JP6733184B2 - Radiation motion imager - Google Patents

Description

The present invention relates to a radiation moving image capturing apparatus.

2. Description of the Related Art Conventionally, there has been proposed a technique for transmitting an outline (overall image) of an image obtained by photographing a human body to a user such as a photographing engineer more quickly. For example, in Patent Document 1, immediately after the image data is acquired, the first image obtained by thinning out the entire image to 1/64 is transferred to the display unit as a preview image, and then the second image subjected to gain correction and the like is displayed. The technique of transferring to the display unit is described.

JP, 2003-325494, A

By the way, when transferring a moving image obtained by a photographing device to an external device such as a display device, first, a thinning process is performed on each of a plurality of frame images forming the moving image, and the obtained thinned image is a preview image. As a result, it is considered that the image data is sequentially transferred to an external device at a predetermined transfer interval, and after the transfer of all the preview images is completed, the remaining image (remaining image) of the frame image that has not yet been transferred is transferred (see FIG. 4A). .. At this time, if the communication path for transferring the preview image is an unstable communication path such as wireless communication, and the transfer interval is short, the preview image planned to be sent when the communication condition becomes poor can be sent out. Stable transfer cannot be performed without delaying the transfer of the next preview image. Therefore, in order to realize stable transfer, it is necessary to allow a sufficient transfer interval until the next preview image is transferred. However, if there is a margin in the transfer interval, it will take time until all frame images including the residual image are transferred to the external device, and the start of the next process such as image analysis and diagnosis will be delayed, and It is efficient.

An object of the present invention is to enable moving images to be transferred stably and efficiently.

In order to solve the above-mentioned problems, the radiation moving image capturing apparatus of the invention according to claim 1 is
An image generation unit that generates a plurality of frame images by shooting a moving image of the subject ,
Decimation processing means for performing decimation processing for reducing the number of pixels on each of the plurality of frame images generated by the image generation means to generate a preview image ,
Transfer means for sequentially transferring the preview images generated by the thinning processing means to an external device;
After the transfer of one of the preview images, the residual image including the remaining part of the frame image that is not transferred as the preview image during the gap time before the transfer of the next preview image is started. The diagnostic or analysis image used for analysis is transferred to the external device by the transfer means, and after the transfer means finishes transferring the preview images of all the frame images captured in the moving image, it is still transferred. Control means for continuously transferring the diagnostic or analysis image that does not exist to the external device ,
Equipped with.

The invention described in claim 2 is the same as the invention described in claim 1,
The transfer means transfers the preview image at a predetermined time interval.

The invention according to claim 3 is the same as the invention according to claim 1 or 2,
The control means controls the transfer amount of the diagnostic or analysis image transferred during the gap time according to the communication status with the external device.

The invention described in claim 4 is the same as the invention described in claim 3,
The control means, based on the response time of an image transfer command transmitted/received to/from the external device when the preview image is transferred by the transfer means, transfers the diagnostic or analysis image to be transferred to the gap time. Control the transfer rate.

The invention according to claim 5 is the same as the invention according to claim 3 or 4,
The transfer means transfers an image to the external device by wireless communication,
The control means obtains the radio wave reception intensity of the wireless communication, and when the obtained radio wave reception intensity falls below a predetermined threshold value, controls so as not to perform transfer during the gap time.

According to the present invention, it becomes possible to transfer a moving image stably and efficiently.

It is a figure showing an example of whole composition of a radiography system in this embodiment. It is a block diagram which shows the functional structure of the FPD cassette of FIG. It is a block diagram which shows the functional structure of the console of FIG. (A) is a figure which shows typically an example of frame image transfer of a moving image, (b) is a figure which shows the frame image transfer of the moving image in this embodiment typically. It is a figure which shows the image transfer sequence from an FPD cassette to a console at the time of transmitting a residual image in a gap time according to a communication condition.

