JPS6139038A - Recorder/reader for radiation picture information - Google Patents

Abstract

PURPOSE:To use an accumulative fluorescent sheet circularly to record and to read out radiation picture information by arranging a shutter for preventing the sheet from the irradiation of radiant rays at the use of a cassette and a shutter operating means on the upper part of the sheet set on a picture recording part. CONSTITUTION:The shutter 101 is moved to the right from its shunting position by a driving motor 102 and positioned on a shielding position that is overlapped on the sheet 30 set on a photographing position of an endless belt 2 to prevent the sheet from the irradiation of radiant rays. Manual operation buttons 80, 81 specify the moving direction of the shutter 101 by operating them from the external. Since the shutter 101 is moved to the shielding position in a radiant ray irradiation field and covers the sheet 30, the sheet 30 is prevented from the exposure of transmitted radiant rays even if the radiant rays are transmitted through the cassette 91. Consequently, complex operation for circulating an exposed sheet and sending the sheet to an erasing part can be omitted, the radiation picture information recording function is expanded and a practical using range is also expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention stores and records radiation image information on a stimulable phosphor,
Regarding a radiation image information recording/reading device that then irradiates the excitation light, detects the stimulated light emitted according to the accumulated and recorded image information, reads the image information, and converts it into an electrical signal.
In more detail, a sheet of stimulable phosphor is recycled within the device, and in addition to the sheet that is recycled,
The present invention relates to a radiation image information recording/reading device that also enables recording of radiation image information on sheets stored in a cassette.

(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, etc.), part of the energy of this radiation is transferred to the phosphor. When the phosphor is then irradiated with excitation light such as visible light, the phosphor exhibits stimulated luminescence in response to the accumulated energy. A phosphor exhibiting such properties is called a stimulable phosphor.

Using this stimulable phosphor, radiation image information of a subject such as a human body is recorded on a sheet of stimulable phosphor, and this is scanned with excitation light to cause stimulated luminescence. A method has been proposed in which an image signal is obtained by photoelectrically reading the image, and this image signal is processed to obtain a radiation image of a subject that is suitable for diagnosis (for example, Japanese Patent Laid-Open Nos. 55-12429 and 56-1982).
No. 11395, No. 55-163472, No. 56-10
No. 4645, No. 55-116340, etc.). This final image may 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.

In addition, for example, a mobile station such as an X-ray imaging unit may be equipped with a radiation image information recording/reading device using a stimulable phosphor sheet, and the mobile station may be used to travel to various locations for group examinations and take X-rays. In some cases, it is inconvenient to stack multiple stimulable phosphor sheets in a row, and there is a limit to the number of sheets that can be loaded onto a moving vehicle. The radiographic image information for each subject is recorded on it, and the image signal obtained by reading it is copied to a recording medium with a large storage capacity such as a magnetic tape, and is stored in a storage medium such as a magnetic tape. If the phosphor sheet is recycled and reused, radiographic images of a large number of objects can be taken using a mobile vehicle, which is extremely useful in practice.

Furthermore, by this cyclical reuse, if continuous shooting is performed,
It can also speed up imaging during group medical examinations.

In view of such demands, the present applicant has proposed a circulating conveyance means for conveying at least one stimulable phosphor sheet as described above along a predetermined circulation path, and a means for conveying at least one stimulable phosphor sheet as described above along a prescribed circulation path, an image recording section that accumulates and records a radiographic image of a subject on the sheet by irradiating the sheet with radiation through the subject; an image reading unit having an excitation light source that emits scanning excitation light; and a photoelectric reading unit that reads stimulated luminescence light emitted from a sheet scanned by the excitation light to obtain an image signal;
A patent has already been filed for a radiation image information recording/reading device that includes an erasing section that releases the residual radiation energy on the sheet before the image is recorded on the sheet after the image is read in the image reading section. (Patent Application No. 58-66730). Note that the erasing section implements a method as shown in, for example, Japanese Patent Laid-Open Nos. 56-11392 and 56-12599. According to this radiographic image information recording/reading device, the many demands mentioned above are met, and radiographic image capturing and reproduction processing operations are significantly streamlined.

On the other hand, when radiographing bones, etc., there is a demand for the sheet to be placed as close to the subject as possible in order to minimize the adverse effects of scattered images from the subject. Radiography is performed by applying a cassette containing a light sheet to the area to be imaged.

The apparatus disclosed in Japanese Patent Application No. 58-66730 is not originally intended for handling the above-mentioned cassettes, but it can only record radiographic image information on the sheets of the cassettes.

