Abstract: 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.

Abstract: An ultrasound image is obtained by subjecting an object containing an ultrasound contrast enhancement agent to a first imaging pulse burst and then to a second release pulse and then to a second imaging pulse to obtain two images and then comparing the two images to obtain an enhanced image.

Abstract: An image formed from compounded frames of ultrasound data acquired with different steering angles is displayed. Each component frame is associated with a scan of the entire displayed region. A majority of scan lines for each component frame are pointed in one direction or the same relative direction, and a minority of the scan lines are steered at different angles within each component frame to scan the rest of the display region, but with a different steering angle for the majority of scan lines of each of the component frames. As a result, the benefits of spatial compounding component frames associated with different steering angles are provided without having to apply filtering to reduce line artifacts.

Abstract: Transducer with different array configurations and methods of using the transducers are provided. An electrode layer on one side of a transducer device defines a one-dimensional array of elements. An electrode layer on an opposite side of the transducer device defines a multi-dimensional array. For example, one transducer device may be used for both two-dimensional imaging and three-dimensional imaging in response to the one-dimensional array and multi-dimensional array electrode configurations. Real time three-dimensional imaging and two-dimensional imaging may be provided with a single transducer. As another example, elements defined by one electrode configuration have a different surface area than elements defined by another electrode configuration. The different configurations on opposite sides of the transducer devices may be a same type (e.g. both one-dimensional arrays) or different types.

Abstract: A noise-adaptive method for processing an ultrasonic image set forms a filtered image set having a selectively enhanced noise component as compared to the original image set. A noise parameter is generated as a function of the image set and the filtered image set, and then the noise parameter is used in ultrasonic image processing. A background noise image is generated from the noise parameter and the original image and is used in ultrasonic image processing.

Abstract: A method and apparatus for ultrasound breast imaging is described. Breast is positioned in between an ultrasound array and a plate with embedded point or line targets. The apparatus and reflections from the targets are used 1) to improve focusing by correcting for tissue delay and amplitude aberration and 2) to improve diagnostics by constructing speed of sound and attenuation coefficient images.

Abstract: A method of manufacturing a two-dimensional ultrasound transducer array is provided in which the transducer array is formed by a plurality of transducer elements sequentially arranged in the azimuth direction and each transducer element has a non-uniform thickness and each transducer is divided into a left and a right half which can be independently excited.

Abstract: A medical ultrasound imaging pulse transmission method transmits at least three pulses, including at least two pulses of different amplitude and at least two pulses of differing phase. The larger-amplitude pulse is transmitted with a larger aperture and the smaller-amplitude pulses are transmitted with respective smaller subapertures. The subapertures are arranged such that the sum of the subapertures used for the smaller-amplitude pulses is equal to the aperture used for the larger-amplitude pulse. In this way, pulses of differing amplitudes are obtained without varying the power level of individual transducer elements, and precise control over pulse amplitude is provided.

Abstract: 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.

Abstract: 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.

Abstract: Methods and systems for forming images of heart by using multiple sets of ultrasound data are described. Each set of data is acquired and processed responsive to a different set of imaging parameters. The imaging parameter sets differ in at least one parameter, such as array position, temporal frequency response or transmit focal depth, so that the images formed using these data sets have, either laterally or axially, different spatial spectra. In one of the preferred embodiments, a set of images is formed responsive to a first imaging parameter set for a first cardiac cycle. Another set of images is formed responsive to a second imaging parameter set for a second cardiac cycle. Then the two sets of images are temporally aligned so that they correspond to the same set of phases of the cardiac cycle. The temporally aligned images may also be spatially aligned and combined. This technique can improve contrast resolution and/or field of view.

Abstract: Two or more temporal indicators are used for interleaving frames from a plurality of physiological cycles. For example, frames of one cycle are separated from the frames of another cycle based on an ECG signal. Data representing an imaged region for each of the frames is then used for temporally aligning the frames. For example, average velocity waveforms calculated from the frames of each of the cycles are fitted together. The temporal position of each of the frames within a base physiological cycle is determined based on the fitting. The interleaved frames provide a higher effective frame rate with improved temporal resolution which is based on the accurate interleaving of the data from the plurality of physiological cycles. Course alignment is provided using one event or temporal indicator. A more refined temporal alignment is provided in response to a second temporal indicator.