(Structure of radiation imaging system)
First, the configuration of this embodiment will be described.
FIG. 1 shows an example of the overall configuration of a radiation imaging system 100 according to this embodiment.
The radiation imaging system 100 is, for example, a system for a round trip for radiation imaging of a patient who is difficult to move, and includes a radiation control device 1, a radiation source 2, an FPD (Flat Panel Detector) cassette 3, and a console 4. , And an access point AP. The radiation control device 1 has wheels and is configured as a movable round trip vehicle on which the console 4 and the access point AP are installed. In the radiation imaging system 100, the radiation control device 1, the FPD cassette 3, and the console 4 can wirelessly communicate with each other via the access point AP.

As shown in FIG. 1, the radiation imaging system 100 is brought into an operating room, an intensive care unit, a hospital room Rc, or the like, and the FPD cassette 3 is placed between, for example, a subject H lying on a bed B and a bed B or illustrated. In this system, the moving image of the subject H is captured by irradiating the radiation from the radiation source 2 in a state where the bed B is inserted into an insertion opening provided on the surface opposite to the subject H. In the present embodiment, moving image shooting means obtaining a moving image by continuously acquiring images of a plurality of subjects in response to one shooting start operation (depression of the exposure switch 102a). A series of images obtained by shooting a moving image is called a moving image. In addition, each of the plurality of images forming the moving image is referred to as a frame image. The moving image shooting includes, for example, dynamic shooting and tomosynthesis shooting.

Hereinafter, each device that constitutes the radiation imaging system 100 will be described.
The radiation control device 1 includes an exposure switch 102a for instructing the photographer to start imaging, a drive circuit (not shown) for driving the radiation source 2, a wireless communication unit (not shown), and the like. Radiation irradiation by the radiation source 2 is controlled based on the irradiation conditions.

The radiation source 2 is connected to the radiation control device 1, is driven by the radiation control device 1, and irradiates the subject H with radiation (X-rays).

The FPD cassette 3 is a portable image capturing device (moving image capturing device) capable of capturing a moving image, and generates a plurality of frame images by capturing a moving image of the subject H according to the radiation irradiation of the radiation source 2.
FIG. 2 shows a functional configuration example of the FPD cassette 3. As shown in FIG. 2, the FPD cassette 3 includes a control unit 31, a detection unit 32, a storage unit 33, a battery 34, a wireless communication unit 35, and the like, and each unit is connected by a bus 36.

The control unit 31 includes a CPU, a RAM and the like. The CPU of the control unit 31 reads out various programs such as a system program and a processing program stored in the storage unit 33, expands them in the RAM, and executes various processes according to the expanded programs.
For example, the control unit 31 controls the switching unit of the detection unit 32 based on the image reading condition input from the console 4 to switch the reading of the electric signal accumulated in each radiation detection element (hereinafter, detection element). Then, by reading the electric signal accumulated in the detection unit 32, the image data of the frame image forming the moving image is generated. Then, the control unit 31 transfers the generated image data to the console 4 by the wireless communication unit 35. Image header information is added to the image data generated in the FPD cassette 3.

The detection unit 32 has, for example, a glass substrate or the like, detects radiation emitted from the radiation source 2 and transmitted through at least a subject at a predetermined position on the substrate according to its intensity, and the detected radiation is electrically converted. This is a so-called direct type detection element in which a plurality of detection elements which are converted into signals and accumulated are arranged two-dimensionally. Note that the detection element may be a so-called indirect detection element that is composed of a scintillator and a semiconductor image sensor such as a photodiode. Each detection element is connected to a switching unit such as a TFT (Thin Film Transistor), and the switching unit controls accumulation and reading of electric signals.

The storage unit 33 is composed of, for example, a semiconductor nonvolatile memory or the like. Various programs and data are stored in the storage unit 33. Further, the storage unit 33 temporarily stores the image data output from the detection unit 32.

The battery 34 supplies electric power to each unit of the FPD cassette 3 under the control of the control unit 31. As the battery 34, for example, a rechargeable battery such as a nickel-cadmium battery, a nickel-hydrogen battery, or a lithium-ion battery can be applied.

