JP2003199736A - X-ray equipment, mobile x-ray equipment, x-ray radiographic system and computer readable storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray radiographic system offering compact construc tion while maintaining the real-time characteristic of a plane detector, and X-ray equipment suitable in its use. <P>SOLUTION: The X-ray equipment comprises the plane detector for acquiring an X-ray image, correcting means for correcting a subject image output from the plane detector, network interface means for connecting it to a predetermined network, and control means for performing first control of creating a reduced image corrected by the correcting means and feeding the reduced image via the network interface means to an image processor for applying image processing to the reduced image and displaying the reduced image after image processing and second control of creating a full-size image corrected by the correcting means following the first control and feeding the full-size image via the network interface means to an image processor for applying image processing to the full-size image. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray imaging apparatus having a flat detector and an X-ray imaging system using the same.

[0002]

2. Description of the Related Art In recent years, digitalization has progressed in the field of simple X-ray photography, and CR (Computed) using a stimulable phosphor is used.
Radiography) device or flat detector (solid-state image sensor) in which photoelectric conversion elements are arranged in a matrix
FPD (Flat Panel Detecto)
r) Devices are becoming popular. In particular, since an X-ray imaging apparatus using a flat panel detector can confirm an image immediately after imaging, it is expected to spread rapidly in the future.

The FPD photographing devices that have been announced so far include a standing photographing type and a recumbent photographing type. However, this is not enough for all imaging parts. Therefore, a thin and lightweight cassette type (portable) imaging device has been recently announced. FIG. 2 shows a block diagram of a photographing system using a cassette type photographing device.

Reference numeral 201 is a cassette photographing unit, 202 is a plane detector, and 203 is a circuit unit including an AD converter and an interface (I / F) unit. The image signal detected by the plane detector is AD-converted by the AD converter of the circuit unit 203, converted into a serial signal by the I / F unit of the circuit unit 203, and converted into an electric signal / optical signal converter (hereinafter referred to as E / O). (Referred to as a converter) 204. Here, the cassette photographing unit 20
The reason for communicating between 1 and the E / O converter by a serial signal in the form of an electric signal is that in the case of cassette imaging, the cable needs to be as thin and flexible as possible in handling the cassette imaging unit.

The E / O converter 204 is a cassette photographing section 2
The serial signal received from 01 is converted into an optical signal. The optical signal is used to improve noise resistance and enable highly reliable communication even when the cable length is long. The optical signal transmitted from the E / O converter 204 is sent to the capture board 206 in the control station 205. Control station 205
Has the function of controlling the entire system, user interface, image processing, communication with devices (image server, diagnostic workstation, printer, etc.) connected to the hospital network.

Here, the capture board 206 is shown in FIG.
Will be explained.

The optical signal 309 received from the E / O converter 204 is converted into an electric signal by the optical / electrical signal converter 301 in the capture board 206. The image signal converted into an electric signal is stored in the frame memory 303 via the multiplexer 302. The FPN (Fi
An xed Pattern Noise image (also referred to as a dark current image) is similarly stored in the FPN memory 304 via the multiplexer 302.

Here, the reason why the FPN image is necessary will be described. Generally, a flat panel detector (flat panel sensor FP
Since D) 202 is made of a semiconductor such as a-Si (amorphous silicon), dark current is accumulated as time passes. That is, the dark current signal is also included in the image signals obtained by one shot. Since this dark current signal becomes noise, it is necessary to remove (subtract) the FPN component from the image signal in order to obtain a true image signal.
The FPN component is generally a function of temperature and storage time. Therefore, since the imaging time varies depending on the imaging region / examinee, the accumulation time of the flat panel detector is measured for each imaging. After imaging, dark current is accumulated for the same time as the accumulation time in a state where the flat panel detector is not irradiated with X-rays. Then, by reading the signal from the flat panel detector, a signal (FPN image) substantially the same as the FPN signal included in the captured image can be obtained. A true image signal is obtained by subtracting this FPN image signal from the image signal obtained by photographing the subject.