Abstract: An ultrasound transducer assembly having a housing, a transducer array mounted in the housing, and active cooling mechanism positioned adjacent to the transducer array for actively removing heat generated by the array by transport of heat energy from the affected site. The active cooling mechanism comprises a thermo-electric cooler which utilizes active thermal transport to remove heat from the transducer. The thermoelectric cooler may be used alone or in combination with a phase change material or other system to subsequently remove the heat from the thermo-electric cooler. The thermo-electric cooler is coupled with the flex-circuit layers of the transducer to efficiently remove heat generated within the component layers of the transducer.

Abstract: Compounding of data representing a same location is provided. The level of compounding is tuned. Different levels of compounding between averaging and selecting a maximum or minimum and/or between minimum and maximum are provided. Ultrasound data to be compounded is weighted. The weights are defined by a smoothly varying functions from a zero value to a unity value or one. The weight for each of the data to be compounded is a function of all of the data to be compounded. One or more variables in the weighting function allows selection of the level of compounding. As a result of these weighting characteristics, a compromise or tuned level of compounding between minimum and selection of a maximum value is provided.

Abstract: A medical diagnostic ultrasonic imaging system includes a transmit waveform generator that uses stored parameters to completely define an arbitrarily complex transmit waveform. Preferably, the stored parameters define an envelope function and a modulation function in a piecewise fashion using a number of sets of quadratic parameters. These quadratic parameters are used to calculate the desired envelope function and modulation function in the log domain, and the envelope and modulation functions are combined in the log domain and then converted to the linear domain. Multiple separate transmit waveforms may be combined in a single channel, and individual channels may be combined prior to application to the transducer elements.

Abstract: Multiple layer elements for a transducer array are provided. Each element comprises two or more layers of transducer material. Various of the elements include one or more of: (1) multiple-layer, multiple-dimensional arrays where the layers are electrically connected through asperity contact, (2) multiple layer array of elements where air or gas separates at least two elements, (3) an even number of layers polymerically bonded together where each layer is electrically connected through asperity contact, (4) multiple-layers where each layer comprises transducer material and electrodes in a substantially same configuration, and (5) electrically isolating electrodes on layers by kerfing or cutting after bonding the layers together.

Abstract: The preferred embodiments described herein provide medical diagnostic ultrasound imaging system transmitter control in a modular transducer system. With these preferred embodiments, transmitters in a medical diagnostic ultrasound imaging system are enabled only when contacts in a scan head are electrically coupled with contacts in a receptacle assembly of a modular transducer system. This prevents high voltages from developing in the receptacle assembly when the scan head is removed from or is not fully engaged with the receptacle assembly. In one preferred embodiment, a detector is used to detect movement of a member comprising the contacts in the receptacle assembly. Other preferred embodiments are provided, and each of the preferred embodiments described herein can be used alone or in combination with one another.

Abstract: An ultrasound image is morphed for perfusion assessment. Various images within a sequence of images or movie clip are mapped to one frame of reference using local warping. Nonlinear local image transformations or other warping based on local estimates of motion are used to interpolate different images to the common reference. The elastic stretching and compression of local image data results in a sequence of images where the same spatial location in each image represents the substantially same spatial location of the imaged tissue. The organ, tissue or region of interest is stationary throughout the sequence of images.

Abstract: A method and system for contrast agent imaging with a catheter transducer is provided. The catheter transducer may comprise an intra-vascular, intra-cardiac or other transducer for insertion into or through a small space. The catheter transducer is inserted within the heart or other portion of a patient. Contrast agents, such as micro-spheres, are injected into the patient. Using the catheter transducer, ultrasonic acoustic energy is transmitted, and reflected energy is received. The reflected energy is responsive to the contrast agents. An image processor generates an image of the tissue and contrast agents as a function of the reflected energy. The image provides an indication of perfusion. Alternatively, the ultrasound system calculates perfusion. By generating intra-vascular images or data, interference from other tissues is avoided. Therefore, the perfusion information obtained may have higher resolution. Images with better resolution better assist doctors in medical diagnosis.

Abstract: A medical diagnostic ultrasound imaging system aligns substantially co-planar two-dimensional images to form an extended field of view using improved compounding methods. Compounding with a finite impulse response is used for more versatile compositing. The compounding is adaptive, such as through adapting the image regions, weighting, or type of compounding as a function of correlation, location within the image, estimated motion or combinations thereof. A user warning is provided as a function of the correlation between images.