Search

CN-121995429-A - Device for calibrating an X-ray system, X-ray apparatus and method for calibrating an X-ray apparatus

CN121995429ACN 121995429 ACN121995429 ACN 121995429ACN-121995429-A

Abstract

According to the invention, an apparatus for calibrating an X-ray system having an X-ray source and an X-ray detector, the calibration apparatus comprising a set of at least two X-ray absorbing elements, each element extending in a longitudinal direction and a lateral direction, characterized in that the apparatus is configured to be able to adjust the position of each element along a closed curve in a plane extending transversely to the lateral direction and parallel to the longitudinal direction, such that the elements in each of a first subset and a second subset of the set of elements are positioned with their longitudinal directions aligned in an alignment direction transverse to the curve, and wherein a first total length of the elements in the first subset in the longitudinal direction is different from a second total length of the elements in the second subset in the longitudinal direction.

Inventors

  • B. Hoffman

Assignees

  • 梅特勒-托莱多有限责任公司

Dates

Publication Date
20260508
Application Date
20251107
Priority Date
20241108

Claims (15)

  1. 1. Device (100) for calibrating an X-ray system (200) having an X-ray source (210) and an X-ray detector (220), the calibration device (100) comprising a set of at least two X-ray absorbing elements (1, 2), each element (1, 2) extending in a longitudinal direction (LO) and a lateral direction (LA), characterized in that the device (100) is configured to be able to follow a closed curve in a plane extending transversely to the lateral direction (LA) and parallel to the longitudinal direction (LO) ) Adjusting the position of each element (1, 2) such that the elements (1, 2) in each of the first (10) and second (20) subsets of the group of elements (1, 2) are positioned with their longitudinal direction (LO) transverse to the curve% ) And wherein a first total length of the elements (1, 2) in the first subset (10) in the longitudinal direction (LO) is different from a second total length of the elements (1, 2) in the second subset (20) in the longitudinal direction (LO).
  2. 2. The device (100) of claim 1, wherein the curve ± ) Comprising a plurality of nested and non-intersecting curves lying in a plane extending transversely to the lateral direction (LA) and parallel to the longitudinal direction (LO) ) Each element (1, 2) is associated with one of the curves ) Is associated with, and the device (100) is configured to be independent of other curves% ) The associated element (1, 2) is positioned along the associated curve # ) The position of each element (1, 2) is adjusted.
  3. 3. The apparatus (100) of claim 2, wherein the curve ± ) Is a concentric curve.
  4. 4. The device (100) according to any one of the preceding claims, wherein the curve ± ) Each of (a) is circular.
  5. 5. The device (100) according to any one of the preceding claims, wherein at least two elements have different longitudinal extension dimensions # )。
  6. 6. The device (100) according to any one of the preceding claims, wherein the elements (1, 2) are discrete elements (1, 2).
  7. 7. The device (100) according to claim 6, wherein the device (100) is configured to be able to adjust the position of the elements such that a channel is formed that extends straight through the curve and in which no elements are located.
  8. 8. The apparatus (100) of any of the preceding claims, wherein at least one of the first subset (10) and the second subset (20) comprises the same curve ± ) The two elements (1, 2) are associated.
  9. 9. The device (100) according to any one of the preceding claims, wherein the first (3) and second (4) lateral ends of the elements (1, 2) are mounted on first (30 a) and second (30 b) supports spaced apart in a lateral direction, and the device is configured to enable independent rotation of the first (30 a) and second (30 b) supports about a common axis (a) extending in a lateral direction (LA) so as to follow a closed curve # ) The position of the elements (1, 2) is adjusted.
  10. 10. The device (100) according to claims 2 and 9, wherein the first support (30 a) and the second support (30 b) each comprise a plurality of first sections (31 a, 31 b) and second sections (32 a, 32 b), respectively, and the device (100) is configured to enable the first sections (31 a, 31 b) and the second sections (32 a, 32 b) to rotate relative to each other, such that the curves ± from different curves ] ) The associated elements (1, 2) are capable of relative movement.
  11. 11. The device (100) according to any one of the preceding claims, wherein the device (100) further comprises a positioning member (40) for positioning the calibration device (100) in the X-ray system (200) in a manner between an X-ray source (210) and an X-ray detector (220).
  12. 12. The device (100) according to any one of the preceding claims, wherein the device (100) further comprises a sensor arranged at the curve # ) An internal stationary X-ray absorber.
  13. 13. An X-ray device (1000) comprising an X-ray system (200), the X-ray system (200) having an X-ray source (210) operative to emit an X-ray beam (211) in a radiation plane and an X-ray detector (220) arranged to be able to receive the X-ray beam (211) and to output a signal in response to a received radiation amount, and a calibration arrangement (100) according to any of the preceding claims, wherein the calibration arrangement (100) is arranged between the X-ray source (210) and the X-ray detector (220) such that when longitudinal directions of elements (1, 2) in the first subset (10) and the second subset (20), respectively, are aligned in an alignment direction, a longitudinal extension dimension of the elements (1, 2) in the first subset (10) and the second subset (20) is located in the radiation plane along a radiation path (R) of the X-ray beam.
  14. 14. The X-ray device (1000) according to claim 13, wherein the X-ray source (210) is configured to be capable of emitting a fan-shaped X-ray beam (211) in a radiation plane, and the X-ray detector (220) comprises a line detector arranged in the radiation plane to receive the radiation beam (211).
  15. 15. A method for calibrating an X-ray system of an X-ray device (1000) according to claim 13 or 14, wherein the method comprises the steps of: -adjusting the positions of the elements (1, 2) of the calibration device (100) to a first position such that the aligned longitudinal directions (LO) of the elements (1, 2) of the first subset (10) lie in the radiation plane; after adjusting the elements (1, 2) to the first position, operating the X-ray source (210) to receive a first signal responsive to a first amount of radiation having passed through the elements (1, 2) of the first subset (10); -adjusting the position of the elements (1, 2) of the calibration device (100) to a second position such that the aligned longitudinal direction (LO) of the elements (1, 2) of the second subset (20) is located in the radiation plane; After adjusting the elements (1, 2) to the second position, operating the X-ray source (210) to receive a second signal responsive to a second amount of radiation having passed through the elements (1, 2) of the second subset (20); An X-ray system (200) is calibrated based on the first signal and the second signal.

