JPH0680457B2 - Radiation image information recording / reading device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention accumulates and records radiation image information on a stimulable phosphor sheet, and then irradiates this with excitation light to produce a bright image according to the accumulated and recorded image information. A radiation image information recording / reading device which detects exhausted light, converts image information into an electric signal by reading, and further performs image processing on the electric signal, if necessary.
More specifically, the present invention relates to a radiation image information recording / reading device in which a stimulable phosphor sheet is circulated and reused in the device.

(Technical Background of the Invention and Prior Art) When a certain type of fluorescent material is irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.), part of the energy of this radiation is When the fluorescent substance is accumulated in the fluorescent substance and then the fluorescent substance is irradiated with excitation light such as visible light, the fluorescent substance emits stimulated emission according to the accumulated energy. A phosphor exhibiting such a property is called a stimulable phosphor.

Using this stimulable phosphor, the radiation image information of a subject such as a human body is once recorded on a sheet of the stimulable phosphor, and this is scanned with excitation light to cause stimulated emission, and this stimulated emission light is used. A radiation image information recording / reproducing method has been proposed in which an image signal is photoelectrically read to obtain an image signal, and the image signal is processed to obtain a radiation image of a subject having good diagnostic suitability (for example, Japanese Patent Laid-Open No. 55-
No. 12429, No. 56-11395, No. 55-163472, No. 56-1046
No. 45, No. 55-116340 etc.). In this method, the final image may be reproduced as a hard copy or may be reproduced on a display such as a CRT.
In such a radiation image information recording / reproducing method, the stimulable phosphor sheet does not finally record the image information, but temporarily stores the image information in order to give the image to the final recording medium as described above. Since it is carried, the stimulable phosphor sheet may be repeatedly used, and if it is repeatedly used as such, it is extremely economical.

Further, for example, a mobile station such as an X-ray radiograph vehicle is equipped with a radiation image information recording / reading device using a stimulable phosphor sheet, and travels to various places for group medical examination to take X-ray images. In this case, it is inconvenient to load a large number of accumulative phosphor sheets on a vehicle, and the number of sheets that can be loaded on a moving vehicle is limited. Therefore, a stimulable phosphor sheet is repeatedly used so that it is mounted on a moving vehicle, radiation image information for each subject is recorded on it, and the image signal obtained by reading it is stored in a storage capacity of a magnetic tape or the like. If it is copied on a large recording medium and the accumulative phosphor sheet is circulated and reused, a radiation image of a large number of objects can be taken by a moving vehicle, which is extremely useful in practice. Furthermore, if the continuous imaging is performed by this cyclic reuse, the imaging speed can be increased in the group medical examination, and the practical effect is extremely large.

Incidentally, in order to reuse the stimulable phosphor sheet as described above, the radiation energy remaining in the stimulable phosphor sheet after the stimulated emission light is read is determined by, for example, JP-A-56-1139.
No. 2, 56-12599, and the residual radiographic image is erased by the method described in JP-A No. 56-12599, and the stimulable phosphor sheet is used again for recording the radiographic image.

Based on the above-mentioned viewpoint, the applicant of the present invention has a circulatory conveying means for conveying a stimulable phosphor sheet capable of accumulating and recording a radiation image along a predetermined circulation passage, and a circulation object in the circulation passage through a subject in the sheet. An image recording unit that accumulates and records radiation image information of a subject on this sheet by irradiating with radiation, and an excitation that scans the sheet in the circulation passage where the radiation image information is accumulated and recorded in the image recording unit. An image reading unit having an excitation light source that emits light, a photoelectric reading unit that obtains an image signal by reading the stimulated emission light emitted from the sheet scanned by the excitation light, the circulation path, and the image Before the image recording is performed on the sheet after the image reading is performed by the reading unit, the erasing unit that releases the residual radiation energy on the sheet is provided as one device. A radiation image information recording / reading device (hereinafter, referred to as a built-in type device) in which the above-mentioned stimulable phosphor sheet is circulated between the above-mentioned parts and repeatedly used by being incorporated into Wish sho 58-6673
No. 0).

By the way, since the radiation image information recording / reproducing system using the above-mentioned device is usually used for medical diagnosis of the human body, etc., in this system, a visible image excellent in observation / interpretation suitability suitable for the purpose of diagnosis is obtained. Is required. In this case, what kind of visible image is suitable for the purpose, for example, what kind of output density level or range of density level, and if contrast is suitable for diagnosis, depends on each purpose. .

Therefore, in order to obtain a more preferable visible image, when reading the radiation image information recorded on the sheet in the image reading unit, an image signal capable of outputting a visible image more suitable for the purpose of diagnosis is used. In order to obtain it, it is desirable to read according to the reading condition according to the purpose.

The above-mentioned reading conditions are the imaging region of the subject (head or chest, etc.), imaging method (simple imaging, contrast imaging, tomography, etc.), diagnostic purpose (whether bone ridge morphology is inspected, blood vessel Radiation irradiation conditions such as tube voltage, tube current, irradiation time, and focus size of the radiation source, which are set and adjusted in consideration of the "type of imaging" (for example, whether to inspect the running state) and this type of imaging. It is decided according to.

