or single activation is entered to cause performance of measurement of multiple parameters, such as measurement of all parameters. Rather than separately configuring and activating measurement of each parameter, one instance of activation triggers scanning for multiple types of parameters. For example, one instance of activation provides for measurement of two tissue characteristics without further activation. A user presses one button, adjusts a final setting, or otherwise triggers a scan, and then a scan is performed for multiple (e.g., all) parameters of interest. Alternatively, the ultrasound scanner detects tissue of interest or other event to automatically trigger scanning for multiple parameters based on a single or one trigger. In yet other alternatives, measurement of each parameter is triggered separately and sequentially.

[0023] In one embodiment, a single acquisition is triggered (e.g., a button press or another scan trigger). The single acquisition is a series of scans measuring two or more parameters without further user triggering or activation. Any combination of multi-parameter measurements can be performed in response to the single trigger or as part of the single acquisition. For example, one or more quantitative ultrasound measurements and corresponding scans are triggered. Example quantitative ultrasound scans can include any number N of fundamental frames, harmonic frames, and / or frames of different steering angles (e.g., M steering angles in M frames or M steering angles per frame). One or more ARFI metrics and corresponding scans are triggered. Acoustic push pulses, reference position measurements, and / or tracking scans are performed in the ARFI. One or more data frames of one parameter can be used to measure another type of parameter. For scans to acquire multiple frames, interleaving between scans of different types of parameters can be used. For example, during a single acquisition, quantitative ultrasound and ARFI sequences or frames are interleaved.

[0024] An ultrasound medical scanner scans tissue of a patient. A beamformer transmits acoustic beams and / or forms receive beams from acoustic echoes. An array of elements of a transducer converts between acoustic energy and electrical energy. The beamformer includes channels connected to the elements. The beamformer generates relatively delayed or phased electrical waveforms for the elements of a transmit aperture using a focusing profile. The transducer converts the electrical waveforms into acoustic energy that causes constructive interference at a focal position and along a scan line as a transmit beam. Acoustic echoes received at the elements are converted into electrical signals for the channels. The beamformer relatively delays and / or phases the electrical signals from different elements in a receive aperture and combines the delayed or phased signals. Dynamic focusing can be used in which the focal point is shifted along a receive line over time by using different focusing profiles due to different positions. The combination by beamforming provides a beamformed sample for each position or receive beam along a receive scan line. Any scan format can be used per frame, such as linear, sector or vector (Vector ).

[0025] In act 12, the ultrasound scanner measures multiple parameters of the multi-parameter ultrasound imaging. Two or more (e.g., first and second) tissue characteristics are measured. Values of the multiple parameters are determined for the tissue of the patient. Example tissue characteristics or parameters include quantitative ultrasound parameters (e.g., nonlinearity coefficient, frequency-dependent attenuation coefficient, frequency-dependent backscatter coefficient, and / or derived parameters (e.g., fat fraction index)) and / or ARFI parameters (e.g., shear wave velocity, complex modulus (storage and / or loss), and / or derived parameters such as fibrosis). One or more parameters can be determined from quantitative and ARFI metrics, such as an inflammation index.

[0026] Any now known or later developed parameters can be measured. Two or more types of parameters are measured in addition to or instead of B-mode, flow mode, or other non-parametric ultrasound metrics. In one embodiment, liver tissue is scanned. The parameters are any two or all three of fibrosis, inflammation, and fat fraction. These tissue characteristics are indicative of the disease state of the patient's liver and can be measured using ultrasound scanning.

