Abstract: A digital scanline signal processor which processes beamformed echo signals includes a normalization circuit, a speckle reduction processor, and a gain stage which amplifies detected echo signals. The normalization circuit applies depth dependent gain to the scanline signals to equalize the amplitudes in channels of the processor with different passband characteristics. A log compression circuit includes two compression functions for low level and high level echo signals.

Abstract: An ultrasonic diagnostic imaging system processes echo information signals by means of a dynamic range map for displayed signals which is varied automatically throughout the image to control the displayed dynamic range and noise rejection level in regions of the image. In a preferred embodiment the displayed dynamic range and noise rejection level varied with both the range (depth) and lateral (scanline to scanline) dimensions of an ultrasonic image.

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.