The wireless communication unit 35 includes a wireless antenna (not shown) and transmits/receives data to/from an external device such as the radiation control apparatus 1 or the console 4 via the access point AP.

The console 4 controls each unit (apparatus) configuring the radiation imaging system 100 based on the inspection order information, displays a preview image transferred from the FPD cassette 3 for imaging confirmation (preview display), and FPD cassette. 3 is a device that provides the frame image transferred from the device 3 for image analysis and diagnosis.

FIG. 3 shows an example of the main configuration of the console 4. As shown in FIG. 3, the console 4 includes a control unit 41, a storage unit 42, an operation unit 43, a display unit 44, a communication unit 45, and the like, and each unit is connected by a bus 46.

The control unit 41 is composed of a CPU, a RAM, and the like. The CPU of the control unit 41 reads out various programs such as a system program and a processing program stored in the storage unit 42, expands them in the RAM, and executes various processes according to the expanded programs.

The storage unit 42 is composed of, for example, an HDD (Hard Disk Drive), a semiconductor non-volatile memory, or the like. Various programs and data are stored in the storage unit 42.

Further, the storage unit 42 stores image capturing conditions (radiation irradiation condition and image reading condition) in association with an imaged site and the like. The radiation irradiation conditions are, for example, an X-ray tube current value, an X-ray tube voltage value, a filter type, a SID (Source to Image-receptor Distance), a pulse rate, a pulse width, a pulse interval, and the like. The image reading condition is, for example, pixel size, image size (matrix size), frame rate, frame interval, or the like. The frame rate matches the pulse rate.

The storage unit 42 also stores examination order information transmitted from a RIS (Radiology Information System) (not shown). The inspection order information includes, for example, inspection identification information (inspection ID, etc.), inspection date, patient information such as the name of the patient who is the subject, and information on each imaging performed in the inspection (imaging ID, imaging site, imaging direction, posture). (Standing, lying) etc.) are included.

The operation unit 43 includes a keyboard having a character input key, a numeric input key, various function keys, and the like, and a pointing device such as a mouse. The operation signal of the key pressed by the keyboard and the operation signal by the mouse are provided. And are output to the control unit 41 as input signals. A pressure-sensitive (resistive film pressure) touch panel (not shown) in which transparent electrodes are arranged in a grid pattern is formed on the screen of the display unit 44, and the display unit 44 and the operation unit 43 are integrally configured. It may be a touch screen.

The display unit 44 includes, for example, a monitor such as a CRT (Cathode Ray Tube) and an LCD (Liquid Crystal Display), and displays various screens according to an instruction of a display signal input from the control unit 41.

The communication unit 45 transmits/receives data to/from the radiation control device 1, the FPD cassette 3, and an external device such as an RIS (not shown) by a wireless system or a wired system.

(Operation of radiation imaging system 100)
Next, the imaging operation in the radiation imaging system 100 will be described.
First, the radiographing technician operates the operation unit 43 on the console 4 to display the inspection order information selection screen on the display unit 44, and selects the inspection order information of the imaging to be performed. After selecting the inspection order information, the imaging technician prepares for imaging such as positioning of the subject H, the radiation source 2, and the FPD cassette 3.

In the console 4, when the inspection order information is selected by the operation of the operation unit 43, the control unit 41 reads out the radiation irradiation condition corresponding to the imaging region of the selected inspection order information from the storage unit 42, and the communication unit 45. The radiation control device 1 is set via the. Further, the control unit 41 reads out the image reading condition corresponding to the imaged region of the selected inspection order information from the storage unit 42 and sets it in the FPD cassette 3 via the communication unit 45.

