Radiographic imaging system and method for positioning one such system

Patent metadata

Field	Value
Publication number	US-10758204-B2
Application number	US-201515524942-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Nov 5, 2014
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

Radiographic imaging system including: an x-ray transmission unit; an x-ray receiver unit; a plate made from a material opaque to x-rays and situated between the transmission unit and the receiver unit, the plate including at least four channels, each channel enabling a part of the x-rays emitted by the transmission unit to pass through the channel; and an image processing unit configured to determine the coordinates of the projected patterns and to calculate a position of the receiver unit from the coordinates of the projected patterns and from the coordinates of the channels.

First claim

The invention claimed is:

1. A radiographic imaging system comprising:
an x-ray transmission unit;
an x-ray receiver unit; and
a plate made from a material opaque to x-rays and situated between the transmission unit and the receiver unit,

wherein:
the plate comprises at least four channels, each channel enabling a part of the x-rays emitted by the transmission unit to pass through the channel;
the receiver unit generates an alignment radiographic image comprising a projected pattern of each channel;
the system comprises an image processing unit configured to determine the coordinates of the projected patterns in the alignment radiographic image, and to calculate a position of the receiver unit from the coordinates of the projected patterns in the alignment radiographic image and from the coordinates of the channels; and
the image processing unit comprises a memory to store parameters of a first geometric transformation matrix linking coordinates of reference patterns respectively with the coordinates of the channels, each reference pattern corresponding to a projection of a channel in a reference radiographic image generated when the receiver unit is located at a reference distance from the transmission unit, the image processing unit is further configured to identify the projected pattern in the alignment image of each channel, to match the projected patterns in the alignment radiographic image respectively with the channels of the plate, to calculate parameters of a second geometric transformation matrix linking the coordinates of the projected patterns in the alignment radiographic image with the coordinates of the reference patterns, and to calculate the position of the receiver unit from the parameters of the first and second matrices.

2. The system according to claim 1 , wherein the plate comprises a single panel in which said at least four channels are formed.

3. The system according to claim 1 , wherein the plate comprises at least two panels, each panel comprising at least one channel from said at least four channels.

4. The system according to claim 3 , wherein the plate comprises four panels.

5. The system according to claim 4 , wherein each panel comprises at least one channel from said at least four channels.

6. The system according to claim 3 , wherein the transmission unit emits an x-ray beam in the direction of the receiver unit and the panels are mounted movable on the transmission unit between a closed position in which said at least four channels are situated inside the x-ray beam, and an open position in which said at least four channels are situated outside the x-ray beam.

7. The system according to claim 3 , wherein the transmission unit emits an x-ray beam in the direction of the receiver unit and the panels are mounted movable on the transmission unit between a closed position in which said at least four channels are situated inside the x-ray beam, and an open position in which said at least four channels are situated inside the x-ray beam.

8. The system according to claim 1 , wherein the plate comprises several channels forming an asymmetric figure.

9. The system according to claim 1 , wherein the plate comprises at least two channels aligned along a first axis, at least two channels aligned along a second axis perpendicular to the first axis, and at least three channels aligned along a third axis inclined with respect to the first and second axes.

10. The system according to claim 1 , wherein the transmission unit and the receiver unit are mobile.

11. The system according to claim 1 , wherein the channels are of cylindrical shape.

12. The system according to claim 11 , wherein the cross-sections of the channels have different diameters from one another.

13. A method for positioning a radiographic imaging system comprising an x-ray transmission unit and an x-ray receiver unit, comprising the following steps:
arranging a plate made from a material opaque to x-rays between the transmission unit and the receiver unit, the plate comprising at least four channels, each channel enabling a part of the x-rays emitted by the transmission unit to pass through the channel;
emitting x-rays by the transmission unit;
generating, by the receiver unit, an alignment radiographic image comprising a projected pattern of each channel;
determining coordinates of the projected patterns in the alignment radiographic image; and
calculating a position of the receiver unit from the coordinates of the projected patterns in the alignment radiographic image and from the coordinates of the channels, wherein
the calculation step comprises a calibration step in which generating a reference radiographic image comprising a projected reference pattern of each channel, by the receiver unit situated at a reference distance from the transmission unit, determining the coordinates of reference patterns, and calculating parameters of a first geometric transformation matrix linking the coordinates of the reference patterns with the coordinates of the channels, an identification step of the projected pattern in the alignment radiographic image of each channel, a matching step of the projected patterns in the alignment radiographic image respectively with the channels of the plate, a calculation step of parameters of a second geometric transformation matrix linking the coordinates of the projected patterns in the alignment radiographic image with the coordinates of the reference patterns, the position of the receiver unit being determined from the parameters of the first and second matrices.

14. The method according to claim 13 , wherein the plate comprises at least two panels mounted movable on the transmission unit, each panel comprising at least one channel from said at least four channels, the transmission unit emits an x-ray beam in the direction of the receiver unit, and, when generating the alignment radiographic image, the panels are moved to a closed position in which said at least four channels are situated inside the x-ray beam, and the panels are moved to an open position in which said at least four channels are situated outside the x-ray beam to generate a diagnostic radiographic image of an object situated between the transmission unit and the receiver unit.

15. The method according to claim 13 , wherein the plate comprises at least two panels mounted movable on the transmission unit, each panel comprising at least one channel from said at least four channels, the transmission unit emits an x-ray beam in the direction of the receiver unit, and, when generating the alignment radiographic image, the panels are moved to a closed position in which said at least four channels are situated inside the x-ray beam, and the panels are moved to an open position in which said at least four channels are situated inside the x-ray beam to generate a diagnostic radiographic image of an object situated between the transmission unit and the receiver unit.

16. The method according to claim 13 , wherein the calculation step comprises calculating angles of orientation of the receiver unit from the parameters of the first and second matrices.

17. The method according to claim 13 , wherein the plate comprises at least four panels, each panel comprising at least one channel from said at least four channels.

Assignees

• Univ Grenoble Alpes
• Surgiqual Inst
• Centre Hospitalier Univ Grenoble Alpes
• Centre Hospitalier Univ De Grenoble Alpes

Inventors

• Grondin Yannick
• Augerat Philippe
• Cinquin Philippe
• Desbat Laurent
• Spencer Benjamin

Classifications

• G01N2223/612

  biological material · CPC title

• G01N2223/40

  Imaging · CPC title

• G01N2223/301

  portable apparatus · CPC title

• G01N23/04

  and forming images of the material · CPC title

• A61B6/587 Primary

  Alignment of source unit to detector unit · CPC title