Ultrasound imaging system having spatial filtering preprocessor

Abstract

An ultrasonic imaging system beamforming architecture comprises a fixed wideband preprocessor section followed by a reduced number of dynamically adjusted delay channels. The preprocessor includes a transform beamformer with spatial filtering followed by a delay beamformer. Each transform preprocessor provides transformation of the local array space data into beam space. One, or combinations, of these beams may then be selected as input signals to an inverse transform which converts the beam space data back into array space data. This re-establishes the spatial array, but with a reduced directional view, allowing an inverse transform of reduced size to be used for the reconstruction. The result is a decrease in the number of channels required by the remainder of the beamformer. If the beam direction specified in the preprocessor sections is different from that specified in the channel delay processor, a resulting error that causes spurious beams to be formed in unwanted directions is mitigated by forming a spatial filter in each preprocessor section using adjacent channel information.