JP2010011972A - Radiographic image diagnostic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiographic image diagnostic system capable of acquiring a timing of exchange and issuing a warning based on a quality difference between a first recording sheet for recording low-energy radiographic image information and a second recording sheet for recording high-energy radiographic image information in energy subtraction. <P>SOLUTION: This radiographic image diagnostic system sets the usable number of times T1 of the first recording sheet and the usable number of times T2 of the second recording sheet, which is larger than T1, acquires sheet type information of the respective recording sheets, and is provided with a usable number-of-times counting section for counting the usable number of times, and a warning processing section warming an operator to stop the use of the recording sheet when the counted used number of times of the recording sheets exceeds the usable numbers of times of the respective types. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a recording sheet management technique in a radiation diagnostic system that reads radiation image information from two recording sheets photographed by low-energy radiation and high-energy radiation and performs diagnosis by energy subtraction, and more particularly Relates to a radiological image diagnostic system capable of preventing erroneous diagnosis due to continuous use of a deteriorated recording sheet.

  Conventionally, when radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.) is irradiated, a part of this radiation energy is accumulated, and then it is accumulated when irradiated with excitation light such as visible light. Using a stimulable phosphor (stimulable phosphor) that emits the amount of stimulated emission light corresponding to the energy, a radiation image of a subject such as a human body is once photographed and recorded on a sheet-like stimulable phosphor, This stimulable phosphor sheet (recording sheet) is scanned with excitation light such as laser light to generate stimulated emission light, and the resulting stimulated emission light is photoelectrically read to obtain an image signal. Based on the above, there is known a radiation imaging system that outputs a radiation image of a subject as a visible image on a recording material such as a photographic material, a CRT, or the like.

Further, in the radiation imaging system using the recording sheet such as the stimulable phosphor sheet, a plurality of image signals are obtained by reading a plurality of radiation images recorded on the recording sheet, and then a radiation image is obtained based on these image signals. Subtraction processing may be performed.
Radiation image subtraction processing refers to processing for obtaining an image corresponding to the difference between a plurality of radiation images taken under different conditions. Specifically, the plurality of radiation images are read at a predetermined sampling interval. Based on a plurality of digital image signals corresponding to each radiographic image, by applying a subtraction process for each corresponding sampling point of the plurality of digital image signals, only a specific subject portion in the radiographic image is emphasized or The process for obtaining the extracted radiation image.

As one of such subtraction processes, an energy subtraction process is known that takes a difference between radiation images of radiations of different energies.
The principle of the energy subtraction process is that a specific part of a subject has different radiation absorption rates with respect to radiation having different energy components. An image is obtained, and a plurality of radiation images are appropriately weighted to obtain a difference between them, that is, a specific portion of the subject is extracted by subtraction.

In addition, as energy subtraction, there is a method called one-shot energy subtraction.
This is an image based on radiations having different energy distributions on each recording sheet by irradiating two recording sheets with an energy separating plate (filter) or the like that changes energy distribution between the recording sheets once. By recording information and taking the difference between these two pieces of radiation image information, energy subtraction processing is performed, and there is very little displacement of the subject image between the two pieces of image information.

  As one system that realizes the one-shot method, for example, two recording sheets that are overlapped with an energy separation filter that absorbs a low energy component of radiation interposed therebetween are arranged at a position facing the subject, The radiation image information (low energy radiation image information) recorded on the first recording sheet on the side close to the subject due to radiation having a relatively low energy component The radiation image information (high energy radiation image information) recorded on the second recording sheet on the side far from the subject is obtained by the radiation having a relatively high energy component that has passed through the energy separation filter, and the two radiation image information is obtained. By generating difference information after reading at a predetermined reading density, energy subtraction processing is performed. You have me.

  For radiographic imaging using energy subtraction processing, for example, in Patent Document 1, reference is made to past information including cumulative exposure amount of a subject, generation of past images, and the like to observe changes over time in an affected area. Is it possible to use either temporal subtraction imaging that generates difference information from two images taken with time difference or dual energy imaging that is 2-shot energy subtraction imaging that obtains a differential image of only soft tissue or bone by the difference? An X-ray diagnostic apparatus has been proposed that determines whether or not to select an optimal imaging method.