Frame memory 303 and FPN memory 3
By simultaneously calling and subtracting the data of the same address from 04, an FPN (dark current) corrected image signal is obtained, and the corrected image signal is the LOG conversion table 3
Sent to 05.

Next, white image data (LOG value) stored in advance in the white image memory 306 from the image signal subjected to LOG conversion (logarithmic conversion) by the LOG conversion table 305.
Is subtracted. This subtraction process is generally called white correction or gain correction, and is for correcting variations in the gain of each pixel of the flat panel detector.

Here, the white correction will be described. The image data for white correction stored in the white image memory 306 is image data obtained in advance by irradiating the entire flat panel detector with uniform X-rays without passing through a subject. 40 of FIG.
1 indicates white image data (for one line) acquired in advance. The white image data is acquired by irradiating the flat panel detector with X-rays uniformly, without passing through the subject, such as every morning or once a week on a regular basis. Reference numeral 402 denotes image data output from the flat panel detector when a subject is photographed. 40
By dividing the second image data by the image data 401, the white-corrected image data 403 is obtained. As described above, subtracting the LOG-converted white image similarly from the LOG-converted captured image on the capture board 206 corresponds to this division.

The image data read from the LOG converter 305 is subtracted from the white correction data read from the white image memory 306 (white correction), and the output frame memory 307 is output.
Memorized in.

The image data on which the FPN correction and the white correction have been performed as described above is the control station 20.
5, the data is stored in the main memory 208 by the CPU 207 via the PCI bus 211.

The capacity of this image is about 720 when the matrix size of the flat panel detector is 2688 × 2688 pixels.
It has a large capacity of 10,000 pixels. In order to make the most of the real-time property of the flat panel detector, it is necessary to display the captured image within a few seconds after the capturing in order for the operator to determine whether the image is proper or not immediately after the capturing.

Therefore, the CPU 207 has the main memory 2
The captured image in 08 is reduced to ⅛, image processing such as gradation processing is performed, and the reduced image after processing is displayed on a liquid crystal display (hereinafter also referred to as a liquid crystal touch panel) 214 with a touch panel, which is a user interface. Is displayed. By checking the reduced image, the operator can determine whether or not a proper image has been shot. If the image is not appropriate, re-imaging can be performed immediately.

If it is confirmed that a proper image is obtained, the operator pushes the photographing end button on the liquid crystal touch panel. When the input of the shooting end button is confirmed, the CPU
207 performs final image processing on the full-size image data in the main memory 208. Upon completion of this image processing, the CPU 207 outputs the processed image to the hard disk 209 in the control station 205.
, And outputs the processed image to an image filing device, a printer or the like connected to the in-hospital LAN via the network card 210.

The most important thing in the above-mentioned system is to display the photographed image within a few seconds after photographing so that it can be immediately judged whether the photographed image is proper or not.
In the system configuration of FIG. 2, the image reading from the cassette photographing unit 201 to the control station 205 is
It takes less than 0.3 seconds because it has a dedicated interface. Further, since the FPN correction and the white correction are also performed by the capture board 206 having dedicated hardware, almost real-time processing is possible.

Therefore, according to the above-described photographing system, since the dedicated hardware is used, the photographed image for confirmation (reduced image) can be displayed within a few seconds after the photographing. For this reason, as with the conventional film / screen system, when the subject moves from the imaging room to another location, it is known that the captured image is not appropriate, and the subject is recalled again to perform the reimaging. The annoyance can be eliminated.

[0019]

However, since the above-mentioned system requires the above-mentioned dedicated hardware, it is difficult to construct the system compactly. For example, a cassette-type imaging apparatus is useful when configuring a mobile-type X-ray imaging apparatus that is carried into a patient's room or the like and used for imaging, but the cassette imaging system described above is applied to a mobile imaging apparatus. If you want to use a large PC (pe
It was not possible to construct a compact system because an rsonal computer housing, an E / O converter, etc. were required.

