Abstract: An ultrasound breast imaging assembly includes first and second compression plates angled with respect to one another, a breast compression area defined between the first and second compression plates, at least one pivot assembly, and an ultrasound probe. The pivot assembly allows relative motion between the first and second compression plates. The ultrasound probe, which is configured to translate over one of the first and second compression plates, includes an active matrix array (AMA) positioned on one of the first and second compression plates.

Abstract: An ultrasound breast imaging assembly includes first and second compression plates angled with respect to one another, a breast compression area defined between the first and second compression plates, at least one pivot assembly, and an ultrasound probe. The pivot assembly allows relative motion between the first and second compression plates. The ultrasound probe, which is configured to translate over one of the first and second compression plates, includes an active matrix array (AMA) positioned on one of the first and second compression plates.

Abstract: An ultrasound breast imaging assembly includes first and second compression plates angled with respect to one another, a breast compression area defined between the first and second compression plates, at least one pivot assembly, and an ultrasound probe. The pivot assembly allows relative motion between the first and second compression plates. The ultrasound probe, which is configured to translate over one of the first and second compression plates, includes an active matrix array (AMA) positioned on one of the first and second compression plates.

Abstract: An ultrasound breast imaging assembly includes first and second compression plates angled with respect to one another, a breast compression area defined between the first and second compression plates, at least one pivot assembly, and an ultrasound probe. The pivot assembly allows relative motion between the first and second compression plates. The ultrasound probe, which is configured to translate over one of the first and second compression plates, includes an active matrix array (AMA) positioned on one of the first and second compression plates.

Abstract: An ultrasound system (1) acquires data using a gray scale mode of operation and a color flow mode of operation. A transducer (10) generates receive signals in response to echo ultrasound waves received from a subject (S) being studied. A gray scale receive channel (9G) generates gray scale data representing movement of portions of the subject, in particular that of blood flow or contrast agents in blood or tissue. A color flow receive channel (9C) generates color flow data (e.g., either power data or velocity data) also representing movement of portions of the subject. A processor (30) combines the gray scale flow data with the color flow data and displays the result on a display monitor (19) such that moving portions of the subject are displayed with a colored gray scale image.

Abstract: An ultrasonic imaging system for displaying color flow images includes a receiver which demodulates ultrasonic echo signals received by a transducer array and dynamically focuses the baseband echo signals. A color flow processor includes a plurality of logic units which perform different algorithms based on the type of examination being conducted.

Abstract: A color adaptive frame averaging method for an ultrasound imaging system adds persistence to images. The color adaptive frame averaging is achieved by computing filter weighting coefficients and using the filter weighting coefficients to compensate for aliased color data. Frame rate compensation is achieved by adjusting the filter weighting coefficients. In accordance with the present invention, the color adaptive frame averaging method comprises a filter, such as an infinite impulse response filter.

Abstract: A time domain technique for implementing an adaptive wall filter improves imaging of low-velocity blood flow by removing signals associated with slowly moving tissue. Adaptive wall filtering is performed by estimating wall velocity and bandwidth, and then filtering the basebanded data with a complex time domain notch filter. The wall velocity estimate determines the center frequency of a wall signal while the wall variance estimate determines the wall signal bandwidth. The complex filter coefficients selected are those which will center the complex notch filter on the wall center frequency, and which will set the filter cutoff frequencies (measured from this center frequency) to match the wall signal bandwidth.

Abstract: A triangulation method and apparatus for measuring the velocity of a flowing material at a point of interest along two lines of sight which have different vector components. The flow velocity along two different image vectors is measured simultaneously by separately processing the signals from left and right reception apertures (14, 16). In one case, the positions of the reception apertures are held constant and conventional dynamic focussing on receive is used to steer the apertures to follow the transmitted energy as a function of range depth. In an alternative case, the transducers included in each reception aperture are dynamically reassigned in order to maintain a fixed triangulation angle. In this case a reception aperture shifts away from the transmission aperture (12) to track the received backscattered ultrasonic energy at a constant triangulation angle.

