JP2602942B2 - X-ray CT system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an industrial or medical X-ray CT apparatus using high-energy X-rays.

[Prior Art] FIG. 3 shows an electron accelerating electron similar to that described in, for example, pages 17 to 19 of “Electronic Engineering Advance Series 9, CT Scanner” published in 1979 by Corona. It is a sectional front view showing a conventional X-ray CT apparatus using an accelerator, for example, an electron linear accelerator. In the figure, (10) is an electron linear accelerator, (1) is an X-ray generation target which is attached to an electron exit of the electron linear accelerator (10) and generates high energy X-rays, and (2) is this X-ray A subject that is set in the irradiation range of high-energy X-rays from the generation target (1) and for which a cross-sectional image is to be obtained, (3) is placed after the subject (2), facing the X-ray generation target (1) X-ray detector, (11) is a table on which the electron linear accelerator (10) is mounted,
(12) is a table on which the X-ray detector (3) is mounted, and these tables (11) and (12) are integrated. (13) is a table on which the entire apparatus is mounted, and on this table, the tables (11) and (12)
Is configured to be rotatable.

The conventional X-ray CT apparatus is configured as described above,
High-energy electron beams emitted from the electron linear accelerator (10) collide with an X-ray generation target (2) to generate high-energy X-rays, and the high-energy X-rays are irradiated on the subject (2). X transmitted through this subject (2)
A line is detected by an X-ray detector (2) including a large number of detection elements, and transmission X-ray data at a certain angle is acquired. Next, the apparatus is slightly rotated to acquire another transmission X-ray data, and thereafter the transmission X-ray data is continuously acquired while rotating the apparatus one after another.

[Problems to be Solved by the Invention] The conventional X-ray CT apparatus has a problem that it takes a long time to acquire data because the electron linear accelerator, the X-ray generation target, and the X-ray detector are mechanically rotated. there were.

The present invention has been made to solve such a problem, and has as its object to obtain an X-ray CT apparatus capable of acquiring data at high speed.

[Means for Solving the Problems] An X-ray CT apparatus according to the present invention comprises: an electron accelerator for accelerating electrons; receiving an electron from the electron accelerator to store a high-energy electron beam; A ring-shaped electron beam storage duct provided with an electron beam extraction window for taking out the entire circumference, and applying a magnetic field to the electrons in the electron beam storage duct to bend the trajectory of the electrons in a direction perpendicular to the magnetic field. Magnetic field applying means for storing the high-energy electron beam in the electron beam storage duct by disposing the electron beam storage duct over its entire circumference, and further bending the electron trajectory when a voltage is applied, An electron beam deflecting electrode for ejecting the electrons from an arbitrary position of the electron beam extraction window of the electron beam storage duct, and arranged concentrically with the electron beam storage duct; When the electrons that have jumped out of the electron beam storage duct collide, the high energy X
A ring-shaped X-ray generating target for generating X-rays, and a ring-shaped X-ray that is arranged concentrically with the X-ray generating ring-shaped target and detects the high-energy X-ray transmitted through a subject placed at the center of the apparatus. And a detector.

[Operation] In the present invention, the electron beam storage duct receives electrons from the electron accelerator and stores high-energy electron beams, and the magnetic field applying means applies a magnetic field to the electrons in the electron beam storage duct and makes the electrons perpendicular to the magnetic field. The high-energy electron beam is stored in the electron beam storage duct by bending the orbit of the electron in the direction of
The electron beam deflection electrode further bends the trajectory of the electrons in the electron beam storage duct to eject electrons from an arbitrary position in the electron beam extraction window, and the X-rays are generated at the position corresponding to the projecting position by the collision of the electrons. Since the ring-shaped target generates high-energy X-rays, data can be acquired at high speed without mechanically moving the X-ray generation source.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a sectional front view showing an embodiment of the present invention, and FIG. 2 is a sectional view of the embodiment shown in FIG. 1 taken along the line AA and viewed in the direction of the arrow. It is a side view. In the figure, reference numeral (4) denotes a ring-shaped electron beam storage duct that receives electrons from the electron linear accelerator (10) and stores high-energy electron beams. A thin electron beam extraction window (5) is provided for extracting the electron beam into the air.
(6) are arranged in upper and lower two rows around the entire circumference in the electron beam storage duct (4), and when a voltage is applied, the trajectory of the electrons is bent so that the electron beam extraction window (4) of the electron beam storage duct (4). 5) Electrode for deflecting an electron beam to cause electrons to fly out from an arbitrary position, (7) is an orbital position of an electron beam stored in a ring shape in an electron beam storage duct (4), and (8) is an electron beam storage duct ( An electromagnet yoke surrounding 4) and (9) are electromagnet coils wound around the electromagnet yoke (8). The electromagnet yoke (8) and the electromagnet coil (9) form a magnetic field applying means, apply a magnetic field to the electrons in the electron beam storage duct (4), and move the trajectories of the electrons in a direction perpendicular to the magnetic field. By bending, the high energy electron beam is stored in the electron beam storage duct (4).

