JPS6291933A - Radiograph information recording and reading device - Google Patents

Abstract

PURPOSE:To use repeatedly a band-shaped flexible storage type phosphor sheet and to make a sheet feeding mechanism simple and to miniaturize a device by rolling and storing the sheet to utilize it. CONSTITUTION:The part of a storage type phoshpor sheet 26 where picture is already read is wound around the second take-up shaft 23 and is stored there. Another part of the storage type phosphor sheet 26 wound around the first take-up shaft 22 is stretched between rolls 27 and 28 simultaneously,and radiograph information is recorded on this part of the storage type phosphor sheet 26. When radiograph information is recorded throughout the storage type phosphor sheet 26 in the lengthwise direction and all of the sheet 26 wound around the first take-up shaft 22 is fed out to the side of the second take-up shaft 23, a motor 24 is driven to rotate the first take-up shaft 22 in the direction of an arrow A.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention involves accumulating and recording radiation image information on a stimulable phosphor sheet, then irradiating the same with excitation light, and emitting light according to the accumulated and recorded image information. It relates to an lll1rA line image information recording/reading device that detects exhausted light, reads image information, and converts it into an electrical signal, and more specifically, a radiation image information recording device that reuses a stimulable phosphor sheet within the device. This relates to a reading device.

(Technical Background and Prior Art of the Invention) When a certain type of phosphor is irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, ultraviolet rays, electron beams, etc.), part of the energy of this radiation is absorbed into the phosphor. When the phosphor is irradiated with excitation light such as visible light, the phosphor exhibits stimulated luminescence depending on the accumulated energy. The photoreceptor is called a storage phosphor (stimulable phosphor).

Using this stimulable phosphor, radiation image information of a subject such as a human body is recorded on a stimulable phosphor sheet (hereinafter referred to as a stimulable phosphor sheet), which is then scanned with excitation light. A method has been proposed in which the stimulated luminescence is produced by photoelectrically reading the stimulated luminescence to obtain an image signal, and the image signal is processed to obtain a radiation image of a subject with good diagnostic suitability (for example, Kaisho 55-12429, Kaisho 55-116340
No. 55-163472, No. 56-11395,
56-1046/15, etc.). This final image can be reproduced as a hard copy or on a CRT. In any case, in such a radiation image information recording and reproducing method, the stimulable phosphor sheet does not ultimately record image information, but temporarily stores the image in order to provide the image to the final recording medium as described above. Since it carries information, the stimulable phosphor sheet may be used repeatedly, and such repeated use is extremely economical.

Also, for example, a radiation image information recording/reading device that uses a stimulable phosphor sheet in a mobile station such as an X-ray mirror vehicle! Prepare A, travel to various locations for group examinations, and perform X-rays.
In such cases, it is inconvenient to load the sheets into a car, and there is a limit to the number of sheets that can be loaded into a moving car. Therefore, a storage+i phosphor sheet is made to be reusable and loaded onto a moving vehicle, and radiographic image information for each subject is recorded on it, and the 1-watt image signal is stored on a magnetic tape or other storage device. By copying radiographic images onto a large recording medium and reusing stimulable phosphor sheets, etc., radiological images of a large number of subjects can be copied using a moving vehicle, which is extremely convenient in practical terms.
It is for use. Furthermore, if continuous imaging is performed through this cyclical reuse, it is possible to increase the speed of copying during mass medical examinations, which is extremely effective in practical use.

In order to reuse the stimulable phosphor sheet as described above, the radiation energy remaining in the stimulable phosphor sheet after the stimulated luminescence light is read can be absorbed by, for example,
No. 2, No. 56-12599, the remaining tli0 is released by irradiating the sheet with light or heat.
The 4-line image may be erased and the stimulable phosphor sheet may be used for re-recording the Iσ-emission tA-ray image.

