JPH0680456B2 - 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, see JP-A-59-192240).

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, it is desirable to further improve the diagnostic performance by performing appropriate image processing on the image signal obtained by the image reading unit. The image processing includes, for example, various kinds of contrast adjustment, density level adjustment, image gradation processing, frequency processing,
It means any kind of possible image processing, such as non-sharp mask processing, which enhances the diagnostic performance depending on the imaging part, or image subtraction.

The above image processing conditions are the imaging site (head, chest, etc.) of the subject, imaging method (simple imaging, contrast imaging, tomography, etc.), diagnostic purpose (whether bone ridge morphology is inspected). , The type of radiography that consists of checking the running state of blood vessels, etc.) and the radiation source tube voltage, tube current, irradiation time, focus size, etc. It is determined according to "irradiation conditions".

As a method for setting the image processing conditions to the optimum conditions, instead of directly determining each condition from the type of imaging and the irradiation condition, a stimulable phosphor sheet in which radiation image information of a subject is stored and recorded is used. Scanning with excitation 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 electric image signal. Also scan the sheet with low-level excitation light, read ahead to read the outline of the radiation image information stored and recorded on this sheet from the stimulated emission light emitted by this scanning, and the radiation image obtained by this read-ahead It is said that image processing conditions for performing predetermined image processing on the electrical image signal obtained by the main reading are determined based on information. The law has been adopted from the conventional. 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-described problems, and eliminates the need to perform prefetching as in the related art and sets the processing conditions at the time of image processing 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 scanned sheet and a photoelectric reading unit that reads the stimulated emission light emitted from the sheet scanned by the excitation light to obtain an image signal; An image processing unit that is connected to a photoelectric reading unit of the image processing unit and performs image processing on the image signal; and in the circulation passage, the image reading unit performs image reading. An erasing unit that releases the residual radiation energy on this sheet prior to image recording on the subsequent sheet, input means for inputting information on the type of imaging and the irradiation conditions of the radiation, and input by the input means It is characterized by further comprising control means for determining an image processing condition in the image processing section based on the determined information and controlling the operation of the image processing section according to the determined image processing condition.

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

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 device according to the first 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 the 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 the completion of reading It has a minute space 66. An image processing unit 8 is connected to the photoelectric reading unit 63 of the image reading unit 6, and the image signal transmitted from the photoelectric reading unit 63 is subjected to image processing in the image processing unit 8.

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 condition setting unit 9 is provided at a position that can be operated from outside the device of the present invention. This condition setting unit 9 is an input board 9A
The imaged region of the subject (whether head or chest, etc.), imaging method (simple or contrast imaging, or tomography, etc.), diagnostic purpose (whether bone ridge morphology is examined, blood vessel running state) The keyboard 9a (see FIG. 2), which is an input means for inputting information regarding the type of radiography, such as whether to inspect), and the tube voltage, tube current, and radiation of the radiation source 10 set according to the type of radiography. An adjustment dial that is an input means for inputting information about irradiation conditions such as irradiation time and focus size.
It has 9b. Further, the condition setting unit 9 directly controls the radiation source 10 on the basis of the information regarding the irradiation condition input by the input unit 9b.
9c, and the reading conditions in the image reading unit 6 and / or the image processing conditions in the image processing unit 8 are set to optimum conditions based on the information on the type of photography and the irradiation conditions input by the input means 9a and 9b. A condition setting memory 9B, a reading controller 9D, and an image processing controller 9E are provided for this purpose. The function of the condition setting unit 9 will be described with reference to the block diagram of FIG.