  Further, in Patent Document 2, as history information of time-lapse subtraction images, information specifying two original images as a basis, information such as creation date, patient ID, imaging region, imaging position, etc. are stored in a database, and later There has been proposed an inter-image calculation method that can be efficiently output and used when necessary.

In general, a recording sheet deteriorates as it is used. Therefore, when the deterioration has progressed to some extent, it is necessary to take measures such as replacement.
Therefore, in Patent Document 3, in order to predict the deterioration of the characteristics of the recording sheet in advance, there is a method of counting the number of times the recording sheet is used and giving a warning when the predetermined number of times is reached to notify the necessity of cleaning or replacement. It is disclosed. Further, Patent Document 4 discloses that the count value is weighted according to a preset condition based on the identification information of the recording sheet and the like when counting the number of times of use.

JP 2004-105643 A JP 2001-218110 A JP 2006-223703 A JP 2006-280737 A

  Here, the low-energy radiation image generated by reading the low-energy radiation image information on the first recording sheet is an image used in normal image diagnosis, while the high-energy radiation is recorded on the second recording sheet. High energy radiation images generated by reading radiation image information are generally used only for subtraction processing. Therefore, when an abnormal part is recognized in the diagnostic image, there is a problem that it is difficult to determine whether the abnormality is caused by a disease in the body of the subject or deterioration of the recording sheet. . In particular, since the radiographic image information recorded on the second recording sheet is not used for diagnosis, there is a problem that it is difficult to detect even if the deterioration progresses.

However, as described above, in Patent Documents 1 and 2, no consideration is given to the deterioration of the recording sheet due to scratches or damage, and the guarantee against them.
Further, although Patent Documents 3 and 4 disclose that the number of times of use is counted and a warning is given to notify the necessity of cleaning or replacement, it is disclosed that there is an abnormality in the photographed image. It is impossible to determine whether it is caused by scratches on the recording sheet or caused by a disease, and this problem cannot be dealt with.

  Therefore, in view of the above circumstances, the present invention estimates whether an abnormal part displayed on an image is a scratch on a recording sheet or a patient's disease in an image obtained by using energy subtraction processing. Another object of the present invention is to provide a radiological image diagnosis system that can prevent the continuous use of a deteriorated recording sheet and can take a radiographic image using an appropriate recording sheet.

  In order to achieve the above object, the present invention records a first recording sheet on which low-energy radiation image information photographed with low-energy radiation is recorded and high-energy radiation image information photographed with high-energy radiation. In a radiographic image diagnostic system that reads radiographic image information from each of the second recording sheets and generates a diagnostic image based on these, an identification information acquisition unit that acquires type information and identification information of each recording sheet; A storage unit that stores the number of times of use durability of each recording sheet that is defined in advance according to the type information, and a use number counting unit that counts the number of times of use of each recording sheet for each identification information of each recording sheet; A warning processing unit that issues a warning when the number of use times of each recording sheet reaches the number of use durability times; The type information of each recording sheet includes at least two for the first recording sheet and the second recording sheet, and the usage durability count for the second recording sheet is the first recording sheet. Provided is a radiographic image diagnosis system characterized in that the radiographic image diagnosis system is set to a value smaller than the use durability count for a recording sheet.

  In the present invention, when the recording sheet identification information is read, the usage count counting unit counts the number of times each recording sheet is used by accumulating the number of readings for each recording sheet identification information. Is preferred.

  Further, each recording sheet preferably includes a storage device that stores its own type information and identification information.

  In addition, it is preferable that the usage count unit counts the usage count of each recording sheet when performing radiography or reading a radiographic image from the recording sheet.

Further, the warning is preferably performed by voice or screen display.
Each recording sheet is preferably made of a stimulable phosphor.

  According to the present invention, in consideration of the difference in properties in use between the first recording sheet (low energy radiation image recording) and the second recording sheet (high energy radiation image recording) in the energy subtraction process, By making the use durability count for the recording sheet less than the use durability count for the first recording sheet, it is possible to prevent the second recording sheet from being used continuously until the deterioration is extremely advanced.

The radiation image diagnostic system of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.
The radiological image diagnosis system of the present invention reads a radiographic image capturing apparatus 10 for capturing a radiographic image shown in FIG. 1 and an image captured by the radiographic image capturing apparatus 10 shown in FIG. A radiation image reading device 30 for performing various processing and image output.