To solve this problem, a photographing system as shown in FIG. 5 is assumed. Reference numeral 501 is a cassette imaging unit, 502 is a flat panel detector, and 503 is a board including an AD converter, a network interface, and an X-ray generator interface. Here, it is assumed that the network interface is for Ethernet (registered trademark) (Ethernet) that is standardly equipped on a commercially available laptop PC. 504 is an Ethernet cable (1
0Base-T or 100Base-TX etc.), 505
Is a laptop PC. 506 is a cassette photographing unit 5
01 power supply.

With this configuration, there is no unit such as an E / O converter, and the standard Ethernet attached to a commercially available PC is used.
Since an et interface (Ethernet I / F) is used, a small laptop PC can be used, which is considered to be effective for configuring a compact mobile photographing device.

The image pickup system as shown in FIG. 5 has a small number of units, is easy to apply to a mobile image pickup device, and is convenient because it does not require any dedicated hardware.
Since it is cheap, it is considered to be a system that can be easily installed in small and medium-sized hospitals.

However, the Ethernet I / F
Has a problem in terms of transfer speed, especially in a network environment in which other devices are also connected. It is difficult to guarantee that the confirmation image is displayed within a few seconds after shooting, as described below.

Here, the matrix size of the plane detector is 2688 × 2688 pixels, and the bit number of the AD converter is 14
Bit. In this case, the capacity of image data obtained by one shot is 7.2 MW (101 Mbit). In case of 10Base-T, the effective transfer rate is 4Mb
If it / sec, the transfer time for one captured image is 25
It takes 25 seconds to read the FPN image after shooting. Therefore, it is impossible to display the confirmation image within a few seconds after shooting. Also, 100Base
Even if -TX is used, the transfer time for one captured image is about 2.5 seconds, and the same time is required for transferring the FPN image. Further, considering the time required for image processing such as gradation processing, also in this case, it is difficult to display the confirmation image within a few seconds after shooting.

The present invention has been made in consideration of the above-mentioned problems, and an object thereof is an X-ray imaging system having a compact structure while utilizing the real-time property of a flat panel detector, and such an X-ray. An object is to provide an X-ray imaging apparatus suitable for constructing an imaging system.

[0026]

The invention according to claim 1 for achieving the above-mentioned object, other objects and further features of the present invention will be apparent from the embodiments described below with reference to the accompanying drawings. To be

[0027]

DETAILED DESCRIPTION OF THE INVENTION An X-ray imaging apparatus as one aspect of the present invention will be described below with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 shows a configuration (block diagram) of an X-ray imaging apparatus according to Embodiment 1 and an X-ray imaging system using the same.

In FIG. 1, 101 is a cassette photographing unit,
102 is a flat panel detector. The matrix size of the flat panel detector 102 is 2688 pixels × 2688 pixels. 11
Reference numeral 3 denotes an X-ray interface, which is a cassette imaging unit 1
01 is used for communication between an X-ray generator (not shown),
For example, it is used to control the X-ray exposure timing. The captured image data read from the plane detector 102 is converted into digital data by the 14-bit AD converter 103, and the captured image frame memory 1 is passed through the multiplexer 104.
It is stored in 05. After the shooting, the flat panel detector 1 displays an FPN (dark current) image at the same storage time as the shooting time required for the shooting.
No. 02, the same processing as the captured image data is performed, and the result is stored in the FPN image frame memory 106.

When the CPU 112 has finished capturing the photographed image and the FPN image, it outputs a reduced image for image confirmation (preview) to a PC (personal) as an image processing apparatus.
control to transmit to the computer 115. Here, first, reading is started from the same address of the photographed image frame memory 105 and the FPN image frame memory 106, and the data of one pixel is read out every eight addresses. As a result, the read image becomes a 1/8 reduced image (the number of pixels is 1/64). Captured image frame memory 105
The image data read from the FPN image frame memory 106 is subtracted for each pixel from the image data read from, and as a result, FPN (dark current) correction of the captured image is performed.

