JPS584532A - X-ray diagnostic equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a modified JLK of the XLA diagnostic device.

Conventionally, when diagnosing hip joint photography, which is common in children, and scoliosis, which is common in junior high school students, there is a problem in the X-ray exposure of the gonads because the imaging site is close to the gonads. Regarding photography, low x! It was considered desirable to use only one amount.

Based on this Wt, nine radiographs are performed using high-sensitivity intensifying screens and high-sensitivity films, prioritizing the minimum necessary image quality and reducing exposure dose.

In addition, in order to reduce radiation exposure, there is a 9X imaging system that applies a high-sensitivity optical image intensifier (hereinafter referred to as 2+) as shown in Figure 1 as a 9-diagnosis system. The device passes through the X-ray aperture 1 from the X-ray tube 1 to obtain the desired XI.
Focus on the IIAIII field and irradiate the subject 3 with X-rays,
The transmitted X-rays are captured by the low-dose imaging device main body 4, converted into visible radiation, amplified, and output. The low-dose imaging device main body 4 has a radiation removal grid and door 5 on its front surface, that is, on the X-ray incident side.
A fluorescent plate C that converts the xIl transmitted through the grid 5 into visible light @ is arranged in the l1 stage of the grid 5, and the visible light image on this fluorescent plate l is converted into light 1, Il through the lens 1.
After being input to and amplified, the B image appearing on the output surface is focused on the film of the instant camera l# via the lens 9, and a photograph is taken. In addition, 11 is X
A high voltage generator that generates a high voltage for supplying the wire tube IK, 12
This is an X-ray control device that controls the XTA tube voltage, tube current, and exposure. After death, this X-ray optical image is converted into an image using light 1.1. JK enters the camera and multiplies the brightness by 10,000 to 10,000 times, and then enters the instant film of the instant camera 10 through the lens p to take a picture. By using a high-sensitivity film like 3000, the X-ray dose is low! ll! This is a representation of the photo taken.

This system enables imaging with a lower amount of xlI than a direct imaging system that uses an intensifying screen or a high-speed film, and has already been completed.

However, since this device amplifies the image and shoots it on film, it has the disadvantage that the images of X@fluoroscopic photography are thin and difficult to see diagnostically. The present invention was made in view of the above-mentioned events, and consists of an X-ray tube that generates X-rays, a fluorescent plate that converts the xIl generated by the X-ray tube and transmitted through the subject into visible light Klll, and this invention. An imaging device that captures the visible light image on the output surface of the optical image intensifier and converts it into a video signal, and an imaging device that amplifies the visible light image on the fluorescent plate and converts this video signal into a digital signal. A device for converting, a device for processing this digitally converted round iron image signal to enhance the image, a device for converting this image-processed output into an analog signal, and a monitor for displaying this analog signal as an Il image. By processing the X-ray transmission image to emphasize the outline of the image, and superimposing this on the image before image processing and displaying it on the monitor, an image that is easy to see for diagnosis with a low X-ray dose is created. The object of the present invention is to provide a 9X41# disconnection fl that can be obtained.Hereinafter, an embodiment of the present invention will be described with reference to Figures 2 to 9.

Figure 2 is a professional diagram showing an embodiment of the present invention, and Tuna 3WA.
is a time chart for explaining its functions. In Fig. 2, the same parts as in Fig. 1 are given the same reference numerals, and the details of M51. FJ8 is omitted.

The basic structure of the device shown in Figure 2 is as follows.
It is exactly the same as the figure.

This device uses i! to transmit X-ray transmission images. In order to process the images, the low-dose X-ray imaging device main body 4 is equipped with an imaging device such as a TV camera camera tube instead of an instant camera, and an image processing device is installed to process the output of this imaging device. The points are different.

That is, the low-dose X-ray imaging apparatus main body 4 is
A grid 5 is provided on the ray incidence side, and a phosphor plate 6 for converting the X-rays transmitted through the grid into a visible X-ray optical image is placed on the at of the grid 5. is guided through lens 7 into light I, I 41, and this light I
1. The image displayed on the output side of # is transferred to the tandem lens system jO.
an imaging device x for converting an optical image into a video signal via
This is a configuration that leads to tvc.

