JP2002248095A - X-ray digital photographing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the handling convenience of a user when a plurality of electronic cassettes are used and to reduce the power consumption of an X-ray digital photographing instrument itself while optimally performing various controls between a control part and a sensor part. SOLUTION: A cassette box 43 capable of housing a plurality of electronic cassettes 48 is provided and a detection means for detecting that the electronic cassettes 48 are housed is provided to the cassette box 43. Based on whether the electronic cassettes 48 are housed in the cassette box 43, various operation controls such as the control of a power supply, the control of photographing preparing operation, the control of the transfer of image data, or the like, of the electronic cassettes 48 are optimally performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray digital photographing apparatus using a solid-state imaging unit.

[0002]

2. Description of the Related Art For radiography for medical diagnosis, a film / screen system combining an intensifying screen and an X-ray photographic film is often used. According to this method,
The X-rays that have passed through the subject contain internal information of the subject, which is converted into visible light in proportion to the intensity of the X-rays by the intensifying screen to expose the X-ray photographic film and form an X-ray image on the film. Recently, X-ray digital photographing apparatuses that convert X-rays into visible light in proportion to the intensity of the X-rays using a phosphor, convert the converted signals into electric signals using a photoelectric conversion element, and further convert the digital signals into digital signals have begun to be used. I have. As this photoelectric conversion element, there is an element using amorphous silicon, and it is possible to form a sensor portion with a large screen, thinly and lightly.

[0003] Therefore, the X-ray sensor portion can be formed in a shape close to the cassette used in the conventional film screen system, and can be used by being moved to various places like the cassette. I have. By using this electronic cassette, it is possible to capture an image of a part that cannot be handled by only two types of sensor units for the chest and abdomen.

Here, a description will be given of a normal general imaging method using an X-ray digital imaging apparatus when these three types of sensors are used. FIG. 9 is a configuration diagram of an imaging system. In the imaging room 1, an X-ray generation unit 10 that emits X-rays to a patient S is provided, and a standing stand 11 is disposed in front of the X-ray generation unit 10. The sensor unit 1 is provided on the standing stand 11.
2 is provided, and is connected to a control unit in the operation room 2 via a cable 13. The solid-state imaging unit 14 in the sensor unit 12 is configured by being attached to the phosphor 15 and the photoelectric conversion unit 16.

Further, at a place relatively distant from the standing stand 11, there is provided a recumbent table 17 to which X-rays are emitted from the X-ray generator 10, and is attached to the surface of the table 17. The sensor unit 18 has a cable 19
Is connected to the sensor connection unit 20 via the. Electronic cassette 21 for use near the lying table 17
Are connected to the sensor connection unit 20 via a cable 22. Here, the cable 22 is usually made of a highly flexible metal or the like, and has a convenient structure because the X-ray technician frequently moves around in the vicinity of the supine table 17. Further, the cable 23 connecting the sensor connection section 20 and the operation room 2 is generally formed of an optical fiber or the like excellent in high-speed data transfer.

In the operation room 2, a control unit 25 connected to the X-ray generation unit 10, the sensor unit 12, the sensor connection unit 20, the X-ray irradiation unit 24 of the imaging room 1, and the control unit 25 are connected. A display unit 26 including a television monitor is arranged.

[0007] The X-ray technician first gives the patient S a radiographing room 1
Instructs appropriate positioning in front of the standing stand 11. When the X-ray technician returns to the operation room 2 and presses the X-ray exposure switch, the X-rays emitted from the X-ray generation unit 10 pass through the patient S and have internal information of the patient S, and the sensor unit 1
2 is incident. X-rays are emitted by the phosphor 15 of the solid-state imaging unit 14.
The X-ray image data converted into visible light proportional to the line and converted into an electric signal by the photoelectric conversion unit 16 is AD-converted, transferred as digital data to the control unit 25 of the operation room 2 via the cable 13, and displayed. It is displayed on the unit 26.