[0027] In one embodiment, the image processor estimates or measures the fat fraction of the patient's tissue. The estimate or measurement is made by scanning the patient. The fat fraction is specific to the patient. The fat fraction of the patient is obtained using one or more characteristics of the patient. Some patients can have the same or similar fat fraction, but different patients can have different fat fractions. For ultrasound estimation of the fat fraction of tissue, an ultrasound medical scanner determines scattering and attenuation from the scanned tissue. Other combinations of quantitative ultrasound parameters can be used. Multiple quantitative ultrasound parameters can be used to measure the complexity of human tissue for accurate characterization of the tissue. For example, a multi-parameter approach is used to estimate liver fat fraction that combines quantitative parameters extracted from the received signals of different wave phenomena, such as scattering and attenuation of longitudinal waves, propagation and attenuation of shear waves, and / or propagation and attenuation of on-axis waves from acoustic radiation force impulse (ARFI) excitation. In one embodiment, the liver fat fraction is estimated by transmitting and receiving a sequence of pulses to estimate scattering parameters, and by transmitting and receiving a sequence of pulses to obtain shear wave parameters. Look-up tables based on empirical studies can be used to relate the various parameter values to fat fraction values.

[0028] In another embodiment, fibrosis is estimated. Fibrosis can be related to shear wave velocity. An ARFI scan is used to measure shear wave velocity. The level or grade of fibrosis is estimated with or without other information, such as patient clinical information and / or ultrasound-based information. Inflammation can be estimated from ultrasound information.

[0029] To measure scattering, an ultrasound scanner scans tissue with ultrasound. A series of transmit and receive events are performed to collect signals to estimate quantitative ultrasound scattering parameters. A measure of scattering measures the response of tissue to longitudinal waves transmitted from the ultrasound scanner. The scattering or echoes of longitudinal waves that impinge on the tissue are measured. Any measure of scattering can be used, such as the spectral slope of the log of the frequency-dependent backscatter coefficient.

[0030] An attenuation coefficient can be measured. A reference model approach is used, but other measures of attenuation coefficient can also be used. Acoustic energy has an exponential attenuation as a function of depth. A measure of acoustic intensity as a function of depth is performed before or without depth gain correction. To remove system effects, the measurement is calibrated based on the measure of acoustic intensity as a function of depth in the model. The measurement can be subject to less noise by averaging over a one-dimensional, two-dimensional, or three-dimensional region. The beamformed samples or acoustic intensity can be converted to the frequency domain, and the calculations are performed in the frequency domain.

[0031] Attenuation is measured as the slope of intensity as a function of depth. Other measures of attenuation can be used, such as shear wave attenuation with distance or time. Tissue displacement as a function of depth from the ARFI-induced longitudinal wave can be used to find the attenuation of the tissue. The maximum amount of displacement, displacement as a function of depth, and / or displacement as a function of time are used to calculate the attenuation. Other measures of propagation can be used instead of or as the attenuation. For example, measures of shear wave propagation or measures of displacement on axis (e.g., ARFI measures).

[0032] Various types of parameters can be measured in response to a single trigger input. The ultrasound scan for measuring two or more different parameters is triggered using one activation instance. The scan sequence for providing information for multiple types of parameters starts and ends due to one trigger event. Different sequences for different parameters are executed one after the other in sequence. Alternatively, the scans for different types of parameters are interleaved (e.g., scans in a first sequence corresponding to a first parameter (e.g., fat fraction) are interleaved with scans in a second sequence corresponding to a second parameter (e.g., fibrosis)).

[0033] The measurements of different parameters are for the same location(s). Alternatively, the measurements for different parameters are at different locations of the same tissue and / or region of interest.

[0034] The measurements are each performed for multiple locations, such as over a spatial distribution of the region of interest. Each or multiple parameters are measured for locations of a one-dimensional, two-dimensional, or three-dimensional distribution within the patient. Alternatively, one or more (e.g., all) parameters are measured for one location or region. For example, fat fraction, inflammation, and / or fibrosis are measured for a single location based on user selection of the location, and / or as one value for the region of interest.

[0035] In act 14, the ultrasound scanner (e.g., image processor) generates an image of the multiple (e.g., two or more) parameter values. The image is generated on a display or printer to show multiple tissue characteristics of the patient tissue. The ultrasound scanner or display device displays the image. In alternative embodiments, the generated image is stored or transmitted over a computer network. For example, the image is transmitted for storage in the patient's computerized medical record of a medical record database.