A television camera controller 2j for controlling the imaging device 11 is provided, and the video signal outputted from the imaging device 11 is sent via the television camera 22 to an image processing device 23 for image processing of the video signal. The one-image analysis device 11, which is designed to give
Ma) Shunkaku, 111m strong 11 (level slice, gray level window, intermediate brightness level emphasis 1 kankaku emphasis, etc.)
Converter 24, which has the functions of LII, converts analog video signals into digital; digital converter 24, which processes this digital conversion output; 11. F-Digital memory for storing data and programs 2-1 consists of a D/A converter @174$ for converting the signal output from the 2J into an analog signal.

In addition, j J tiX! 1 is a controller that controls the timing of shooting and the timing of transmitting video signals, and 1# is a controller that displays the output of image processing device II (image-processed analog signal (video t11 signal) as an image). This is a monitor display device by

In this apparatus with the above configuration, the X-ray control train 12 is driven by the control output of the controller 11, and the high voltage generator 11 is driven by the control output of the controller 11. Generate voltage and tube current for a set time, XIII IK4t, L. to this! The xII tube 1 emits X-rays as shown in Figure 3 (a).

This X-ray has an aperture of 3. After narrowing down to the desired irradiation field,
3Ks is irradiated on the subject, and a low dose of X is transmitted through this subject 1.
The light enters the radiography apparatus main body 4. The transmitted X-rays then pass through a grid and door 5 on the front side of the low-dose X-ray imaging apparatus main body 4, where scattered rays are removed and an image is formed on a fluorescent plate 6.

As a result, the transmitted X@ is converted into an optical image by the fluorescent plate 6, and becomes a visible image. - The visible groove on the fluorescent plate 6 is formed by the lens 1, and the light 1.1. The light 1. is imaged on the incident side of a. Il amplifies the incident image and displays it on the output side. The body appearing on the output side is guided to the imaging device jJ through the tandem lens system 20, and the captured mouth image @@21 is controlled by the TV control gain 22VC and extracted as a video signal as shown in Fig. 3(b). be done.

In FIG. 3(b), A, 1. C, D, IC, and F each indicate a field or frame, and when X-ray exposure starts, the level of the extracted video signal is low because there is little image accumulation in the first field, and the level of the extracted video signal is low in the next field. Since the accumulation time is longer than that, the level is slightly higher than the previous time, and in subsequent fields, the level stabilizes, and after the end of X-ray exposure, there is no emission again. This video signal is input to the VD converter 14VC of the Fi image processing device 11, and after being A/D converted, it is converted into a digital signal.
! The image section is layered by Rose and Su25, and the digital memory is stored in the digital memory.
As shown in the figure, in addition to image enhancement, the TV video signal (field total frame) addition function is used. digital·
The iji image processed data stored in the memory 1dK is read out sequentially, and the analog signal ($1
13wA(@))Kjltt,%=JII indicator 11#
is input. Then, it is displayed as a jjKiji image on the monitor display device. This display (iii) has been processed to enhance the image, so it is an easy-to-read image.

The large signal sent to the monitor display device 2# in this manner is printed on a film in a multi-format format (not shown) used in the field of CT scanners and nuclear medicine.
The displayed image itself can be photographed with an instant camera, etc., and saved as a copy.In addition, the reason why the image processing device j3 adds the video signal is because this system wants to take images with as low a dose as possible, so it is not possible to use the regular image. Signal level V, = 1.0 (V, -,) (video 0.
This is because it is intended to operate at a marginal level below (7V, synchronization signal 0.3V).

For example, let us assume here that the overlapping process of 20 fields is carried out at a normal video level of 1/201i1&.

Now, considering a vertebronchiasis diagnostic device, the size of the fluorescent plate 6 is 500 m in length and 400 m in width, and a rare earth fluorescent plate with the Xg amount vs. fluorescent plate brightness characteristics shown in Fig. 4 is used. Lens 1 has a focal length of 40mm and brightness r1 = 0.7
5. Also light 1.1. # is a small, high-performance image intensifier that has a secondary electron multiplication function. For example, it uses Hamamatsu TV's Channel/Rate (M-C-P) to greatly amplify weak incident light and output it. I made it so that
20 input surfaces φ.

FIG. 5 shows an example of the brightness wIL% for an output surface with a size of 30 mm. Furthermore, tandem lens system 2
0 is the focal length of the M-C-P@ lens fm-95m
g+, v4 Lusa F1 = 0.95 t L, focal length of the lens of the imaging device 21, = 33■, brightness F, -0,75
shall be. Further, an image is formed on the imaging surface of the imaging device 1!1 with a diameter of approximately 10 φ, and the output luminance of the CP is set to yAICcd/wI]. Also, the luminous flux divergence R, is the wing, lπ1g (:1wm・*/vl)
・・・・・・・・・(1) 3 Here, magnification ■ 2” 95 ' Lens transmittance 7 , -Q,
For irradiation of the image plane of the me device 21, consider the configuration shown in Fig. 7 using two Mendham lenses LIILI, and assume that the illumination of the projection lens [E is two stones] ・-・
(2) F is the effective brightness and R#i is the subject luminous flux divergence.