As a method for setting the processing conditions to the optimum conditions, instead of directly determining each condition from the type of imaging and irradiation conditions, excitation of a stimulable phosphor sheet in which radiation image information of a subject is stored and recorded Scanning with light, the stimulated emission light emitted from the sheet by this scanning is read by photoelectric reading means according to predetermined reading conditions to obtain an electrical image signal, prior to the main reading, than the excitation light used for this main reading in advance. The sheet is scanned by low-level excitation light, pre-reading is performed to read out the outline of the radiation image information accumulated and recorded on this sheet from the stimulated emission light emitted by this scanning, and the radiation image information obtained by this pre-reading A method of determining the reading condition based on the above has been conventionally used. However, this method requires a total of two readings, the pre-reading and the main reading, and it takes a long time to read, especially when a large number of examinees such as a group examination requiring high speed are targeted. Has the problem of being inefficient. Further, even when pre-reading, the excitation light irradiates the sheet, so that the consumption of the excitation light source is accelerated, and the sheet itself is frequently irradiated with the excitation light, so that the number of times of use is reduced.

(Object of the Invention) The present invention has been made in view of the above problems, and eliminates the need to perform pre-reading as in the related art, and sets a reading condition when reading image information by a simple operation. It is an object of the present invention to provide a built-in type device having a mechanism that enables the above.

(Structure of the Invention) A built-in type apparatus according to the present invention is a circulation conveyance means for conveying a stimulable phosphor sheet capable of accumulating and recording radiation image information along a predetermined circulation passage, and the circulation passage to the circulation passage. An image recording unit that accumulates and records the radiation image information of the subject on the sheet by irradiating the sheet with radiation through the subject, and the radiation image information is accumulated and recorded in the image recording unit in the circulation passage. An image reading unit having an excitation light source that emits excitation light for scanning the formed sheet, and a photoelectric reading unit that obtains an image signal by reading the stimulated emission light emitted from the sheet scanned by the excitation light; Therefore, before the image is recorded on the sheet after the image is read in the image reading section, the residual radiation energy on this sheet is changed. An erasing unit to be emitted, an input unit for inputting information on the type of imaging and the irradiation condition of the radiation, a reading condition in the image reading unit is determined based on the information input by the input unit, and the determination is made. It is characterized in that it comprises a reading condition setting unit comprising a control means for controlling the operation of the image reading unit according to the reading condition.

It should be noted that the type of imaging means the imaging site, the imaging method, the diagnostic purpose, etc. as described above, and the radiation imaging condition means the tube voltage, tube current, irradiation time, focus size, etc. of the radiation source.

The reading condition setting section determines input conditions such as a keyboard for inputting the type of imaging and radiation irradiation conditions, and the reading conditions based on various information input by the input device, and an image is read via a reading controller or the like. And a control unit for outputting the reading condition to the reading unit. Specifically, for example, the control unit determines a reading condition based on various kinds of input information, and therefore, a storage unit such as a condition setting memory that stores the various conditions and the reading condition in association with each other. And a controller for inputting the set conditions to the image reading unit.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing an embodiment of the apparatus according to the present invention.

As shown in the figure, this apparatus has an L-shaped circulation passage 1, and the stimulable phosphor sheet 2 is circulated and conveyed on the circulation passage 1 by a circulation conveyance means 3 such as a conveyance roller or a conveyance belt.

An image recording unit (imaging unit) 5, an image reading unit 6, and an erasing unit 7 are sequentially arranged on the circulation passage 1 in the sheet advancing direction (direction of arrow A).

In the imaging unit 5, the radiation emitted from the radiation source 10 passes through the subject 11 and enters the sheet 2, whereby the radiation image information of the subject is accumulated and recorded on the sheet 2.

The photographed sheet is conveyed in the direction of arrow A by the circulation conveyance means 3 such as a driving roller and a conveyance belt along the circulation path, and enters the image reading unit 6.

The image reading unit 6 reads an excitation light source 62 that emits excitation light 61 such as a laser beam that scans the sheet 2, and a photomultiplier that reads the stimulated emission light emitted from the sheet 2 by scanning the excitation light to obtain an electrical image signal. And the photoelectric reading unit 63. 64 is a galvanometer mirror. Since the image reading unit 6 performs reading while advancing the sheet 2 at a constant speed, the space 65 for one sheet where the sheet 2 is located immediately before the start of reading and the sheet 65 where the sheet 2 is located immediately after completion of reading It has a minute space 66.

The read sheet 2 is erased by the circulatory conveying means 3 to be erased by
Sent to.

The erasing unit 7 has a erasing light source such as a fluorescent lamp, a tungsten lamp, a sodium lamp, a xenon lamp, and an iodine lamp.
A large number of 71 are provided, and the sheet 2 is irradiated with visible light from the erasing light source 71 to release the residual radiation energy on the sheet.

The erased sheet is sent to the photographing section 5 again by the circulating / conveying means 3.