[0036] The image shows the values of different types of parameters. For example, different aspects of the image (e.g., color and gray scale or brightness) map to different parameters. Changes in color show changes in values of one type of parameter, and changes in brightness or gray scale show changes in values of another type of parameter. Alternatively, the values of different parameters are represented in different portions of the image, such as in different sections (e.g., quarters or halves) of the image. Figure 2An example is shown with the shear wave velocity map 20B, the fat fraction map 20C and the inflammation map 20D shown separately. The B-mode image 20A is also shown in one of the quadrants. The shear wave velocity map 20B, the fat fraction map 20C and the inflammation map 20D are shown as color overlays in the region of interest 22, with the remaining spatial representation of the tissue being a repetition of the B-mode image 20A. Other arrangements showing different parameter values can be used.

[0037] The image represents the spatial distribution of each of the plurality of parameters. Different values of a given parameter can be provided for different locations in the region of interest 22 or across the image. The parameter values are mapped to display values using a linear or non-linear mapping. The spatial distribution provides a one-, two- or three-dimensional representation of the parameter values. A table or other representation of the values for each parameter at a plurality of locations can be used. In alternative or additional embodiments, the image shows one value for each parameter. For example, a graph, colorization and / or alphanumeric text representing the value of the parameter for a single location is generated.

[0038] The image can include other information. For example, annotations, highlights, colorizations or overlays representing other information are provided.

[0039] The image shows two parameters simultaneously. In other embodiments, a sequence of images is generated, with each image in the sequence representing the value(s) of a different given parameter or set of parameters.

[0040] In actions 16 and 18, other information is determined and displayed. The other information helps in making a diagnosis from the ultrasound scan of the ultrasound scanner. Quality indicators for the measurements and / or the relationship of one or more of the values to a population are displayed. The other information is displayed in the image together with the value(s) of the different parameters, or separately. Actions 16 and 18 correspond to two different types of other information. The information of action 16 is displayed simultaneously or separately from the information of action 18.

[0041] The display of the quality indicators and / or the relationship is as part of the image. For example, Figure 2 The image of Fig. 4 shows four quality indicators 24, one for each image and corresponding parameter, and one for the B-mode image. It is possible that no quality indicator is provided for one or more of the parameters. In other embodiments, additional quality indicators are provided for each parameter. In yet other embodiments, the relationship is displayed with the image instead of or in addition to the quality indicators. In alternative embodiments, the display of the quality indicators and the relationship is separate from the image, such as being displayed as part of a radiology report separate from the generated image. The relationship and the quality indicators can be displayed separately or together.

[0042] In act 16, the ultrasound scanner (e.g., image processor) displays one or more quality indicators on a display. The quality indicators show an estimate(s) of the reliability of the tissue property measurements.

[0043] Any number of quality indicators can be provided for any given parameter. The user can select which quality metrics are displayed for which parameters.

[0044] Various quality indicators can be used, such as region of interest quality estimation, acquisition quality, and / or measurement consistency quality. Any of a variety of factors can be used for a given quality indicator. Any function, such as a weighted average, can be used to combine factors used to estimate a quality indicator.

[0045] For region of interest quality, the placement of the region of interest relative to the patient tissue is used to indicate quality before and / or after the measurement parameter. The homogeneity of the tissue in the region of interest (e.g., lack of variance), the presence of blood vessels, and / or the location relative to one or more landmarks (e.g., relative to the liver capsule or segment 8 of the liver) can be used.

[0046] For acquisition quality indicators, the quality of the ultrasound data acquired for a parameter is estimated. This estimation occurs after the acquisition of the scan data. The signal-to-noise ratio (SNR), the usable frequency band (e.g., the range of frequencies adequately sampled in the acquisition), and / or the deviation from a linear or other fit of the data can indicate the quality of the acquisition. Inadequate transducer contact, motion, shadowing, clutter noise, transducer failure, or other error sources in the acquisition can be estimated.

[0047] For measurement consistency, the quality of the parameter value is estimated. After the parameter is estimated, the quality of the estimate is determined. The variability of the measurement within the region of interest (e.g., due to tissue heterogeneity) and / or the variability due to different scan angles (e.g., due to tissue anisotropy) are used.