(1A) is arranged concentrically with the electron beam storage duct (4),
An X-ray generation ring-shaped target that generates X-rays at a position corresponding to the position where the electrons jump out by colliding with the electrons jumping out from the electron beam storage duct (4).
The same subject as shown in the figure, (3A) is a ring that is arranged concentrically with the X-ray generating ring-shaped target (1A) and detects high-energy X-rays transmitted through the subject (2) placed at the center. X-ray detector.

The X-ray CT apparatus of the present invention is configured as described above. A high energy electron beam, for example, 0.5 MeV or more accelerated by the electron linear accelerator (10) is incident on the electron beam storage duct (4), and the electromagnet ( 8), (9) electron beam storage duct (4)
The electron beam stored in the center of the electrode is used to deflect the electron beam (6)
The electron beam is deflected by applying a high pulse voltage to it, rapidly bent at a duct position near the center where a magnetic field is strong, and taken out from vacuum into the air through an electron beam take-out window (5). 1A) to generate high-energy X-rays. The generated high-energy X-ray passes through the subject (2) and is located at a position facing the ring-shaped target (1A) for X-ray generation (3A).
Is detected by

By adjusting the voltage of the electron beam deflecting electrode (6) in this manner, the position of the X-ray source on the X-ray generating ring-shaped target (1A) can be freely changed by 360 °, thereby changing the position of the subject (2). The data necessary for image reconstruction of the transverse image can be acquired at high speed.

[Effects of the Invention] As described above in detail, the present invention provides an electron accelerator for accelerating electrons, receives electrons from the electron accelerator, stores high-energy electron beams, and takes out the stored electrons in the center direction. A ring-shaped electron beam storage duct provided with an electron beam extraction window for the entire circumference, and applying a magnetic field to the electrons in the electron beam storage duct to bend the trajectory of the electrons in a direction perpendicular to the magnetic field. Magnetic field applying means for storing the high-energy electron beam in the electron beam storage duct, and being disposed around the entire circumference of the electron beam storage duct, further bending a trajectory of the electron when a voltage is applied to the electron beam. An electron beam deflecting electrode for ejecting the electrons from an arbitrary position of the electron beam extraction window of the electron beam storage duct; An X-ray generating ring-shaped target that generates high-energy X-rays at a position corresponding to the position where the electrons have jumped out by colliding with the electrons that have jumped out of the sagittal storage duct; And a ring-shaped X-ray detector for detecting the high-energy X-rays transmitted through the subject placed at the center of the apparatus. The transmitted X-rays can be detected over the entire circumference, and the data of the entire circumference can be collected at high speed by changing the X-ray generation position without mechanically moving the X-ray generation source.

Furthermore, since an electron beam storage duct for storing high energy electron beams is provided, and extremely high energy X-rays can be used, the invention can be applied to a large subject. Since a device for a large object is generally large, it is very structurally advantageous not to move the X-ray source mechanically.

[Brief description of the drawings]

FIG. 1 is a sectional front view showing an embodiment of the present invention, and FIG.
FIG. 3 is a sectional side view of the embodiment shown in FIG. 1 cut along the line AA and viewed in the direction of the arrow, and FIG.
FIG. 3 is a sectional front view of the CT apparatus. (1A) is a ring-shaped target for X-ray generation, (2) is a subject, (3A) is a ring-shaped X-ray detector, (4) is a ring-shaped electron beam storage duct, (5) is an electron beam extraction window, ( 6) is an electrode for electron beam deflection, (8) is an electromagnet yoke, and (9) is an electromagnet coil. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. An electron accelerator for accelerating electrons, and an electron beam extraction window for receiving high-energy electron beams by receiving electrons from the electron accelerator and for extracting the stored electrons in the center direction is provided over the entire circumference. A ring-shaped electron beam storage duct, and applying a magnetic field to the electrons in the electron beam storage duct to bend the trajectory of the electrons in a direction perpendicular to the magnetic field so that the high-energy electron beam is transmitted to the electron beam storage duct. A magnetic field applying means for storing the electron beam, arranged around the entire circumference of the electron beam storage duct, and further bending the trajectory of the electrons when a voltage is applied from an arbitrary position of the electron beam extraction window of the electron beam storage duct. An electron beam deflecting electrode for ejecting the electrons, and an electron that is arranged concentrically with the electron beam storage duct and collides with the electrons that have jumped out of the electron beam storage duct. A ring-shaped target for generating X-rays that generates high-energy X-rays at a position corresponding to the position at which the electrons jump out; and a concentric arrangement with the ring-shaped target for X-ray generation,
An X-ray CT apparatus, comprising: a ring-shaped X-ray detector that detects the high-energy X-ray transmitted through a subject placed at the center of the apparatus.