JPH0523772B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an X-ray diagnostic apparatus used for taking fluoroscopic images or CT images.

(Prior Art) Conventionally, treatment planning simulators in X-ray treatment apparatuses often capture CT images (tomographic images) in addition to conventional transmission images.

FIG. 2 is a diagram showing a conventional X-ray therapy apparatus that takes the CT images. In FIG. 2, reference numeral 1 denotes an X-ray tube, which irradiates a subject 2 with X-rays. 3 is an image intensifier (hereinafter abbreviated as "image intensifier"), which
It converts the transmitted X-rays into an optical image.
4 is a TV camera, as described above. It converts the optical image from 3 into a TV video signal. Note that the X-ray tube 1, the subject 2, . 3 and TV camera 4 are arranged on the same straight line, and X-ray tube 1 and . 3. The TV camera 4 rotates in the direction of arrow A with the subject 2 in between, and the above-mentioned CT image (tomographic image) is obtained.
is now available.

According to the X-ray diagnostic apparatus configured in this way,
X-rays are emitted from the X-ray tube 1 to the subject 2, and the X-ray tube 1 and... 3-4 TV camera systems are subject 2
It rotates in the direction of the arrow A. Then, the X-rays emitted from the X-ray tube 1 pass through the subject 2, and the transmitted X-rays... 3 into an optical image, and further into a TV video signal by a TV camera 4. By using the 3-TV camera 4 system as a detector for CT images,
Data is collected and a CT image is obtained.

(Problems to be Solved by the Invention) However, the above conventional X-ray diagnostic apparatus has the following problems. The detector for CT images is
A wide dynamic range is required to improve the image quality of CT images. Here, the dynamic range is, for example, the ratio between the saturation charge amount of the image sensor of the TV camera 4 and the noise charge amount. However, in the TV camera 4, since the noise charge is large, the dynamic range becomes narrow. For this reason, a dynamic range of only about 60 to 70 dB could be secured, resulting in a problem that the image quality of CT images deteriorated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an X-ray diagnostic apparatus that can increase the dynamic range of the detection means, improve the accuracy of images, and improve the image quality of CT images.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems and achieve the objects, the present invention takes the following measures. That is, the present invention
an X-ray tube that emits X-rays; an image intensifier that is placed opposite the X-ray tube with a subject in between and converts an X-ray image transmitted through the subject into an optical image; and the X-ray tube. and a rotational drive mechanism that rotatably supports the image intensifier and the image intensifier around the subject; an optical path distribution means that distributes the optical path of the output image output from the image intensifier in at least two directions; and the optical path distribution. It consists of a TV camera system that captures and displays the output image of the upper image intensifier distributed in one direction by a means, and solid-state photoelectric conversion elements arranged in one dimension.
a one-dimensional sensor that detects a predetermined straight line portion of the output image of the image intensifier distributed in other directions by the optical path distribution means and obtains X-ray projection data of the subject; means for obtaining a tomographic image by subjecting multidirectional X-ray projection data regarding the subject detected by the one-dimensional sensor to reconstruction processing as the X-ray tube and the image intensifier rotate around the subject; It is characterized by having the following.

(Effects) By taking such measures, the following effects are achieved. According to the present invention, an X-ray image emitted from an X-ray tube and transmitted through a subject is converted into an optical image by an image intensifier, and this optical image is distributed in at least two directions by an optical path distribution means,
During fluoroscopy, one optical image is captured by a TV camera system and displayed as a fluoroscopic image, and during tomographic imaging, a predetermined straight line portion of the other optical image is
A tomographic image is obtained by being detected as X-ray projection data by each solid-state photoelectric conversion element of the one-dimensional sensor and subjected to reconstruction processing, so that a high-quality tomographic image can be obtained.

(Embodiment) FIG. 1 is a schematic configuration diagram showing an embodiment of an X-ray diagnostic apparatus according to the present invention. Note that the same parts as those shown in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. The features of this embodiment are as follows. 3
and TV camera 4. 3 is provided with a detection means 5 for one-dimensionally detecting the optical image from 3.
In FIG. 1, the X-ray diagnostic apparatus is constructed as follows.

The detection means 5 is as described above. The range 5a is arranged on the output side of the lens 5a, and the range 5a is arranged after the lens 5a. A half mirror 5b that distributes the optical image of 3 to a TV camera 4 and a one-dimensional sensor 5e to be described later, ranges 5c and 5d that input the optical image from the half mirror 5b, and a primary optical image that passes through the lens 5c. One-dimensional sensor 5 that detects the source
It is composed of e and. The one-dimensional sensor 5e
is, for example, a linear CCD (solid-state imaging device), which allows for a large device area.
Therefore, this one-dimensional sensor 5e can handle a large amount of saturation charge, so that it has a wide dynamic range and can secure a dynamic range of about 100 dB. The one-dimensional sensor 5e has.
The arrangement is such that only the output of the linear portion near the center of the line 3 is input.

