JP2005241985A - Radiation image conversion panel and radiation image reader using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correctly correct image information with an extremely simple constitution by eliminating the need for a system which manages correspondence relation between a radiation image conversion panel and its correction information. <P>SOLUTION: An stimulable phosphor sheet IP is provided with an IC chip 31 which holds correction information and while the correction information is read by a correction information recording part 33, radiation image information recorded on the stimulable phosphor sheet IP is read by a read unit 38, and the obtained radiation image information is corrected with the correction information read out of the IC chip 31 to generate proper radiation image information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radiation image conversion panel that converts irradiated radiation into image information and a radiation image reading apparatus using the radiation image conversion panel.

  For example, radiation image information of a subject such as a human body is temporarily recorded on a recording medium using a storage phosphor, and the radiation image information is reproduced on a photosensitive material such as a photographic film or output as a visible image to a display device. A system for making it known is known.

  The stimulable phosphor accumulates a part of this radiation energy when irradiated with radiation, and then outputs stimulated emission light according to the accumulated radiation energy when irradiated with excitation light such as visible light or laser light. It is a phosphor. Since the radiation energy accumulated in the stimulable phosphor is removed by irradiating the erasing light, radiation image information can be repeatedly recorded on the stimulable phosphor panel, which is a recording medium using this. .

  By the way, it is very difficult to uniformly apply or form the stimulable phosphor on the support. Therefore, for example, even if radiation having a uniform dose is irradiated on the entire surface of the stimulable phosphor panel, uniform image information may not be obtained. Further, when the stimulable phosphor panel is repeatedly used, there is a possibility that a partial decrease in sensitivity is caused including the influence of damage and the like.

  Therefore, in order to solve such a problem, for example, by uniformly irradiating the stimulable phosphor panel with radiation, a so-called solid image is recorded, then the image information is read, and the image defect information and its position are read. The information is extracted and stored in the image defect detection device, the radiographic image information of the subject is recorded on the stimulable phosphor panel, and the radiographic image information is read and stored in the image defect detection device. There is a conventional technique in which correction is performed according to image defect information and position information (see Patent Documents 1 and 2).

JP-A-10-282596 JP-A-10-328174

  However, in the above-described prior art, the image defect information and its position information are held in the image defect detection device independently of the stimulable phosphor panel. There is a need for a system that manages the correspondence between panels and their image defect information.

  The present invention has been made to solve the above-described problems, and eliminates the need for a system for managing the correspondence between the radiation image conversion panel and its correction information, and corrects image information correctly with a very simple configuration. An object of the present invention is to provide a radiation image conversion panel capable of performing the above and a radiation image reading apparatus using the same.

  According to the present invention, the correction information of the radiation image conversion panel is held in the correction information holding means provided in the panel, so that the image information read from the radiation image conversion panel can be corrected correctly using the correction information. (Invention of claim 1)

  In this case, the radiation image conversion panel has a stimulable phosphor layer, stores image information by irradiating radiation, reads the image information by irradiating excitation light, and irradiates erasing light. Thus, a stimulable phosphor panel from which the image information is erased can be applied (the invention according to claim 2).

  In addition, as the correction information holding means, for example, a correction information storage element that can read and record correction information in a non-contact state, such as an IC tag represented by RFID (Radio Frequency identification), is applied. (Invention of claim 3).

  Further, as the correction information holding means, a magnetic tape capable of reading and recording the correction information can be applied (the invention according to claim 4).

  The correction information holding means can hold sensitivity correction data for correcting the sensitivity of the radiation image conversion panel or shading correction data for correcting shading as correction information (inventions according to claims 5 and 6).

  Furthermore, the present invention provides a radiological image reading apparatus that reads image information from a radiographic image conversion panel, reads correction information from correction information holding means held in the radiographic image conversion panel by correction information reading means, and uses image information reading means. Corrected image information can be obtained by reading the image information from the radiation image conversion panel and correcting the image information based on the correction information by the correction processing means (the invention according to claim 7). .