[0048] The quality indicators are based on empirical, mathematical functions, statistics, or other information. For example, fuzzy logic is used to determine the quality. In this approach, a membership function is defined empirically for each parameter (e.g., SNR, maximum displacement), and the outputs of each membership function are summed to generate a likelihood of the quality given the input parameters for a location. The maximum of the sum corresponds to the quality to be assigned. As another example, machine learning from a set of training samples or data with known ground truth values for quality is used to determine a statistical or matrix function of the quality. A probability function indicates the likelihood of each quality given a location, and the quality with the highest probability is selected. The quality determination is performed using a lookup table, a fuzzy logic function, a programmed function, or a matrix function.

[0049] The quality at each location depends on the data at that location, not the data at other locations. In alternative embodiments, spatial filtering or information from adjacent locations can be used to classify the quality at a given location.

[0050] The quality indicator(s) are displayed as a map, representing quality as a function of location. The quality at different locations is shown. Figure 2 An example is shown in which a small map 24 of the region of interest shows the quality selected by location. The quality estimated by location is mapped to the color, gray scale, brightness, or another feature of the small map 24. Larger or smaller spatial representations can be used. The map 24 can be interactive, such as where the map 24 is zoomed in by hovering or clicking on the map 24. Separate maps 24 can be provided for individual quality indicators. Alternatively, one quality indicator is used for each parameter, or the quality indicator displayed is a combination of multiple quality scores for the parameter.

[0051] In another embodiment, the quality indicator is a bar chart, a plot, a graph, or alphanumeric text. Figure 3 An example is shown in which the quality is provided for one location or for a region of interest. Measurements for the location or region are given for each parameter. UDFF is ultrasound-derived fat fraction, UIS is ultrasound inflammation score, and SWS is shear wave speed. For each of these parameters, three quality indicators are provided - region of interest (ROI), acquisition (ACQ), and variance or consistency (VAR). The color or gray scale of the bar chart indicates the estimated value of the quality. For example, the VAR quality indicator for SWS is low, while the ROI and ACQ are high. Three quality levels (low, medium, high) are provided. Other levels of resolution can be used.

[0052] In act 18, the ultrasound scanner (e.g., image processor) displays on the display one or more relationships of the measured values to population or published statistical data. The relationship shows where the parameter values measured for the patient fall along a spectrum of disease. Statistical data from other sources can reflect a grading or indexing of disease severity. By displaying the relationship, the severity of the given patient is represented in a way that conveys more diagnostic information. More metrics than absolute measures are provided to aid in reviewing the ultrasound imaging.

[0053] An indication of the relationship of the measured tissue properties to population statistics is displayed. Any of a variety of display formats can be used. In one embodiment, a histological grading is used. Figure 4An example box plot showing histological grading of liver assessment is shown. The measured parameters or tissue characteristics are UDFF, UIS, and SWS. The horizontal line 40 for each parameter represents the ultrasound measured value of that tissue characteristic. Disease states are divided into low, mild, moderate, and severe, but other divisions can be used. For each state, the box represents 50% of the range (e.g., 25%-75% of the cases), with the dashed horizontal line showing the median value, and the whiskers represent the maximum and minimum values for that state. Other box plots or histological grading representations of the relationship can be used (e.g., patient to population statistical data measured values).

[0054] The population information comes from available groupings, such as patients examined at a hospital, in a region, or as part of a study for each disease. For example, published meta-analysis data is used. Data from one or more studies or trials is aggregated to determine statistical data for disease states.

[0055] In another embodiment, the relationship indicates measured values relative to a receiver operator characteristic (ROC) curve. Population statistical information is used to form the ROC curve. The relationship is provided by plotting where the measured values are located along the ROC curve.

[0056] In yet another embodiment, the relationship is shown as a probability of membership. Population information indicates value ranges for each state of the disease. Bayesian analysis is used to compute likelihood functions. For example, the likelihood functions are P(fibrosis grade | SWS) = P(SWS | fibrosis grade) x P(fibrosis grade) / P(SWS); P(inflammation grade | UIS) = P(UIS | inflammation grade) x P(inflammation grade) / P(UIS); and P(fatty change grade | UDFF) = P(UDFF | fatty change grade) x P(fatty change grade) / P(UDFF).