The photographing engineer presses the exposure switch 102a when the preparation for photographing is completed.
When the exposure switch 102a is pressed, the radiation control apparatus 1 transmits a shooting start instruction to the console 4 and the FPD cassette 3, and starts moving picture shooting. That is, the radiation control device 1 drives the radiation source 2 in synchronization with the FPD cassette 3 based on the set radiation irradiation condition to irradiate the radiation (pulse irradiation) at predetermined time intervals. The control unit 31 of the FPD cassette 3 generates and generates a frame image by accumulating and reading charges in the detection element of the detection unit 32 every time radiation irradiation is performed based on the set image reading condition. The image data of the frame image is transferred to the console 4 by the wireless communication unit 35. In the console 4, the image data transferred from the FPD cassette 3 is sequentially preview-displayed on the display unit 44, and after the photographing is completed, the image data of the frame image transferred from the FPD cassette 3 is provided to image analysis, diagnosis and the like.

Here, if the image data is transferred using a stable communication path with a sufficiently high data transmission speed, there is no problem in transmitting the entire image data of each frame image from the FPD cassette 3 to the console 4 as it is. .. However, as in the present embodiment, for example, when image data is transferred through a communication path such as a wireless communication with an insufficient data transmission rate or an unstable communication path, if the entire image data of the generated frame image is transferred at once. In the console 4, it takes time until the preview display for shooting confirmation is displayed, or the motion of the subject is unnaturally expressed in the preview display because each frame image is not transferred at constant time intervals. The harmful effects of will occur. On the other hand, the preview display is for confirming the shooting positioning, and does not require a high-definition image like diagnosis and analysis.

Therefore, for example, as shown in FIG. 4A, in the FPD cassette 3, every time image data of one frame image is generated, thinning processing for reducing the number of pixels is performed on the generated image data to sequentially preview the image data. An image (first image) is transferred to the console 4 by the wireless communication unit 35 at a fixed time interval Tf (hereinafter, referred to as preview transfer interval Tf), and transfer of preview images of all frame images generated by moving image shooting is completed. If the remaining image (second image) generated by the remaining image data that has not been transferred as the preview image of each frame image is transmitted later, it takes time until the preview display is performed on the console 4, Negative effects such as unnatural movements are mitigated. At this time, in order to be able to stably transmit each preview image within the preview transfer interval Tf even when the communication state deteriorates on an unstable communication path such as a wireless communication path, the preview transfer interval Tf is set. It is necessary to set a time with some margin. However, if the preview transfer interval Tf is set to have a margin, when the data is transmitted at the normal data transmission rate, a gap time Tu is generated before the next preview image is transmitted. It is inefficient because it takes time to start the next process such as image analysis and diagnosis.

Therefore, in the present embodiment, as shown in FIG. 4B, the control unit 31 of the FPD cassette 3 thins out the generated image data every time the image data of one frame image is generated in moving image shooting. Processing is performed (for example, image data is acquired from the frame image at a predetermined pixel interval of the detection unit 32, and the data amount is thinned to 1/4), and the console is performed by the wireless communication unit 35 as preview images at successive preview transfer intervals Tf. Send to 4. At this time, according to the communication status with the console 4, the control unit 31 sets the preview image of the frame images to the gap time Tu after the transfer of one preview image until the transfer of the next preview image is started. The wireless communication unit 35 is configured to generate and sequentially transfer a remaining image formed of the remaining images not transferred as (for example, when the preview image is thinned to 1/4, the remaining 3/4 image data). Control. When the photographing is completed and the transfer of the preview images of all the frame images is completed, the control unit 31 continuously transfers the untransferred residual images to the console 4 by the wireless communication unit 35. As a result, the remaining images can be efficiently transferred, so that the transfer of the image data of all the frame images of the moving image can be completed earlier, and the work of the next process such as image analysis and diagnosis can be started earlier. Is possible.