  Further, based on the image information read from the supplied radiation image conversion panel, correction information is created by the correction information creation means, and the correction information is recorded in the correction information holding means of the radiation image conversion panel by the correction information recording means. Thus, the radiation image conversion panel can be associated with the correction information in the radiation image reading apparatus (the invention according to claim 8).

  Furthermore, as a radiation image conversion panel, it has a stimulable phosphor layer, accumulates image information by irradiating radiation, reads the image information by irradiating excitation light, and irradiates erasing light. When the stimulable phosphor panel from which the image information is erased is applied, an erasing unit is disposed in the radiation image reading device, and the radiation energy remaining in the radiation image conversion panel from which the image information has been read is used. By erasing, the stimulable phosphor panel can be reused (the invention according to claim 9).

  According to the present invention, by providing correction information holding means for holding correction information in the radiation image conversion panel, a system for managing the correspondence relationship between the radiation image conversion panel and the correction information is not required, and it is extremely simple. Desired image information can be obtained by correcting image information correctly with the configuration.

  FIG. 1 is a configuration diagram of a radiation image reading apparatus 10 of the present embodiment. The radiographic image reading apparatus 10 includes a cassette loading unit 14 in an upper portion of a casing 12, and stores a stimulable phosphor sheet IP (radiation image conversion panel) in which radiographic image information is accumulated and recorded in the cassette loading unit 14. The cassette 18 is loaded.

  As shown in FIG. 2, the cassette 18 includes a main body portion 24 that stores the stimulable phosphor sheet IP, and a lid member 28 that can be opened and closed with respect to the main body portion 24, from the opening portion 26 of the lid member 28. The storage phosphor sheet IP is configured to enter and exit.

  The stimulable phosphor sheet IP is composed of a flexible panel, and the IC chip 31 (RFID) that stores correction information (to be described later) or the like is stored in a portion that does not affect the recorded radiographic image information. Correction information holding means and correction information storage element) are mounted. In this case, if the member made of a heavy element such as lead is disposed on the side of the IC chip 31 where the radiation is irradiated or the cassette 18 corresponding to the part, the stimulable phosphor sheet IP is irradiated with the radiation. In this case, it is possible to reliably avoid the situation where the correction information stored in the IC chip 31 is destroyed.

  The stimulable phosphor sheet IP is formed by vapor-depositing a columnar stimulable phosphor layer on a support substrate made of a hard material such as glass, when the conveyance path in the radiation image reading apparatus 10 can be configured in a straight line. It can also be a rigid panel. Further, when the specific stimulable phosphor sheet IP and the specific cassette 18 always correspond, the IC chip 31 may be mounted on the cassette 18 side.

  In the vicinity of the lid member 28 of the cassette 18 loaded from the cassette loading unit 14 of the radiation image reading apparatus 10, the suction plate 20 sucks and extracts the stimulable phosphor sheet IP from the cassette 18 with the lid member 28 opened. And a nip roller 22 for sandwiching and conveying the stimulable phosphor sheet IP taken out by the suction disk 20 are disposed.

  A correction information reading / recording unit 33 (correction information) that reads correction information and records correction information with respect to the IC chip 31 mounted on the stimulable phosphor sheet IP is provided at a portion facing the lid member 28. Reading means, correction information recording means). In this case, the correction information is, for example, sensitivity correction data for correcting sensitivity deterioration of the stimulable phosphor sheet IP due to repeated use, sensitivity deterioration due to partial damage, etc., application of the stimulable phosphor It includes shading correction data for correcting sensitivity unevenness caused by unevenness. The correction information can be stored in the IC chip 31 together with the position information on the stimulable phosphor sheet IP.

  A curved conveyance path 34 having a plurality of conveyance rollers 30a to 30h and a plurality of guide plates 32a to 32i is formed continuously with the nip roller 22. The conveyance path 34 conveys the stimulable phosphor sheet IP supplied from the cassette 18 to a desired part.