Therefore, from the above formula 11112, = 1.06
8m (1w5x) -・-(3) Here, considering the amount of incident light on the imaging device 21, for example, if the imaging device 2
If 1 is a 1-inch bisifune, then the light incidence to obtain a signal output current of 0.2 [Voice A) (standard value) from its charging conversion characteristics is 120 (lux). On the other hand, M-C- The output spectral characteristics of P have a wavelength peak near 55o [field] and have p-sag characteristics, and the spectral sensitivity characteristics are close to those of vidicon. Carnicon vs. Vidicon is about 3 when using P-20 spectral sensitivity characteristics:
The ratio of l is the ratio of l.Here, if we use a 1-inch carnicon as the imaging device, as mentioned above, it is three times more sensitive than a vidicon, so the light incidence to obtain the above 0.2 [μA] is ■ = 40 [stone]・・・・・・・・・(4
), the imaging system (21 and 11) outputs the standard video output V, when the Calnicon output signal is 0.2 [μA], and the thickness is 1.0 (V, , ) (By'). 7 (V), synchronous signal output O, S (V).)
As mentioned above, if the standard 1/2o video level operation is used, then from the fourth equation, the following equation is obtained:
...(5) 0 is the desired input to the imaging plane of the imaging device 11.

9. If the video signal is added for 20 fields using Izoen Riso Funai 2I, the X-ray exposure time shown in Figure 3 (a) K is 16.7 [:1111-・s] To L Te 1
6.7 (m sag) x 20=334 (ms)
Therefore, the X-exposure time is 0.334 (-...).

Also, from the third and fifth equations, 1.0611. -2 B, = 1.887(”, ~] ・・・・・・・・・(
6) From the M-CP characteristics in Figure @5, it is actually 1i as TFil (Tybical)! Considering the characteristics of a, B, = 1.88
7, the input illuminance of M-C-P is 0, 6 (sm lux) --
111,-(7). Next, consider the input of M-C-P. Let the output brightness of the fluorescent plate be B t (c'/g),
If the luminous flux divergence is R1°M-C-P incident luminous flux E1, then the light from the fluorescent plate C becomes light 1. The lens 1 that guides IIK has the configuration shown in FIG. 6, and in this case, the illuminance E of the projected image ′ projected through the lens L, which has the transmittance T of the subject with luminous flux divergence R, is the lens t, The magnification factor of s, F is len, leL.

brightness.

From the relationship, it is expressed as J z * J [1um@t+/m' ]
, Tl =0.8 +20 F, -Q, 75, H, g soo, K-3,
14, -1,03311 (:1ux) = 1033 J (m 1ux) ・
--------(9) So from the above (7) and (8), 1033B, = 0.6 J = 0.0 Q O58C"d/g] = 0.0005
8X0.292(ft-L)-0,000189(:f
t-L) ・・・・・・Since αQ, the incident X-ray dose Fi1.8 to obtain a brightness of 81 from the example of the fluorescent plate characteristics in the KI4 diagram
(”/, i, ).T shooting time 0.33
4 Ca@e), so s o X O-334=0.01002 [:mR
]=10.02CμR] Therefore, in this hypothetical calculation, 10[μR/1ik+tl
) will be the imaging dose.

From this K, direct shooting system (jl & sharpness intensifying screen (
For example, when using FS type) and standard film (for example, Sakura A type film), the required incident X-ray dose is approximately 100
If it is 0 (μR/1 image), this device, which requires only 10 [“8/]” incident X-ray dose, can reduce the amount by about 1/1ooK@ compared to the direct 1i1i1i interview imaging system.