Abstract: A method for estimating the velocity of flow containing a cloud of ultrasound scatterers using time-domain cross-correlation of baseband data. When the scatterers move from one range cell to another between firings, the returning echo signals from adjacent firings will look like time-shifted copies of each other. When the data is basebanded, however, the signals no longer look like time-shifted copies of each other because the baseband process divides the incoming signal into complex quadrature signals. The relative amounts in the real and imaginary parts will be dependent on the relative phase of the incoming signal and the complex mixer, and is therefore range dependent. A scattered signal that may be all real in one firing will have both I and Q components in the next firing when the scatterer has moved by several range cells. This is compensated for by rotating the baseband data for the second firing, prior to cross-correlation, by an angle equivalent to 2 .pi.

Abstract: A multi-lag method for estimating both high and low velocities of blood flow from a single set of firings in situations where both high-velocity and low-velocity signals are of interest. A color flow processor uses multiple lags in the firing sequence. The normal lag of unity is used for high-velocity estimation; lags greater than unity are used for low-velocity estimation. A normal firing sequence is set up with a pulse repetition frequency that allows accurate velocity estimation of the highest flow velocity that the operator expects. This sequence yields data that is appropriately wall filtered, and a high-velocity estimate is made by correlation over adjacent firings, that is, firings 1 and 2, 2 and 3, 3 and 4, and so on, to the end of the packet, are respectively correlated. The same data is then used to provide a low-velocity estimate. The correlation is calculated between firings that are spaced by multiple units of the pulse repetition interval, e.g.

Abstract: A color flow processor has a fuzzy logic processor for determining when an adaptive wall filter can be turned off in response to the condition wherein flow signal will be treated as wall signal. The fuzzy logic processor uses details of wall velocity and power, as well as variance, to determine whether the measured echo signal component to be filtered truly represents the wall velocity only. The general rule applied by the fuzzy logic processor would be that if the wall velocity is LOW and the wall variance is LOW and the wall power is HIGH, than the adaptive filter is turned ON, where LOW and HIGH are fuzzy values. Use can be made of information from previous states, either temporally or spatially, allowing the system to adapt itself to each study or over time.

Abstract: An ultrasonic imaging system for displaying color flow images includes a receiver which demodulates ultrasonic echo signals received by a transducer array and dynamically focuses the baseband echo signals. A color flow processor includes a frequency domain adaptive wall filter which automatically adjusts to changes in Doppler-shifted frequency and bandwidth of the wall signal components in the focused baseband echo signals after the echo signals have undergone Fourier transformation into the frequency domain. The mean Doppler-shifted frequency of the resulting filtered baseband echo signals is used to indicate velocity of moving scatterers and to control color in the displayed image.

Abstract: An ultrasonic imaging system for displaying color flow images includes a receiver which demodulates ultrasonic echo signals received by a transducer array and dynamically focuses the baseband echo signals. A color flow processor includes a time domain adaptive wall filter which automatically adjusts to changes in frequency and bandwidth of the wall signal components in the focused baseband echo signals. The mean frequency of the resulting filtered baseband echo signals is used to indicate velocity of flowing reflectors and to control color in the displayed image.

Abstract: In digital subtraction angiography a low X-ray energy temporal subtraction image is displayed on a video monitor. Regions in the temporal image frame that contain motion artifacts are outlined by using a cursor. The coordinates of the pixels in the defined outlined region are stored in a processor memory. The data for a related hybrid subtraction image are developed and stored. The processor then effects substitution of the hybrid subtraction image pixels, that fall within the same defined region, into the temporal subtraction image. The combined image data are transferred to a display controller memory which controls display of the combined image on a monitor. A method and means are provided for automatically determining the optimum value of the weighting coefficient applied to the high energy temporal subtraction image that results in the most complete cancellation of everything in the two images except the contrast medium filled blood vessel when the high and low energy temporal images are subtracted.