Abstract: A method and an apparatus for segmenting three-dimensional projected velocity images by limiting the volume of velocity data projected onto the imaging planes. If the volume of interest contains flowing blood, i.e., an artery or vein, the Doppler shift present in the ultrasound reflected from the flowing blood can be detected and then used to limit the amount of velocity data which is projected. Only pixels having velocity values within a predetermined range are projected onto the imaging plane.

Abstract: A method and an apparatus for three-dimensional imaging of ultrasound data by combining projections of intensity data with projections of velocity or power data from a volume of interest. The apparatus is an ultrasound scanner which collects B-mode or color flow images in a cine memory, i.e., for a multiplicity of slices. The data from a respective region of interest for each slice 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 on a plurality of rotated image planes using a ray-casting technique. The combined intensity and velocity or power 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.

Abstract: A method and an apparatus for improving the segmentation of a three-dimensional B-mode image by limiting the volume of pixel intensity data projected onto the imaging planes. If the volume of interest contains moving ultrasound scatterers, e.g., blood flowing in an artery or vein, the Doppler shift present in the ultrasound reflected from the flowing blood can be detected and then used to limit the amount of pixel data which is projected. The velocity or power data is used to identify those intensity values to be projected onto the imaging plane. This is accomplished by locating a reference data volume of pixels for which the velocity or power value is non-zero and then defining a source data volume which is essentially a function of that reference data volume. The reference data volume comprises pixels acquired from echo return signals reflected by the moving ultrasound scatterers.

Abstract: An ultrasound imaging system for displaying edge-enhanced topographic flow power data surrounded by B-mode anatomical data without masking out any significant edge-enhanced topographic flow power data and without displaying any significant flow power background noise. An improved high-pass topographic filter is used to enhance the edges of the flow in the displayed image in both the horizontal (lateral) and vertical (range) directions. The two-dimensional topographic filter is a digital filter with three taps in each dimension and is incorporated in the acoustic line memory. Also, the raw flow power data is compressed down to 7 bits in such a way that the transfer function is shifted away from zero input power. In this way, the system gain can be set to effectively zero out most of the background noise. After the flow power data passes through the high-pass topographic filter, it is mapped to values between -128 and +127 (8 bits) with zero in the middle.