Three dimensional image reconstruction from single plane x-ray fluorograms

• US 6,587,541 B2
• Filed: 09/30/2002
• Issued: 07/01/2003
• Est. Priority Date: 12/20/2000
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: Cedara Software, Corp (International Business Machines Corporation)
• Inventors: Menhardt, Wido
• Primary Examiner(s): Bruce, David V.
• Application Number:
  US10/260,466
• Publication Number:
  US 20030043969A1
• Time in Patent Office: 274 Days
• Field of Search: 378/4, 378/10, 378/62, 378/98, 378/901
• US Class Current: 378/62
• 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 2211/436 Limited angle
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

A method is provided to reconstruct the three-dimensional image of an X-ray contrast agent-filled object having at least one plane of symmetry using a single plane two-dimensional X-ray projection. The projection is obtained by irradiating the object with X-rays substantially perpendicular to a selected plane of symmetry of the object. The absorbance value of each pixel in the projection, which is related to the distance travelled by the X-ray within the object, is then divided by 2 to define the z coordinates on each side of the x-y plane of symmetry of the object. The z coordinates together with the x,y coordinates of each pixel define the three-dimensional contour of the object.

Claims

1. A method of constructing a three dimensional image from a two-dimensional X-ray projection of an object, the method comprising steps of:

a) filling the object to be imaged with an X-ray agent, said X-ray agent attenuating X-rays;

b) generating an X-ray absorbance profile by irradiating said agent-filled object with X-rays substantially perpendicularly to a selected plane of said object, said object is substantially symmetrical about said selected plane thereof, wherein said X-ray absorbance profile has an x, y coordinates on said selected plane and has an absorbance parameter (P) related to a distance (D) travelled by the X-ray; and

c) producing a three-dimensional image of said object using said X-ray absorbance profile, by dividing the X-ray absorbance parameter by two and processing said divided absorbance parameter into a z-coordinate with respect to the x, y coordinate of the corresponding absorbance profile.

2. The method according to claim 1, wherein said X-ray agent is substantially uniformly filled in the object to be imaged.

3. The method according to claim 1, wherein said X-ray agent has a pre-selected concentration (c) and absorption coefficient (ε

) wherein said absorbance parameter (P) is represented by the equation;

P=cε

D, where D is said distance travelled by the X-rays.

4. The method according to claim 3, wherein said z-coordinates are presented as follows:

a (+Z) coordinate=+D/2 and a (−

Z) coordinate=−

D/2.

5. The method according to claim 1, further comprising steps of:

before said step a), generating a mask absorbance profiles by irradiating the object to be imaged with X-rays substantially perpendicularly to substantially the same plane selected in said step b);

before said step c), subtracting said mask absorbance profile from said X-ray absorbance profile obtained in the step b) to define a final X-ray absorbance profile, wherein said final X-ray absorbance profile is utilized in said step c).

6. A method of constructing a three dimensional image from a two-dimensional X-ray image of an object, the method comprising steps of:

a) filling the object to be imaged with an X-ray agent, said X-ray agent attenuating X-rays;

b) generating a two-dimensional X-ray image with respect to a selected plane of said object by irradiating said agent-filled object with X-rays substantially perpendicularly to said selected plane of the object, said object is substantially symmetrical about said selected plane of the object, wherein said two-dimensional X-ray image includes a plurality of picture elements, each picture element having an x, y coordinates on said selected plane and having an X-ray absorbance parameter (P) indicating a distance D(x, y) travelled by the X-ray; and

c) producing a three-dimensional image of said object using said two-dimensional X-ray image, by dividing the X-ray absorbance parameter of each picture element by two and processing said divided absorbance parameter into a z-coordinate with respect to each corresponding picture element, thereby to generate x, y and z coordinates presenting a three-dimensional image of said object.

7. The method according to claim 6, wherein said X-ray agent is substantially uniformly filled in the object to be imaged.

8. The method according to claim 6, wherein said X-ray agent has a pre-selected concentration (c) and absorption coefficient (ε

), wherein said absorbance parameter (P) is represented by the equation;

P=cε

D(x, y).

9. The method according to claim 8, wherein said z-coordinates are represented as follows:

a (+Z) coordinate=+D (x, y)/2, and a (−

Z) coordinate=−

D(x, y)/2.

10. The method according to claim 6, further comprising steps of:

before said step a), generating a two-dimensional mask image by irradiating the object to be imaged with X-rays substantially perpendicularly to substantially the same plane selected in said step b);

before said step c), subtracting said mask image from said two-dimensional X-ray image obtained in said step b) to define a final two-dimensional X-ray image, wherein said final two-dimensional X-ray image is utilized in said step c).

11. An apparatus for constructing a three dimensional image from a two-dimensional X-ray projection of an object, the apparatus comprising:

a) means for filling the object to be imaged with an X-ray agent, said X-ray agent attenuating X-rays;

b) means for generating an X-ray absorbance profile by irradiating said agent-filled object with X-rays substantially perpendicularly to a selected plane of said object, said object is substantially symmetrical about said selected plane thereof, wherein said X-ray absorbance profile has an x, y coordinates on said selected plane and has an absorbance parameter (P) related to a distance (D) travelled by the X-ray; and

c) means for producing a three-dimensional image of said object using said X-ray absorbance profile, by dividing the X-ray absorbance parameter by two and processing said divided absorbance parameter into a z-coordinate with respect to the x, y coordinate of the corresponding absorbance profile.