System and method for ultrasound imaging of regions containing bone structure
Systems and methods for processing ultrasound data are provided. The disclosure includes using at least one computer hardware processor to perform obtaining ultrasound data generated based, at least in part, on one or more ultrasound signals from an imaged region of a subject, the ultrasound data comprising fundamental frequency ultrasound data and harmonic frequency ultrasound data, calculating shadow intensity data based at least in part on the harmonic frequency ultrasound data, generating, based at least in part on the fundamental frequency ultrasound data, an indication of bone presence in the imaged region, generating, based at least in part on the shadow intensity data, an indication of tissue presence in the imaged region, and generating an ultrasound image of the subject at least in part by combining the indication of bone presence and the indication of tissue presence.
1. An ultrasound imaging method, comprising:
using at least one computer hardware processor to perform:
obtaining ultrasound data generated based, at least in part, on one or more ultrasound signals from an imaged region of a subject,
the ultrasound data comprising a plurality of ultrasound data values each corresponding to a respective voxel in a set of voxels that correspond to the imaged region,
the ultrasound data comprising fundamental frequency ultrasound data and harmonic frequency ultrasound data;
calculating, for each respective voxel, shadow intensity data based at least in part on the harmonic frequency ultrasound data;
calculating a noise-to-shadow intensity ratio for each respective voxel based on (a) an expected shadow intensity value for the respective voxel calculated from a noise-only image, and (b) the shadow intensity data;
forming, based at least in part on the fundamental frequency ultrasound data and the noise-to-shadow intensity ratio, an image resulting from bone amplitude mapping;
forming, based at least in part on the noise-to-shadow intensity ratio and the harmonic frequency ultrasound data, an image resulting from tissue amplitude mapping; and
generating a bone-enhanced ultrasound image of the subject at least in part by combining the image resulting from bone amplitude mapping and the image resulting from tissue amplitude mapping.
2. The method of claim 1 , wherein the forming of the image resulting from the bone amplitude mapping comprises:
identifying, based at least in part on the shadow intensity data, an initial indication value of bone presence for each respective voxel that corresponds to the imaged region;
combining the initial indication values and the fundamental frequency ultrasound data to form combined bone values; and
transforming the combined bone values using a mapping amplitude function to obtain the image resulting from the bone amplitude mapping.
3. The method of claim 2 , wherein the identifying of the initial indication value of bone presence comprises: for each respective voxel that corresponds to the imaged region, identifying the initial indication value of bone presence based on the noise-to-shadow intensity ratio.
4. The method of claim 2 , wherein the combining of the initial indication values and the fundamental frequency ultrasound data comprises, for each respective voxel, multiplying the initial indication value of bone presence by the fundamental frequency ultrasound data to obtain the combined bone values.
5. The method of claim 1 , wherein the obtaining of the ultrasound data comprises band pass filtering the one or more ultrasound signals to obtain the fundamental frequency ultrasound data and the harmonic frequency ultrasound data.
6. The method of claim 1 , wherein the obtaining of the ultrasound data comprises performing pulse inversion imaging.
7. The method of claim 1 , wherein the calculating of the shadow intensity data comprises calculating a shadow intensity value for a first of the set of voxels at least in part by calculating a weighted sum of harmonic frequency ultrasound data values corresponding to voxels in the set of voxels at least in part by calculating a weighted sum of harmonic frequency of voxels that are located at least a threshold number of voxels away from the first voxel.
8. The method of claim 7 , wherein the threshold number of voxels is greater than or equal to an axial resolution of an imaging system used to generate the ultrasound data.
9. The method of claim 1 , wherein the combining of the image resulting from the bone amplitude mapping and the image resulting from the tissue amplitude mapping is performed to achieve a predetermined bone-to-tissue contrast and/or a predetermined contrast-to-noise ratio.