Therefore, the present applicant proposed a circulating means for transporting a stimulable phosphor sheet capable of storing and recording radiation images along a predetermined circulation path, and a means for irradiating radiation onto the sheet through a subject in the circulation path. An image recording unit that accumulates and records radiation image information of the subject on this sheet;
In the circulation path, there is an excitation light beam that emits excitation light that scans the sheet on which radiographic image information has been accumulated and recorded in the image recording section, and the luminescence that is mediated by the sheet that has been scanned by this excitation light. Read the exhaust light and convert the image signal to 1
an image reading section consisting of a photoelectric reading means; and a radiation source located in the circulation path that remains on the sheet prior to recording an image on the sheet after the image reading is performed in the image reading section. An erasing section that emits energy is incorporated into one device, and the stimulable phosphor sheet is circulated between the sections and used repeatedly.
I would like to first propose a ray image information recording/reading device (Japanese Patent Application Laid-open No. 192240/1983). According to the radiation image information recording/reading device having such a structure, it is possible to record and read radiation image information continuously and efficiently.

However, the radiation image information recording/reading apparatus d3 has a disadvantage in that the structure of the circulation path and circulation conveyance means for the stimulable phosphor sheet is complicated, and the apparatus tends to be large-sized.

Therefore, a stimulable phosphor sheet is formed into an endless belt shape, and this sheet is rotated to form an image recording section and an image reading section J.
It is also considered that the data is sent sequentially to 3 and the erasing section, but in this case, considering the size of the space occupied by the endless belt,
The problem is that the area of available stimulable phosphor sheets is small. Therefore, when radiographic image recording (Iil shadows) is performed continuously with such a device, several images can be taken continuously at the beginning, but soon the available portion of the stimulable phosphor sheet 1~ is used up. It is easy to cause a situation where the dark shadow has to be interrupted until reading and erasing from the recorded area are completed.

(Object of the Invention) The present invention was made in view of the above-mentioned circumstances, and a stimulable phosphor sheet can be used repeatedly, and a feeding mechanism for this sheet can be fabricated in a 34th grade by a commercial diary. It is an object of the present invention to provide a recording unit 1y with a radial diameter of 1 ray, which is capable of recording images continuously, and also capable of continuous recording (lli1 shadow) many times.

(Configuration of Source IIJ) The radiation/lFj radiation image information recording/reading device of the present invention is characterized in that a band-shaped flexible stimulable phosphor sheet is wound and stored for use. In other words, one end side and the other end side of the sheet as described above are respectively wound around a first winding shaft and a second winding shaft arranged at a distance from each other, and the sheet is transported by a sheet feeding means. The sheet 1- is moved back and forth between the two winding shafts 't11, and the image recording section irradiates the stimulable phosphor sheet stretched between the two winding shafts with fA rays having image information. The image reading unit and the erasing unit as described above,
The image is read and erased.

(Implementation) Mr. 8 yen) The present invention will be described in detail below based on the embodiments shown in the drawings.

FIG. 1 shows a radiation image information recording and reading apparatus according to one embodiment of the present invention. As an example, the device of the present 1M embodiment is formed of a main body 20 that can be stored in a wall 10 of a hospital examination room, etc., and a radiation source storage section 30. When the main body 2043 and the radiation source storage section 30 are not in use, they are respectively stored in recesses 11.12 in the wall surface 10, and when in use (at least when recording an image), they are each held by grasping the handles 21.31 and 10 pulled out.

FIG. 2 shows the structure of the main body 20 and the radiation source storage section 30 in detail. As shown in the figure, a first winding shaft 22 and a second winding shaft 23 are arranged in parallel with each other with an interval between them within a casing 29 of the main body 20. These winding shafts 22, 23 are rotated in the directions of arrows A and B, respectively, by motors 24, 25 serving as sheet feeding means. The first winding shaft 22 has a
As shown in (e), one end of the stimulable phosphor sheet 2G capable of storing and recording radiation image information is wound. this? B Stackable fluorescent sheet 2G available! It is formed into a long strip using a flexible support, and the other end is connected to the second winding shaft 2.
3, and is cut off from the other end by the second winding shaft 23. Further, the stimulable phosphor sheet 26 is stretched between rows 527.28 between both winding shafts 22.23. Furthermore, here? The 5-layer phosphor sheet 26 has a flexible support that allows good transmission of radiation, which will be described later, on the upper side in the figure, and a l0 layer on the support.
The stimulable phosphor layer is disposed on the lower side.