FIG. 1 is a perspective view of an embodiment illustrating a configuration of a radiographic image capturing apparatus 10.
In FIG. 1, a radiographic imaging apparatus 10 (hereinafter referred to as an imaging apparatus 10) irradiates a subject A with radiation emitted from a radiation source and transmits transmitted radiation of the subject A to a stimulable phosphor sheet (hereinafter referred to as a recording sheet). To record.

  The imaging apparatus 10 includes an X-ray source 12, a first filter 14, a first recording sheet 22, a second filter 24, and a second recording sheet 26.

The first recording sheet 22 and the second recording sheet 26 are made of a storage phosphor. The recording sheets 22 and 26 are provided with recording sheet identification information that is an ID unique to each recording sheet, and each recording sheet is read by reading the recording sheet identification information in the radiation image reading device 30 described later. Management of information about.
The identification information of each recording sheet is recorded on a part of the sheet, for example, and is read by an identification information reading unit 38 to be described later. In the present embodiment, as an example, a barcode is given to the recording sheet, and the identification information of each recording sheet is acquired by reading the barcode with the identification information reading unit 38 included in the radiation image reading device 30. Good.

  In this configuration, the X-ray a0 emitted from the X-ray source 12 passes through the first filter 14, and the subject A is irradiated by the X-ray a1 that has passed through the first filter 14.

  The X-ray a2 that has passed through the subject A is irradiated onto the first recording sheet 22, and a part of the energy of the X-ray a2 is accumulated in the first recording sheet 22, thereby causing the subject to be recorded on the first recording sheet 22. The X-ray image of A is accumulated and recorded.

  The X-ray a3 that has passed through the first recording sheet 22 further passes through the second filter 24, and the X-ray a4 that has passed through the second filter 24 is irradiated onto the second recording sheet. As a result, the X-ray image of the subject A is also accumulated and recorded on the second recording sheet 26.

  2A shows the energy distribution of the X-ray a0 immediately after being emitted from the X-ray source 12, and FIG. 2B shows the energy distribution of the X-ray a1 after passing through the first filter 14. Show. In these figures, the horizontal axis represents X-ray energy (kev), and the vertical axis represents the number of photons having each energy (relative value).

  The X-ray a immediately after being emitted from the X-ray source 12 is substantially continuous except for some peaks as shown in FIG. 2A, and is distributed in the range of 15 kev to 80 kev in this embodiment. .

  The first filter 14 is, for example, a 0.2 mm thick filter made of Sn, and has a K-edge in which the X-ray absorptance changes rapidly at 30 kev. For this reason, the X-ray a1 transmitted through the first filter 14 has a spectrum separated into an X-ray a1 ′ in the low energy region R1 and an X-ray a1 ″ in the high energy region R2. The subject A is irradiated with the X-ray a1 thus separated.

The stimulable phosphor forming the first recording sheet 22 is made of, for example, BaFBr: Eu ²⁺ and has a layer thickness of 150 μm. In the first recording sheet 22, X-ray a 1 ′ in the low energy region R 1 is absorbed, among X-rays a 1 transmitted through the first filter 14. Accordingly, the first X-ray image by the X-rays in which the ratio of the X-rays a1 ′ of the low energy region R1 of the subject A is considerably high is accumulated and recorded on the first recording sheet 22.

  The second filter 24 is, for example, a 0.5 mm thick filter made of Cu, which cuts the X-ray a1 ′ in the low energy region R1 and passes the X-ray a1 ″ in the high energy region R2.

  The X-ray a3 transmitted through the first recording sheet 22 includes some X-rays in the low energy region R1 transmitted without being absorbed by the first recording sheet 22. Therefore, by transmitting through the second filter 24, the X-ray a4 transmitted through the second filter 24 is substantially only the X-ray in the high energy region R2.

The stimulable phosphor that forms the second recording sheet 26 is made of, for example, BaFBr: Eu ²⁺ , similar to the stimulable phosphor that forms the first recording sheet, but the layer thickness is doubled to 300 μm. is there. Since the layer is thus thickened, the X-ray a4 composed of the X-ray a1 ″ in the high energy region R2 that has passed through the second filter 24 is sufficiently absorbed by the second recording sheet. Therefore, the second X-ray image accumulated and recorded on the second recording sheet 26 is an X-ray image by X-rays of the high energy region R2 of the subject.