FIG. 8 shows a modification of the present invention. In the case of the device shown in Figure 2,
While the output of the imaging device 21 is added by the image processing device 23 to compensate for the lack of level, in this modification, the imaged value @j1 is blanked during the X-ray exposure period, and the video signal is Extraction is stopped and extraction is started after X-ray exposure is completed.@ Therefore, in this device, the controller 1aK controls the timing of X-ray exposure and blanking control of the imaging device 21. I am trying to get them to do this. That is, as shown in Figure 9 (1) K, blanking is applied for several fields in time with the X-ray exposure, and during this period, the reading of the image g# signal is stopped and my accumulation is performed. When the X-ray exposure is finished, the television controller 22 releases the blanking, so the imaging device 21 transmits the photographed image to the television controller 22.
If tX is an image pickup tube, its light guide 11 is taken out as a video signal at the scanning speed of jzz.
By forming an image on the input target surface, which is the IL surface, 11 loads of electricity is formed on the input target surface according to the amount of incident light, and this is extracted as a video signal by scanning with an electron beam. Even if the incident illuminance is weak, it is possible to extract a video signal of sufficient level by accumulating the input signal for a predetermined period of time.
During the line 1 period, blanking is applied to stop the generation of the electron beam, and after X-irradiation, the blanking is performed to extract the video signal as shown in FIG. 3(b). Imaging device 2
Similarly, when 1 is a solid-state *** child (CCD), image reading is stopped during the blanking period, and reading is performed at the blanking period elapsed value.

The video signal extracted in this way is shown in Figure 9'(-)
As shown in the figure, the level is high in the first field, and the level decreases in the subsequent fields due to less residual charge. This video signal is added to the iji image processing m bale and r isotal memory 26 in the image processing device 11,
This is then read out, converted into analog by the D/MU converter 21, and then given to the monitor display device 29 for display.
) shows the output after D/MU conversion. In this way, in the apparatus shown in FIG. 8, the image pickup device 11121 is blanked for a long period of several frames to operate as a storage tube.

The readout efficiency of the video signal is better than in the example shown in FIG. 3, and therefore, the X-ray imaging time is longer than in the previous embodiment, and a lower radiation dose can be expected.

As described in detail above, the present invention uses a fluorescent plate to provide light 1.1.
7) An imaging device such as a television camera was connected to the X-ray imaging device to be used, and the X-ray image was extracted as a video signal, and this video signal was emphasized and displayed using 1IiifIIt processing, making the image easier to see. In addition, since the images of each field subjected to 1111 processing are added together and used, a sufficiently high level of isthmus image can be obtained even with a method of irradiating X-rays with a low X-ray dose for a short time. It is possible to provide an X@diagnostic value device that has excellent features such as being able to promote dose conversion.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can be practiced by making appropriate changes within the scope of the invention.

[Brief explanation of drawings]

Figure 1 is a professional diagram showing the configuration of a conventional device, Figure 21cl.
This is part 1 of the present invention! A block diagram showing the example, Figure 3 is a time chart for explaining its operation, Figure 4 is a diagram showing the relationship between the amount of incident X-rays on the fluorescent plate and the brightness of the fluorescent plate, and Figure 5 is a time chart for explaining the operation.
-A diagram showing the brightness characteristics of P-C, FIGS. 6 and 7 are diagrams for explaining lens system calculations, FIG. 8 is a block diagram showing a modification of the present invention, and FIG. 9 is its operation. It is a time chart for explaining. I: X-ray tube, 4: Low reduction imaging device, 5: Grid, do, i: Fluorescent plate, 1: Lens, 8: High-sensitivity optical image intensifier , 10... tandem lens system, Ill... imaging device, 22... television camera controller, 13... image processing device, 12...
X-ray side mG, 14... ADD articulator, 15... Dinotal Zorose, 26... Digital memory,
27...D/MU converter, 29...Monitor display device. Applicant's agent Patent attorney Takeshi Suzue Hikosai 5 - Sai 6v! J Patent Office Commissioner Haruki Shimada 1 Indication of the case Patent Application No. 1983-101624 7 2. Name of the invention agent

Claims (1)

[Claims] (1) Optical image intensity that amplifies the visible light image of 1116N and 't-no-X1jjifl color exposure': a device that transmits 5 hours through the subject and converts the nine X-rays into a visible light image. and an imaging device that captures the output image of the optical image intensifier, converts it into a video signal, and outputs it. A third image processing device that adds and outputs the video signals of two images, and a device that displays the video signal after this addition as an An Xll# sectioning device which is characterized by reducing the dose by increasing the amount of radiation and making the image easier to see by performing image processing.Q) The imaging device has an X-ray exposure period of the
Accumulate the incident image from K by stopping the extraction of the image signal,
An X-ray diagnostic apparatus according to item 1 of the patent application, characterized in that the readout efficiency of video signals is improved to reduce radiation dose.