Description

Device for calibrating an X-ray system, X-ray apparatus and method for calibrating an X-ray apparatus Technical Field The invention relates to a device for calibrating an X-ray system having an X-ray source and an X-ray detector, the calibration device comprising a set of at least two X-ray absorbing elements, each element extending in a longitudinal direction and in a lateral direction. The calibration device is particularly suitable for calibrating an X-ray system in which an object to be examined is transported along a transport path between an X-ray source and an X-ray detector. The invention also relates to an X-ray device comprising an X-ray system and a calibration arrangement and to a method for calibrating an X-ray device. Background X-ray systems have a variety of applications, including product inspection. In the food industry, for example, it is very important to reliably detect foreign matter in food. For this purpose, the object to be examined can be transported along a transport path between an X-ray source and an X-ray detector of the X-ray system, for example by means of a belt conveyor. The X-ray source may generate a fan beam and the X-ray detector may be arranged to be capable of receiving the X-ray beam and may be configured to be capable of outputting a signal in response to the received amount of radiation. In this way, a two-dimensional X-ray image of the object to be examined can be created. In the example of food inspection described above, the X-ray image may allow for the inference of the presence of foreign matter in the food. The X-ray system is based on the physical phenomenon of X-ray absorption. For monochromatic beams, according to(Beer-lambert law) the absorption is directly related to the distance X that the X-rays travel in the homogeneous volume. Here the number of the elements to be processed is,Is the intensity of the incident radiation, I is the intensity of the transmitted radiation, and b is the X-ray absorption coefficient depending on the material. The X-ray system must be calibrated regularly to ensure that the output signal of the detector is indicative of the amount of radiation received. This is because the characteristics of the X-ray system, in particular the characteristics of the X-ray source and the X-ray detector, may change over time. Furthermore, the characteristics of newly produced X-ray systems may not be fully understood. For example, an X-ray detector may include a scintillation material responsive to incident X-ray radiation. The scintillation material may not be homogeneous. Furthermore, for a line detector made of a plurality of individual detector elements, the detector elements may have slightly different properties, and therefore the detector may need to be calibrated before use. In a common calibration procedure, a so-called phantom, which is an object with known absorption properties, is placed within the X-ray beam in such a way that it is located between the X-ray source and the X-ray detector. The output signal of the detector is recorded for a phantom and the X-ray system may be calibrated such that the output signal indicates the amount of radiation that must have passed through the phantom. In some calibration procedures, a phantom with spatially varying absorption characteristics is required to perform the calibration. Various possible calibration means (phantoms) are known in the art. Typically, the calibration device is adapted to calibrate a specific type of X-ray system. US 5,214,578 discloses a method for calibrating an X-ray system having an X-ray source and an X-ray detector, wherein the X-ray detector is rotatable about an object under investigation along an axis, and wherein a circular phantom is positioned with its centre eccentric with respect to the axis of rotation of the X-ray system. The calibration device is well suited for calibrating an X-ray system having a rotatable detector. JP 719190 B2 discloses a calibration device for an X-ray CT scanner. The calibration device includes a plurality of concentric layers, and at least one of a composition and a concentration of a substance contained in each of the plurality of layers is different from each other at a plurality of rotation angles. The calibration device is scanned at a plurality of different rotation angles. The calibration device is well suited for calibrating an X-ray system based on scanning at different rotation angles. US 4,400,827 discloses a calibration device for calibrating a rapid sequence radiography. The calibration device comprises a disk on which a plurality of X-ray absorbing elements having different thicknesses in a direction perpendicular to the disk surface are arranged in a stepwise manner along the periphery of the disk. The disk rotates along a central axis perpendicular to its surface in synchronization with a cine mechanism of the cine-radiography apparatus, thereby changing the thickness of the X-ray absorbing material of the disk for