Method of determining physical parameters of bodily structures

• US 20040161137A1
• Filed: 02/12/2003
• Published: 08/19/2004
• Est. Priority Date: 02/12/2003
• Status: Active Grant

• Current Assignee: Pie Medical Imaging B.V. (Esaote SpA)
• Original Assignee: Pie Medical Imaging B.V. (Esaote SpA)
• Inventors: Lokkerbol, Coenraad Christiaan Albert, Aben, Jean-Paul Maria Michel
• Granted Patent: US 7,155,046 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 7/55 from multiple images
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume

Abstract

A method is disclosed to accurately determine spatial parameters (for example, the diameter, cross-sectional area and segment length) of bodily structures like human arteries. This is done by determining the three-dimensional position of these structures from two monoplane X-ray angiographic images obtained at arbitrary but different orientations with respect to the structure of interest. The images may be taken at a different moment, so a monoplane X-ray system can be used. Movement of the structure of interest in between the two X-ray exposures is allowed. The three-dimensional information obtained this way is subsequently used to correct the measurements of above mentioned parameters for commonly encountered error sources.

Claims

1. A method, comprising:

accessing at least two digital images I_i of a bodily structure and a reference object, where

each of the digital images shows the bodily structure and at least a portion of the reference object;

the view direction for each image I_i is defined by a unit vector v_i; and

there are at least two images I_i1 and I_i2 taken at different instants, such that there is an angle α

between the normal vectors v_i1 and v_i2 of the respective images, where −

180°

<

α

<

180°

, and α

∉

{−

90°

, 0°

, 90°

}; and

quantifying one or more spatial parameters of the bodily structure using I_i1 and I_i2.

2. The method of claim 1, wherein said one or more spatial parameters is a length.

3. The method of claim 1, wherein said one or more spatial parameters is a diameter.

4. The method of claim 1, wherein said structure is a vessel.

5. The method of claim 1, wherein at least one of images I_i1 and I_i2 is a subtracted image.

6. The method of claim 1, wherein α

is in the set of angles comprising;

angles between about −

150° and

about −

30°

, and

angles between about 30° and

about 150°

.

7. A method, comprising:

accessing at least two digital images I_i of a bodily structure and a reference object, where

each of the digital images shows the bodily structure and at least a portion of the reference object;

the view direction for each image I_i is defined by a unit vector v_i; and

there are at least two images I_i1 and I_i2 taken at different instants, such that there is an angle α

between the normal vectors v_i1 and v_i2 of the respective images, where −

180°

<

α

<

180°

, and α

≠

0°

; and

quantifying one or more spatial parameters of the bodily structure using I_i1 and I_i2;

wherein

the bodily structure moves between capture of images I_i1 and I_i2.

8. The method of claim 7, wherein said one or more spatial parameters is a length.

9. The method of claim 7, wherein said one or more spatial parameters is a diameter.

10. The method of claim 7, wherein said structure is a vessel.

11. The method of claim 7, wherein at least one of images I_i1 and I_i2 is a subtracted image.

12. The method of claim 7, wherein α

is in the set of angles comprising;

angles between about −

150° and

about −

30°

, and

angles between about 30° and

about 150°

.

13. A method, comprising:

acquiring a first image and a second image, each image showing a bodily structure and at least a portion of a calibration object;

selecting a first plurality of n points along a path in the first image;

selecting a second plurality of n points along the path in the second image;

converting each of the first plurality of points into three-dimensional coordinates using information derived from the portion said first image that shows the calibration object.

14. The method of claim 13, wherein said converting comprises scaling the first image.

15. The method of claim 13, further comprising establishing a rotation matrix, a scaling matrix, and a translation matrix that are together effective to convert a vector from the first image into three-dimensional space.