Abstract: Significant liver growths such as HCC lesions are detected during a contrast agent ultrasound exam by their early reception of contrast and brightening following a bolus injection, as compared with surrounding normal tissue and benign growths. A pixel classifier looks for and identifies pixel or voxel regions where this early wash-in of contrast occurs and denotes these pixel or voxel locations in a parametric image. The pixel classifier analyzes pixel or voxel values from a sequence of images and identifies suspicious regions in an image by uniquely coding the points in a parametric liver image where early wash-in occurs.

Abstract: A combined ultrasound imaging and therapy transducer includes a linear array of imaging transducer elements. First and second linear arrays of therapy transducer elements extend longitudinally along respective first and second sides of the imaging transducer elements and are canted inwardly toward each other. The imaging and therapy transducer is used with an ultrasound imaging system to locate clots in a region of interest. After the region of interest has been perfused with a microbubble contrast agent, the therapy transducer elements are driven by an amplifier located in the transducer to dissolve the clot. The use of the imaging transducer elements and the therapy transducer elements can be interleaved so that the therapy can be conditioned on an ultrasound image showing substantial destruction of the contrast agent microbubbles, re-perfusion of microbubbles in the region of interest, or the continued presence of the clot.

Abstract: An ultrasonic imaging system transmits waveforms containing first and second major frequency components which are intermodulated by passage through a nonlinear medium or interaction with a contrast agent microbubble to produce a difference frequency component. In an illustrated embodiment the transmit waveforms are square waves exhibiting only odd harmonic components. The first and third harmonic components are intermodulated by nonlinear effects to produce a difference frequency signal at the second harmonic frequency.

Abstract: A method and device for imaging contrast agents which oscillate nonlinearly in a nondestructive mode at an MI in excess of 0.1 is described. Three transmit pulses are transmitted in each beam direction which are differently modulated. In an illustrated embodiment the transmit pulses are symmetrically differently phase modulated at 0°, 120° and 240°. The echoes received in response to each transmit pulse are stored and combined by a pulse inversion processor. Pulse inversion processing results in separation of the third harmonic to the relative exclusion of the first and second harmonic signal components. Third harmonic images of the contrast image are formed which exhibit a relatively low tissue background.

Abstract: A combined ultrasound imaging and therapy transducer includes a linear array of imaging transducer elements. First and second linear arrays of therapy transducer elements extend longitudinally along respective first and second sides of the imaging transducer elements and are canted inwardly toward each other. The imaging and therapy transducer is used with an ultrasound imaging system to locate clots in a region of interest. After the region of interest has been perfused with a microbubble contrast agent, the therapy transducer elements are driven by an amplifier located in the transducer to dissolve the clot. The use of the imaging transducer elements and the therapy transducer elements can be interleaved so that the therapy can be conditioned on an ultrasound image showing substantial destruction of the contrast agent microbubbles, re-perfusion of microbubbles in the region of interest, or the continued presence of the clot.

Abstract: An ultrasonic imaging system transmits waveforms containing first and second major frequency components which are intermodulated by passage through a nonlinear medium or interaction with a contrast agent microbubble to produce a difference frequency component. In an illustrated embodiment the second major frequency is twice the frequency of the first major frequency, resulting in a difference frequency signal at the first major frequency. Two differently modulated transmit waveforms are transmitted and the difference frequency component is separated by pulse inversion.

Abstract: An ultrasonic diagnostic imaging method and system produce diagnostic contrast images depicting both tissue perfusion and flow velocity in larger vessels by utilizing both linear and nonlinear imaging techniques. A sequence of echoes from differently modulated transmit pulses is received and processed in different ways to detect nonlinear signals from microbubble-perfused tissue and Doppler blood flow in larger vessels. The Doppler flow signals may be either linear or nonlinear or a mixture of both. A decision circuit classifies the detected signals for display pixels in a perfusion and/or flow and/or tissue image. Separate perfusion and flow images can be simultaneously displayed or an image of both perfusion and flow can be displayed.

Abstract: A combined ultrasound imaging and therapy transducer (10) includes a linear array of imaging transducer elements (14). First and second linear arrays of therapy transducer elements (18, 20) extend longitudinally along respective first and second sides of the imaging transducer elements and are canted inwardly toward each other. The imaging and therapy transducer is used with an ultrasound imaging system to locate clots in a region of interest. After the region of interest has been perfused with a microbubble contrast agent, the therapy transducer elements are driven by an amplifier located in the transducer to dissolve the clot. The use of the imaging transducer elements and the therapy transducer elements can be interleaved so that the therapy can be conditioned on an ultrasound image showing substantial destruction of the contrast agent microbubbles, re-perfusion of microbubbles in the region of interest, or the continued presence of the clot.

Abstract: The present invention relates to monitoring the focus of a therapeutic transducer in an interactive real-time manner by turning off the ultrasound transmits of the imaging transducer but continuing to receive in all directions with an imaging probe in order to identify the therapeutic beam focus. The therapeutic focused beam acts as the only transmit and as long as there is a scatterer at the focus, a strong receive signal will be generated to identify the focus.

Abstract: An ultrasound imaging system transmits a broad beam of ultrasound into tissues that are perfused with blood containing microbubbles. The ultrasound has an intensity that is sufficient to destroy the microbubbles in the tissues. A plurality of ultrasound imaging beams are then transmitted into the tissues over a sufficient period to allow the tissues to re-perfuse, and reflections from the transmitted imaging beams are processed to provide a perfusion image. The transmitted microbubble-destroying ultrasound may be in the form of a single beam or a plurality of beams that insonify a substantially larger area than the area insonified by the transmitted imaging beams. As a result, the microbubbles are all destroyed at substantially the same time, and the imaging ultrasound is transmitted only into regions of the tissues from which ultrasound reflections will be received.