  In this way, the energy is sufficiently separated by the first filter 14 and the second filter 24, and the first and second X-rays a1 ′ in the low energy region R1 and the X-rays a1 ″ in the high energy region R2 The second X-ray images are accumulated and recorded on the first recording sheet 22 and the second recording sheet 26, respectively.

  In the above example, the first filter 14 is used. However, when the first filter 14 is not used, the energy of the X-ray a0 (= a1 ′) and the X-ray a4 ′ transmitted through the second filter 24 is used. The distribution is as shown in FIG. 3, and the separation of low energy and high energy is worsened, so it is preferable to provide the first filter 14. In the above description, the first recording sheet and the second recording sheet have been described as having different thicknesses. However, by using the same configuration including the thickness, one recording sheet can be used as the first recording sheet. And the second recording sheet.

  FIG. 4 is a perspective view of an embodiment showing a configuration of a radiological image reading apparatus included in the radiological image diagnostic system of the present invention. The radiographic image reading apparatus 30 (hereinafter referred to as the reading apparatus 30) shown in the figure is substantially orthogonal to the main direction X while irradiating the recording sheet with excitation light and scanning in the main scanning direction (main direction) X. The image is transported in the sub-scanning direction (sub-direction) Y, scanned two-dimensionally, and the radiation image recorded on the recording sheet is read. The reading device 30 includes a main scanning optical unit 32, a sub-scanning transport unit 34, a stimulating light detection unit 36, an identification information reading unit 38, an image storage unit 40, an image processing unit 42, and an image display. A unit 44, a usage count unit 46, and a warning processing unit 48 are included.

  The main scanning optical unit 32 is a part that polarizes the excitation light in the main direction X and scans the recording sheet. The main scanning optical unit 32 includes a laser light source 50 that emits laser light as excitation light, a polygon mirror 52 that is an optical deflector, a scanning lens group 54 that includes an fθ lens, an optical path changing mirror 56, And an optical mirror 58. These components are arranged in this order along the traveling direction of the laser beam.

  The sub-scanning conveyance unit 34 is a part on which a recording sheet is placed and conveyed in a sub-direction Y that is substantially perpendicular to the main direction X. In the case of the illustrated example, a belt conveyor is used as the sub-scanning conveyance unit 34. The belt conveyor includes an endless belt 60 and two rollers 62 and 64 disposed in the endless belt 60 so as to stretch the endless belt 60. The endless belt is moved in the sub-direction Y by rotating the rollers 62 and 64.

  The stimulated emission light detection unit 36 is a part that receives the stimulated emission light emitted from the recording sheet when irradiated with excitation light, and photoelectrically converts it to an electrical signal. The stimulating light detection unit 36 includes a condensing guide 66, a photomultiplier (PMT) 68 that photoelectrically converts the stimulating light, and an A / D converter 70.

  The light collecting guide 66 is made by molding a light guide material. The condensing guide 66 is disposed at a position facing the condensing mirror 58 so that the incident end face of the stimulated emission light extends along the main direction X, and is provided on the condensing end face (exit end face) of the stimulated emission light. The light receiving surface of the PMT 68 is coupled. An electrical signal (analog voltage) output from the PMT 68 is supplied to the A / D converter 70 and converted into digital data. In this way, the recording sheet is read, and radiation image data is obtained.

  The identification information reading unit 38 reads the barcode 22a (26a) previously given to the recording sheet 22 (26) as recording sheet identification information unique to each recording sheet, and acquires the barcode information. The acquired recording sheet identification information is transmitted to the usage count counting unit 46.

  The image storage unit 40 stores the first image signal and the second image signal which are image signals of the first recording sheet 22 and the second recording sheet 26 converted into digital data by the A / D converter 70. To do.

  The image processing unit 42 calculates a difference image of a radiographic image by X-rays carried by each image signal based on the first and second image signals. At this time, the difference image is generated with substantially the same resolution as the radiation image based on the first image signal. For this reason, the difference image has a high resolution. The calculated difference image is displayed on the image display unit 44 as a diagnostic image and used for diagnosis. The method for calculating the difference image will be described in detail later.

