Method and apparatus for three-dimensional imaging in the fourier domain

• US 20030118223A1
• Filed: 12/02/2002
• Published: 06/26/2003
• Est. Priority Date: 08/10/2001
• Status: Active Grant

• Current Assignee: VisionGate, Inc.
• Original Assignee: VisionGate, Inc.
• Inventors: Nelson, Alan C., Rahn, J. Richard
• Granted Patent: US 6,741,730 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G06T 11/006 Inverse problem, transformation from projection-space into object-space, e.g. transform methods, back-projection, algebraic methods
• CPC Class Codes: G06T 2211/421 Filtered back projection [FBP]

Abstract

Two or more two-dimensional Fourier transforms are acquired from different perspectives of a three-dimensional object region. A three-dimensional Fourier transform is then constructed using tomographic methods, permitting the application of image analysis algorithms analogous to those used for two-dimensional images.

Claims

1. A method for multi-dimensional imaging of an object region, the method comprising the steps of:

a) passing light through an object region to produce transmitted light rays;

b) capturing the light rays by at least one optical element, each of said at least one optical element having a back focal plane;

c) using at least one detector to capture a power spectrum of a two-dimensional Fourier transform, where the at least one detector is located in a back focal plane of the least one optical element; and

d) repeating steps a)-c) for two or more viewpoints about an arc at least partially encircling the object region to obtain multiple two-dimensional Fourier transforms.

2. The method of claim 1, further comprising the step of using an image analysis computer algorithm to extract features of interest from one or more of the multiple two-dimensional Fourier transforms.

3. The method of claim 1 wherein the optical element is selected from the group consisting of a lens and reflective surface.

4. The method of claim 1 further comprising the step of passing the light through a spatial filter placed in an optical path between the light source and the object region.

5. The method of claim 1, in which the light rays captured by the at least one optical element are transmitted through the object region prior to passing through the at least one optical element.

6. The method of claim 1, in which the light rays pass through the object region after passing through the at least one optical element.

7. The method of claim 1, further comprising the step of reconstructing the multiple two-dimensional Fourier transforms to create a three-dimensional Fourier transform.

8. The method of claim 7, further comprising the step of using an image analysis computer algorithm to extract features of interest from the three-dimensional Fourier transforms.

9. The method of claim 7, further comprising the step of employing a mask and an image analysis algorithm to construct of a cross-correlation function of the object region with a previously examined object region.

10. The method of claim 7, further comprising the step of employing an image analysis algorithm to construct of an autocorrelation function of the object region.

11. The method of claim 9, in which the previously examined object region is a cell.

12. The method of claim 9, in which the previously examined object region is an artifically generated phantom.

13. A system for multi-dimensional imaging of an object region, the system comprising:

a light source;

an object region including at least one feature of interest, the object region being disposed in an optical path to be illuminated by the light source;

at least one detector located in the optical path to receive light passing through the object region; and

at least one lens located in the optical path between the object region and the at least one detector such that a Fourier plane is created in the back focal plane of the lens, where the at least one detector is located in the Fourier plane for mapping a spatial frequency distribution of the at least one feature of interest.

14. The system of claim 13 wherein the light source comprises a laser.

15. The system of claim 13 further comprising a spatial filter placed in an optical path between the light source and the object region.

16. The system of claim 13 further comprising an aperture placed in an optical path between the light source and the object region.

17. The system of claim 13 wherein the at least one detector comprises a detector selected from the group consisting of CCD, CMOS, solid state image sensors, and solid state image sensor detector arrays.

18. A parallel-beam optical tomography system for imaging an object of interest having at least one feature of interest, the parallel-beam optical tomography system comprising:

a light source projecting a column of light along an optical path;

an object containing tube located along the optical path, wherein the object of interest is held within the object containing tube;

at least one detector array, where each of the at least one detector array is located to receive emerging radiation from the object of interest; and

at least one lens located in the optical path between the object of interest and the at least one detector array such that a Fourier plane is created in a back focal plane of the lens, where the at least one detector is located in the Fourier plane for mapping a spatial frequency distribution of the at least one feature of interest.

19. The system of claim 18 wherein the at least one detector comprises a detector selected from the group consisting of CCD, CMOS, solid state image sensors, and solid state image sensor detector arrays.

20. The parallel-beam optical tomography system of claim 18 wherein the object of interest comprises a cell.

21. The system of claim 18 wherein the light source comprises a laser.

22. The system of claim 18 further comprising a spatial filter placed in the optical path between the light source and the object region.

23. The system of claim 18 further comprising an aperture placed in the optical path between the collimated light source and the object region.