Abstract: An ultrasonic diagnostic imaging system and method are described which produce tissue harmonic images containing both fundamental and harmonic frequency components. Such a blended image takes advantage of the performance possible with the two types of ultrasonic echo information and can advantageously reduce near field clutter while improving signal to noise performance in the far field of the image.

Abstract: An ultrasonic imaging apparatus and method are described for imaging nonlinear response objects such as contrast agents and tissue with reduced speckle artifacts. A pulse sequence of two or more pulses of differing amplitude, polarity, and/or phase characteristics is transmitted in each beam direction and an ensemble of echoes is received for each sampled point in the image field. The echoes are combined by different nonlinear signal separation processes and these results are combined to reduce image speckle by a frequency compounding effect. Nonlinear separation techniques which can be used include pulse inversion, power modulation, and combined power modulation/pulse inversion.

Abstract: An ultrasonic imaging apparatus and method are described for imaging nonlinear response objects such as contrast agents at greater depths. Transmit pulses include two fundamental frequency components, one of which is to produce harmonic components at the fundamental frequency of the other component. In the presence of a contrast agent these harmonic components are used for imaging the contrast agent. When the contrast agent is not present imaging is performed using the fundamental echoes of the other echo frequency. Preferably the harmonic frequency of the first fundamental component is aligned with the second fundamental frequency. The technique is especially useful when imaging contrast agents at low MI and at significant depths in the body.

Abstract: An ultrasonic imaging method and apparatus are described for imaging the coronary arteries of the heart. The vascular system is infused with an ultrasonic contrast agent. A volumetric region of the heart wall including a coronary artery is three dimensionally scanned. A projection image of the volumetric region is produced from the scanning, providing a two dimensional contrast image of the coronary artery with the appearance of an angiogram. Preferably the coronary artery signals are segmented from contrast signals emanating from the myocardium and the heart blood pool so that the coronary arteries are clearly highlighted and distinct in the ultrasonic angiogram.

Abstract: An ultrasonic imaging apparatus and method are described for imaging nonlinear response objects such as contrast agents at greater depths. Transmit pulses include two fundamental frequency components, one of which is to produce harmonic components at the fundamental frequency of the other component. In the presence of a contrast agent these harmonic components are used for imaging the contrast agent. When the contrast agent is not present imaging is performed using the fundamental echoes of the other echo frequency. Preferably the harmonic frequency of the first fundamental component is aligned with the second fundamental frequency. The technique is especially useful when imaging contrast agents at low MI and at significant depths in the body.

Abstract: Apparatus and methods are disclosed for the detection and imaging of ultrasonic contrast agents. Ultrasonic apparatus is provided for coherent imaging of ultrasonic contrast agents, and for detecting harmonic contrast agents. The inventive apparatus includes a dual display for simultaneously viewing a real time image which displays the location of the contrast agent and a triggered contrast image. Methods of contrast agent detection and imaging include the measurement of perfusion rate characteristics, multizone contrast imaging, multifrequency contrast imaging, tissue perfusion display, and high PRF contrast image artifact elimination.

Abstract: Nonlinear tissue or contrast agent effects are detected by combining echoes from multiple, differently modulated transmit pulses below the second harmonic band. The received echoes may even overlap the fundamental transmit frequency band. The modulation may be amplitude modulation or phase or polarity modulation, and is preferably both amplitude and phase or modulation. The present invention affords the ability to utilize a majority of the transducer passband for both transmission and reception, and to transmit pulses which are less destructive to microbubble contrast agents.

Abstract: Apparatus and methods are disclosed for the detection and imaging of ultrasonic contrast agents. Ultrasonic apparatus is provided for coherent imaging of ultrasonic contrast agents, and for detecting harmonic contrast agents. The inventive apparatus includes a dual display for simultaneously viewing a real time image which displays the location of the contrast agent and a triggered contrast image. Methods of contrast agent detection and imaging include the measurement of perfusion rate characteristics, multizone contrast imaging, multifrequency contrast imaging, tissue perfusion display, and high PRF contrast image artifact elimination.

Abstract: An ultrasonic diagnostic imaging system is described for performing nonlinear echo signal imaging with intermodulation product (sum or difference frequency) components. The system includes a digital transmitter which develops digital waveforms for two frequencies of a transmit beam. The digital waveforms are combined, converted to analog waveforms, and applied as transmit signals to the elements of a transducer array. In an alternate embodiment, a library of digital, multifrequency waveforms is maintained, from which a desired digital waveform is selected, converted to an analog waveform, and applied as transmit signals to the elements of a transducer array.

Abstract: An ultrasonic imaging method and apparatus are described for imaging the coronary arteries of the heart. The vascular system is infused with an ultrasonic contrast agent. A volumetric region of the heart wall including a coronary artery is three dimensionally scanned. A projection image of the volumetric region is produced from the scanning, providing a two dimensional contrast image of the coronary artery with the appearance of an angiogram. Preferably the coronary artery signals are segmented from contrast signals emanating from the myocardium and the heart blood pool so that the coronary arteries are clearly highlighted and distinct in the ultrasonic angiogram.