Acuson Corporation

Siemens Medical Solutions Usa, Inc.

Patrick J Phillips

Ismayil M Guracar

David J Napolitano

Gregory L Holley

Charles E Bradley

James E Chomas

John Alexander Hossack

Christopher R Cole

Thilaka S Sumanaweera

Kutay F Ustuner

Seshadri Srinivasan

Lewis J Thomas

Rickard C Loftman

Samuel H Maslak

Bhaskar S Ramamurthy

Sriram Krishnan

Lewis Jones Thomas, Iii

Ching-Hua Chou

Danhua Zhao

Robert W Steins

John Douglas Marshall

John P Madden

Zafer Zamboglu

Highly specific measurements of flow in vessels, such as the coronary artery, can be obtained by processing cubic fundamental information. By showing flow in vessels with a high degree of contrast-to-tissue specificity, ultrasound based 3D contrast agent based coronary artery angiograms may be possible. Measurement and display of the velocity of agent from the cubic fundamental signal is provided simultaneously with display of cubic fundamental energy, such as providing a display map indexed by both energy and velocity. High pulse repetition frequency (PRF) for cubic fundamental detection in conjunction with long velocity measurement intervals may increase low velocity sensitivity and measurement precision. Pulsed wave (PW) Doppler may be improved by using a cubic fundamental sensitive pulse sequence. Using cubic fundamental sensitive techniques with other motion estimation techniques, such as two-dimensional velocity estimation or speckle tracking, may operate better than using other contrast agent detection techniques because of substantially reduced clutter.

Contrast agent imaging with agent specific ultrasound detection

Contrast agents are characterized with ultrasound. Flowing or unbound contrast agents are distinguished automatically from bound or relatively stationary contrast agents. The bound or relatively stationary contrast agents are highlighted on a display. A processor distinguishes different types of contrast agents or contrast agents in different binding states with relative signal strength or velocity. Attached contrast agents are differentiated from phagocytosed contrast agents. Monitoring absolute signal strength as a function of time may indicate binding. Any one or more of these features may be used.

Advanced characterization of contrast agents with ultrasound

System parameters for contrast agent medical imaging are conveniently set. A simplified contrast agent configuration is provided where an appropriate contrast agent detection technique and/or contrast agent imaging parameters are achieved consistently and more often then exists with current methods. Examination workflow is improved for contrast agent studies by offering one contrast agent imaging mode or configuration that is dynamically determined and optimized based on the user's selected transmit level and/or a real-time measurement of the contrast agent signals. A simplified user interface provides one contrast agent imaging mode without a need to switch between multiple modes or contrast agent detection techniques and associated contrast agent imaging parameters. The contrast agent detection technique and imaging parameters are adjusting or selected based on changes in the transmit levels for contrast agent imaging. Either a single user input control or real time measurements are used to select a transmit level, resulting in automatic selection of adjustment of the detection technique and/or imaging parameters. Appropriate contrast agent detection techniques and imaging parameters are selected for each given transmit level without the user having to switch the mode or configuration of the system during an imaging session. As a result, contrast agent examinations are simplified while minimizing suboptimal selection by a user.

Adaptive contrast agent medical imaging

A method is provided to improve the frame-rate in color-flow ultrasound imaging using simultaneous spatially-distinct transmit beams with one or more frequency bands per transmit beam. Pulses of different center frequencies are used simultaneously in different (lateral and/or elevational) directions, thereby reducing the scanning time and improving the frame-rates. Optionally, a multi-modal pulse is used, and flow is estimated separately for the different frequencies. The flow estimates for these pulses are appropriately combined to improve low-velocity sensitivity and to reduce aliasing. A flow sample count with two or more different pulse repetition intervals can be used to further improve low-flow sensitivity and minimize aliasing.

Ultrasound color flow imaging at high frame rates

Velocity scale is automatically determined for ultrasound imaging. Receive signals corresponding to different pulse repetition intervals are used to estimate velocities. The different velocities are used to determine the velocity scale. For example, the different pulse repetition intervals are obtained by selecting different sets of signals from a group of signals for a scan line. As another example, the different pulse repetition intervals are obtained by transmitting for a scan line with changing, such as increasing, pulse repetition intervals. The lower pulse repetition interval of a pair of intervals associated with a sign change in the phase is used for the velocity scale. In yet another example, at least two demodulation frequencies are used for a broadband transmit in at least two sets, each set with a different pulse repetition interval. Velocities are estimated for a greater number of pulse repetition intervals than transmitted using the broadband pulses.

Automatic velocity scale identification for medical diagnostic ultrasound

Contrast agents are manipulated with acoustic radiation force while ultrasound imaging. Continuous waves for acoustic radiation force are transmitted. Substantially simultaneously, pulsed waves for imaging are transmitted. Low mechanical index continuous and pulsed waves may be used to increase binding efficiency of drug containing contrast agents with the tissue for treatment. Various techniques may be used to minimize the effect of the continuous waves on imaging with the pulsed waves. The acoustic radiation force may be transmitted with an amplitude profile and/or unfocused or defocused.

