General Electric Company

David D Becker

Mir Said Seyed-Bolorforosh

Michael J Washburn

David John Muzilla

Anne Lindsay Hall

Xiao-Liang Xu

Doralie Martinez

William Thomas Hatfield

Larry Y Mo

Todd Michael Tillman

Edward D Nonnweiler

Michael J Harsh

Gregory R Bashford

Masayoshi Honda

Shinichi Ishiguro

Kevin McCann

A method and an apparatus for color mapping of flow power data in which the flow states containing information of most interest to the user are enhanced, while flow states not containing information of interest are suppressed. This is accomplished using a color mapping having three segments which are connected at upper and lower knee points, the latter being settable either automatically or via operator inputs. In the automatic mode, the host computer determines the positions of the knee points based on analysis of a single or a mean image frame of power Doppler data or based on system parameters (e.g., dynamic range) set by the operator. The host computer then constructs a color mapping having the determined knee points and loads that color mapping into the video processor.

Method and apparatus for optimal data mapping of power doppler images

An ultrasound imaging system having an adaptive spatial filter the filter coefficients of which, for particular image parameter sample, are determined by counting the number of neighboring image parameter samples having zero or near-zero values. If the number of zero or near-zero values in a data window is greater than a predetermined threshold, the data in the window is passed, not filtered. This filter has two advantages over other spatial filters. First, image parameter data samples having only zero or near-zero neighboring values (i.e., isolated 'point noise') are not smeared. Second, boundaries such as the edge of color in a vessel (where the surrounding area is black, i.e., the color image parameter values are zero or near zero) are not smoothed as much as in conventional filters, preserving the sharpness of the edge.

Method and apparatus for adaptive filtering by counting acoustic sample

An analytical method for automatic tracing of a Doppler time-velocity waveform envelope. At the core of this algorithm is a maximum frequency detection mechanism which is based on searching for the highest frequency bin whose spectral amplitude exceeds a certain noise threshold. The method is based on a theoretical noise amplitude distribution in the video spectral domain. In particular, the method uses a precise model of the statistical distribution of the video spectral power of white noise to establish a threshold for maximum frequency detection. Input to the noise model is the average white noise level in the video spectral display, which can be computed using either of two analytical methods.

Method and apparatus for automatic tracing of Doppler time-velocity

A method and an apparatus for increasing the spatial resolution and sensitivity of a color flow image while maintaining a desired acoustic frame rate. The ultrasound energy is concentrated at a more narrowly defined focal region, which allows for increased flow sensitivity and vessel filling. Better flow uniformity across the color region of interest is also achieved. The method uses multiple transmit focal zones, and transmit and receive apertures having low f-numbers. Using multiple focal zones with low f-numbers allows for tight focusing over a larger depth-of-field. Unique waveforms and unique gain curves are used for each focal zone. Each focal zone is fired on a separate acoustic frame. An adaptive frame averaging algorithm is used to blend together the in-focus data from each of these acoustic frames before the data is displayed.

Method and apparatus for enhancing resolution and sensitivity in color

A method and an apparatus for mitigating aliasing when imaging moving fluid or tissue using velocity Doppler shift data. To eliminate the effects of slight aliasing in the velocity mode, symmetrical (or non-directional) velocity/color maps are used to map positive and negative velocity data of the same magnitude to the same color and same display intensity. If the pulse repetition frequency is adjusted so that only subtle aliasing is present, an optimal frame averaging of the data can be achieved by removing the sign of the velocity data either before or during frame averaging.

Method and apparatus for mapping color flow velocity data into display

A method and an apparatus for three-dimensional imaging of ultrasound data by constructing projections of data from a volume of interest. An ultrasound scanner collects B-mode or color flow images in a cine memory, i.e., for a multiplicity of slices. A multi-row transducer array having a uniform elevation beamwidth is used to provide reduced slice thickness. The data from a respective region of interest for each of a multiplicity of stored slices is sent to a master controller, such data forming a volume of interest. The master controller performs an algorithm that projects the data in the volume of interest onto a plurality of rotated image planes using a ray-casting technique. The data for each projection is stored in a separate frame in the cine memory. These reconstructed frames are then displayed selectively by the system operator. Segmentation of three-dimensional projection images is enhanced by decreasing the thickness and increasing the resolution (i.e., decreasing the point spread function) of the two-dimensional slices from which the projections are derived. The slice thickness is decreased by increasing the elevational focus of the beam. The two-dimensional resolution is increased by opening the aperture, i.e., decreasing the f-number, and by increasing the band-width.

Method and apparatus for enhancing segmentation in three-dimensional

A method and an apparatus for frame averaging ultrasound imaging data. A one-tap IIR filter is used to average the corresponding pixel data of two frames. The frame averaging is a function of a normalized difference between the pixel data of the two frames. This is achieved by taking the absolute difference between the signal levels of the current frame and the previous frame and dividing the result by the arithmetic (or geometric) mean of the two data. A multitude of look-up tables of output values are generated off-line. Each look-up table is designed to be used under a specific set of operating parameters. In response to the user's selection of these operating parameters, the system downloads a selected frame-averaging look-up table from system memory. During subsequent system operation, the downloaded look-up table outputs values which are a function of the normalized difference between the previous and current frame data used to address the look-up table.

Method and apparatus for ultrasound imaging using normalized difference

A method for optimizing the beam distribution to obtain the highest frame rate together with the least amount of acoustic noise while limiting the spatial aliasing to an acceptable level. The beam distribution is adjusted according to the scan format and as a function of the beam width, which is proportional to the product of the F number and the operating wavelength. As the F number changes in going from the shallow depth to a deeper depth, the number of beams fired to construct an image would change correspondingly. In addition, if the F number is changing in going from the center of image to the edge of the image, the separation of the fired beams would change. Alternatively, if the operating frequency is being changed in going from shallower depths to deeper depths or in going from the center of image to the edge of the image, the beam spacing is changed in order to fire the optimum number of beams at all times, and thereby obtain the highest frame rate. Another variation is to have a beam distribution which depends on the spatial resolution of the display unit. For a sector scan, the number of beams which are fired at the shallower depths can be made smaller than the number of beams fired at the deeper depths. Once the beam distribution has been defined, the sequencing of beam firings must be determined to maximize the frame rate.

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Milwaukee, WI, United States of America

David D Becker