A photographing table 32 is provided at a position facing the stimulable phosphor sheet 2G stretched between [1 to 27 and 28 above]. For example, there is a
It houses a radiation OA radiation source 33 such as a radiation tube, and in the use state f when this full radiation source storage part 30 and main body 20 are pulled out from the wall surface 1o, III) 1 radiation source 33 is placed in the 1Iil shadow stage Go to 32. Subject? 5 (subject) 34, the subject 34 is placed, for example, on his back on the imaging table 32-A, and the radiation source 33 is activated in this state.

As a result, the radiation 35 that has passed through the subject 34 is irradiated onto the stretched stimulable/fluorescent sheet 26, and the stimulable/fluorescent sheet 26 is exposed to the stimulable/fluorescent sheet 26 (more specifically, the Radiation image information of the subject 34 is accumulated and recorded on the phosphor layer. As is clear from the above description, in the present embodiment apparatus, the imaging stage 32a3 and the radiation source 3 are
3 constitutes an image recording section 40. In this actual embodiment, the legs of the subject 34 are supported by the support stand 15 which can also be stored within the wall surface 10.

An image reading section 50 is provided below the stimulable phosphor sheet 26 in the region near the 255th take-up shaft 23. The image reading unit 50 includes a laser light source 51, an optical deflector 53 such as a polygon mirror that reflects and deflects Rayleigh light 52 as excitation light emitted from the laser light source 51,
A long mirror 59 that reflects the deflected laser beam 52 and scans it one-dimensionally on the sheet 2G (more specifically, on the stimulable phosphor layer), and a nip roller that sandwiches the stimulable phosphor sheet 26. A driving row ``''-/28 as a sub-scanning means rotated at a constant speed, and a light-receiving surface extending along the scanning line (main scanning line) on the phosphor sheet 26 which has an accumulation property by the laser beam 52. A long photomultiplier tube (A photomultiplier tube 17-) 54, J as a photoelectric reading means arranged in
5 and an elongated condensing reflection mirror 55 disposed along the elongated optical multiplexer tube 54. ril
After the radiographic image information of the subject 34 is accumulated and recorded on the stimulable phosphor sheet 1 26 as described above, the sheet 26 is moved to the right in the figure by rotating the drive roller 28. Constant speed-r: Conveyed. At this time, the second winding shaft 23 is rotated, and the Mg phosphor sheet 26 is wound around the shaft 23.

Further, the first winding shaft 22 side is provided with an appropriate zero by a known means.
A load is applied so that the stimulable phosphor sheet 26 remains under tension at all times. While the sheet 26 is conveyed, the laser light source 51 and the optical deflector 53 are activated, and the laser light 52 scans the sheet 2G. From the part of the stimulable phosphor sheet 26 that is irradiated with the laser beam 52, the sheet 26 accumulates and records r: bll
Stimulated luminescent light 56, which serves as a preliminary line drawing, is illuminated. This stimulated luminescence light 56 is efficiently detected by the elongated photomultiplier tube 54 either directly or after being reflected by the condensing reflection mirror 55. While the main scanning of the laser beam 52 is performed as described above, the ultimate firefly nine body sheet 26 is conveyed as described above and the m1 scanning is performed, so that the sheet 26 is two-dimensionally recorded with 114 bright lights. The exhaust light 56 (ie, radiation image information) is read. The read image signal S outputted from the long photomultiplier tube 54 is amplified, digitized, and subjected to image processing in the reading circuit 51, and is sent to the image reproducing device (not shown) to reproduce the radiographic image (
9 information is used for reproduction. This playback device may be a display means such as a CRT, a recording device that performs optical scanning recording on a photosensitive film, or for that purpose, image signals are stored in an image file on a -0 optical disk, magnetic disk, etc. It may be replaced with ¥2 position.