[0057] Figure 5 An example is shown. The measured values for a patient are provided as a liver panel. The likelihood of each disease state for each parameter is given. For example, the patient is most likely (75%) to have mild fatty change, is likely (e.g., 40% each) to have moderate to severe inflammation, and is most likely (e.g., 50%) to have mild fibrosis. Other representations of the likelihood and / or relationship can be displayed.

[0058] Figure 6 An embodiment of a parametric ultrasound medical imaging system is shown. The system implements the method or other methods. Figure 1 Multiple parameters are measured. Values from the measurements are provided with quality indicators and relationships to other patients.

[0059] The system includes a transmit beamformer 60, a transducer 62, a receive beamformer 64, a user input 65, an image processor 66, a display 68, and a memory 67. Additional, different, or fewer components can be provided. For example, a network interface is provided for interacting with a database and / or computerized patient record.

[0060] The system is a medical diagnostic ultrasound imaging system. In alternative embodiments, the system is a personal computer, a workstation, a picture archiving and communication system (PACS) station, or other arrangement for real-time or post-acquisition imaging at the same location or distributed over a network.

[0061] The transmit and receive beamformers 60, 64 form a beamformer for scanning (e.g., transmit and receive operations) using the transducer 62. A sequence of pulses is transmitted and responses are received based on the beamformer's operation or configuration. The beamformer scans for measuring fat fraction and imaging tissue.

[0062] The transmit beamformer 60 is an ultrasound transmitter, memory, pulse generator, analog circuitry, digital circuitry, or combinations thereof. The transmit beamformer 60 is operable to generate waveforms for multiple channels with different or relative amplitudes, delays, and / or phasing. One or more beams are formed as sound waves are transmitted from the transducer 62 in response to the generated electrical waveforms. A series of transmit beams are generated to scan a two-dimensional or three-dimensional region. Sector, Vector ), linear, or other scan formats can be used. Different scan line angles, F numbers, and / or waveform center frequencies can be used for multiple scans of the same region. For flow or Doppler imaging and shear imaging, a scan sequence is used along the same line or multiple lines. The sequence can include, in Doppler imaging, multiple beams along the same scan line before scanning an adjacent scan line. For shear imaging, scan or frame interleaving can be used (i.e., scanning an entire region before scanning again). Line or line group interleaving can be used. In alternative embodiments, the transmit beamformer 60 generates plane waves or diverging waves for faster scanning.

[0063] The transducer 62 is an array that generates acoustic energy from electrical waveforms. For an array, relative delays or phasing focus the acoustic energy. A given transmit event corresponds to different elements transmitting acoustic energy at substantially the same time with a given delay.

[0064] The transducers 62 are 1-dimensional, 1.25-dimensional, 1.5-dimensional, 1.75-dimensional, or 2-dimensional arrays of piezoelectric or capacitive thin film elements. The transducers 62 include a plurality of elements for converting between acoustic and electrical energy. The receive signals are generated in response to ultrasound energy (echoes) impinging on the elements of the transducers 62. The elements are connected with channels of the transmit and receive beamformers 12, 16. Alternatively, a single element with a mechanical focus is used.

[0065] The receive beamformer 64 includes a plurality of channels with amplifiers, delay elements, and / or phase rotators, and one or more adders. Each channel is connected with one or more transducer elements. The receive beamformer 64 is configured by hardware, firmware, or software to apply relative delays, phases, and / or apodization to form one or more receive beams in response to each imaging transmission. The receive beamformer 64 outputs data representing spatial locations using the receive signals. The relative delay and / or phasing and summing of signals from different elements provides beamforming.

[0066] The receive beamformer 64 can include filters, such as filters to isolate second harmonic or other band of information relative to the transmit band. Such information is more likely to include desired tissue, contrast, and / or flow information. In another embodiment, the receive beamformer 64 includes a memory or buffer and a filter or adder. Two or more receive beams are combined to isolate information of a desired band, such as second harmonic, third fundamental, or another band.