The FPN-corrected image data is LOG (logarithmically) converted by the LOG converter 107 and then stored in the frame memory 108. On the other hand, the white image data that has been acquired and LOG-converted in advance before shooting is stored in the white image frame memory 109 in advance, such as being transmitted from the PC 115 to the cassette shooting unit 101 in advance.

Next, pixels of the same address are simultaneously called from each frame memory, and subtraction is performed by the subtractor. However, when reading white image data from the white image frame memory, data of one pixel is read every eight addresses. As a result, white-corrected (gain-corrected) image data is obtained. The reduced image data subjected to the FPN correction and the white correction as described above is stored in the output frame memory 110. This reduced image data is Ether
It is transmitted to the PC 115 via the net I / F 111. This reduced image data has a matrix size of 3
36 pixels x 336 pixels (about 1.5 Mbits),
Even 10Base-T can be transferred in about 0.4 seconds.

The PC 115 subjects the received reduced image data to image processing such as gradation conversion processing, and displays the processed image as a confirmation image on its display. With the above configuration and operation, it is possible to provide the operator with an image for confirmation within a few seconds after shooting.

The cassette photographing unit 101 sends the reduced image on which the FPN correction and the white correction have been performed to the PC 115, and then,
The same operation as the above-described operation of generating and transmitting the reduced image is performed, and the FPN-corrected and white-corrected full-size (original size) image data is transmitted to the PC 115. However,
In this case, all the image data (all pixel data) is read from each frame memory and the necessary processing is performed, instead of performing the interlaced reading from each frame memory as described above.

When the operator confirms the confirmation image and inputs to instruct the completion of photographing, the PC 115 performs necessary image processing on the full-size image data transmitted later,
It is saved in a storage device (hard disk or the like) in the PC 115. If the PC 115 is connected to a hospital network (not shown), the final image (full-size image after processing) should be output to an external device (image server device, printer, etc.) that is also connected to the hospital network. You can also

(Second Embodiment) FIG. 6 shows an X-ray imaging apparatus and an X-ray imaging system using the same according to the second embodiment.

The system of this embodiment is the same as that of the first embodiment.
It is an extension of the system. Since the mobile X-ray imaging apparatus is carried to a hospital room and used for imaging, it is desirable that it be as small and lightweight as possible. In this embodiment,
The in-hospital network installed in each hospital room is used.
Further, a cassette photographing device equipped with a plane detector and a small monitor for displaying a confirmation image are incorporated in a mobile photographing device, and a control station for performing heavy processing such as image processing is installed in a control room in the hospital. With such a configuration, it is not necessary to carry a control station, and it is possible to provide a compact and lightweight mobile X-ray imaging apparatus while taking advantage of the merits of the X-ray imaging apparatus using the flat panel detector.

The present embodiment will be described below with reference to FIG. Reference numeral 601 denotes an in-hospital network (in-hospital LAN), which has LAN connection connectors 602 and 607-609 in the patient room 1, the patient room 2, the patient room 3 and the imaging room, and is connected to the control station 610 in the control room. Further, various devices (image file server device, printer, etc.) not shown in the hospital network 601
Etc. are also connected.

Reference numeral 606 is a mobile type X equipped with a moving carriage.
The mobile imaging device 606 is a line imaging device, and includes a cassette imaging unit 604 equipped with a flat panel detector and a liquid crystal monitor 605 with a touch panel for displaying a confirmation image. The operator carries the mobile photographing device 606 to the patient room, and first, the cassette photographing unit 604 and the liquid crystal monitor 60.
5 is L of the in-hospital network 601 installed in the hospital room
The AN connector 602 is connected via a hub 603. The cassette photographing unit 604 is configured similarly to the cassette photographing unit 101 of the first embodiment shown in FIG.