After the X-ray technician confirms that the radiographing has been performed normally on the display unit 26, he goes to the radiographing room 1 and selects the selection switch 27 which is a sensor selecting means attached to the side portion of the lying table 17. Is pressed to instruct the patient S to perform appropriate positioning for imaging on the lying table 17. The signal from the selection switch 27 is transferred to the control unit 25 via the sensor connection unit 20. After the positioning of the patient S is completed, the X-ray technician returns to the operation room 2 and performs X-ray imaging again. The X-rays enter the sensor unit 18 with the internal information of the patient S, and the image data is transferred to the control unit 25 in the same manner.

In this case, when it is desired to take an image of a part which is difficult to photograph with the sensor unit 18 attached to the supine table 17, for example, an ankle part, the supine table 1 is used.
The electronic cassette 21 is arranged near the front end of the camera 7 for photographing. When the X-ray technician presses the selection switch 28, imaging using the electronic cassette 21 becomes possible.

[0010]

As described above, it is expected that the electronic cassette 21 will be used more frequently due to its excellent portability in photographing an area where photographing is difficult. Further, it is possible to prepare an electronic cassette 21 having an optimum characteristic according to an imaging part or the like, so that a higher quality diagnostic image can be obtained. Therefore, it is expected that a plurality of electronic cassettes 21 will be used in one imaging room 1 more and more, and in such a case, the following problem occurs.

That is, the electronic cassette 2 having various characteristics
Since there are a plurality of the electronic cassettes 2, there is a problem with the storage location of the electronic cassette 21 and
There is a problem of identification such as whether to use 1 or not. Also,
The device itself has a problem that power consumption increases in proportion to the number of electronic cassettes 21 or a problem that control of photographing operation and image data transfer performed between the control unit 25 and the electronic cassette 21 becomes complicated. Occurs.

[0012] An object of the present invention is to solve such a problem, to improve the convenience of handling by a user when using a plurality of electronic cassettes, to reduce power consumption, and to further improve various kinds of electronic cassettes. An object of the present invention is to provide an X-ray digital imaging apparatus in which control is optimally performed.

[0013]

An X-ray digital imaging apparatus according to the present invention for achieving the above object has a solid-state imaging section sensitive to X-rays and has a cassette type electronic cassette which can be separated from the apparatus main body. A cassette storage box capable of storing a plurality of the electronic cassettes and having a control unit that controls the solid-state imaging unit, and a detection unit that detects that the electronic cassette is stored in the cassette storage box. It is characterized by having.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a configuration diagram of an imaging system according to an embodiment. An X-ray generator 41 is provided in the imaging room 31, and a standing stand 41 and a lying table 42 are provided in front of the X-ray generator 40 in two irradiation directions.
Is provided, and a cassette storage box 43 is disposed in a part of the photographing room 31.

A sensor unit 44 and a selection switch 45 are mounted on the front surface of the standing stand 41. The sensor unit 44 has a phosphor 46 for converting X-rays into visible light proportional to the intensity, and a visible light having a light intensity. And a detachable solid-state imaging unit as an electronic cassette 48. Also,
A sensor unit 50 having the same structure as the sensor unit 44 and a selection switch 51 are attached to the lower part of the recumbent table 42. Further, the cassette storage box 43 stores a plurality of electronic cassettes 48a to 48e having optimal characteristics according to a part to be photographed.

On the other hand, a control unit 52 and a display unit 53 connected to the control unit 52 are provided in the operation room 32.
The incoming and outgoing signals by the control unit 52 are wired, wireless, optical fiber 5
4, 55, 56, etc., the X-ray generator 4 of the imaging room 31
0, sensor units 44 and 50, and cassette storage box 43.

As described in the conventional example, the sensor section and the control section 52 are generally connected by a cable such as a metal or an optical fiber. However, especially the electronic cassette 4
In order to take advantage of the characteristics of the sensor unit having excellent portability as shown in FIG. 8, it is desirable that image data transfer or operation control be performed wirelessly without connecting the sensor unit and the control unit 52 with a cable. It is. In recent years, as a wireless interface technology that has attracted attention, there is a Bluetooth technology or an infrared technology. However, these data transmission speeds are currently limited to several Mbit / sec, and are not sufficient for transmitting medical image data of 100 Mbit or more.