The usage count section 46 (hereinafter referred to as the count section 46) counts the number of times the recording sheet is used.
The count unit 46 correlates with each recording sheet identification information, sheet type information indicating whether the recording sheet is the first recording sheet or the second recording sheet, and the number of times the recording sheet is used according to each sheet type information. And a count value, which is the number of times the recording sheet is used, is stored.
Based on the recording sheet identification information received from the identification information reading unit 38, the counting unit 46 counts the number of times the identification information of a certain recording sheet has been received. Further, when the count value reaches the use endurance number set in advance by the counting unit 46, the warning processing unit 48 is instructed to execute the warning process.

  The warning processing unit 48 performs warning processing for the user so as to replace the recording sheet in response to an instruction from the counting unit 46.

  Next, the operation of the reading device 30 will be described. In the present embodiment, first, the first recording sheet 22 is read, and then the second recording sheet 26 is read.

  The laser light emitted from the laser light source 50 enters the polygon mirror 52 and is reflected while being polarized in the main direction X according to the rotation of the polygon mirror 52. Subsequently, the focus of the laser beam is adjusted so as to be focused on the recording sheet by the scanning lens group 54, and the optical path is changed (reflected) by the optical path changing mirror 56 so as to be directed to the recording sheet, and irradiated onto the recording sheet. Is done.

  On the other hand, the first recording sheet 22 placed on the belt conveyor is conveyed in the sub-direction Y at a constant speed. That is, the first recording sheet 22 is scanned two-dimensionally by being sub-scanned by the sub-scanning conveyance unit 34 while being main-scanned by the main-scanning optical unit 32.

  When the first recording sheet 22 is irradiated with a laser beam, the first recording sheet 22 emits a stimulated emission light having a light amount corresponding to the radiation energy accumulated therein. This stimulated emission light is incident directly on the entrance of the condensing guide 66 or reflected by the condensing mirror 58 and enters the entrance of the condensing guide 66, and the PMT (photoelectric conversion circuit) 68 is collected by the condensing guide 66. Is propagated to. Thereafter, the photostimulated emission light is photoelectrically converted by the PMT 68 and converted to radiation image data (analog voltage).

  The radiation image data is converted into digital data corresponding to the analog voltage by the A / D converter 70, supplied to the image storage unit 40, and stored. As a result, a first radiation image SO1 is obtained from the first recording sheet 22.

  In addition, simultaneously with the process of obtaining the first radiation image SO1 by the above-described method, the identification information reading unit 38 reads and reads the barcode 22a that is the recording sheet identification information provided on the first recording sheet 22. The recording sheet identification information (barcode information) is transmitted to the counting unit 46.

  The count unit 46 stores the number of times of receiving identification information of a certain recording sheet. That is, when the recording sheet identification information of the first image signal SO1 is received, the count information indicating how many times the same recording sheet identification information has been received in the past is searched. Then, the value of the stored count information is increased by 1.

  When the processing of the first recording sheet 22 is completed, the second recording sheet 26 is subsequently set in the reading device 30, and the same processing as in the case of the first recording sheet is performed, and the second image signal SO2 is converted into an image. While being stored in the storage unit 40, the identification information reading unit 38 reads the recording sheet identification information of the second recording sheet 26 and transmits it to the counting unit 46. The counting unit 46 increments the value of the corresponding count information by 1 based on the received recording sheet identification information.

Thus, the first image signal SO1 and the second image signal SO2 stored in the image storage unit 40 corresponding to each recording sheet are read from the image storage unit 40 and input to the image processing unit 42. Is done. In the image processing unit 42, based on the input first image signal SO1 and second image signal SO2, the sampling points corresponding to each other of the two image signals SO1 and SO2 are
S1 = Wa.SO1-Wb.SO2 + C
(Wa and Wb are weighting factors, and C is a bias)
According to the weighting subtraction, that is, the subtraction process, whereby the first radiation image by the low energy X-ray and the second by the high energy X-ray carried by the first image signal SO1 and the second image signal SO2, respectively. An image signal S1 corresponding to the difference image from the radiation image is generated.

At this time, the image signals S1 and S2 are used in a high-resolution state before image processing such as scratch removal, and a difference image is generated. Therefore, the resolution of the difference image is the first image signal. This is substantially the same as the radiation image made of SO1. Thereby, a high-resolution difference image can be obtained. When the difference image has a high resolution, the deterioration of the second recording sheet is easily displayed as an image, so that a higher effect can be obtained in the present invention.
The generated image signal S1 is transmitted to the image display unit 44, and a visible image (energy subtraction image) based on the image signal S1 is displayed as a radiographic image for use in diagnosis.