Next, the operator orients the subject and takes an image. After the imaging (X-ray exposure) is completed, the cassette imaging unit 604 first performs FPN correction and white correction on the 1/8 reduced image (captured image) as in the first embodiment. The operation thereafter is different from that of the first embodiment. When the correction of the reduced image is completed, the CPU 112 performs simple image processing (gradation processing or the like) on the reduced image. The processed image is transmitted to the liquid crystal monitor 605 and displayed on the liquid crystal monitor 605 as a confirmation image. When the image processing such as the gradation processing gives an excessive load to the CPU 112, the corrected reduced image is transmitted to the control station 610 as the image processing apparatus and the control station 610 is operated as in the first embodiment. After the image processing of the reduced image is performed by 610, the confirmation image after processing may be transmitted to the liquid crystal monitor 605. However, in this case, the reduced image is once transmitted from the cassette photographing unit 604 to the control station 610 via the in-hospital network 601, and the processed image is transmitted from the control station 610 to the liquid crystal monitor 605 via the in-hospital network 601. It is necessary to consider that it takes a transfer time for

Next, the operator determines whether or not the photographed image displayed on the liquid crystal monitor 605 is appropriate. If the image is appropriate, the operator presses the shooting end button on the liquid crystal monitor 605 with a touch panel. The cassette photographing unit 604, which has received the photographing end signal based on the signal, causes the full-size image F
After performing PN correction and white correction, the hospital network 60
The corrected full-size image is transmitted to the control station 610 as the image processing apparatus via 1. The control station 610 performs necessary image processing on this image, and then the control station 61
The image is stored in a storage unit (hard disk 209, etc.) inside 0, and the processed image is output to an external device (image file server device, printer, etc.) (not shown) on the in-hospital network 601. As described above, one shooting cycle is completed.

When it is necessary to take a picture at another place, the operator
The mobile photographing device 606 including the cassette photographing unit 604 and the liquid crystal monitor 605 with a touch panel can be moved to another place (another room, a photographing room, or the like), and desired photographing can be performed by the same procedure and operation as described above. it can.

(Other Embodiments) In order to operate various devices in order to realize the functions of the above-described embodiments or to execute processing steps, the above-described embodiment is implemented by a computer in an apparatus or system connected to the various devices. By supplying a program code of software for realizing a function of a form or executing a processing step, and a computer (CPU or MPU or the like) in the apparatus or system operates the various devices according to a stored program. Realization of the functions of the above-described embodiments or execution of processing steps is also included in the scope of the present invention.

Further, in this case, the program code itself of the software realizes the functions of the above-described embodiments or executes the processing steps, and the program code itself and the program code for supplying the program code to the computer. Means, such as a storage medium storing such program code, constitutes the present invention.

A storage medium for storing the program code is, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-R.
OM, magnetic tape, non-volatile memory card, ROM
Etc. can be used.

Further, by executing the supplied program code by the computer, not only the functions of the above-described embodiments are realized or the processing steps are executed, but also the OS (in which the program code runs on the computer). Needless to say, the program code constitutes the present invention when the functions of the above-described embodiments are implemented or the processing steps are executed in cooperation with an operating system) or other application software.

Further, after the supplied program code is stored in the memory provided in the function expansion board of the computer or the function expansion unit connected to the computer, the function expansion board or function expansion is performed based on the instruction of the program code. Even when the CPU or the like included in the unit performs some or all of the actual processing and the processing realizes the functions of the above-described embodiments or executes the processing steps, the program code constitutes the present invention. Needless to say.

The program described above can be a transaction target not only in the form of being stored in the computer-readable storage medium described above, but also as an independent transaction target in the form of online distribution using the Internet or other communication networks. Needless to say.

As described above, according to the first embodiment, an imaging system can be constructed easily and compactly by using the cassette imaging device and the small and lightweight PC, and the imaging utilizing the real-time property of the flat panel detector is carried out. The system can be built.

Further, according to the second embodiment, by separating many functions of the control station by using the in-hospital network, a mobile photographing apparatus which is small and lightweight and which utilizes the real-time property of the flat panel detector is realized. Can be provided.