That is, a cassette is placed on the photographing stand of the image recording section of the device, and the subject is placed closely against the cassette,
What is necessary is to drive the radiation source to turn on. The radiation image information thus recorded on the sheet of the cassette can be read using a dedicated image reading device.

However, when radiography is performed using the cassette as described above, the recirculating sheet placed at the imaging position of the image recording section of the apparatus is exposed to the radiation that has passed through the cassette.

Therefore, even though recording and reading are not performed, it is necessary to circulate the sheet in order to erase the fog caused by the exposure in the erasing section, which makes the operation cumbersome.

(Objective of the Invention) Accordingly, the present invention makes it possible to record and read radiation image information by using a stimulable phosphor sheet in a cyclical manner, and without exposing the stimulable phosphor sheet to light.
It is an object of the present invention to provide a radiation image information recording/reading device capable of recording radiation image information on a sheet stored in a cassette.

(Structure of the Invention) The radiation image information recording/reading device of the present invention comprises a stimulable phosphor sheet circulation conveying means as described above, an image recording section, an image reading section, and an erasing section. In the image information recording/reading device, a shutter is provided above the sheet in the image recording section to prevent radiation from being irradiated to the sheet when the cassette is used, and a shutter operation means for controlling the movement of the shutter is provided in the device. It is characterized by the fact that it is located inside. The shutter is movable between a shielding position that is within the radiation irradiation field and prevents radiation from being irradiated to the sheet, and a retreat position that is outside the irradiation field and allows radiation to be irradiated to the sheet. It has a size that covers the sheet and is made of a material with high radiation absorption ability, such as lead. Further, the shutter operating means moves the shutter between the shielding position and the retracted position by an external operation.

When recording radiation image information on a sheet stored in a cassette, if the shutter is placed in the shielding position, the sheet being circulated in the device will be covered from above by the shutter and will not be irradiated with radiation. (This can prevent the sheet from being exposed to radiation.

(Embodiment) Hereinafter, an actual 11M embodiment of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows an IMtIR-like device according to the present invention, which captures and records radiographic images of the chest, abdomen, etc. while the subject is lying down. Inside the device 1 are endless belts 2.3.4.5.6.7.8.9.10.11.
12.13 and endless belt 3.4.7.10.1
1.12.13 Guide roller that rotates driven by 14.15.
16.17.18.19.20 and guide plate 21.22
．． 23.24.25.26 and nip roller 27.28
A sheet circulation conveyance system is provided, which constitutes a circulation path. In this sheet circulation conveyance system, for example, six stimulable phosphor sheets 30 are circulated and conveyed at appropriate intervals in the direction of the arrow in the figure.

Endless belt 2 arranged at the top of the circulation conveyance system
A photographing stand 41 is provided above, and this photographing stand 41
A radiation source 42 such as an X-ray source is provided at a position facing the imaging position on the endless belt 2 (the right side of the endless belt 2 in FIG. The image recording unit 40 is configured by the source 42 . Further, a shutter 101 made of lead and driven by a drive motor 102 and having a size that covers at least the sheet 30 is provided between the photographing table 41 and the endless belt 2.
It is movable along a shirt starter guide 103 provided in parallel with.

Sheet 3 used for radiography of patient 43
0 is placed at the imaging position on the endless belt 2 as shown, and the radiation source 42 is driven to turn on while the subject 43 is lying down on the imaging table 41. As a result, subject 43
The transmitted radiation image of the subject 4 is projected onto the sheet 30.
3 radiographic image information is accumulated and recorded on the sheet 30.

At this time, the shutter 101 is in a retracted position that does not overlap the sheet 30 in the photographing position, allowing the sheet 30 to be irradiated with X-rays.