  In order to determine whether each recording sheet is a first recording sheet on which low-energy radiation is recorded or a second recording sheet on which high-energy radiation is recorded, a radiographic image is taken together with the radiographic image. Information indicating whether the radiation at that time is low-energy radiation or high-energy radiation is stored in association with the recording sheet identification information of the recording sheet, and may be automatically acquired, an operator, etc. However, you may make it acquire by inputting the information which shows whether the radiation at the time of imaging | photography of a radiographic image is a low energy radiation or a high energy radiation.

Next, management of the number of uses will be described.
In FIG. 4, the recording sheet identification information acquired by reading the barcode 22 a (26 a), which is the recording sheet identification information provided on each recording sheet, by the identification information reading unit 38 is sent to the counting unit 46. The counting unit 46 counts the number of readings for each recording sheet identification information. That is, the number of times each recording sheet identification information is read corresponds to the number of times each recording sheet is used. That is, when a certain recording sheet identification information is read for the first time, the recording sheet identification information and the count value 1 are associated with each other and stored in the counting unit 46. If certain recording sheet identification information is already registered, the count value corresponding to the recording sheet identification information is updated by +1.

  The above description is an example in which the barcode is read from the recording sheet at the timing of reading the radiographic image information from the recording sheet, the acquired recording sheet identification information is transmitted to the counting unit 46, and the number of uses is counted. The invention is not limited to this, and the recording sheet identification information may be read at the time of radiography, or used for each recording sheet by transmitting the recording sheet identification information directly input from the operator to the counting unit 46. The number of times may be counted.

In the count unit 46, as described above, the use durability count for each type information of the recording sheet is registered in advance. As the recording sheet type information, at least after the first recording sheet arranged in front of the second filter 24 and recording the first X-ray image by the X-ray in the low energy region, and the second filter 24. It includes two second recording sheets that are arranged and record a second X-ray image by X-rays in a high energy region.
In this embodiment, the usage durability count of the first recording sheet is T1, and the usage durability count of the second recording sheet is T2.

  As described above, the radiation image information (high energy radiation image information) recorded on the second recording sheet is generally used only for the subtraction process and is not directly displayed. In the present invention, in view of the situation that even if there is an abnormality in the subtraction image, it is not known whether the subtraction image is caused by a scratch on the second recording sheet or a disease. Considering the possibility that the sheet has progressed in a state where deterioration cannot be seen, the use durability count T2 of the second recording sheet is made smaller than the first use durability count T1, which is the normal durability count. That is, T2 <T1.

  Based on the recording sheet identification information received from the identification information reading unit 38, the count unit 46 searches the count value C that is the type information of the recording sheet, the number of times of use durability, and the number of times of use of the recording sheet. C is compared with the use durability count T1 or T2 according to the type information.

First, when the type information of the recording sheet is the first recording sheet, the use durability count T1 is compared with the count value C. When C ≧ T1, the count unit 46 instructs the warning processing unit 48 to warn that the usage durability has been exceeded and the recording sheet may be deteriorated.
The warning processing unit 48 issues a warning to the user according to the instruction. The warning may be performed by, for example, outputting a warning sentence such as “Replace the first recording sheet with a new one” or outputting it on a monitor or the like.
If C <T1, it is assumed that the recording sheet can be used continuously, and no warning is given.

Similarly, when the recording sheet type information is the second recording sheet, the use durability count T2 is compared with the count value C. If C ≧ T2, the count unit 46 instructs the warning processing unit 48 to warn that the usage durability has been exceeded and the recording sheet may be deteriorated.
The warning processing unit 48 issues a warning to the user according to the instruction. The warning may be performed, for example, by outputting a warning sentence such as “Replace the second recording sheet with a new one” or by outputting it on a monitor or the like.
On the other hand, if C <T2, it is considered that the recording sheet can be used continuously, so that no warning is given.

  The above example is an explanation in the case where the type of recording sheet for each recording sheet is determined as the recording sheet for the first recording sheet or the recording sheet for the second recording sheet. The invention is not limited to this, and can also be applied to the case where the same recording sheet is shared by the first recording sheet and the second recording sheet.