Contrast agent manipulation with medical ultrasound imaging

A transmit sequence for contrast agent imaging that improves sensitivity and minimizes image artifacts. The number of pulses and the interleaving of spatially distinct pulses between spatially co-linear pulses are selected such that a substantially similar pulse sequence for substantially each line in a scanned region is generated. A collateral pulse from a different scan line is interleaved between at least two imaging pulses along a scan line of interest. Such pulse sequences provide sensitive contrast agent imaging with minimized spatial variation. In another aspect, responsive signals representing the first and second scan lines are obtained. Intensities associated with the signals are determined. The intensities associated with the first scan line are compared to a value. The signals associated with the first scan line are replaced by the signals associated with the second scan line, signals associated with the first and second scan lines, or neighboring signals in time or space as a function of the comparison. Thus, signals associated with an image artifact may be replaced by signals along other scan lines so good spatial resolution is maintained.

Contrast imaging beam sequences for medical diagnostic ultrasound

System parameters for contrast agent medical imaging are conveniently set. A simplified contrast agent configuration is provided. One contrast agent imaging mode or configuration is dynamically determined and optimized based on the user's selected transmit level and/or a real-time measurement of the contrast agent signals. A simplified user interface provides one contrast agent imaging mode without a need to switch between multiple modes or contrast agent detection techniques and associated contrast agent imaging parameters. The contrast agent detection technique and imaging parameters are adjusted or selected based on changes in the transmit levels for contrast agent imaging. Appropriate contrast agent detection techniques and imaging parameters are selected for each given transmit level without the user having to switch the mode or configuration of the system during an imaging session.

A medical diagnostic ultrasonic imaging system acquires receive beams from spatially distinct transmit beams. The receive beams alternate in type between at least first and second types across the region being imaged. The first and second types of receive beams differ in at least one scan parameter other than transmit and receive line geometry, and can for example differ in transmit phase, transmit or receive aperture, system frequency, transmit focus, complex phase angle, transmit code or transmit gain. Receive beams associated with spatially distinct ones of the transmit beams (including at least one beam of the first type and at least one beam of the second type) are then combined. In this way, many two-pulse techniques, including, for example, phase inversion techniques, synthetic aperture techniques, synthetic frequency techniques, and synthetic focus techniques, can be used while substantially reducing the frame rate penalty normally associated with such techniques.

Diagnostic ultrasound imaging method and system with improved frame rate

Automated determination and setting of an ultrasound system transmit power level is provided for contrast agent imaging. Low mechanical index imaging of contrast agents allows substantially continuous imaging of contrast agents without destruction. By comparing data associated with different transmit power levels, different delays between acquisition or different acquisition sequences, a contrast agent imaging transmit power generally minimizing destruction of contrast agents and maximizing signal-to-noise ratio is automatically determined.

Automated power level for contrast agent imaging

The gain for multiple mode imaging and/or contrast agent imaging is automatically adjusted. The gain algorithm separately determines gain parameters for two different types of imaging, such as tissue and contrast agent imaging. The gain based on the contrast agent image may be optimized to provide maximum sensitivity, such as by mapping noise values measured prior to injection of contrast agent to low values within the dynamic range or somewhat below the display dynamic range. The automatic gain based on the contrast agent image may be free of variance calculations. One of the two gain parameters is selected as the system gain, or the two gain parameters are combined to form the system gain. The presence of contrast agents within the image may be determined, and different gain parameters used based on the presence or absence of contrast agents. Various ones or combinations of the gain adjustments summarized above may be used.

Automatic gain compensation for multiple mode or contrast agent imaging

Methods and systems for detecting contrast agents is provided. Differences between different sized vessels throughout a period of contrast agent enhancement are identified without significantly depleting the available contrast agent. Dual detection paths are used for imaging, such as one path for detecting nonlinear response and another path for detecting differences between the responses to two or more pulses. Where echoes from two or more pulses of acoustic energy are combined to detect the nonlinear response, the nonlinear response may also include signals originating from a loss-of-correlation (LOC) or motion between received pulses. These signals generated from LOC or motion can be produced from agent disruption where a second received echo is different from a first received echo due to a change in a bubble's shape (i.e., destruction), or from simple spatial translation between acoustic pulses as seen from the same spatial location, respectively. Together the LOC or motion signals and the nonlinear signals can differentiate contrast agent from tissue. Additional information is gained by detecting signals more responsive to difference or motion information. Each path detects different relative amounts of nonlinear response and responses caused by differences between echo signals of multiple pulses. Various systems and methods for detecting contrast agents where one path preferentially detects difference or motion signals and another path preferentially detects nonlinear energy are provided.

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Sunnyvale, CA, United States of America

Patrick J Phillips