The portion of the stimulable phosphor sheet 2G whose image has been read as described above is wound around the second winding Ikl 123 and stored therein. At the same time, the first winding shaft 22
Another part of the stimulable phosphor sheet 26 that had been wound around the stimulable phosphor sheet 26 is now stretched between the rollers 27 and 28, and this part of the stimulable phosphor sheet 26 is irradiated in the same manner as described above. f
J4 line image information can be recorded. In this way, radiation image information is recorded over approximately the entire length of the stimulable phosphor sheet 26, and all of the sheets 26 that had been wound and stored around the first winding shaft 22 are moved to the second δ-taking shaft 23. Once it is fed out, the motor 24 is driven and the first winding shaft 22 is rotated in the direction of the arrow. As a result, all of the stimulable phosphor sheets 1-2G that have been wound around the second winding shaft 23 and which have not been used for image reading are returned to the first winding shaft 22, but at this time, the rollers 27, 28 The Tf phosphor sheet 26 passes through the erasing section 60 disposed between the sheets 1 and 1.
26 undergoes image (g! (remaining@)) erasure.This erasing section 6
For example, the erasing light source 61 includes a large number of erasing light sources 61 arranged below the stretched sheet 26. These erasing light sources 61 are composed of, for example, fluorescent lamps and emit light mainly in the excitation wavelength range of the stimulable phosphor of the sheet 26, and the sheet 2G is returned to the first winding shaft 22 side. It will be lit on occasion. After reading the image 9, the stimulable phosphor sheet 26
The remaining radiation energy is released from the sheet 26 by irradiating the sheet with the above-described light.

In this way, the stimulable phosphor sheet 26 whose afterimages have been erased to the extent that radiation image information can be recorded again is stored in the first apricot collector 22, so this sheet 26 can be used. This makes it possible to repeat the above-described image recording (III shadow) and reading. As the erasing light source 61, in addition to the above-mentioned fluorescent lamp, for example, Japanese Patent Laid-Open No. 56-113
A tungsten lamp, a halogen lamp, an infrared lamp, a xenon flash lamp, etc. as shown in No. 92 may be arbitrarily selected and used. Further, the erasing unit 60 includes a large number of erasing light sources 61 as described above, and also includes, for example, an LED.
(Light E hitting D 1ode)
It may be constructed from a planar light source such as a panel in which two-dimensionally arranged panels or an EL (electroluminescence) board.

In addition, the real I7i! ! In the embodiment, the first winding shaft 22
A secondary erasing light source 70 for performing so-called secondary erasing is provided between the image recording section 40 and the image recording section 40 . This secondary erasing light source 70 is derived from a light source similar to the erasing light source 61 of the erasing section 60, and is used to feed the stimulable phosphor sheet 2G from the first winding shaft 22 for recording radiation image information. When the sheet 26 is erased, the sheet 26 is irradiated with erasing light. After the image (afterimage) of the M stacked phosphor sheet 26 has been erased in the erasing section 60, if it has not been used for a long time and has been stored on the first winding shaft 22, the sheet 26 may , radioactive elements such as (g) Ra contained as impurities in the phosphor, and radiation energy from environmental radiation (a component that causes noise in the stored recorded information) may be accumulated. By irradiating the sheet 2G with erasing light from the secondary erasing light source 70 immediately after image recording as described above,
This radiation energy is also emitted. Note that the secondary erasing light is blocked by the light shielding plate 71.12 so as not to be irradiated onto the stimulable phosphor sheet 26 before image reading.

As described above, after the radiation image information is accumulated and recorded on the stimulable phosphor sheet 2G, this IJIi radiation image information is immediately
Although the case where the image is read by the image reading section 50 has been described, the present apparatus can also be used so that the reading of the image by the image 8I reading section 50 is postponed and a large number of image recordings (photographs) are performed one after another.

In other words, in this case, remove all of the stimulable phosphor sheet 26 in the area where the image has been recorded! After the series of image recording is completed, the sheet 26 is returned from the second take-up@23 to the 18th take-up shaft 22 side.
At that time, the image reading section 50 may read the image. In this case, the erasing light emitted by the erasing light source 61 is blocked by the light shielding plates 62 and 63, and is prevented from being irradiated onto the stimulable phosphor sheet 26 before the image 8I is read. In addition,
Especially when image reading is postponed as mentioned above,
The image reading may be performed after the main body 20 and the OA radiation source storage section 30 are stored within the wall surface 10.