Therefore, in the present embodiment, these wireless communication methods are used for command communication, photographing timing control, and transfer of preview images, which do not require high speed, and large capacity and high speed are required. The transfer of the detailed image for diagnosis (overall image) will be described as using a wired communication method using a cable such as an optical fiber.

Here, the preview image is a display for confirming the dose of X-rays and the blur and position of the photographed image.
It does not perform inspection or diagnosis on this image, but merely displays an outline of the result of imaging. The preview image is classified into a reduced image, a bit-compressed image, and the like according to a method of creating the preview image, and a method combining them can be performed.

The reduced image is an image created by so-called thinning transfer. For example, the reduction ratio is determined based on the ratio of all pixel data of the image pickup means to the minimum pixel data required for display as a display image. Can be determined. In other words, thinning control is performed at a ratio of one pixel to M pixels by means of a selector circuit or the like and sequentially transferred to the control unit, and a simple image display is performed based on this image data.

Here, "M" is determined as a value suitable for a displayable pixel of the monitor. For example, when the total number of pixels of the two-dimensional image sensor is 2688 × 2688 pixels and the monitor displayable pixels are 336 × 336 pixels, M = 8.
(M = 2688/336). Therefore, transfer to the display control unit can be performed at a ratio of one pixel to eight pixels, so that the transfer rate is 1/8 of the all-pixel reading rate.

On the other hand, a bit-compressed image is, for example, an image composed of only upper or lower 1 byte (8 bits) when one pixel is composed of 2 bytes (16 bits). In this case, the transfer rate is の of the all-pixel read rate. Further, by combining these two methods, the image transfer rate can be further reduced.

The two-dimensional image pickup device has a characteristic that dark current is accumulated even in the absence of a signal, irrespective of the light receiving method such as CCD or amorphous silicon. In the tonality photographing, it also causes a decrease in image quality. Further, since this dark current changes depending on the ambient temperature and the like, it is necessary to take an image in a series of image capturing sequences.

As described above, the preview image described above is merely an image for displaying an outline.
In some cases, dark current correction is not performed, but it is also possible to use image data that has been subjected to dark current correction as needed.

The method of acquiring dark current image data used for dark current correction is generally a method of acquiring the image data each time a photograph is taken, which is optimal from the viewpoint of the obtained image quality. However, in order to shorten the image processing time, For example, a method using dark current image data obtained in the previous imaging, a method using an average value of dark current image data in a plurality of imagings, and the like have been proposed. Comparing the corrected image data obtained by these methods with the corrected image data obtained by the dark current image data acquired every time of photographing is not equivalent, but the monitor performance or the simplified image display. In consideration of the above, the image is sufficiently satisfactory.

By storing the dark current image data in a memory in the photographing unit or the control unit, preview image processing can be performed in advance without waiting for accumulation, signal processing, and transfer of the dark current signal. Thus, the processing time can be reduced.

In the present embodiment, image data that is not thinned out or compressed for such a preview image is called an entire image. Optimal image processing (main image processing) for inspection and diagnosis is performed on this entire image, and it can be displayed on a diagnostic monitor or transferred to a printer for printing if necessary. It is.

In the present embodiment, the electronic cassette 48 has a built-in power supply, and the power supply can be controlled by the above-described wireless communication.

Here, as described in the conventional example, the sensor used in the X-ray digital imaging shifts from the sleep state, which is a power saving state when not in use, that is, a low current state, to a normal current state in which imaging is possible. . Normally, since the photoelectric conversion unit 47 of the sensor units 44 and 50 requires several seconds for a transition period until the image capturing is enabled, the next image capturing cannot be performed during that time. If all the electronic cassettes 48 are simultaneously set in the image-capturing state, the problem of the waiting time is eliminated, but the life of the solid-state imaging unit is usually shortened in inverse proportion to the time of the image-capturing state. Therefore, in the present embodiment, the electronic cassettes 48a to 48e stored in the cassette storage box 43 are shifted to the sleep state by means described below.

