US 6,705,994 B2 · Tissue inhomogeneity correction in ultrasound imaging

Abstract

A method of imaging a site of interest in a body using an ultrasound probe comprising a plurality of ultrasound transducer elements comprises obtaining an ultrasound image of a pass zone between the ultrasound probe and the site of interest. The image includes the site of interest and a plurality of tissue regions in a pass zone between the site of interest and the ultrasound probe. Boundaries of a selected tissue region in the pass zone are determined from the image. Focusing delay times are then computed for each ultrasound transducer element based in part on the speed of sound in the selected tissue region other than an average speed of sound in body tissue, and the boundaries of the selected tissue region. Preferably, a speed about the speed of sound in the selected tissue region is used and more preferably the speed of sound in the selected tissue region is used. Refraction may be considered, as well. Ultrasound imaging of the site of interest is then conducted employing the computed delay times. Fat and bone tissue regions are typically selected if present. Other tissue regions may be selected, as well. The boundaries of the tissue region or regions may be determined by segmentation. Tissue inhomogeneity is thereby compensated for, improving image contrast resolution. Ultrasound imaging systems and software are also disclosed. A new ultrasound probe comprising high and low frequency transducer elements is also disclosed.

Claims57

Dependent claims

A method of imaging a site of interest in a body using an ultrasound probe, the ultrasound probe comprising a plurality of ultrasound transducer elements, the method comprising:

obtaining an ultrasound image of a pass zone of the body between the site of interest and the ultrasound probe, the image including the site of interest and a plurality of tissue regions in the pass zone;
determining, from the image, boundaries of a selected tissue region in the pass zone;
computing respective focusing delay times for each transducer element associated with an ultrasound beam passing through the selected tissue region, the computed focusing delay times computed based, at least in part, on a speed of sound in, and the determined boundaries of, the selected tissue region, wherein the speed of sound is a speed other than an average speed of sound in body tissue;
and
conducting an ultrasound imaging scan of the pass zone employing the computed focusing delay times.

2 more elements

A method of imaging a site of interest in a body using an ultrasound probe, the ultrasound probe comprising a plurality of ultrasound transducer elements, the method comprising:

conducting a first ultrasound imaging scan of a pass zone of the body between the site of interest and the ultrasound probe with the ultrasound probe, wherein the pass zone comprises a plurality of tissue regions and the first ultrasound imaging scan employs initial transmission delays and initial reception delays for each transducer element, the initial transmission and reception delays being based, at least in part, on an average speed of sound in body tissue for each one of the tissue regions in the pass zone;
obtaining an ultrasound image of the pass zone from the first ultrasound imaging scan, the image including the site of interest and the plurality of tissue regions in the pass zone;
segmenting a selected tissue region from surrounding tissue regions in the image;
computing a respective adjusted transmission delay for each transducer element transmitting an ultrasound beam through the selected tissue region, each adjusted transmission delay computed based, at least in part, on a speed about a speed of sound in, and the segmented boundaries of, the selected tissue region, such that ultrasound beams transmitted by the plurality of transducer elements will constructively interfere at a selected focal point proximate the site of interest;
computing respective adjusted reception delays for each transducer element receiving an ultrasound beam passing though the selected tissue region, the adjusted reception delays being computed based, at least in part, on a speed about a speed of sound in, and the segmented boundaries of, the selected tissue region, such that ultrasound beams reflected from reflecting bodies in the pass zone are in phase after detection;
and
conducting a second ultrasound imaging scan of the site of interest employing the adjusted transmission delays and the adjusted reception delays.

4 more elements

An ultrasound imaging system comprising:

an ultrasound imaging probe comprising a plurality of transducer elements;
wherein the system is configured to:
determine, from ultrasound imaging data obtained of a pass zone between a site of interest in a body and the ultrasound probe, boundaries of a selected one of a plurality of tissue regions in the pass zone;
and
compute a respective focusing delay time for each transducer element associated with an ultrasound beam passing through the selected tissue region during imaging, the delay times computed based, at least in part, on a speed of sound in, and the determined boundaries of, the selected tissue regions, wherein the speed of sound is other than an average speed of sound in body tissue.

2 more elements

Software residing on a machine readable medium for operating a system for imaging of a site of interest in a body using an ultrasound probe, the ultrasound probe comprising a plurality of transducer elements, the software comprising instructions for causing the system to:

determine, from ultrasound imaging data obtained of a pass zone between a site of interest in the body and the ultrasound probe, boundaries of a selected one of a plurality of tissue regions in the pass zone;
and
compute a respective focusing delay time for each transducer element associated with an ultrasound beam passing through the selected tissue region during imaging, the focusing delay times computed based, at least in part, on a speed of sound in, and the determined boundaries of, the selected tissue region, wherein the speed of sound is other than an average speed of sound in body tissue.

A method of computing focusing delay times for use in ultrasound imaging of a site of interest in a body using an ultrasound probe, the ultrasound probe comprising a plurality of ultrasound transducer elements, the method comprising:

determining, from ultrasound imaging data of a pass zone between a site of interest in the body and the ultrasound probe, boundaries of a selected one of a plurality of tissue regions in the pass zone;
and
computing respective focusing delay times for each transducer element associated with an ultrasound beam passing through the selected tissue region during imaging, the respective delay times being computed based, at least in part, on a speed of sound in, and the determined boundaries of, the selected tissue region, wherein the speed of sound is other than an average speed of sound in body tissue.

Dependencies are inferred from the claim text.

Tissue inhomogeneity correction in ultrasound imaging

Life of this patent

Tissue inhomogeneity correction in ultrasound imaging

Life of this patent

Abstract

Claims57