For example, when C <T2 is smaller, the recording sheet can be used as the first recording sheet or the second recording sheet.
In the case of T2 ≦ C <T1, the recording sheet can be used as the first recording sheet, but cannot be used as the second recording sheet. A warning such as “This recording sheet cannot be used any more as the second recording sheet. It can be used as the first recording sheet” is output.
Further, if T1 ≦ C, the recording sheet cannot be used as the second recording sheet or the first recording sheet, and a warning such as “Please replace with a new recording sheet” is given. Should be output.

As described above, by setting different usage durability numbers for the first and second recording sheets depending on the type, it is possible to prevent the use of each recording sheet beyond the usable number of times. Therefore, a good diagnostic image can be obtained without generating noise such as scratches due to deterioration of the recording sheet when the diagnostic image is generated.
Further, the type of the recording sheet is not limited to the first and second recording sheets, but may be set as appropriate according to the material and size of the recording sheet. In this case, the usage durability is set according to each type.

  In this embodiment, the number of times the recording sheet is used is counted and stored by the counting unit 46. However, the present invention is not limited to this, and the recording sheet and its cassette have a built-in memory. And it is good also as a structure which records the use frequency of each recording sheet in this memory.

  The radiation image diagnostic system of the present invention has been described in detail above. However, the present invention is not limited to the above-described various embodiments, and various improvements and modifications may be made without departing from the gist of the present invention. Of course.

It is the schematic which shows the structure of the radiographic imaging apparatus in the radiographic image diagnosis system which concerns on this invention. 2A is a diagram showing an X-ray energy distribution immediately after being emitted from a radiation source, and FIG. 2B is a diagram showing an X-ray energy distribution after passing through the first filter. . It is a figure which shows the X-ray energy distribution on the 1st recording sheet when there is no 1st filter, and the X-ray energy distribution which permeate | transmitted the 2nd filter. It is the schematic which shows the structure of the radiographic image reading apparatus in the radiographic image diagnostic system which concerns on this invention.

Explanation of symbols

10 Radiation imaging equipment 12 Radiation source (X-ray source)
DESCRIPTION OF SYMBOLS 14 1st filter 22 1st recording sheet 24 2nd filter 26 2nd recording sheet 30 Radiation image reading apparatus 32 Main scanning optical part 34 Sub-scanning conveyance part 36 Detection part of stimulating emitted light 38 Identification information reading part DESCRIPTION OF SYMBOLS 40 Image memory | storage part 42 Image processing part 44 Image display part 46 Use frequency count part 48 Warning processing part 50 Laser light source 52 Polygon mirror 54 Scanning lens group 56 Optical path changing mirror 58 Condensing mirror 60 Endless belt 62, 64 Roller 66 Condensing Guide 68 Photomultiplier (PMT)
70 A / D converter

Claims (6)

Radiation images from each of the first recording sheet on which low-energy radiation image information photographed by low-energy radiation is recorded and the second recording sheet on which high-energy radiation image information photographed by high-energy radiation is recorded In a radiological image diagnostic system that reads information and generates a diagnostic image based on the information,
An identification information acquisition unit for acquiring type information and identification information of each recording sheet;
A storage unit that stores the number of times of use durability of each recording sheet defined in advance according to the type information;
For each identification information of each recording sheet, a usage number counting unit that counts the number of times each recording sheet is used,
A warning processing unit that issues a warning when the number of times of use of each recording sheet reaches the number of times of use durability,
The type information of each recording sheet includes at least two for the first recording sheet and for the second recording sheet,
The radiation image diagnostic system according to claim 1, wherein the usage durability count for the second recording sheet is set to a value smaller than the usage durability count for the first recording sheet.   The radiographic image according to claim 1, wherein when the recording sheet identification information is read, the usage count counting unit counts the number of times each recording sheet is used by accumulating the number of readings for each recording sheet identification information. Diagnostic system.   The radiographic image diagnosis system according to claim 1, wherein each recording sheet includes a storage device that stores its type information and identification information.   The radiographic image diagnosis system according to any one of claims 1 to 3, wherein the usage count section counts the usage count of each recording sheet when performing radiography or reading a radiographic image from the recording sheet. .   The radiological image diagnosis system according to claim 1, wherein the warning is performed by voice or screen display.   The radiographic image diagnosis system according to claim 1, wherein each recording sheet is made of a stimulable phosphor.

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