By the way, in order to eliminate the influence of variations in profile conditions or to obtain radiographic images that are highly suitable for observation and interpretation,
? ? The recording state of radiation image information accumulated and recorded on the transparent phosphor sheet 26 or the subject 34 such as the chest or abdomen
The recording pattern (hereinafter collectively referred to as "accumulated recording information") determined by the facial features, imaging methods such as simple copying and contrast imaging, etc., is recorded prior to outputting a visible image for observation and interpretation. Based on this accumulated record information,
It is necessary to determine reading conditions such as the reading gain and recording scale factor in the reading circuit 57, or the image processing condition f1. A method disclosed in Japanese Patent Application Laid-Open No. 58-67240 is known as a method of grasping the accumulated record information of a radiation image prior to outputting a visible image. This method uses excitation light of a lower level than the excitation light that should be irradiated during the reading operation (hereinafter referred to as "main reading") to obtain a visible image for observation and interpretation. ? ! i Perform a reading operation (hereinafter referred to as "pre-reading") to grasp the accumulated recording information of the radiographic image stored and recorded on the phosphor sheet 26, and grasp the outline of the N product record of the radiographic image. When performing actual reading, reading conditions such as the reading gain and recording scale factor or image processing conditions are optimally determined based on this pre-reading information. This kind of "read ahead" and [
To carry out main reading 1 in this apparatus, for example, 1 pre-reading is performed when the stimulable phosphor sheet 26 is fed to the second winding shaft 23 side after image recording, and then the stimulable phosphor sheet 26 is may be shifted from the second winding shaft 23 to the first winding shaft 22 side and perform the above-mentioned "main reading" at this time.

The elongated photomultiplier tube 54 described above is explained in detail in, for example, the specification of Japanese Patent Application No. 156255/1983 filed by the present applicant, but here, a brief description will be given with reference to FIGS. 4 and 5. Explain. As shown in Figure 4 (A>, <8)
The photoelectron intensifier 8 tube 54 has an electrode structure generally called a box shape. This photoelectron multiplier 8 tube 54
The main body 1 is made of glass or the like and has a vacuum inside.
A photocathode (photocathode) 153 that emits photoelectrons is provided within the photocathode 153 facing a long light-receiving surface 152. Below this photocathode 153, a plurality of (13 in this example) quarter-cylindrical two Electrode (dynode) 154 with secondary electron emission effect
A multiplication unit 167 in which 16G to 16G are combined is provided. This increase (lowest dynode 16G of fS section 167
A shield electrode 168 is provided opposite to the shield electrode 168, and an anode 169 collects the electron flow multiplied by the -F multiplier 167 and takes it out as a signal. Each of these electrodes is electrically connected in a one-to-one correspondence to each terminal 172 of a terminal group 170 provided on the side opposite to the light-receiving surface 152.

Note that the dynodes 154 to 165 and the shield electrode 168 are fixedly held within the main body 151 by a support member 171 formed of an insulator.

FIG. 5 shows an electric circuit 180 for driving the photomultiplier tube 54 and extracting the photoelectric output. In FIG. 5, each part of the photomultiplier tube 54 is given the same reference numeral as in FIG. A negative high voltage is applied to the photocathode 153 via a negative high voltage application terminal 181. Further, the negative high voltage applied to the negative high voltage application terminal 181 is divided by the bleeder resistor group 182, and the dynode 154.16
13, respectively. In addition, shield electrode 1
68 is grounded, and the anode 169 is grounded via a resistor 183 and is input to one terminal of an amplifier 184.

The other terminal of the amplifier 184 is grounded, and the photoelectrically converted image information is taken out as an electrical signal from an output terminal 185. Note that the long photomultiplier tube 54 is as follows:
[Not limited to the box-shaped electrode structure described above, other electrode structures such as the Venetian blind electrode structure as shown in the specification of Japanese Patent Application No. 60-156255 mentioned above are also applicable. may be used.

The photoelectric reading means used in the present invention is not particularly limited to this long photomultiplier tube 54, but for example, as shown in JP-A-59-192240, a relatively small light-receiving surface can be used. A device in which a photodetector and a condenser are optically coupled may also be used. However, the long photomultiplier tube 54 described above suffers from an increase in the size of the device due to the use of the large condenser, and a decrease in photodetection efficiency due to leakage of stimulated luminescence from the condenser. In particular, it is particularly suitable because it can eliminate at once the increase in the cost of koji due to the formation of a condensing body with a complicated shape. In addition, when such a long photomultiplier tube 54 is used, it may be used in combination with the above-mentioned condensing reflecting mirror 55.
In combination with an integrating tube as shown in the specification of No.
As shown in the specification of 58g, it is also possible to improve the light collection efficiency by combining the above-mentioned integrating cylinder with a reflective optical element.

