Abstract: Transmit based axial whitening is provided. Ultrasonic waveforms to be transmitted are designed to provide for wideband imaging characteristics prior to detection. Rather than transmitting a waveform having a spectral magnitude as white or flat as possible, waveforms with adjusted spectral content, such as spectrally bi-modal waveforms are generated in order to compensate for subsequent effects. Prior to detection, a more wideband or whiter signal response is provided in response to the transmitted waveform. Any of various alterations of the transmit waveform, such as asymmetric, spectrally bi-modal or other characteristics in anticipation of a system transfer function or physical phenomena through which the signal passes electronically or acoustically to result in a wideband or white spectral magnitude and generally linear spectral phase is used. The transmit waveform is altered to improve the imaging characteristics of the downstream processing.

Abstract: To improve real time 3D imaging performance, acquisition, beamforming, coherent image forming and/or image processing parameters are varied as a function of the viewing direction selected by the user. For example, the scan planes are oriented relative to the viewing direction. As a result rapid 3D rendering is provided without complex additional data interpolation or other 3D rendering processes. In another example, data along the lateral axis that is perpendicular to the viewing direction (i.e., display lateral axis) is acquired with parameters adapted to maximize field of view, detail and contrast resolution, while data along the lateral axis that is parallel to the viewing direction is acquired with compromised field of view, detail or contrast resolution. As a result, a high volume rate 3D imaging is achieved with 2D-equivalent detail resolution, contrast resolution and field of view along the display lateral axis.

Abstract: A medical imaging system automatically acquires two-dimensional images representing a user-defined region of interest despite motion. The plane of acquisition is updated or altered adaptively as a function of detected motion. The user-designated region of interest is then continually scanned due to the alteration in scan plane position. A multi-dimensional array is used to stabilize imaging of a region of interest in a three-dimensional volume. The user defines a region of interest for two-dimensional imaging. Motion is then detected. The position of a scan plane used to generate a subsequent two-dimensional image is then oriented as a function of the detected motion within the three-dimensional volume. By repeating the motion determination and adaptive alteration of the scan plane position, real time imaging of a same region of interest is provided while minimizing the region of interest fading into or out of the sequence of images.

Abstract: Adaptive grating lobe suppression is provided. Received ultrasound data is measured, compared or otherwise processed to determine the presence of grating lobe energy. A further process is then altered as a function of the level of grating lobe energy. In one embodiment, the adaptive grating lobe suppression is implemented in the receive beamformer. Data representing a virtual element is formed as a normalized sum of data from adjacent sparse elements. The data from the adjacent elements is correlated to determine the presence of grating lobe energy as a function of the amount of shift associated with the peak correlation. A phase shift is applied to the data representing the virtual element where sufficient grating lobe energy is determined. In another embodiment, an amount of grating lobe energy is measured by comparing data from prior to a filter with filtered data. The filter is selected to isolate main lobe energy from grating lobe energy.

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 medical diagnostic ultrasonic imaging system analyzes receive signals generated by the system to adaptively set the interline delay and/or the transmit power to optimize frame rate while reducing or eliminating the wraparound artifact associated with transmit events that are too closely spaced in time for currently prevailing imaging conditions.

Abstract: An ultrasonic imaging system includes a processor that varies the receive signal path parameters as a function of the signal to noise ratio of the echo signal. Background noise information is either acquired by imaging with the transmitters turned off, or estimated by using the known differences in bandwidth and correlation lengths of the signal and noise, or computed based on a system noise model using currently prevailing system parameters. Acquired receive signals are then processed as a nonlinear function of the comparison between the acquired receive signal and the background noise values. The family of SNR adaptive processors includes the SNR adaptive filtering in at least one of the azimuth, elevation and time dimensions, SNR adaptive high pass, band pass, and whitening filtering, SNR adaptive synthesis, and SNR adaptive compounding.

Abstract: The front-end gain of a medical diagnostic ultrasonic imaging system receiver is adaptively set by acquiring receive samples that vary in range, generating a gain function that varies in range as a function of envelope amplitude of the receive samples, and then controlling the front-end gain with the gain function. In this way, front-end gain is set in accordance with the currently prevailing imaging conditions, and front-end gain that is excessively high or low is avoided. Transmitter gain is adaptively set to limit or prevent front-end gain saturation of the receiver.

Abstract: An ultrasonic imaging system and method provide whitening using a two dimensional pre-detection filter followed by low pass filtering using a two dimensional post-detection filter to reduce speckle variance and enhance spatial resolution of the resulting image. The amplitude of the whitened signal can be adjusted as a function of variance or gradient of the ultrasonic receive signal to reduce undesired side lobes.

Abstract: A medical ultrasound diagnostic imaging system includes a delay system that applies a composite delay profile to signals to or from respective transducer elements. One composite delay profile includes a first, substantially point-focus delay profile for a first set of the transducer elements and a second, substantially point-focus delay profile for a second set of the transducer elements. The first and second delay profiles cause ultrasonic energy from the respective first and second sets of the transducer elements to constructively add at first and second respective spaced focal zones in either transmit or receive. Another composite delay profile includes first and second portions that substantially correspond to respective parts of a point-focus delay profile, and third and fourth portions that are intermediate the point-focus delay profile and respective tangents.

Abstract: A display processor for an ultrasonic imaging system includes a two-dimensional filter to generate a smoothed image signal I.sub.p from a high spatial resolution image signal I.sub.D. I.sub.p is optimized for high contrast resolution and good tissue differentiation, and I.sub.D is optimized for high detail resolution and the display of fine structural details. I.sub.p and I.sub.D are applied as addressing inputs to a look-up table that provides an output image signal I.sub.O that combines both detail resolution of I.sub.D and contrast resolution of I.sub.p. I.sub.O can display detail resolution as brightness and contrast resolution as color. I.sub.O can also be formed as a weighted combination or sum of I.sub.p and I.sub.D.