[0067] In cooperation with the transmit beamformer 60, the receive beamformer 64 generates data representing the region. By scanning the region of interest with ultrasound, data (e.g., beamformed samples) are generated. By repeating the scan, ultrasound data representing the region at different times, frequencies, and / or scan angles is acquired. Different scans can be performed for measuring values of different parameters. One or more scans or frames of data (ultrasound data representing the response from the patient at a given time or period) can be used to measure multiple parameters. The beamformers 60, 64 are configured to scan tissue within a patient using the transducers 62. The scan is for each of a plurality of types of parameters in ultrasound medical imaging. For example, the patient's liver is scanned. Quantitative ultrasound and shear wave (e.g., ARFI) scans are performed for estimating fibrosis, inflammation, and fat fraction from ultrasound.

[0068] The receive beamformer 64 outputs beam-summed data representing spatial locations. Data for a single location, locations along a line, locations for a region, or volumetric locations are output. Dynamic focusing can be provided. Data for different types of metrics are acquired through a series of scans that are shared or interleaved. B-mode or Doppler scans can be performed separately or using some of the same data. Scans for parameter estimation can use image data or data acquired for B-mode or Doppler imaging, or can use data from scans for parameter estimation only (e.g., ARFI scans).

[0069] The user input 65 is a keyboard, touch screen, mouse, trackpad, slider, button, knob, roller ball, and / or another computer user input device. The user input 65 in combination with the display 68 is a user interface for user interaction with the system. The user input 65 can be used to trigger a parameter scan. In one embodiment, a single input or activation of the user input 65 triggers a scan of multiple parameters. After interaction with the user interface to configure the system, the user input 65 is used to start a scan with a single activation. The beamformers 60, 64 are configured to scan multiple types of parameters in response to a single activation on the user interface.

[0070] The image processor 66 is a B-mode detector, Doppler detector, pulsed wave Doppler detector, correlation processor, Fourier transform processor, application specific integrated circuit, general purpose processor, control processor, image processor, field programmable gate array, digital signal processor, analog circuitry, digital circuitry, combinations thereof, or other now known or later developed device for detecting and processing displayed information from beamformed ultrasound samples.

[0071] In one embodiment, the image processor 66 includes one or more detectors and a separate image processor. The separate image processor is a control processor, general purpose processor, digital signal processor, application specific integrated circuit, field programmable gate array, network, server, set of processors, combinations thereof, or other now known or later developed device for calculating values of different types of parameters from beamformed and / or detected ultrasound data, for estimating data quality and / or parameter values, and for determining relationships of parameter values to population or study statistics. The separate image processor is configured by hardware, firmware, and / or software to perform Figure 1 any combination of one or more of the actions 12-18 shown in FIG. 1.

[0072] The image processor 66 is configured to estimate one or more values of each of a plurality of types of parameters or tissue characteristics. Scan data and / or detected data are used to estimate parameter values for one or more locations. Other data, such as data from a patient's medical history, can also be used. For each type of parameter, values are calculated from the scan data and / or detected data.

[0073] The image processor 66 is configured to determine one or more quality indicators for the one or more estimates. One or more quality indicators can be computed for each type of parameter. The scan data, detected data, and / or the estimates are used to determine the value of the quality indicators.

[0074] The image processor 66 is configured to generate one or more panels showing the estimates relative to the published values for the disease state category. Any relationship of the values estimated for the patient to population or study statistics can be used. The panels are alphanumeric text, graphs, charts, maps, or other display information relating the patient values to other patient values. The relationship is shown for one or more of the parameters.

[0075] The image processor 66 is configured to generate images. For example, the images include two or more representations of the same tissue based on two or more estimated parameters, such as spatial distributions of shear wave velocity, fat fraction, inflammation, fibrosis, backscatter, attenuation, nonlinearity coefficient, complex modulus, and / or another ARFI or quantitative ultrasound parameter. The images can include non-parametric representations of the tissue, such as B-mode, M-mode, flow or color mode, and / or another type of ultrasound detection. The parametric maps can be presented separately or as overlays of the region of interest within a B-mode representation. Figure 2 An example image is shown with three parametric maps 22 overlaid on a B-mode representation.