Further, in the above-described embodiment, the image reading section 50 and the erasing section 60 are arranged below the stimulable phosphor sheet 26, but the sheet 26 is arranged so that its phosphor layer is located on the upper surface side. The image reading section 50 and the erasing section 6
0 may be placed above this sheet 26. However, in order to utilize the space between both winding shafts 22, 23 for rightward movement and to achieve miniaturization of the apparatus, it is preferable to arrange the image reading section 50 and the erasing section 60 as in the sailboat mode. In addition, especially when the erasing section is formed in a small size,
This erasing section may be disposed between the image reading section and the second winding shaft 23, and the stimulable phosphor sheet 2G sent to the second winding shaft 23 side may be erased immediately after the image is read. good.

Furthermore, as shown in FIG. 3, the radioactive J-ray image information recording and reading apparatus of the present invention arranges the radiation source storage section 30 and the main body 20 at a distance from each other in the horizontal direction. Of course, it is also possible to form the image so as to record a similar image.

Also, the first winding shaft 22, the second winding shaft 23 and v1i? The stimulable phosphor sheet 26 is housed in a unit that can be attached to the main body 20, and when using stimulable phosphor sheets of different types (for example, sensitivity, etc.), the usage sequence can be easily changed by replacing the unit. 1-20 may be replaced.

(Results of the Invention) As explained in detail above, the radiation image information recording/reading device of the present invention uses the stimulable phosphor sheet repeatedly within the device, so it can be used in the M-secant line pattern very economically. can be done.

However, in the apparatus of the present invention, a flexible stimulable phosphor sheet is wound and stored in the apparatus, and this sheet is picked up, rewound, and conveyed, so that the sheet feed m41'
4 can be made quite simple and extremely compact. Moreover, as mentioned above, since the stimulable phosphor sheet is wound inside the device, it is possible to store a sufficiently good stimulable phosphor sheet in the device even if it is formed into a small size. It becomes possible to process the sequence 11a in a short time.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing a radiation image information recording/reading apparatus according to a first embodiment of the present invention, FIG. 2 is a schematic side view of the apparatus according to the embodiment, and FIG. FIG. 4 (△) is a perspective view showing a long photomultiplier used in the device of the present invention; FIG. 4 (B) is a sectional view taken along line I-I of the image information recording/reading device; , FIG. 5 is a circuit diagram showing a drive circuit for the photomultiplier tube. 20...Main body 22...First winding shaft 23...Second winding shaft 24.25...Motor 26...Storage phosphor sheet 27...Roller 28...Drive Roller 30... Radiation source storage unit 32... Mug table 33... Radiation source 34... Subject '835... Radiation 40... Both image recording unit 50... Image reading unit 51 ... Laser light source 52 ... Laser light 5
3...Light (-Internal unit 54...Photomultiplier tube 56...Photostimulated luminescent light 57...Reading circuit 60...Erasing unit 61...Erasing light source Fig. 3 Fig. 2 44fklk 'L@71 A

Claims (1)

[Claims] A first winding shaft for winding one end of a band-shaped flexible stimulable phosphor sheet capable of storing and recording radiation image information; a second winding shaft that is arranged at a distance and winds the other end of the sheet; a sheet feeding means that reciprocates the sheet between the first and second winding shafts; and both shafts. an image recording unit that accumulates and records the radiation image information on the sheet by irradiating the sheet stretched between the sheets with radiation having both image information; an image reading section that irradiates the sheet with excitation light from an excitation light irradiation means and reads stimulated luminescence light emitted from the sheet by the irradiation of the excitation light with a photoelectric reading means to obtain an image signal; A radiation image information recording/reading device comprising an erasing section that releases radiation energy remaining on a sheet after image reading is performed prior to recording an image on the sheet.