FIG. 2 is a block circuit diagram of the electronic cassettes 48a to 48e, the cassette storage box 43 and the control unit 52. The inside of the electronic cassettes 48a to 48e is mainly composed of a solid-state imaging unit 61 and a control electric circuit 62. Inside the cassette storage box 43, detection means 63a to 63e such as detection switches for detecting that the electronic cassettes 48a to 48e are stored, the box internal controller 64, the parallel / serial conversion circuit 6
5. Electric / optical conversion module 66, line driver 6
7. A line buffer 68 is provided.

On the other hand, the image capturing electric circuit of the control section 52 includes a processing device 71, an internal memory 72, an optical / electrical conversion module 73, a serial / parallel conversion circuit 74, a line buffer 75, a communication controller 76, and a line receiver 77. , IO port 78, wireless control circuit 79, wireless transmission / reception module 80, frame memory 81, defective pixel table 82, image data correction controller 8
3. It is composed of a frame memory 84 and the like.

Further, as shown in FIG. 3, the control electric circuit 62 of the electronic cassette 48 includes a processing device 91, an AD conversion circuit 92, a buffer memory 93, a parallel / serial conversion circuit 94, a wireless control circuit 95, a wireless transmission / reception module. 96.

In such a configuration, the signal states of the detecting means 63a to 63e in the cassette storage box 43 are as follows.
The IO port 7 in the control unit 52 is controlled by the detection signal line DL.
The processing device 71 determines whether the electronic cassette 48 is stored or not. When the electronic cassette 48 is stored, the processing device 71 transmits the stored electronic cassette 4.
8, a sleep state transition command is transmitted through the command line CL. Thereby, all the electronic cassettes 48 stored in the cassette storage box 43 are
Goes to sleep.

Normally, information specific to each of the sensor units 44 and 50 is required for photographing. For example, it is pixel defect information indicating which pixel of the solid-state imaging unit 61 of the electronic cassette 48 does not function normally, and this information is necessary for finally displaying an image properly. In addition, the control unit 52 also needs an energizing time for determining the life of the solid-state imaging device. Depending on the use of the sensor units 44 and 50, it is conceivable that the phosphor 46 is different, or the photo timer or the grid is not provided, so that the processing in the control unit 52 is also different.

For example, the sensor units 44 and 50 have a non-volatile storage device capable of holding data regardless of whether the power is turned on or off, and information unique to the sensor units 44 and 50 is stored in the storage device. A method may be employed. Then, the stored electronic cassette 48 is sent from the processing unit 71 in the control unit 52 to the sensor units 44 and 5.
By receiving the unique information transmission command of 0, the unique information stored in the storage device is transmitted to the control unit 52. The control unit 52 that has received this stores the information in the internal memory 72 of the control unit 52.

When performing radiography, the X-ray technician first inputs a radiographed part using input means (not shown) connected to the control unit 52. The processing device 71 in the control unit 52 determines which electronic cassette 48 is most suitable for the imaging from the imaging part information and the unique information of the electronic cassette 48 in the internal memory 72, and displays the display unit 53 or the cassette storage box. An optimal electronic cassette 48 corresponding to 43 is displayed.

The X-ray technician displays the displayed electronic cassette 48a.
Among them, the electronic cassette 48a is taken out of the cassette storage box 43 and carried to the sensor unit 50. At this time, the detection means 63a detects that the electronic cassette 48a has been removed from the cassette storage box 43. Then, the processing device 71 in the control unit 52 controls the detached electronic cassette 48a.
A photographable state transition command is transmitted through the line CL.

Further, as described above, the internal memory 72 in the control section 52 stores the unique information of all the electronic cassettes 48a to 48e stored in the cassette storage box 43. The control unit 52 extracts the unique information relating to the detached electronic cassette 48a from the information, and rewrites the contents of the defective pixel information table 82 to the information of the electronic cassette 48a.

Then, the X-ray technician places the electronic cassette 48a on the sensor unit 50 of the supine table 42, instructs the patient S to perform appropriate positioning, and gives the operation room 3
Return to 2 and press the X-ray exposure switch. The X-rays emitted from the X-ray generation unit 40 pass through the patient S and enter the electronic cassette 48a with the internal information of the patient S. The X-ray image data displaced to visible light by the phosphor 46 and further converted to an electric signal by the photoelectric conversion unit 47 is converted to digital data by an AD conversion circuit 92 in a control electric circuit 62 in the electronic cassette 48a. You.