At the right end position in the figure of the sheet circulation conveyance system, there is an image reading unit 50.
is provided. In this image reading section 50, a laser light source 51 is installed above the endless belt 8 constituting the reading section 50, and a laser light source 51 is installed to scan the output laser light 52 in the width direction of the sheet 30 on the endless belt 8. A mirror 53, a galvanometer mirror 54, a mirror 55, and a mirror 56 are provided, and as the galvanometer mirror 54 swings back and forth, the laser beam 52 is main-scanned over the sheet 30 on which the radiation image is stored and recorded. Note that, after a radiation image is recorded on the sheet 30 in the image recording section 40, the sheet 30 is conveyed to the image reading section 50 by the drive of the sheet circulation conveyance system. Further, a condensing reflection mirror 57 is disposed along the main scanning line at the scanning position of the laser beam 52 on the sheet 30, and the stimulated luminescence light emitted from the sheet 30 by the irradiation of the laser beam 52 is directly or condensed. After being reflected by the reflective mirror 57, the photo beam enters the condensing optical element 58 from the incident end surface 58A of the condensing optical element 58, and is connected to the exit end surface 58B of this element 58 while being guided through the condensing optical element 58 by total reflection. The stimulated luminescence light is received by the circle 59 and read out photoelectrically. Laser light 5 as above
At the same time as the main scanning of No. 2 is performed, the sheet 30 is conveyed by the endless belt 8 in the direction of the arrow in the figure (that is, the direction substantially perpendicular to the main scanning direction) and sub-scanned, so that the entire surface of the sheet 30 is scanned. The stored radiation image information is read. The image signal read by the photomultiplier 59 is sent to an image processing circuit (not shown), subjected to necessary image processing, and then sent to a necessary image reproduction device. As mentioned above, this reproducing device may be a display such as a CRT, a recording device that performs optical scanning recording on a photosensitive film, or a device that temporarily records data on a storage device such as a magnetic tape for that purpose.

Note that the distance required for reading radiation image information from one sheet 30 is generally longer than the distance R required for recording radiation image information on the sheet 30 (Jli shadow), but it is possible to read the recorded sheet 30. For example, endless belt 7.6.
By leaving one sheet at a time on 5.4.2, it is possible to use the six sheets 30 one after another and record only the short poems. Furthermore, as shown in JP-A No. 58-89245, prior to the above-mentioned reading operation (main reading) to obtain a visible image for observation and interpretation, excitation light with a lower intensity than that to be irradiated in the main reading is used. Using excitation light of a certain level, a read operation (pre-reading) is performed to grasp the accumulated record information of radiation image information accumulated and recorded on the stimulable phosphor sheet in advance, and the accumulated record information of the radiographic image information is read. If you understand this, then perform the actual reading, adjust the reading gain appropriately based on the pre-read information, or perform appropriate signal processing, you can eliminate the influence of fluctuations in imaging conditions, or obtain radiation with excellent observation and interpretation aptitude. Although an image can be obtained, the sheet 30 fed onto the endless belt 9 after reading the image is also
By reversing the endless belt 9 and the endless belt 7.8 and returning them to the image reading position, the above-mentioned "
Pre-reading jl “I can do book reading J.

The sheet 30 whose images have been read is sent to the erasing section 70 by the endless belt 9. This erasing unit 70 consists of a box 71 and a large number of erasing light sources 72 such as fluorescent lamps arranged inside this box 71. After the shutter 73 is opened, the sheet 30 is inserted into the nip roller. 2
It is conveyed by the endless belt 9 until it touches 7. The sheet 30 is then rotated by the rotating nip roller 27.
is sent into the box 71. When the sheet 30 is fed into the box 71, the shutter 73 is closed, and then the erasing light source 72 is turned on. These erasing light sources 72 mainly emit light in the excitation wavelength range of the stimulable phosphor of the sheet 30, and the radiation energy remaining in the sheet 30 after reading the image is absorbed by the sheet 30 in this manner. The light is emitted from the sheet 30 upon irradiation with light. Note that at this time, since the # shutter 73 is closed, erasing light does not leak and enter the image reading section 50 and generate noise in the read signal.

The sheet 30, on which the afterimage has been erased to such an extent that radiation image information can be recorded again, is discharged from the erasing unit 70 by rotating the nip roller 28.

The discharged sheet 30 is transferred to an endless belt 10°11.
12.13, the sheet is conveyed to the endless belt 2 of the image recording section 40, but if another sheet 30 gets stuck first, the endless belt 13.12.11.10
It is placed on top and waits. Furthermore, when the image recording and reading work is completed for the time being, the last sheet 30 is
After the residual image has been erased at 0, the nip roller 27 is rotated in the opposite direction to the above, so that it is sent onto the endless belt 9 and is turned on the belt 9.

As explained above, the endless belts 2 to 13 and the nip rollers 27 and 28 that constitute the sheet circulation conveyance system
The image recording section 40, the image reading section 50, and the erasing section 7
Related to the operation of 0! The sheet 30 is conveyed or placed under the LJ control (this can be done by employing a known sequence control).

