Systems and methods for focus control in x-rays

Patent metadata

Field	Value
Publication number	US-11246208-B2
Application number	US-201916666436-A
Country	US
Kind code	B2
Filing date	Oct 29, 2019
Priority date	Apr 24, 2019
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

A method may include obtaining a feedback or a reference value of a tube voltage applied to a radiation source of a radiation device for generating radiation rays. The method may also include determining, based on the feedback or the reference value of the tube voltage, a specific value of a focusing parameter associated with a focusing device of the radiation device. The method may further include causing the focusing device to shape a focus of the radiation rays according to the determined value of the focusing parameter. The focus of the radiation rays may satisfy an operational constraint under the specific value of the focusing parameter.

First claim

We claim:

1. A system, comprising:
at least one storage device storing executable instructions, and
at least one processor in communication with the at least one storage device, when executing the executable instructions, causing the system to perform operations including:
obtaining a feedback or a reference waveform of a tube voltage applied to an x-ray radiation source of an x-ray radiation device for generating x-ray radiation rays;
determining a falling edge or a rising edge of the feedback or the reference waveform of the tube voltage;
determining a changing rate of a focusing parameter based on the falling edge or the rising edge of the feedback or the reference waveform of the tube voltage;
determining, based on the changing rate of the focusing parameter, a specific value of the focusing parameter associated with a focusing device of the x-ray radiation device; and
causing the focusing device to shape a focus of the x-ray radiation rays according to the determined value of the focusing parameter, wherein the focus of the x-ray radiation rays satisfies an operational constraint under the specific value of the focusing parameter.

2. The system of claim 1 , wherein the at least one processor is further configured to cause the system to perform the operations including:
generating, based on at least a portion of the x-ray radiation rays detected by a detector of the x-ray radiation device, one or more images using an energy imaging technique.

3. The system of claim 1 , wherein the operational constraint includes that a size of the focus of the x-ray radiation rays is in a range when the tube voltage changes according to a reference waveform.

4. The system of claim 1 , wherein the operational constraint includes that a size of the focus of the x-ray radiation rays is equal to a fixed value when the tube voltage changes according to a reference waveform.

5. The system of claim 1 , wherein the focusing device is configured to shape the focus of the x-ray radiation rays by generating an electric field under a focusing voltage, and the focusing parameter includes the focusing voltage.

6. The system of claim 1 , wherein the focusing device is configured to shape the focus of the x-ray radiation rays by generating a magnetic field under a focusing current, and the focusing parameter includes the focusing current.

7. The system of claim 1 , wherein to determine, based on the feedback or the reference waveform of the tube voltage, the specific value of the focusing parameter associated with the focusing device, the at least one processor is further configured to cause the system to perform the operations including:
obtaining a relationship between the tube voltage and the focusing parameter with respect to a specific size of the focus; and
determining, based on the relationship, the specific value of the focusing parameter corresponding to the feedback or the reference waveform of the tube voltage.

8. The system of claim 7 , wherein the relationship between the tube voltage and the focusing parameter includes multiple groups of values of the tube voltage and the focusing parameter, each group including a value of the tube voltage and a corresponding value of the focusing parameter.

9. The system of claim 7 , wherein the relationship between the tube voltage and the focusing parameter includes multiple groups of ranges of the tube voltage and values of the focusing parameter, each group including a range of the tube voltage and a corresponding value of the focusing parameter.

10. The system of claim 9 , wherein to determine, based on the relationship, the specific value of the focusing parameter corresponding to the feedback or the reference waveform of the tube voltage, the at least one processor is further configured to cause the system to perform the operations including:
determining a specific range of the tube voltage which the feedback or the reference waveform belongs to; and
determining, based on the relationship and the specific range of the tube voltage, the specific value of the focusing parameter corresponding to the feedback or the reference waveform of the tube voltage.

11. The system of claim 1 , wherein to determine, based on the feedback or the reference waveform of the tube voltage, the specific value of the focusing parameter associated with the focusing device, the at least one processor is further configured to cause the system to perform the operations including:
obtaining a relationship between the focusing parameter and time with respect to a specific size of the focus; and
determining, based on the relationship and a time point when the feedback or the reference waveform is obtained, the specific value of the focusing parameter corresponding to the feedback or the reference waveform of the tube voltage.

12. The system of claim 11 , wherein to obtain a relationship between the focusing parameter and time with respect to the specific size of the focus, the at least one processor is further configured to cause the system to perform the operations including:
determining, based at least in part on a first time length that it takes for the focusing parameter to change from a minimum value to a maximum value when the tube voltage switches from a first voltage to a second voltage within the first time length, a first changing rate of the focusing parameter changing from the minimum value to the maximum value;
determining, based at least in part on a second time length that it takes for the focusing parameter to change from the maximum value to the minimum value when the tube voltage switches from the second voltage to the first voltage within the second time length, a second changing rate of the focusing parameter changing from the maximum value to the minimum value; and
determining, based at least in part on the first changing rate or the second changing rate, the relationship between the focusing parameter and time.

13. A system, comprising:
at least one storage device storing executable instructions, and
at least one processor in communication with the at least one storage device, when executing the executable instructions, causing the system to perform operations including:
obtaining a first reference waveform of a tube voltage of an x-ray radiation source of an x-ray radiation device, the first reference waveform describing a change of the tube voltage with time;
determining, based on the first reference waveform, a second reference waveform of a focusing parameter associated with a focusing device of the x-ray radiation device, the second reference waveform describing a change of the focusing parameter with time;
causing a high voltage generator to provide the tube voltage according to the first reference waveform to the x-ray radiation source for generating x-ray radiation rays; and
causing the focusing device to shape a focus of the x-ray radiation rays according to the second reference waveform, wherein the focus of the x-ray radiation rays satisfies an operational constraint when the tube voltage changes according to the first reference waveform.

14. The system of claim 13 , wherein the first reference waveform is defined by one or more switching parameters of the tube voltage, and the one or more switching parameters include at least one of
a first voltage,
a second voltage higher than the first voltage,
a first time length that it takes for the tube voltage to change from the first voltage to the second voltage,
a second time length that it takes for the tube voltage to change from the second voltage to the first voltage,
a third time length that the tube voltage is maintained at th

Assignees

• Shanghai United Imaging Healthcare Co Ltd

Inventors

• Zhu Guoping
• Wu Jinglin
• Zhang Tieshan
• Chen Siming
• Chu Xu

Classifications

• H01J35/147

  Spot size control · CPC title

• H05G1/58

  Switching arrangements for changing-over from one mode of operation to another, e.g. from radioscopy to radiography, from radioscopy to irradiation {or from one tube voltage to another} · CPC title

• H05G1/32

  Supply voltage of the X-ray apparatus or tube · CPC title

• H05G1/52 Primary

  Target size or shape; Direction of electron beam, e.g. in tubes with one anode and more than one cathode · CPC title

• A61N5/10

  X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy (A61N5/01 takes precedence) · CPC title