As described above, X-ray photography is performed, and image data is first temporarily stored in the buffer memory 93 in the electronic cassette 48a. Eventually, this diagnostic image is transferred to the control unit 52 and displayed on the display unit 53 or stored in a storage medium. The X-ray technician needs to confirm whether a desired image has been captured. The preview image, which is an image for confirmation, is required to have immediacy from the end of shooting to the display of the image. The preview image, which does not require a large capacity as compared with the diagnostic image, is reduced or compressed by the above-described method, and is subjected to dark current correction as needed, and is controlled immediately after shooting by the wireless transmission / reception modules 96 and 80. It is transferred to the unit 52 and displayed on the display unit 53.

The X-ray technician checks the displayed image, determines whether or not to perform re-imaging, and when all imaging is completed, stores the electronic cassette 48 a in the cassette storage box 43. When the detection unit 63a detects that the electronic cassette 48a is stored, the processing unit 71 in the control unit 52
Outputs a diagnostic whole image data transfer command to the electronic cassette 48a. Electronic cassette 48 receiving the instruction
“a” outputs the entire image data stored in the buffer memory 93 to the cassette storage box 43.

In the cassette storage box 43, under the control of the internal controller 64, the data is transferred to the control unit 52 by the line IL via the serial / parallel conversion circuit 65 and the electric / optical conversion module 66. The image data transferred in this manner is input to an image capturing electric circuit in the control unit 52, passes through an optical / electrical conversion module 73, and a serial / parallel conversion circuit 74, and is stored in a frame memory 81.
Is written to. Then, the image data is corrected by the defective pixel information table 82, and the image data correction controller 8 corrects the image data.
3 is stored in the frame memory 84.
Is written to.

In this manner, the X-ray photography and the image data transfer are performed, but the once-removed electronic cassette 48 is removed.
Is valid until another electronic cassette 48 is newly taken out, and the content of the defective pixel information table 82 in the control unit 52 is also held as it is. In the case where X-ray imaging is not performed even after a certain period of time from the removal, the electronic cassette 48 can be automatically shifted to the sleep state due to the problem of the life of the solid-state imaging unit 61. It is.

FIG. 4 is a flowchart showing the entire flow of the X-ray imaging routine performed by such an imaging technician. Further, FIG. 5 shows an optimum cassette automatic selection process, FIG. 6 shows a process at the time of cassette removal detection, FIG. 7 shows a process from X-ray imaging to preview image display, and FIG. The flowchart of the process at the time is shown respectively.

In this embodiment, the sleep state and the photographable state are switched depending on whether or not the electronic cassette 48 is stored in the cassette storage box 43. Cassette 4
It is also possible to switch off / on the power supply 8. In this case, the electronic cassette 48 is set in the cassette storage box 4.
If the power is turned off immediately after being stored in the storage unit 3, the acquisition of the unique information cannot be performed. Therefore, for example, a sequence in which the power is turned off after a sensor information transmission end command is received is performed. Switching on can be performed without inconvenience.

The switching between the sleep state / capturing enabled state and the switching off / on of the power of the electronic cassette 48 is performed not only by the detection means 63a to 63e of the cassette storage box 43 but also by the control unit 52 or the sensor unit 44,
It is also possible to carry out by input means such as 50 input switches.

[0047]

As described above, the X-ray digital radiographing apparatus according to the present invention is provided with a cassette storage box capable of storing a plurality of electronic cassettes, and detects whether the electronic cassette is stored in the cassette storage box. However, by switching the control to the electronic cassette specific information, even when a plurality of electronic cassettes are used, the convenience of handling by the user is improved, and the power consumption of the device itself is reduced, Further, various controls between the control unit and the sensor unit can be optimally performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an imaging system according to an embodiment.

FIG. 2 is a block circuit configuration diagram of an internal configuration of an electronic cassette, a cassette storage box, and a control unit.

FIG. 3 is a block circuit configuration diagram of a control electric circuit.

