Imaging Systems Featuring Waveguiding Compensation

• US 20110049384A1
• Filed: 06/03/2008
• Published: 03/03/2011
• Est. Priority Date: 10/19/2007
• Status: Active Grant

• Current Assignee: Revvity Health Sciences Incorporated (Revvity, Inc.)
• Original Assignee: VisEn Medical, Inc. (Revvity, Inc.)
• Inventors: Mohajerani, Pouyan, Yared, Wael I., Kempner, Joshua
• Granted Patent: US 8,492,734 B2
• Time in Patent Office: Days
• US Class Current: 250/458.1
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/415 the glands, e.g. tonsils, adenoids or thymus
• CPC Class Codes: G01N 2021/6439 with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 2021/6491 Measuring fluorescence and transmission; Correcting inner filter effect
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G06T 11/003 Reconstruction from projections, e.g. tomography
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating

Abstract

In certain embodiments, the invention relates to systems and methods for altering an image to compensate for variation in one or more physical and/or supervenient properties (e.g., optical absorption and/or scattering) in heterogeneous, diffuse tissue, thereby attenuating the effects of tissue waveguiding. The methods enable the proper identification of emission image regions that evidence waveguiding of electromagnetic radiation, and enables compensation of emission images for such waveguiding. The methods preserve the depth localization accuracy of the FMT approach and improve optical reconstruction in the targeted areas while eliminating spurious components of fluorescence from the acquired data set. Calibration methods for probe concentration mapping are also presented.

Claims

1. A method for compensating an image for waveguiding effects, the method comprising:

(a) detecting excitation light emanating from at least part of a heterogeneous diffuse object at one or more wavelengths, thereby acquiring an intrinsic image;

(b) detecting emission light emanating from at least part of said heterogeneous diffuse object at one or more wavelengths, thereby acquiring a detected emission image, said emission light emitted by an imaging probe located within or on said heterogeneous diffuse object as a result of excitation by said excitation light;

(c) creating an estimated emission image using at least said intrinsic image; and

(d) altering said detected emission image using at least said estimated emission image, thereby compensating said detected emission image for waveguiding effects.

2. The method of claim 1, wherein each of step (a) and step (b) comprises detecting light transmitted through at least part of said heterogeneous diffuse object.

3. The method of claim 1, wherein said heterogeneous diffuse object is a mammal.

4. The method of claim 1, wherein said heterogeneous diffuse object comprises biological tissue.

6. The method of claim 1, wherein said heterogeneous diffuse object is transilluminated with excitation light.

7. The method of claim 1, wherein said heterogeneous diffuse object is epi-illuminated with said excitation light.

8. The method of claim 1, wherein said excitation light detected in step (a) comprises near-infrared light.

9. The method of claim 1, wherein said emission light comprises fluorescent light emitted by said probe.

10. The method of claim 1, wherein step (c) comprises applying a statistical estimator to said intrinsic image to create said estimated emission image.

12. The method of claim 1, wherein step (d) comprises subtracting said estimated emission image from said detected emission image.

13. The method of claim 1, comprising determining a coincidence mask from said intrinsic image and said detected emission image.

14. The method of claim 13, wherein step (d) comprises subtracting said estimated emission image from said detected emission image to obtain a residual image, and applying said coincidence mask to said residual image to obtain said waveguiding-compensated emission image.

16. The method of claim 1, wherein said intrinsic image and said detected emission image are 2-D images or are used in tomographic reconstruction to obtain a tomographic image.

18. The method of claim 1, further comprising repeating steps (a)-(d) to obtain a plurality of emission images compensated for waveguiding effects.

19. The method of claim 18, wherein said plurality of waveguiding-compensated emission images is used in tomographic reconstruction to obtain one or more tomographic images.

22. The method of claim 18, comprising determining a Born ratio from one or more of said waveguiding-compensated emission images and further masking said one or more waveguiding-compensated emission images.

23. The method of claim 1, wherein said probe is a near-IR probe.

5. (canceled)

11. (canceled)

15. (canceled)

17. (canceled)

20-21. -21. (canceled)

24. A method of imaging a region within an object, the method comprising:

(a) administering to said object a probe comprising a fluorophore;

(b) directing excitation light into and/or onto said object at multiple locations;

(c) detecting excitation light emanating from or transmitted through at least part of said object, thereby acquiring an intrinsic image;

(d) detecting fluorescent light emitted from said probe within or on a surface of said object, thereby acquiring a detected emission image; and

(e) processing data from said intrinsic image and said detected emission image to provide a representation of said region within said object, said representation compensated for waveguiding effects, wherein step (e) comprises;

(i) creating an estimated emission image using at least said intrinsic image and altering said detected emission image using at least said estimated emission image; and

(ii) determining a coincidence mask from said intrinsic image and said detected emission image and altering said detected emission image using at least said coincidence mask.

29. The method of claim 24, wherein step (e) comprises determining a concentration or concentration map of said probe using calibration measurements of a phantom of said object.

25-28. -28. (canceled)

30. A fluorescence molecular tomography imaging system comprising:

an excitation light source;

an optical imaging chamber configured to direct excitation light from said excitation light source into an object disposed within said chamber at multiple locations;

a detector configured to detect at multiple locations excitation light emanating from said object, thereby acquiring an intrinsic image, and fluorescent light emitted from one or more probes within or on a surface of said object, thereby acquiring a detected emission image; and

a processor configured to process data from said intrinsic image and said detected emission image to provide a representation of said region within said object, said representation compensated for waveguiding effects, wherein said processor is configured to perform the following;

(i) create an estimated emission image using at least said intrinsic image and alter said detected emission image using at least said estimated emission image; and

(ii) determine a coincidence mask from said intrinsic image and said detected emission image and alter said detected emission image using at least said coincidence mask.