FIG. 5 shows an image transfer sequence from the FPD cassette 3 to the console 4 when the remaining image is transmitted in the gap time Tu according to the communication status. Note that FIG. 5 shows an image transfer sequence when the RSSI value indicating the radio wave reception intensity at the time of transferring the third preview image is below a predetermined threshold value.
Generally, when performing image transfer, the entire image data to be transmitted is not transmitted at once, but divided into n times by a predetermined amount of data, and image transfer commands are transmitted and received n times. (N is a positive integer). The transfer amount D (byte) of data transferred in one image transfer command is predetermined based on the communication path to be used and the like. Also in the present embodiment, as shown in FIG. 5, when transferring the image data of each preview image and each residual image, a plurality of images are transferred between the wireless communication unit 35 of the FPD cassette 3 and the communication unit 45 of the console 4. The image transfer command is exchanged once to transfer the image data by the transfer amount D. The image transfer command is composed of a transmission side command C1 sent from the transfer source to the transfer destination and a response side command C2 sent from the transfer destination to the transfer source. The transmission-side command C1 includes a command ID, image data for the transfer amount D, and the like. Further, the image header information is also included in the first image transfer command of each image data. The response side command C2 includes the command ID of the image data that has been completely received.

The control unit 31 transmits the preview image and then displays the next preview image according to the communication status with the console 4 during the transfer of each preview image generated by performing the thinning process on each frame image forming the moving image. The gap transfer amount Z (byte) to be transferred in each gap time Tu until transmission is determined, and the remaining image of the determined gap transfer amount Z is transferred in the gap time Tu.

For example, the control unit 31 first measures the response time (s) required from the transmission of the transmission-side command C1 to the reception of the response-side command C2 during the transfer of each preview image. Based on that, the data transfer amount W (Mbps) per second and the time Tp (s) required for preview image transfer at that time are calculated (estimated).

Next, the control unit 31 subtracts Tp(s) from the preview transfer interval Tf(s), which is a fixed time, to calculate the gap time Tu until the next preview image transfer. Then, the gap transfer amount Z (byte) transferred in the current gap time Tu is calculated by the following (Equation 1).
Gap transfer amount Z = Data transfer amount W per second W × Gap time Tu (Equation 1)

Further, the control unit 31 causes the wireless communication unit 35 to acquire the RSSI value indicating the radio wave reception intensity at a predetermined timing during the transfer of each preview image (for example, when the preview image transfer is completed). Then, when the RSSI value is less than the predetermined threshold value, the control unit 31 sets the gap transfer amount Z to be transferred in the gap time Tu until the next preview image transfer to 0, and the communication unit 45 displays the remaining image in the gap time Tu. Control not to transfer. This is because if the RSSI value is less than the predetermined threshold value, the communication status is bad, and if the remaining image is transferred during the gap time Tu, it may affect the transfer of the next preview image.

In this way, since the transfer amount D transferred in each gap time Tu is controlled according to the communication status with the console 4, it is possible to perform stable and stable image transfer according to the communication status, and the preview transfer interval in the console 4 is possible. It is possible to perform stable and efficient preview display of a moving image in accordance with Tf.

As described above, according to the FPD cassette 3 of the present embodiment, the control unit 31 performs a thinning process for reducing the number of pixels on each of a plurality of frame images obtained by shooting a moving image to generate a preview image. , The generated preview images are sequentially transferred to the console 4 at the preview transfer interval Tf. At that time, the control unit 31 wirelessly communicates the residual image including the remaining portion not transferred as the preview image during the gap time Tu after the transfer of one preview image until the transfer of the next preview image is started. The unit 35 causes the wireless communication unit 35 to continuously transfer to the console 4 the remaining images that have not yet been transmitted after transmitting all the preview images of the moving image shooting.
Therefore, by utilizing the gap time Tu, it is possible to stably and efficiently transfer a moving image obtained by shooting a moving image. As a result, it is possible to minimize the waiting time until the start of the next process such as image analysis and diagnosis.

In addition, the control unit 31 controls the transfer amount D transferred in each gap time Tu according to the communication status with the console 4, for example, based on the response time of the image transfer command at the time of transferring each preview image and the RSSI value. Therefore, it is possible to perform a stable image transfer according to the communication status without difficulty, and it is possible to perform a stable and efficient preview display of a moving image on the console 4 according to the preview transfer interval Tf.

Note that the description content in the above-described embodiment is a preferred example of the present invention, and the present invention is not limited to this.