FIG. 4 is an operation flowchart of the entire X-ray imaging routine by the imaging technician;

FIG. 5 is an operation flowchart of an optimal cassette automatic selection process.

FIG. 6 is an operation flowchart when cassette removal is detected.

FIG. 7 is an operation flowchart from X-ray imaging to preview image display.

FIG. 8 is an operation flowchart when cassette storage is detected.

FIG. 9 is a configuration diagram of a conventional imaging system.

[Explanation of symbols]

 Reference Signs List 40 X-ray generator 41 Standing stand 42 Recumbent table 43 Cassette storage box 44, 50 Sensor unit 46 Phosphor 47 Photoelectric converter 48a to 48e Electronic cassette 52 Control unit 53 Display unit 61 Solid-state imaging unit 62 Electricity for control Circuits 63a to 63e Detecting means 64 Box internal controller 65 Parallel / serial conversion circuit 66 Electric / optical conversion module 68, 75 Line buffer 71, 91 Processing device 72 Internal memory 73 Optical / electric conversion module 74 Serial / parallel conversion circuit 76 Communication controller 77 Line receiver 79, 95 Wireless control circuit 80, 96 Wireless transmission / reception module 81, 84 Frame memory 82 Defective pixel table 83 Image data correction controller 92 AD conversion circuit 93 Buffer memo

Claims (14)

[Claims] An electronic cassette of a cassette type having a solid-state imaging unit sensitive to X-rays and separable from an apparatus main body;
A cassette storage box capable of storing a plurality of the electronic cassettes and having a control unit for controlling the solid-state imaging unit, and detection means for detecting that the electronic cassette is stored in the cassette storage box. An X-ray digital imaging apparatus characterized by the above-mentioned. 2. The X-ray apparatus according to claim 1, wherein the state of the detection unit is monitored by the control unit, and the electronic cassette housed in the cassette housing box is set to a power saving state. Digital photography device. 3. The state of the detecting means is monitored by the control unit, and when the electronic cassette is removed from the cassette storage box, a transition of the removed electronic cassette to a photographable state is started. The X-ray digital imaging apparatus according to claim 1. 4. The electronic apparatus according to claim 2, wherein the electronic cassette is set to a power saving state when the electronic cassette in a photographable state is not photographed even after a predetermined time has elapsed. Line digital photography equipment. 5. The control section monitors the state of the detection means, and transfers sensor unique information of the electronic cassette to the control section when the electronic cassette is stored in the cassette storage box. The X-ray digital imaging apparatus according to claim 1, wherein: 6. The apparatus according to claim 5, wherein the control unit has information input means such as an imaging part, and selects the optimal electronic cassette from the sensor-specific information in accordance with the input information. The X-ray digital imaging apparatus according to the above. 7. The X-ray digital imaging apparatus according to claim 6, wherein a display means specifies that only the optimal electronic cassette is a valid sensor. 8. The control unit monitors the state of the detection unit, and starts transferring image data to the control unit after X-ray imaging when the cassette is removed from the cassette storage box. Item 7. An X-ray digital imaging apparatus according to Item 1. 9. The control unit monitors the state of the detection unit, and starts transferring image data to the control unit when the electronic cassette is stored in the cassette storage box. Item 7. An X-ray digital imaging apparatus according to Item 1. 10. The state of the detecting means is monitored by the control unit, and the power of the electronic cassette is turned off after a lapse of a predetermined time since the electronic cassette is stored in the cassette storage box. The X-ray digital imaging apparatus according to claim 1. 11. A state of the detecting means being monitored by the control unit, and when the electronic cassette is removed from the cassette storage box, a power supply of the removed electronic cassette is turned on. An X-ray digital imaging apparatus according to claim 10. 12. The electronic cassette has a rechargeable power supply for monitoring a state of the detection means by the control unit, and the electronic cassette stored in the cassette storage box is charged. X according to claim 1
Line digital photography equipment. 13. The X-ray digital imaging apparatus according to claim 1, wherein the electronic cassette transfers preview image data to the control unit by a wireless communication method after X-ray imaging. 14. The X-ray digital imaging apparatus according to claim 1, wherein the electronic cassette transfers the entire image data to the control unit by a wired communication method.