The data collection device 6 receives the sensor signal from the one-dimensional sensor 5e and collects CT image data. The image reconstruction device 7 reconstructs the data-collected signals. monitor 8
displays the reconstructed image on the screen. Note that a monitor 9 is provided to display the CT image obtained by the TV camera 4. Normal.
During fluoroscopy, the entire system is mechanically stationary, but when taking CT images, the X-ray tube 1 and the above-mentioned...
The third system rotates in the direction of the arrow A with the subject 2 in between.

Next, the operation of the embodiment configured as described above will be explained. First, X-rays are emitted from the X-ray tube 1 to the subject, and the X-ray tube 1 and... The third system rotates relative to the subject 2. Then, the X-rays emitted from the X-ray tube 1 pass through the subject 2. 3 into an optical image. And this optical image is the lens 5
The light is distributed to a one-dimensional sensor 5e and a TV camera 4 by a half mirror 5b via a. That is, the optical image from the half mirror 5b is detected one-dimensionally and with a high dynamic range by the one-dimensional sensor 5e via the lens 5c. This detection signal is collected by a data collection device 6, and an image is reconstructed by an image reconstruction device 7 and displayed on a monitor 8 as a CT image.

On the other hand, the optical image input to the TV camera 4 is
It is converted into a TV video signal by the TV camera 4 and displayed on the monitor 9.

According to such an embodiment, . From 3 outputs
When collecting CT image data, the detection means 5
With the one-dimensional sensor 5e, a large one-dimensional element area is ensured, and a large amount of charge can be handled and detected, so CT image data can be obtained with a wide dynamic range of about 100 dB. and about
Data can be obtained with a wide dynamic range of 100dB. As a result, the image accuracy can be significantly improved to about 30 dB from the dynamic range that was previously only 70 dB, making it possible to obtain high-quality CT images. Furthermore, by switching the detection means 5, a single X-ray diagnostic apparatus can perform normal fluoroscopic imaging as well as CT image imaging, improving convenience.

Note that the present invention is not limited to the embodiments described above. In the embodiment described above, the half mirror 5
b, but other than this half mirror 5b
A method may also be used in which a 100% reflecting mirror is inserted only when the CT image is taken. In this case,
．． The output utilization efficiency of 3 becomes 100%. It goes without saying that various other modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] The present invention includes an X-ray tube that irradiates X-rays, and an image that is placed opposite to the X-ray tube with a subject in between and converts an X-ray image transmitted through the subject into an optical image. an intensifier; a rotational drive mechanism that rotatably supports the X-ray tube and the image intensifier around a subject; and divides the optical path of an output image output from the image intensifier into at least two directions. a TV camera system for capturing and displaying an output image of the upper image intensifier distributed in one direction by the optical path distributing means, and a solid-state photoelectric conversion element arranged in one dimension;
a one-dimensional sensor that detects a predetermined straight line portion of the output image of the image intensifier distributed in other directions by the optical path distribution means and obtains X-ray projection data of the subject; means for obtaining a tomographic image by subjecting multidirectional X-ray projection data regarding the subject detected by the one-dimensional sensor to reconstruction processing as the X-ray tube and the image intensifier rotate around the subject; Since it is equipped with The optical image of one side is displayed on the TV.
The image is captured by a camera system and displayed as a fluoroscopic image, and during tomographic imaging, a predetermined straight line portion of the other optical image is detected as X-ray projection data by each solid-state photoelectric conversion element of the one-dimensional sensor and used for reconstruction processing. Therefore, high-quality tomographic images can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of an X-ray diagnostic apparatus according to the present invention. FIG. 2 is a schematic configuration diagram showing an example of a conventional X-ray diagnostic apparatus. 1... X-ray tube, 2... Subject, 3... Image intensifier (.), 4... TV camera, 5... Detection means, 5a, 5c, 5d... Lens, 5b... Half mirror , 5e... one-dimensional sensor, 6... data acquisition device, 7... image reconstruction device, 8, 9... monitor.

Claims (1)

[Scope of Claims] 1. An X-ray tube that irradiates X-rays, and an image input device that is arranged opposite to the X-ray tube with a subject in between and that converts an X-ray image transmitted through the subject into an optical image. an intensifier; a rotational drive mechanism that rotatably supports the X-ray tube and the image intensifier around the subject; and an optical path of an output image output from the image intensifier in at least two directions. A TV camera system that captures and displays an output image of the image intensifier that is distributed in one direction by the optical path distribution means, and solid-state photoelectric conversion elements arranged in one dimension. ,
a one-dimensional sensor that detects a predetermined straight line portion of the output image of the image intensifier distributed in other directions by the optical path distribution means and obtains X-ray projection data of the subject; and by driving the rotary drive mechanism. As the X-ray tube and the image intensifier rotate around the subject, multi-directional X-ray projection data regarding the subject detected by the one-dimensional sensor is subjected to reconstruction processing to create a tomographic image. 1. An X-ray diagnostic apparatus characterized by comprising: means for obtaining.