For example, in the above-described embodiment, the case where the second image transferred in the gap time Tu is the remaining residual image that is not transferred as the preview image of each frame image has been described as an example, but the present invention is not limited to this. For example, each frame image may be an image in which a correction process such as an offset correction or a gain correction or another image process is performed.

Further, although cases have been described with the above embodiments as examples where the present invention is applied to a system for round trip, the present invention is also applicable to a radiation imaging system that performs imaging in an imaging room.

Further, in the above embodiment, the present invention has been described by taking as an example the case where the present invention is applied to a radiation imaging apparatus for imaging a human body using radiation, specifically, the FPD cassette 3. However, a moving image of a human body is captured. It is not particularly limited as long as it is.

Further, in the above-described embodiment, the case has been described as an example where the radiation source 2 reads the pulsed radiation with the FPD cassette 3 to generate a moving image, but the radiation source 2 continues to emit a low dose. The moving image may be generated by reading the radiation emitted without interruption with the FPD cassette 3 at predetermined time intervals.

Further, in the above-described embodiment, the case where the preview transfer interval Tf is constant has been described as an example. However, the preview transfer interval Tf may be slightly different depending on the frame images.

Further, in the above embodiment, the case where the frame image of the moving image is transferred to the console 4 has been described as an example, but the external device of the transfer destination may be, for example, an engineer's tablet terminal or the like, and is not particularly limited. ..

Further, in the above-described embodiment, one access point AP is installed so as to be movable in the radiation control device 1 for rounds, but a plurality of access points AP may be provided. Some or all of the access points may be fixedly installed in the hospital. Further, the communication between the respective devices may be directly performed in an ad hoc mode or the like without using the access point AP.

Further, in the above description, an example in which a hard disk, a semiconductor nonvolatile memory, or the like is used as a computer-readable medium of the program according to the present invention is disclosed, but the invention is not limited to this example. As another computer-readable medium, a portable recording medium such as a CD-ROM can be applied. Further, a carrier wave is also applied as a medium for providing the data of the program according to the present invention via a communication line.

In addition, the detailed configuration and detailed operation of each device constituting the radiation imaging system can be appropriately changed without departing from the spirit of the present invention.

100 radiation imaging system 1 radiation control device 102a exposure switch 2 radiation source 3 FPD cassette 31 control unit 32 detection unit 33 storage unit 34 battery 35 wireless communication unit 36 bus 4 console 41 control unit 42 storage unit 43 operation unit 44 display unit 45 Communication unit 46 Bus AP Access point

Claims (5)

An image generation unit that generates a plurality of frame images by shooting a moving image of the subject ,
Decimation processing means for performing decimation processing for reducing the number of pixels on each of the plurality of frame images generated by the image generation means to generate a preview image ,
Transfer means for sequentially transferring the preview images generated by the thinning processing means to an external device;
After the transfer of one of the preview images, the residual image including the remaining part of the frame image that is not transferred as the preview image during the gap time before the transfer of the next preview image is started. The diagnostic or analysis image used for analysis is transferred to the external device by the transfer means, and after the transfer means finishes transferring the preview images of all the frame images captured in the moving image, it is still transferred. Control means for continuously transferring the diagnostic or analysis image that does not exist to the external device ,
A radiographic image capturing apparatus including. The radiation moving image capturing apparatus according to claim 1, wherein the transfer unit transfers the preview image at a predetermined time interval. The radiation moving image capturing apparatus according to claim 1, wherein the control unit controls a transfer amount of the diagnostic or analysis image transferred in the gap time according to a communication state with the external device. The control means, based on the response time of an image transfer command transmitted/received to/from the external device when the preview image is transferred by the transfer means, transfers the diagnostic or analysis image to be transferred to the gap time. The radiation moving image capturing apparatus according to claim 3, wherein the transfer amount is controlled. The transfer means transfers an image to the external device by wireless communication,
The control unit acquires the radio wave reception intensity of the wireless communication, and when the acquired radio wave reception intensity falls below a predetermined threshold value, controls so as not to perform transfer during the gap time. The radiation moving image capturing apparatus described.

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