Abstract: An ultrasonic diagnostic imaging system and methods are described which produces ultrasonic images from harmonic echo components of a transmitted fundamental frequency. Preferably, a programmable digital filter is used to pass harmonic echo components for image processing to the exclusion of fundamental frequency signals. In a preferred embodiment, artifacts are removed by producing decorrelated replicas of the harmonic signals, which are then combined and used for imaging. To produce an image in the presence of depth dependent attenuation of high frequency echo signals, both fundamental and harmonic echo signals are processed and used to produce an image blended from components of both fundamental and harmonic echo signals.

Abstract: A technique for scanning an image field with adjacent beams of ultrasonic energy is provided in which initially transmitted beams are transmitted along beam directions at the lateral sides of the image field. Subsequent beams are alternately transmitted on either side of the initially transmitted beams and at lateral locations which converge toward the center of the image field until the full image field has been scanned. In an alternate embodiment initially transmitted beams are transmitted on one side of the center of the image field, subsequent beams diverge from the locations of the initially transmitted beams, and concluding beams laterally converge at a location on the other side of the center of the image field.

Abstract: An ultrasonic diagnostic system is provided which automatically sets up the TGC characteristic to be used for a given ultrasound examination. Upon user selection of a particular ultrasound application, a setup controller accesses a predetermined TGC characteristic for the selected application. The predetermined TGC characteristic is used to control the gain of a TGC amplifier and is also displayed to the user. By adjustment of a series of TGC controls the user can vary the TGC characteristic from the predetermined characteristic.

Abstract: An ultrasonic diagnostic imaging system is provided in which a portion of an ultrasonic image can be selected for enlarged display as a "zoom" image. When the image portion is displayed in its enlarged format, the bandwidth of a filter in the ultrasonic information path is extended to increase the information content of the image portion when displayed in its enlarged format. The bandwidth is continuously optimized to maximize information content in consideration of the characteristics of the display while preventing the generation of scintillation artifacts caused by attempts to display information of an excessive bandwidth.

Abstract: A technique for scanning an image field with adjacent beams of ultrasonic energy is provided in which initially transmitted beams are transmitted along beam directions down the center of the image field. Subsequent beams are alternately transmitted on either side of the initially transmitted beams and at increasing lateral locations in said field with respect to the locations of the initially transmitted beams until the full image field has been scanned. In a preferred embodiment a waiting period is added to the pulse repetition interval of each transmission to allow time for multipath reflections to dissipate. The waiting periods are longer during initial transmissions in the vicinity of the center of the image field, and decline as beams are transmitted at increasing lateral locations of the field. The scanning technique provides a reduction in multipath reflection artifacts while maintaining a smoothly varying or uniform temporal disparity in the transmission times of adjacent beams.

Abstract: Disclosed is an ultrasonic method of measuring the movement of a particle in a test region. The method comprises processing a modulated signal returned from the test region to detect a first range of feature data and then processing a modulated signal returned from the test region to detect a second range of feature data. The second range of feature data is then compared to the first range of feature data to determine the positional displacement between at least one feature in the second range of feature data and the closest adjacent feature in the first range of feature data. The positional displacement indicates the movement of a particle in the test region. Also disclosed is an apparatus for carrying out the foregoing method.