Rendering a global illumination image from a volumetric medical imaging data set

Patent metadata

Field	Value
Publication number	US-10467798-B2
Application number	US-201615383114-A
Country	US
Kind code	B2
Filing date	Dec 19, 2016
Priority date	Dec 19, 2016
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

An image rendering apparatus includes processing circuitry to obtain a volumetric medical imaging data set representative of a region of a material; associate one particular extinction color with the material; determine, based on the particular extinction color, a chromatic attenuation profile representative of color value as a function of intensity and as a function of depth in the material, the chromatic attenuation profile showing how the material having the particular extinction color changes in appearance with changes in the depth; obtain, from a user, a color value; determine a modified extinction color for the material based on the color value obtained from the user; and render a global illumination image from the volumetric medical imaging data set using the modified extinction color.

First claim

The invention claimed is:

1. An image rendering apparatus, comprising:
processing circuitry configured to
obtain a volumetric medical imaging data set representative of a region of a selected type of tissue;
associate one particular extinction color with the selected type of tissue;
determine, based on the one particular extinction color, a chromatic attenuation profile representative of color values as a function of both intensity and depth in the selected type of tissue, the chromatic attenuation profile including a plurality of points defined for a range of depths and a range of intensities and showing how a rendering of a homogeneous region of the selected type of tissue, having the one particular extinction color, would change in appearance with changes in the depth of the selected type of tissue as a result of illumination by a virtual light source;
display, to a user, the determined chromatic attenuation profile;
obtain, from the user, a modified color value for a particular point in the displayed chromatic attenuation profile, the particular point being determined by input from the user;
calculate a modified extinction color for the selected type of tissue based on the particular point and the obtained modified color value for the particular point in the displayed chromatic attenuation profile; and
render a global illumination image from the volumetric medical imaging data set using the modified extinction color.

2. The apparatus according to claim 1 , wherein the processing circuity is further configured to determine the chromatic attenuation profile by, for each of a plurality of depths in the selected type of tissue, determining a corresponding color value at that depth, based on an accumulated opacity of the selected type of tissue at that depth.

3. The apparatus according to claim 2 , wherein the processing circuitry is further configured to determine a modified chromatic attenuation profile, based on the modified extinction color, and display the modified chromatic attenuation profile to the user.

4. The apparatus according to claim 3 , wherein the processing circuity is further configured to determine the modified extinction color by determining a first modified extinction color for a first intensity value, and interpolating or extrapolating the first modified extinction color at the first intensity value to obtain a modified extinction color for one or more further intensity values.

5. The apparatus according to claim 1 , wherein the processing circuitry is further configured to obtain, from the user, the modified color value for the particular point on the displayed chromatic attenuation profile, the point being determined by a user-selected intensity and a determined depth; and
determine the modified extinction color based on the modified color value at the selected intensity and the determined depth.

6. The apparatus according to claim 1 , wherein the processing circuitry is further configured to
determine and display, based on the chromatic attenuation profile, a characteristic depth in the material;
obtain, from the user, the modified color value for the characteristic depth; and
determine the modified extinction color based on the modified color value at the characteristic depth.

7. The apparatus according to claim 6 , wherein the characteristic depth indicated by the processing circuitry is a depth at which a pre-determined proportion of light entering the selected type of tissue is attenuated by the selected type of tissue.

8. The apparatus according to claim 6 , wherein the processing circuitry is further configured to calculate the modified extinction color based on the modified color value comprises using an equation:
c′=c *{circumflex over ( )}(log(1 −a )/log(1 −k ))

wherein c′ is the modified extinction color, c* is the modified color value, a is opacity, and k is accumulated opacity at the characteristic depth.

9. The apparatus according to claim 1 , wherein the processing circuitry is further configured to render, using the extinction color or the modified extinction color, the global illumination image of a substantially homogeneous object formed of the selected type of tissue, the substantially homogeneous object having a predetermined shape and a constant intensity value.

10. The apparatus according to claim 9 , wherein the predetermined shape comprises at least one of a sphere, a first tubular structure, and at least one further tubular structure having at least one of a different thickness, orientation, and angle of lighting than the first tubular structure.

11. The apparatus according to claim 9 , wherein the processing circuitry is further configured to receive user input indicative of at least one of the predetermined shape and the constant intensity value.

12. The apparatus according to claim 1 , wherein the processing circuitry is further configured to
display, to the user, at least one color value derived from the one particular extinction color;
obtain an adjustment of each displayed color value; and
determine the modified extinction color based on the at least one color value and the adjustment.

13. The apparatus according to claim 12 , wherein the adjustment of each color value received from the user comprises an offset.

14. The apparatus according to claim 13 , wherein the processing circuitry is further configured to apply the offset to at least one further color value to obtain at least one further extinction color.

15. The apparatus according to claim 1 , wherein the processing circuitry is further configured to display, to a user, a user interface comprising at least one of the chromatic attenuation profile, an image of a substantially homogeneous object, and an extinction color modulation plot.

16. The apparatus according to claim 15 , wherein the processing circuitry is further configured to obtain, via the user interface, a user input comprising at least one of the modified color value, a predetermined shape, and a constant intensity value.

17. The apparatus according to claim 1 , wherein the processing circuitry is further configured to associate the one particular extinction color with the selected type of tissue by, for at least one intensity value of the selected type of tissue, obtaining a color and an opacity for the selected type of tissue at the at least one intensity value, and determining a corresponding extinction color at the at least one intensity value based on the obtained color and obtained opacity, wherein the determining of the one particular extinction color comprises using an equation:
Extinction value c =1−(1 −a ){circumflex over ( )}(1 −c )

wherein c is each of red, green, and blue, and a is opacity.

18. The apparatus according to claim 1 , wherein the processing circuitry is further configured to associate the one particular extinction color with the selected type of tissue by using an extinction color transfer function for the selected type of tissue, the extinction color transfer function relating extinction color to intensity value.

19. The image rendering method, comprising:
obtaining a volumetric medical imaging data set representative of a region of a selected type of tissue;
associating one particular extinction color with the selected type of tissue;
determining, based on the one particular extinction color, a chromatic attenuation profile representative of color values as a function of both intensity and depth in the selected type of tissue, the chromatic attenuation profile including a plurality of points defined for a rang

Assignees

• Toshiba Medical Sys Corp
• Canon Medical Systems Corp

Inventors

• Day Timothy
• Wahrenberg Magnus
• Reynolds Steven
• Chau Gerald
• Smout Andy

Classifications

• G06T2210/41

  Medical · CPC title

• A61B6/037

  Emission tomography · CPC title

• A61B6/461

  Displaying means of special interest · CPC title

• G06T15/08 Primary

  Volume rendering · CPC title

• A61B8/461

  Displaying means of special interest · CPC title