  A scanning unit 36 that emits a laser beam B, which is excitation light, and scans the stimulable phosphor sheet IP is disposed in the lower central portion inside the casing 12. The scanning unit 36 includes a laser oscillator 37 that outputs a laser beam B, a polygon mirror 39 that is a rotary polygon mirror that deflects and scans the laser beam B, and a reflection that reflects the laser beam B and guides it to the storage phosphor sheet IP. A mirror 41 is provided. Although not shown, a condensing optical system for condensing the laser beam B on the stimulable phosphor sheet IP is also provided as appropriate.

  The laser beam B emitted from the scanning unit 36 is applied to the stimulable phosphor sheet IP from between the transport rollers 30d and 30e constituting the transport path 34. Further, a reading unit 38 (image information reading means) is disposed in the vicinity of the scanning unit 36. The reading unit 38 has one end connected to the stimulable phosphor sheet IP between the conveying rollers 30d and 30e and the other end of the light collecting guide 40, and is connected to the other end of the condensing phosphor 40. The photomultiplier 42 converts the stimulated emission light obtained from the sheet IP into an electric signal. In the present embodiment, the photomultiplier 42 has a long shape in a direction orthogonal to the conveyance direction of the stimulable phosphor sheet IP, but may have another shape.

  Between the nip roller 22 and the conveyance roller 30a constituting the conveyance path 34, an erasing unit 46 (erasing means) for removing radiation energy remaining on the stimulable phosphor sheet IP from which the radiation image information has been read is disposed. The The erasing unit 46 has a plurality of erasing light sources 48 composed of halogen lamps or the like.

  FIG. 3 shows the configuration of the control circuit of the radiation image reading apparatus 10. A control unit 50 that performs overall control of the radiographic image reading apparatus 10 is attached to the touch panel 52 for operating the radiographic image reading apparatus 10 or displaying its operation state and the stimulable phosphor sheet IP. Correction information reading / recording section 33 for reading and recording correction information to / from IC chip 31, reading unit 38 for reading radiation image information recorded on the stimulable phosphor sheet IP, and correction information based on the radiation image information Are connected to a correction information generating unit 54 for generating the radiation image information, a correction processing unit 56 for correcting the radiation image information according to the correction information, and an erasing unit 46 for erasing the radiation energy remaining in the stimulable phosphor sheet IP.

  The radiation image reading apparatus 10 of the present embodiment is basically configured as described above, and the operation thereof will be described next.

  First, the process of creating correction information will be described based on the flowchart shown in FIG.

  A uniform image (solid image) is recorded by uniformly irradiating the stimulable phosphor sheet IP with radiation without interposing a subject (step S1).

  Next, the cassette 18 containing the stimulable phosphor sheet IP on which the uniform image is recorded is loaded into the cassette loading unit 14 of the radiation image reading apparatus 10 (step S2). In this case, a mode for creating correction information is selected using the touch panel 52.

  When the cassette 18 is loaded, a lid opening mechanism (not shown) is driven, and the lid member 28 is opened in the radiation image reading apparatus 10. Next, the suction disk 20 sucks the stimulable phosphor sheet IP in the cassette 18 and supplies it to the nip roller 22. The nip roller 22 supplies the stimulable phosphor sheet IP to the conveyance path 34. The conveyance path 34 drives the conveyance rollers 30a to 30h and conveys the stimulable phosphor sheet IP along the guide plates 32a to 32i.

  The stimulable phosphor sheet IP is sub-scanned and conveyed between the conveyance rollers 30d and 30e, and the stimulable fluorescence is emitted in the main scanning direction in which the laser beam B, which is excitation light emitted from the scanning unit 36, is orthogonal to the sub-scanning direction. The body sheet IP is scanned. That is, the laser beam B output from the laser oscillator 37 is reflected and deflected by the polygon mirror 39 that rotates at high speed, and then guided to the storage phosphor sheet IP through the reflection mirror 41.

