JPH0444742A - X-ray ct device - Google Patents

Abstract

PURPOSE:To manufacture an X-ray CT device with the present vacuum tube manufacturing technology and dispense with a rotator by combining two or more electron beam tubes to form a comical hollow core possible to receive a subject, and concentrically providing an X-ray detector in the hollow core. CONSTITUTION:Electron beam tubes 1-3 have outer forms such that a conical hollow core possible to receive a subject can be formed by the combination of the three. An electron beam generating source 5, a deflecting means 6, and a target 7 are provided in the inner part of the electron beam tubes 1-3 so that X-rays can be radiated toward the central axis of the hollow core. In the conical hollow core, an X-ray detector 4 is provided concentrically to the hollow core, so that each channel is directed to the concentric axis. Thus, the constitution is such that an inspected body is irradiated with X-rays by the electron beam tubes 1-3 of divided structure, and the strength of the permeated X-ray is detected by the X-ray detector 4, so that the single bodies of the electron beam tubes 1-3 can be significantly miniaturized, compared with conventional ones, and manufactured with the present vacuum tube manufacturing technology. As the X-ray detector 4 is concentrically disposed in the conical hollow core, no rotator is required.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an X-ray CT apparatus for tomographically imaging a subject;
In particular, the present invention relates to an improvement in an X-ray CT apparatus that does not require a mechanical rotation drive unit (rotator) when scanning an object.

(Prior Art) Conventionally, X
As disclosed in Japanese Unexamined Patent Publication No. 54-152489, an @CT apparatus equipped with a plurality of X-ray tube-detection type sets has been proposed.

In the case of a six-X-ray device equipped with a plurality of X-ray tube-detection type sets, it is necessary to rotate both the X-ray tube and the X-ray detector, which places a considerable burden on the rotator.

On the other hand, as an X-ray CT device that does not require raw data, a ring-shaped target type traveling X-ray tube CT (fifth generation X-ray CT device) has been proposed.

In the case of this ring-shaped target type scanning X-ray WCT, a huge electron beam tube is used as the electron beam tube, especially when the structure is such that a human body is scanned as the object.

(Problem to be solved by the invention) Therefore, this type of conventional X, IX that does not require raw data
If a CT device is to be manufactured, a vacuum tube manufacturing technology that is even more advanced than the current one is required, and mass production is not possible. However, since this type of conventional X-ray CT equipment uses a huge electron beam tube, a large dedicated space is required when using a film, so a large imaging room is required. There were some inconveniences such as having to prepare the cow.

The present invention was made in response to the above circumstances, and its purpose is to manufacture [7] using current vacuum tube manufacturing technology.
XIJ, which has a configuration that does not require raw data.
The purpose of the present invention is to provide a CT device.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an external shape that can form a conical hollow core capable of accommodating a subject in combination of two or more, and a large an electronic beam tube 1 having a structure capable of emitting X-rays toward the central axis of the conical air core, and an X disposed coaxially with the conical air core within the conical air core The device is characterized by comprising a line detector.

(Function) With the configuration of the X-ray CT apparatus according to the present invention, a single electron beam tube can be manufactured using current vacuum tube manufacturing technology.

Furthermore, since the combination of each electron beam tube and X-ray detector corresponds to a configuration that includes multiple X-ray tube-detection type sets that have been proposed in the past, it is possible to perform a single tomography at high speed. ,
Alternatively, it becomes possible to perform multiple tomographic imaging at a slower speed.

(Example) Fig. 1 is a block diagram showing the outline of an X-ray CT apparatus according to an embodiment of the present invention, and Fig. 2 is a block diagram showing the outline of the external shape and internal structure of a single electron beam tube. be.

The X-ray CT apparatus of this embodiment includes an electron beam 1, tubes 1 to 3, and an X-ray detector 4, which are used in combination, as shown in FIG. A single unit of -C is made to have the external shape and structure as shown in Fig. 2.

That is, the electron beam tubes 1 to 3 form a conical air core capable of accommodating the subject P to be photographed by combining the two electron beam tubes 1 to 3. It has a structure in which an electron beam generation source 5, deflection means 6, and target 7 are provided inside the electron I-beam tubes 1 to 3 so that X-rays can be emitted toward the target.

The X-ray detector 4 is arranged coaxially with respect to the conical air core within a conical air core formed by combining one electron beam tube 1 to 3, and each channel is oriented toward the coaxial center. It is something.

When the X-ray CT apparatus of this embodiment, which is provided with the electron beam tubes 1 to 3 and the X-ray detector 4, and the subject P are viewed from the side, the relationship is as shown in FIG. 3. In addition, in Figure 3,
When an electron beam is emitted from the electron beam generation source 5, this electron beam is guided onto the target 7 by the deflection means 6 having a deflection coil 6a and a deflection plate 6b, and an X-ray fan beam is generated from the target 7. The subject P is exposed to radiation.

At this time, the intensity of the X-rays transmitted through each point of the subject P is detected by the detector 2, and based on the detection signal, a CT image is reconstructed by a reconstruction means (not shown) and displayed on a monitor. become.