By selecting the keyboard 9a provided on the input board 9A and adjusting the adjustment dial 9b, information regarding the type of photography and irradiation conditions is input to the condition setting unit 9. The information on the irradiation conditions is first sent directly to the radiation controller 9c, and a radiation irradiation condition setting signal 9c is issued from the radiation controller 9C based on the sent information and sent to the radiation source 10. 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 in which the reading condition and the image processing condition are stored in advance for each type of photographing and irradiation condition. The condition setting memory 9B outputs an image processing condition setting signal 9e via the image processing controller 9E and a reading condition setting signal 9d via the reading controller 9D based on the respective input information, and is inputted. Appropriate image processing conditions and / or reading conditions based on this information are set in the image processing unit 8 and / or the image reading unit 6, respectively.

In determining the reading conditions, it is not always necessary to determine all the reading conditions based on the input information regarding the type of photography and the irradiation conditions, 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.

By the way, in the embodiment described above, the information on the type of photographing and the information on the irradiation condition are independently input, but the irradiation condition can be automatically determined depending on the type of photographing, and the input operation can be performed. It is also possible to determine the image processing condition and the reading condition by inputting only the information regarding the type of photographing. That is, an irradiation condition setting memory that stores the irradiation condition for each type of image capturing may be provided in the control unit, and the image processing condition and the reading condition may be set based on the signal emitted from the irradiation condition setting memory.

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

Next, another embodiment of the present invention will be described with reference to FIG.

This device is exactly the same as the above-described device in the mechanism of repeatedly carrying out recording and reading of image information by cyclically carrying the sheet to the photographing section 5, the image reading section 6, the erasing section 7 and the like by the circulation carrying means, and is therefore the same. The same numbers are given to the parts and the description thereof is omitted.

The photoelectric reading unit 63 of the image reading unit 6 is connected to an image processing unit (image processing device) 18 provided outside the device. Further, the type of imaging and the irradiation condition of radiation are input to a position operable from the outside of the recording and reading device, and the reading condition in the image reading unit 6 and / or the image outside the device are input based on the input information. A condition setting unit 9 that determines an image processing condition in the processing unit 18 is provided. The details of the condition setting unit 9 are completely the same as those in the first embodiment described above, and are omitted here. Needless to say, the image processing unit 18 may be arranged at any position within a range controllable by the condition setting unit 9 provided in the apparatus body. Of course, the condition setting unit 9 may be separated from the apparatus main body and provided at another position, as described in the first embodiment.

(Effects of the Invention) As described in detail above, according to the apparatus of the present invention, the reading condition and / or the image processing condition selects an imaging type from a large number, and the radiation irradiation condition is set to the imaging type. Since it is set by a simple operation to adjust according to
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 at the time of group medical examination. 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, FIG. 4 is a schematic view showing another embodiment of the device according to the present invention. 1 ... Circulation passage, 2 ... Storage phosphor sheet 3 ... Circulation conveyance passage, 5 ... Image recording unit, 6 ... Image reading unit, 7 ... Erase unit, 8 ... Image processing unit, 9 ... … Condition setting section 9A …… Input board, 9B …… Condition setting memory 9D …… Read controller 9E …… Image processing controller 18 …… Image processing device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masamitsu Ishida 798, Miyadai, Kaisei-cho, Ashigaragami-gun, Kanagawa Fuji Photo Film Co., Ltd. (56) Reference JP-A-58-66934 (JP, A) JP-A-59 -165047 (JP, A) JP-A-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. Image reading unit having an excitation light source for emitting excitation light and a photoelectric reading unit for reading the stimulated emission light emitted from the sheet scanned by the excitation light to obtain an image signal, and a photoelectric reading unit of the image reading unit An image processing unit that is connected to the image processing unit for performing image processing on the image signal, and records an image on a sheet in the circulation passage after the image is read by the image reading unit. Prior to being performed, an erasing unit that releases the residual radiation energy on this sheet, an input unit for inputting information on the type of imaging and the irradiation conditions of the radiation, and an imaging type input by the input unit. A control means for determining an image processing condition in the image processing unit on the basis of information regarding a radiation irradiation condition and controlling the operation of the image processing unit according to the determined image processing condition. Radiation image information recording / reading device.