[0076] The image processor 66 is configured to generate a display of the quality indicators and / or population relationships. The display(s) are part of the image, such as Figure 2 The quality indicators 24. Alternatively, the quality indicators and / or population relationships are shown separately from the parametric images and / or each other. The quality indicators and population relationships can be displayed as part of a radiology or medical record report provided with the parametric images.

[0077] The image processor 66 operates in accordance with instructions stored in the memory 67 or another memory. The memory 67 is a non-transitory computer readable storage medium. Instructions for implementing processes, methods, and / or techniques discussed herein are provided on a computer readable storage medium or memory, such as a cache, buffer, RAM, removable media, hard disk, or other computer readable storage media. Computer readable storage media include various types of volatile and non-volatile storage media. The functions, acts or tasks illustrated in the figures or described herein are implemented in response to the one or more sets of instructions stored in or on the computer readable storage medium. The functions, acts or tasks are independent of the particular type of instructions set, storage media, processor or processing strategy and can be performed by software, hardware, integrated circuits, firmware, micro-code and the like, operating individually or in combination. Likewise, processing strategies can include multiprocessing, multitasking, parallel processing and the like.

[0078] In one embodiment, the instructions are stored on a removable media device for reading by a local or remote system. In other embodiments, the instructions are stored at a remote location for transmission over a computer network or telephone line. In yet other embodiments, the instructions are stored within a given computer, CPU, GPU, or system.

[0079] The display 68 is a device for displaying one or two dimensional images or three dimensional representations, such as a CRT, LCD, projector, plasma, printer, or other display. Two dimensional images represent spatial distributions in an area. Three dimensional representations are rendered from data representing spatial distributions in a volume. The display 68 is configured by the image processor 66 or other device by inputting data to be displayed, such as one or more images. The display 68 displays images representing tissue, such as a liver.

[0080] In one embodiment, the display 68 displays estimates of a plurality of different parameters, quality indicators for one or more values or parameters, and / or one or more panels reflecting relationships of one or more of the values of one or more of the parameters to population statistics. For example, an image is displayed. The image includes two or more representations of the scanned tissue, one for each type of parameter. The image also shows one or both of (1) one or more quality indicators and (2) one or more panels. Different information is displayed in the same image, or can be shown in separate (e.g., sequential) images.

[0081] While the application has been described above with reference to various embodiments, it should be understood that many changes, modifications and substitutions can be made by one having ordinary skill in the art without departing from the scope of the application. It is therefore intended that the foregoing detailed description be viewed as an illustration rather than a limitation, and that the following claims, including all equivalents, be the limiting article.

Claims

1. A method of parametric ultrasound imaging with an ultrasound scanner, the method comprising: activating (10) multi-parametric ultrasound imaging of a patient; in response to an instance of the activating (10), measuring (12) by the ultrasound scanner all two or more parameters of the multi-parametric ultrasound imaging; generating (14) an image of values of the two or more parameters; and displaying (16, 18) a quality indicator of the measuring (12) and a relationship of one or more of the values to a population, the quality indicator being labeled as an indicator of quality in the display and being provided separately from the values of the two or more parameters, the quality indicator comprising a region of interest quality, an acquisition quality, and a measurement consistency quality, the region of interest quality representing a quality of placement of a region of interest with respect to tissue of the patient, the acquisition quality representing a quality of acquired scan data used to measure the two or more parameters, and the measurement consistency quality representing a quality of the measured values of the two or more parameters, the relationship being displayed as a box plot of a histological grading having a plurality of grades, with the one or more values of the patient referencing a display spectrum of values of the population of the histological grading, each of the spectra being for a different one of the plurality of grades and showing values of the population for the respective grade.

2. The method of claim 1, wherein the activating (10) comprises inputting a single trigger input by a user, and wherein the measuring (12) comprises measuring (12) the two or more parameters in response to the single trigger input.