As described above, in this embodiment, X-rays are irradiated to the subject P by the divided electron beam tube consisting of three electron beam tubes 1 to 3, and the X-rays transmitted through the subject P are detected by the X-ray detector 4. Since the configuration is such that the intensity of the beam is detected, the electron beam tube 1
3 can be made much smaller than the electron beam tube in the conventional ring-shaped target scanning X-ray tube CT. Therefore, a single electron beam tube 1 can be obtained using current vacuum tube manufacturing technology.

Furthermore, since the combination of each of the electron beam tubes 1 to 3 and the X-ray detector 4 corresponds to a configuration including a plurality of conventionally proposed X-ray tube-detection type sets, a single tomography can be performed at high speed. This makes it possible to carry out multiple tomographic imaging at lower speeds.

FIG. 4 is a block diagram showing the configuration of an embodiment when performing a single tomography at high speed. In the figure, the drive timings of high voltage generators 8 to 10 that supply power to electron beam tubes 1 to 3 are controlled by a timing generator 11.

With this control, X-rays can be emitted simultaneously from two of the electron beam tubes 1 to 3.

For example, X irradiated from electron beam tubes 1 to 3, respectively.
In the relationship where the fan angle θ of the X-ray fan beam is set to 60°, and the X-ray fan beams are made non-interfering with each other,
In conventional fifth generation scanning, scanning is performed toward a target at θ+180°. In this embodiment, as shown in FIG. 5, for example, a first target 7a on the target 7 of the electron beam tube 1 and a first target 7a on the target 7 of the electron beam tube 2 are spaced apart from each other by θ/2+90° when viewed from the center of rotation. Scanning is performed from two locations, such as the second target 7b. As a result, in the fifth generation scan according to this embodiment, one scan time is halved compared to the conventional scan.

Furthermore, when a block connection configuration as shown in FIG. 4 is employed, each of the electron beam tubes 1 to 3 can be warmed up simultaneously under the control of the timing generator 11.

In addition, in the fifth generation XvACT device of this example,
I am trying the following.

FIG. 6 shows a configuration for determining the slice width for the subject P in the X-ray detector 4. As shown in the figure, a photodiode 13 and a scintillator 1 are mounted on a substrate 12.
The slice width for the subject P can be determined by simply moving the slit width adjustment mechanism 15 made of lead in the body axis direction of the subject P on the X-ray detector 4 on which the X-ray detectors 4 are stacked.

FIG. 7 shows a device to prevent missing views in X-ray CT images.
3 shows a configuration in which the ends of adjacent electron beam tubes are overlapped with each other.

[Effects of the Invention] As explained above, since the X-ray CT apparatus of the present invention uses an electron beam tube that can be manufactured using current vacuum tube manufacturing technology,
It is suitable for mass production, and furthermore, these electron beam tubes are combined to form a conical air core that can accommodate the object, and an X-ray detector is coaxially arranged within this conical air core to reduce the need for low-chip production. Because of this structure, the dedicated space required for installation is significantly less than that of the conventional method. Furthermore, since the configuration corresponds to a configuration including a plurality of conventional X-ray tube-detection type sets, advantages such as being suitable for high-speed scanning and multiplex scanning can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the outline of an X@CT apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing the outline of the external shape and internal structure of a single electron beam tube, and FIG. A diagram schematically showing an X-ray CT apparatus and a subject viewed from the side according to an embodiment of the invention, FIG. 4 is a block diagram showing an embodiment when performing high-speed scanning, and FIG. An explanatory diagram of the principle of high-speed scanning by the invented device; FIG. 6 is a diagram showing the configuration for determining the slice width; FIG. 7 is a diagram showing the configuration for preventing skipped views of the reconstructed X-ray CT image. It is a diagram. 1.2.3...Electron beam tube 4...X-ray detector 5...Electron beam source 6...Deflection means 7...Target 8.9. ],,O...High pressure generator]1...Timing generator 12...Substrate 13...Photodiode 14...Scintillator 15...Slit width adjustment mechanism

Claims (5)

[Claims] (1) An electron beam that has an outer shape that can form a conical hollow core capable of accommodating a subject in combination of two or more, and that has a structure that can emit X-rays toward the central axis of the conical hollow core. An X-ray CT apparatus comprising: a tube; and an X-ray detector disposed within the conical hollow core coaxially with respect to the conical hollow core. (2) The X-ray CT apparatus according to claim 1, further comprising a control means for simultaneously emitting X-rays from at least two of the electron beam tubes.
T device. (3) The X-ray CT apparatus according to claim 1, further comprising a control means for simultaneously warming up each of the electron beam tubes. (4) In the X-ray CT apparatus according to claim 1, a slit width adjustment mechanism is provided only on the X-ray detector side, so that the slit width in the body axis direction of the subject can be adjusted. Ray CT device. (5) In the X-ray CT apparatus according to claim 1, when two or more of the electron beam tubes are combined to form a conical hollow core, the ends of adjacent electron beam tubes are overlapped. Characteristics of X-ray CT equipment.