  The stimulable phosphor sheet IP irradiated with the laser beam B outputs stimulated emission light corresponding to the stored and recorded radiation image information. This stimulated emission light is guided to a photomultiplier 42 that constitutes the reading unit 38 via a light collecting guide 40 that is arranged close to the stimulable phosphor sheet IP in the main scanning direction, and is converted into an electrical signal. (Step S3).

  The correction information generation unit 54 performs correction information generation processing based on the radiation image information converted into the electrical signal (step S4). In this case, the radiographic image information is recorded by uniformly irradiating the stimulable phosphor sheet IP with radiation. However, a part of the stimulable phosphor sheet IP is damaged or accumulated. If there is uneven application of the fluorescent material, sensitivity deterioration with time, etc., sensitivity unevenness, shading, or sensitivity fluctuations occur. Therefore, the correction information creation unit 54 creates correction information that can be corrected to obtain uniform radiation image information with a predetermined sensitivity in association with position information on the stimulable phosphor sheet IP.

  On the other hand, the stimulable phosphor sheet IP from which the radiation image information has been read is conveyed to the conveying roller 30h side, and then conveyed in reverse by the conveying path 34, and the erasing unit 46 disposed between the nip roller 22 and the conveying roller 30a is removed. Through the cassette 18. At this time, the erasing light source 48 that constitutes the erasing unit 46 is turned on, and the erasing light that is output is irradiated onto the stimulable phosphor sheet IP, thereby removing the remaining radiation energy.

  When the stimulable phosphor sheet IP is stored in the cassette 18, the correction information reading / recording section 33 is activated, and the correction information created by the correction information creating section 54 is recorded on the IC chip 31 together with the position information ( Step S5).

  The cassette 18 containing the stimulable phosphor sheet IP from which the radiation energy is removed and the correction information is recorded on the IC chip 31 is discharged from the radiation image reading apparatus 10 (step S6), and then the desired radiation image information is stored. Used for shooting.

  Next, a desired radiographic image information reading process will be described based on the flowchart shown in FIG.

  The stimulable phosphor sheet IP on which the correction information is recorded is irradiated with radiation through the subject to record the subject image on the stimulable phosphor sheet IP (step S11).

  Next, the cassette 18 containing the stimulable phosphor sheet IP is loaded into the cassette loading unit 14 of the radiation image reading apparatus 10 (step S12). In this case, a mode for performing a normal reading process is selected using the touch panel 52.

  When the cassette 18 is loaded, the correction information reading / recording unit 33 is energized and the correction information recorded on the IC chip 31 of the stimulable phosphor sheet IP is read (step S13).

  Next, the lid member 28 is opened, and the suction disk 20 sucks the stimulable phosphor sheet IP and supplies it to the conveyance path 34 by the nip roller 22. The stimulable phosphor sheet IP is sub-scanned and transported between the transport rollers 30d and 30e disposed in the transport path 34, and is subjected to main scanning with the laser beam B from the scanning unit 36, and the resulting photostimulated light emission is obtained. Is read two-dimensionally as radiation image information by the reading unit 38 (step S14).

  Therefore, the correction processing unit 56 corrects the read radiation image information according to the correction information acquired in step S13 and its position information, and generates radiation image information in which sensitivity, shading, and the like are corrected (step S15).

  In this case, the correction information for correcting the radiation image information is correction information read from the IC chip 31 of the stimulable phosphor sheet IP, and there is no possibility that correction information of other stimulable phosphor sheets IP is mixed. Correct correction processing can be performed. In addition, since it is not necessary to manage the correspondence between the stimulable phosphor sheet IP and the correction information, the system configuration can be extremely simplified.