By the way, as mentioned above, when radiographing a bone region or the like, for example, it may be desirable to arrange the stimulable phosphor sheet as close to the subject 43 as possible. Therefore, as shown in FIG. 2, a cassette 91 containing a sheet 90 similar to the sheet 30 is placed at the imaging position on the imaging table 41, the subject 43 is placed on top of the cassette 91, and the radiation source 42 is placed on top of the cassette 91. When the light is turned on, the patient 4 will be placed on the sheet 90 of the cassette 91.
Three transmission radiographic images are stored and recorded, and the above requirements are met. The image of the sheet 90 in the cassette 91 in which radiographic image information has been stored and recorded is read using another device exclusively for reading information from both parties.

Prior to radiography using the cassette 91 as described above, the shutter 101 is activated by the drive motor 10.
2, it moves from the retracted position to the right in the figure, overlaps the sheet 30 placed on the endless belt 2 at the photographing position, and reaches a shielding position that prevents the sheet 30 from being irradiated with radiation. Positioned. This drive motor 1
02 are controlled by manual operation buttons 80 and 81, and these buttons can be operated from the outside to control the shutter 101.
indicates the direction of movement. When the manual operation button 80 is pressed, the drive motor 102 is activated to move the shutter 10.
1 moves the shutter guide 103 from the shelter position to the shielding position.
When the manual operation button 81 is pressed, the shutter 101 returns from the shielding position to the retracted position. The manual operation button 80, 81, drive motor 102, and shutter guide 103 constitute operating means for the shutter 101.

When performing imaging using the cassette 91 in this manner, the shutter 101 moves to the shielding position within the radiation irradiation field and covers the sheet 30 in the normal position (imaging position), so that radiation does not pass through the cassette 91. Even if transmitted, the sheet 30 is not exposed by this transmitted radiation. When radiography using the cassette 91 is completed, the manual operation button 81 is pressed to drive the drive motor 102 and return the shutter 101 to the sheltered position out of the radiation irradiation field.

In addition to the cassette 91 containing the stimulable phosphor sheet 90 as described above, it is also possible to perform radiography using a cassette containing conventional X-ray photographic film.
In that case, the shutter 101 may be moved to the shielding position in exactly the same manner.

(Effects of the Invention) The radiation image information recording/reading device of the present invention has the above-mentioned implementation 1s.
As is clear from Mr. B's explanation, the stimulable phosphor moves cyclically through the photographing, reading, and erasing sections.
Since the sheet can be used repeatedly and has a compact overall structure, it is extremely advantageous in practice. Furthermore, the apparatus of the present invention can perform radiography on a stimulable phosphor sheet stored in a cassette or an X-ray photographic film, etc., without wasting exposure on a stimulable phosphor sheet that is used repeatedly. The radiation image information recording function is expanded by eliminating the need for the troublesome operation of circulating the sheets and sending them to the erasing section, and the range of practical use thereof is greatly expanded.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an embodiment of a radiation image information recording/reading device according to the present invention, and FIG. 2 is a partial schematic diagram showing the state of the embodiment device when a cassette is used for imaging. 1... Radiographic image information reading device 2-13... Endless belt 14-20... Guide rollers 21-26... Guide plate 27.28... Nip roller 30.90... Accumulative fluorescence Body sheet 40... Image recording section 41... Photographing stand 42...
・Radiation source 43... Subject (subject) 50.
... Image reading section 52 ... Laser light 51 ... Laser light source 53.55.56.57 ... Mirror 54 ... Galvanometer mirror 58 ... Condensing optical element 59 ... Photomultiple 70
...Erasing section 72...Erasing light source 80.81
...Manual operation button 101...Shutter 102...Drive motor 1
03...Shatta guide

Claims (1)

[Scope of Claims] Circulating conveyance means for conveying at least one stimulable phosphor sheet capable of accumulating and recording radiographic images along a predetermined circulation path; an image recording section that accumulates and records a radiographic image of a subject on the sheet by irradiating it with radiation; and an excitation light that is located in the circulation path and scans the sheet on which the radiographic image has been accumulated and recorded in the image recording section. an image reading unit having an excitation light source that emits light, and a photoelectric reading unit that reads stimulated luminescence light emitted from a sheet scanned by the excitation light to obtain an image signal; after the image is read in the image reading unit; an erasing section that releases residual radiation energy on the sheet before an image is recorded on the sheet; an erasing section that is provided above the sheet of the image recording section and has a size that covers the sheet; a shutter that is movable between a shielding position that is within the irradiation field and prevents radiation from being irradiated to the sheet, and a retracted position that is outside the radiation irradiation field and allows radiation to be irradiated to the sheet; A radiographic image information recording/reading device comprising: a shutter operating means for moving the shutter between the shielding position and the retreat position by an external operation.