A reading condition setting unit 9 is provided at a position that can be operated from outside the apparatus of the present invention. This reading condition setting unit 9
On the input board 9A, the imaging site of the subject (head or chest, etc.), imaging method (simple imaging, contrast imaging, tomography, etc.), diagnostic purpose (whether the bone crest morphology is inspected or not) A keyboard 9a (see FIG. 2), which is an input means for inputting information regarding the type of radiography, such as whether or not the traveling state is inspected, and the tube voltage and tube current of the radiation source 10 set according to the type of radiography. An adjusting dial 9b is provided as an input means for inputting information regarding irradiation conditions such as radiation irradiation time and focus size. Further, the reading condition setting unit 9 includes a radiation controller 9C that directly controls the radiation source 10 based on the information regarding the irradiation condition input by the input unit 9b, and the imaging input by the input units 9a and 9b. A reading condition setting memory 9B and a reading controller 9D for setting the reading condition in the image reading unit 6 to the optimum condition based on the information on the type and the irradiation condition. The function of the reading condition setting unit 9 will be described with reference to the block diagram of FIG.

By selecting the keyboard 9a and adjusting the adjustment dial 9b provided on the input board 9A, information regarding the type of photography and the irradiation conditions is input to the reading condition setting unit 9. The information on the irradiation conditions is first sent directly to the radiation controller 9C, and the radiation irradiation condition setting signal 9c is issued based on the information sent from the radiation controller 9C and the radiation source 10
Sent to. According to this signal 9c, radiation is irradiated from the radiation source 10 under the conditions that match the irradiation conditions input.

On the other hand, the information on the type of photographing and the irradiation condition is sent to the condition setting memory 9B which stores the reading condition for each type of photographing and irradiation condition in advance. The condition setting memory 9B outputs a reading condition setting signal 9d via the reading controller 9D based on each input information, and an appropriate reading condition based on the input information is set in the image reading unit 6. It

When determining the reading conditions, it is not always necessary to determine the photographing of all the reading conditions based on the input information regarding the type and the irradiation condition, and only some important reading conditions may be determined. Such reading conditions include, for example, a reading gain and a scale coefficient. The reading gain is a parameter indicating the left and right positions of the line indicating the reading condition in FIG. 3, and is the output signal at what level the input signal of a predetermined level (for example, a predetermined stimulated emission light amount) input to the reading means. It regulates whether or not it is output as (image signal). The scale factor is a parameter indicating the slope of the line indicating the reading condition in FIG. 3, and regulates the relationship between the level range of the input signal input to the reading means and the level range of the output signal. It is a thing.

The reading condition setting unit 9 does not necessarily have to be provided in the apparatus body, but may be installed in, for example, an operation room so that only the reading condition setting signal is transmitted to the apparatus body and the radiation source.

(Effects of the Invention) As described in detail above, according to the apparatus of the present invention, the reading condition is selected from a large number of types of imaging, and the irradiation condition of radiation is easily adjusted according to the type of imaging. Since it is set by a simple operation, there is no need to perform pre-reading as in the conventional case, the time required for recording and reading is shortened, and a great effect is exerted particularly in group medical examinations. Further, the consumption of the excitation light is reduced, and the amount of the sheet that is irradiated with the excitation light in one circulation is reduced, so that the life of the sheet is increased.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the apparatus according to the present invention, FIG. 2 is a block diagram for explaining the function of the control unit in the above embodiment, and FIG. 3 is a graph showing an example of reading conditions. is there. 1 ... Circulation path, 2 ... Storage fluorescent sheet 3 ... Circulation conveyance path, 5 ... Image recording section 6 ... Image reading section, 7 ... Erase section 9 ... Reading condition setting section 9A .... Input board 9B …… Reading condition setting memory 9D …… Reading controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masamitsu Ishida 798 Miyadai, Kaisei-cho, Ashigarashie-gun, Kanagawa Fuji Photo Film Co., Ltd. (56) References JP-A-61-95341 (JP, A) JP-A-58 -66934 (JP, A) JP 59-165047 (JP, A) JP 57-19700 (JP, A)

Claims (1)

[Claims] 1. Circulating and conveying means for circulating and conveying a plurality of stimulable phosphor sheets capable of accumulating and recording radiation image information independently of each other along a predetermined circulation passage, wherein the sheet is provided in the circulation passage. An image recording unit that accumulates and records the radiation image information of the subject on this sheet by irradiating the subject with radiation, and scans a sheet in the circulation passage where the radiation image information is accumulated and recorded in the image recording unit. An excitation light source that emits excitation light, and an image reading unit having a photoelectric reading unit that obtains an image signal by reading the stimulated emission light emitted from the sheet scanned by this excitation light, in the circulation passage, Before the image is recorded on the sheet after the image is read by the image reading unit, the erasing unit that releases the residual radiation energy on the sheet, And an input means for inputting information on the type of imaging and the irradiation condition of the radiation, and a reading gain and a reading scale in the image reading unit based on the information on the type of imaging and the irradiation condition of the radiation input by the input means. A radiation image information recording / reading apparatus, comprising: a reading condition setting unit configured to determine a coefficient and control the operation of the image reading unit according to the determined reading gain and reading scale coefficient.