  On the other hand, in the stimulable phosphor sheet IP from which the radiation image information has been read, the residual radiation energy is removed by the erasing light output from the erasing light source 48 that constitutes the erasing unit 46 (step S16). It is stored and discharged to the outside (step S17).

  In the above-described embodiment, the correction information is recorded on the IC chip 31 such as an RFID. However, a magnetic tape is attached to the stimulable phosphor sheet IP instead of the IC chip 31, and correction is performed on the magnetic tape. It can also be configured to record and read information. The correction information may be recorded on the IC chip 31 or the magnetic tape of the stimulable phosphor sheet IP using a device other than the radiation image reading device 10.

  Furthermore, the correction information does not necessarily need to be stored in association with the position information of the stimulable phosphor sheet IP. That is, for example, as shown in FIG. 6, from the stimulable phosphor sheet IP, an image region G1 in which radiation image information is recorded and a non-image region G2 in which no radiation image information is recorded can be discriminated and read. In this case, correction information including the edge portions e1 and e2 is created and stored, and when arbitrary radiation image information is read from the stimulable phosphor sheet IP, the edge portions e1 and e2 of the correction information and the edge of the radiation image information By collating the parts e1 and e2, the radiation image information correction process can be performed without holding the position information.

It is a block diagram of a radiographic image reading apparatus. It is composition explanatory drawing of the storage fluorescent substance sheet and cassette which are loaded into a radiographic image reading apparatus. It is a control circuit block diagram of a radiographic image reading apparatus. It is a flowchart which produces correction information. It is a flowchart of a reading process and a correction process of radiation image information. It is explanatory drawing of the relationship between correction information and the image area | region of a stimulable phosphor sheet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Radiation image reading device 18 ... Cassette 33 ... Correction information reading recording part 36 ... Scanning unit 38 ... Reading unit 46 ... Erase unit 54 ... Correction information creation part 56 ... Correction processing part IP ... Storage phosphor sheet

Claims (9)

In a radiation image conversion panel that converts irradiated radiation into image information,
A radiation image conversion panel comprising correction information holding means for holding correction information for the image information read from the panel. The radiation image conversion panel according to claim 1,
The panel has a stimulable phosphor layer, accumulates image information by irradiating radiation, reads the image information by irradiating excitation light, and irradiates erasing light to retrieve the image information. A radiation image conversion panel comprising a stimulable phosphor panel to be erased. In the radiation image conversion panel according to claim 1 or 2,
The radiological image conversion panel, wherein the correction information holding unit includes a correction information storage element capable of reading and recording the correction information in a non-contact state. In the radiation image conversion panel according to claim 1 or 2,
The radiographic image conversion panel, wherein the correction information holding means is a magnetic tape capable of reading and recording the correction information. In the radiation image conversion panel according to claim 1 or 2,
The radiation image conversion panel, wherein the correction information is sensitivity correction data of the panel. In the radiation image conversion panel according to claim 1 or 2,
The radiation image conversion panel according to claim 1, wherein the correction information is shading correction data of the panel. In a radiation image reading apparatus that reads image information from a radiation image conversion panel,
Correction information reading means for reading correction information for the image information read from the radiation image conversion panel from correction information holding means held in the radiation image conversion panel;
Image information reading means for reading the image information from the radiation image conversion panel;
Correction processing means for correcting the image information based on the correction information;
A radiation image reading apparatus comprising: The radiographic image reading apparatus according to claim 7.
Correction information creating means for creating the correction information based on the image information read by the image information reading means;
A radiographic image reading apparatus comprising correction information recording means for recording the created correction information in the correction information holding means. The radiographic image reading apparatus according to claim 7 or 8,
The radiation image conversion panel has a stimulable phosphor layer, accumulates image information by irradiating radiation, reads the image information by irradiating excitation light, and irradiates erasing light to irradiate the image. It consists of a stimulable phosphor panel from which image information is erased,
The apparatus includes a erasing unit that irradiates the storable phosphor panel with the erasing light.

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