US 5,961,461 A · Method and apparatus for adaptive B-mode image enhancement

Abstract

A method and an apparatus for adaptively enhancing the B-mode image during post-detection image processing in an ultrasound imaging system. A low pass filter which smooths out speckle and a high pass filter which enhances edges are placed in parallel signal paths connected to the output of an envelope detector in a B-mode processor. The signals in the high pass filter path are logarithmically compressed before high pass filtering. The signals in the low pass filter path are logarithmically compressed after low pass filtering. Respective weighting factors are applied to the low- and high-pass-filtered signals by an adaptive weighting device, which may take the form of a processor or a look-up table. The weighted low- and high-pass-filtered signals are then summed and optionally input to an anti-aliasing low pass filter before decimation and scan conversion.

Claims20

Dependent claims

A B-mode processor for an ultrasound imaging system, comprising:

an envelope detector comprising an output;
first means for logarithmic data compression comprising an input connected to receive said output of said envelope detector and an output;
high pass filtering means for enhancing edges comprising an input connected to receive said output of said first logarithmic data compression means and an output;
first low pass filtering means for smoothing speckle comprising an input connected to receive said output of said envelope detector and an output;
second means for logarithmic data compression comprising an input connected to receive said output of said first low pass filtering means and an output;
and
adaptive means for image enhancement comprising input means connected to at least one of said outputs and means for outputting a signal representing the sum of a first weighting factor applied to a signal output from said high pass filtering means plus a second weighting factor applied to a signal output from said first low pass filtering means, said first and second weighting factors being determined as a function of a signal received from one of said outputs.

4 more elements

An ultrasound imaging system comprising:

a transducer array comprising a multiplicity of piezoelectric transducer elements;
a beamformer comprising a multiplicity of beamformer channels;
switching means for coupling said piezoelectric transducer elements and said beamformer channels;
an envelope detector coupled to receive a stream of digital samples representing a receive beam from said beamformer and output a stream of digital samples representing an envelope;
means for logarithmically compressing said stream of digital samples representing an envelope to produce a logarithmically compressed digital sample stream;
means for high pass filtering said logarithmically compressed digital sample stream to produce a high-pass-filtered logarithmically compressed digital sample stream representing an image having enhanced edges;
means for low pass filtering said stream of digital samples representing an envelope to produce a low-pass-filtered digital sample stream having smoothed speckle;
means for logarithmically compressing said low-pass-filtered digital sample stream to produce a logarithmically compressed low-pass-filtered digital sample stream;
means for generating an image-enhanced signal representing the sum of a first weighting factor applied to said high-pass-filtered logarithmically compressed digital sample stream plus a second weighting factor applied to said logarithmically compressed low-pass-filtered digital sample stream;
and
means for displaying an image derived from said image-enhanced signal.

8 more elements

Dependencies are inferred from the claim text.

Method and apparatus for adaptive B-mode image enhancement

Life of this patent

Method and apparatus for adaptive B-mode image enhancement

Life of this patent

Abstract

Claims20