3. The method of claim 1, wherein the measuring (12) comprises measuring (12) two or more parameters of a liver of the patient, and wherein the two or more parameters comprise levels of fibrosis, inflammation, and fat fraction of the liver of the patient.

4. The method of claim 1, wherein the displaying (16) the quality indicator comprises displaying (16) the quality indicator as a map representing quality as a function of location.

5. The method of claim 1, wherein the generating (14) the image comprises generating (14) the image with two different spatial representations of the two or more parameters, and wherein the displaying (16, 18) comprises displaying (16, 18) the quality indicator and / or the relationship as part of the image.

6. The method of claim 1, wherein the displaying (18) comprises displaying (18) the relationship of the value of one of the two or more parameters to a histological grading of the population or displaying (18) the relationship of the value of one of the two or more parameters as a membership probability based on the population.

7. A system for parametric ultrasound medical imaging, the system comprising: a transducer (62); a beamformer (60, 64) configured to scan tissue within a patient with the transducer (62), the scanning being for first and second types of parametric ultrasound medical imaging; an image processor (66) configured to estimate a first value of a first type and a second value of a second type from the scan to determine first and second indicators of quality of the estimates of the first and second values, respectively, the indicators of quality including region of interest quality, acquisition quality, and measurement consistency quality, the region of interest quality representing quality of placement of the region of interest with respect to patient tissue, the acquisition quality representing quality of acquisition of scan data for measuring the two or more parameters, and the measurement consistency quality representing quality of the measured values of the two or more parameters, and to generate first and second panels showing the first and second values for the patient relative to and distinguished from published values of disease state categories, the published values being population values, wherein the relationship of the first and second values for the patient to the population values is shown in the panels, and wherein each panel includes a histological grading, the histological grading including a distribution with respect to different categories, with the first or second values shown with respect to each different category; and a display (68) configured to display the first and second values, the first and second indicators, and the first and second panels.

8. The system of claim 7, wherein the tissue in the patient includes a liver, and wherein the first and second types include two or more of fibrosis, inflammation, and fat fraction.

9. The system of claim 7, further comprising a user interface (65, 68), wherein the beamformer (60, 64) is configured to scan both the first and second types in response to a single activation on the user interface.

10. A method of parametric ultrasound imaging with an ultrasound scanner, the method comprising: measuring (12) first and second tissue properties of patient tissue by an ultrasound scanner; generating (14) an image showing the first and second tissue properties of the tissue; displaying (16) first and second indicators of reliability of the measurements (12) of the first and second tissue properties, respectively, each of the first and second quality indicators including separate region of interest quality, acquisition quality, and measurement consistency quality, the region of interest quality representing quality of placement of the region of interest with respect to patient tissue, the acquisition quality representing quality of acquisition of scan data for measuring the two or more parameters, and the measurement consistency quality representing quality of the measured values of the two or more parameters; and displaying (18) first and second indicators of the measurements (12) of the first and second tissue properties of the patient tissue, respectively, relative to population statistics, the first and second tissue properties being displayed as box plots of a histological grading by category relative to the population statistics.

1. A system for parametric ultrasound imaging, the system comprising: an ultrasound scanner (10) configured to measure first and second tissue properties of patient tissue; an image processor (66) configured to estimate a first value of a first type and a second value of a second type from the scan to determine first and second indicators of quality of the estimates of the first and second values, respectively, the indicators of quality including region of interest quality, acquisition quality, and measurement consistency quality, the region of interest quality representing quality of placement of the region of interest with respect to patient tissue, the acquisition quality representing quality of acquisition of scan data for measuring the two or more parameters, and the measurement consistency quality representing quality of the measured values of the two or more parameters, and to generate first and second panels showing the first and second values for the patient relative to and distinguished from published values of disease state categories, the published values being population values, wherein the relationship of the first and second values for the patient to the population values is shown in the panels, and wherein each panel includes a histological grading, the histological grading including a distribution with respect to different categories, with the first or second values shown with respect to each different category; and a display (68) configured to display the first and second values, the first and second indicators, and the first and second panels.

Images