Surface parameter adaptive ultrasound image processing
The depth buffer of a GPU is used to derive a surface normal or other surface parameter, avoiding or limiting computation of spatial gradients in 3D data sets and extra loading of data into the GPU. The surface parameter is used: to add shading with lighting to volume renderings of ultrasound data in real time, to angle correct velocity estimates, to adapt filtering or to correct for insonifying-angle dependent gain and compression. For border detection and segmentation, intersections with a volume oriented as a function of target structure, such as cylinders oriented relative to a vessel, are used for rendering. The intersections identify data for loading into the frame buffer for rendering.
1. A method for processing ultrasound data as a function of a surface, the method comprising:
writing to a depth buffer of a graphics processing unit as a function of first ultrasound data, the first ultrasound data representing samples in a volume of a patient;
processing second ultrasound data as a function of data from the depth buffer, the data of the depth buffer indicating the surface, the first ultrasound data being the same or different than the second ultrasound data;
generating an image as a function of the processed, second ultrasound data; and
identifying the surface from the data from the depth buffer and determining an orientation of the surface relative to an insonification angle, and wherein processing comprises varying an M- or B-mode imaging parameter as a function of a cosine of difference of the insonification angle and the orientation.
2. The method of claim 1 wherein writing to the depth buffer comprises identifying coordinates of first ultrasound data closest to a viewer and greater than a threshold.
3. The method of claim 1 further comprising:
detecting a surface parameter from the data from the depth buffer;
wherein processing the second ultrasound data comprises processing as a function of the surface parameter.
4. The method of claim 3 wherein detecting the surface parameter comprises detecting a surface normal, surface coordinates, principal curvature direction, Gaussian curvature or combinations thereof.
5. The method of claim 1 further comprising deriving surface information from the data from the depth buffer, and wherein processing comprises shading the second ultrasound data as a function of the surface information.
6. The method of claim 1 wherein processing comprises angle correcting velocity estimates as a function of the data from the depth buffer.
7. The method of claim 1 wherein writing comprises identifying first ultrasound data associated with a series of substantially parallel surfaces corresponding generally to a target surface and writing coordinates of the first ultrasound data closest to a center of the target surface and greater than a threshold, and wherein processing comprises identifying a border as a function of the coordinates.
8. The method of claim 1 further comprising identifying the surface from the data from the depth buffer, and wherein processing comprises filtering the second ultrasound data as a function of the surface.
9. The method of claim 1 wherein processing comprises processing with the graphics processing unit.
10. A method for processing ultrasound data as a function of a surface, the method comprising:
identifying a surface of a specular target from data representing samples in a volume of a patient;
determining an orientation of the surface relative to an insonification angle;
varying an M- or B-mode imaging parameter as a function of a dot product between the insonification angle and the orientation; and
generating an image as a function of the M- or B-mode imaging parameter.
11. The method of claim 10 wherein varying the M- or B-mode imaging parameter comprises correcting brightness as a function of the orientation.
12. The method of claim 10 wherein varying the M- or B-mode imaging parameter comprises correcting gain, compression or both gain and compression as a function of the orientation.
13. The method of claim 10 wherein identifying the surface comprises writing coordinates of first ultrasound data closest to a viewer and greater than a threshold to a depth buffer of a graphics processing unit as a function of first ultrasound data.
14. The method of claim 10 wherein determining the orientation comprises detecting a surface normal, surface coordinates, principal curvature direction, Gaussian curvature or combinations thereof.
15. The method of claim 10 further comprising:
generating the image as an insonification angle dependent gain corrected image, the image generated as a function of the varied M- or B-mode imaging parameter.