Although the preferred embodiments of the present invention have been described above, the present invention can be variously modified and changed within the scope of the gist thereof.

[0052]

As described above, according to the present invention, the X-ray imaging system having a compact structure while utilizing the real-time property of the flat panel detector, and the X-ray imaging system suitable for constructing such an X-ray imaging system are provided. A line imaging device can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment.

FIG. 2 is a block diagram showing a conventional configuration.

FIG. 3 is a block diagram showing the configuration of a capture board.

FIG. 4 is a diagram for explaining white correction.

FIG. 5 is a block diagram showing an assumed configuration.

FIG. 6 is a block diagram showing the configuration of the second embodiment.

[Explanation of symbols]

101 Cassette shooting department 102 flat panel detector 103 AD converter 104 multiplexer 105 Captured image frame memory 106 FPN image frame memory 107 LOG converter 108 frame memory 109 White image frame memory 110 output frame memory 111 Ethernet interface 112 CPU 113 X-ray interface 114 Ethernet cable 115 PC 601 Hospital network 602 LAN connector 603 hub 604 cassette shooting unit 605 LCD monitor with touch panel 606 Mobile photography device 607, 608, 609 LAN connector 610 Control station

Claims (11)

[Claims] 1. A flat panel detector for acquiring an X-ray image, a correction unit for correcting a subject image output from the flat panel detector, and a network interface unit for connecting to a predetermined network. An image processing apparatus for generating a reduced image corrected by the correction unit, performing image processing on the reduced image via the network interface unit, and displaying the reduced image after the image processing. To the full-size image corrected by the correction means, and the full-size image is transmitted to the full-size image through the network interface means in lag behind the first control. X-ray imaging having control means for performing second control for sending the image to an image processing device for image processing Shadow device. 2. A flat panel detector for obtaining an X-ray image, a correction unit for correcting the subject image output from the flat panel detector, and image processing for the subject image corrected by the correction unit. Image processing means for performing, network interface means for connecting to a predetermined network, and a reduced image corrected by the correcting means is generated, and the reduced image is subjected to image processing by the image processing means,
A first control for displaying a reduced image after the image processing on a display device is performed, and a full size image corrected by the correction unit is generated after the first control, and the full size image is An X-ray imaging apparatus comprising: a control unit for performing a second control for sending the image to the full-size image to an image processing apparatus via a network interface unit. 3. A flat panel detector for acquiring an X-ray image, a correction unit for correcting a subject image output from the flat panel detector, and a network interface unit for connecting to a predetermined network, A reduced image corrected by the correction unit is generated, the reduced image is subjected to image processing via the network interface unit, and the reduced image after the image processing is sent to a predetermined display device. First control for sending to the image processing apparatus for generating a full size image corrected by the correction means, and the full size image is generated via the network interface means after the first control. And a control means for performing a second control for sending to the image processing apparatus for performing image processing on the full size image. Characteristic X-ray imaging device. 4. The X-ray imaging apparatus according to claim 1, wherein the network interface unit is for Ethernet (registered trademark). 5. The X-ray imaging apparatus according to claim 1, wherein the correction unit performs FPN correction and / or white correction on the subject image. 6. The X-ray imaging apparatus according to claim 1, wherein the reduced image is used to generate a preview image for determining suitability of the subject image. . 7. The X-ray imaging apparatus according to claim 1, wherein the network interface unit is connected to the image processing apparatus via a network cable. 8. The X-ray imaging apparatus according to claim 2, wherein the network interface unit is connected to a LAN. 9. A mobile X-ray imaging apparatus comprising the X-ray imaging apparatus according to any one of claims 1 to 3. 10. An X-ray imaging system, comprising the X-ray imaging apparatus according to claim 1 and an image processing apparatus. 11. A computer-readable storage medium storing a program for realizing the function of the X-ray imaging apparatus according to claim 1.