JP5350079B2 - X-ray imaging apparatus and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To alter a time-out period of an FPD in accordance with the state of a system. <P>SOLUTION: Whether the FPD remains attached or not is determined in S202. If the FPD remains attached, proceed to S203. If the determination that patient information is not entered is made in S203, proceed to S204, and the time-out period for applying bias is read and is set, for example, at zero. If an examination is not started, and especially an imaging protocol is not entered while the patient's information is entered in S203, proceed to S209. Then, a time-out period for applying bias is read and is set, for example, at 2 minutes. In the same manner, if the patient information is entered, and the imaging protocol is entered in S203, proceed to S210. A time-out period for applying bias is read and is set, for example, at 10 minutes. Further, if the FPD remains unattached in S202, proceed to S208. Detachment operation is carried out, and proceed to S205. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an X-ray imaging apparatus that optimizes imaging preparation time and a control method thereof.

  In recent X-ray imaging apparatuses intended for medical diagnosis, digital X-ray imaging apparatuses employing an FPD (Flat Panel Detector) that converts an electrical signal proportional to the intensity of X-rays are used. In particular, since an image can be confirmed immediately after shooting in FPD, it is possible to immediately determine whether or not a failure has occurred immediately after shooting without waiting for film development processing, and the execution of shooting orders can be performed quickly. That is, it is possible to improve the imaging efficiency per hour for the X-ray engineer who is the user.

  However, in general, an FPD requires a predetermined time for image quality stability from power-on to photographing as in Patent Document 1 in order to correct system noise as compared with an analog film.

  The FPD is composed of a phosphor, a photoelectric conversion element, and a switch TFT, and it is known that the sensitivity of the FPD decreases in inverse proportion to the energization time. Therefore, it is not good for the image quality to leave the FPD in a bias application state in which photographing is always possible. In addition, in order to reduce power consumption, control is performed to time out the bias application state after a predetermined time has elapsed.

  In order to perform such bias application control, the FPD and the controller are connected by a cable having a signal line and a power supply line. However, compared with analog film, the cable is less convenient for handling before photographing, and may interfere with other devices and infusion tubes when, for example, examining a patient in an intensive care unit.

  Therefore, as in Patent Document 2, it is required to position the patient with the cable connecting the FPD removed at the connector portion, or to perform X-ray irradiation in a separated state. This separation operation is called a detach operation. I'm calling. On the other hand, for this detach operation, an operation for reconnecting the connector and returning to the normal state is called an attach operation.

JP-A-10-104766 JP 2000-254115 A

  In the above-described system configuration in which the FPD cable is detachable, the power cannot be supplied to the FPD if the cable is removed. That is, after reconnecting the cable, a waiting time of, for example, at least 10 seconds is required until image noise can be stably captured. Therefore, unless a bias is preliminarily applied to the FPD, there is a problem in that it is not possible to immediately use the camera when it is desired to take a picture and the usability is impaired.

  An object of the present invention is to improve the convenience of the user and reduce the power consumption of the system by changing the connection state and shortening the time until imaging by the X-ray imaging sensor becomes possible. An X-ray imaging apparatus and a control method therefor are provided.

  In order to achieve the above object, an X-ray imaging apparatus according to the present invention is an X-ray imaging apparatus that images an X-ray image as a digital image by an X-ray imaging sensor comprising an FPD, and the connection state of the X-ray imaging sensor Detecting means, storage means for storing control parameters for X-ray imaging, command communication means for changing the control parameters, measuring means for measuring a timeout period of bias application to the X-ray imaging sensor, and inspection It is characterized by comprising detection means for detecting the progress state and transmission means for transmitting a control command.

  In order to achieve the above object, a method for controlling an X-ray imaging apparatus according to the present invention includes: an X-ray imaging apparatus that captures an X-ray image as a digital image by an X-ray imaging sensor including an FPD; The method includes a step of setting a timeout period for bias application to the X-ray imaging sensor, a step of measuring the bias application time, and a step of stopping the bias application of the X-ray imaging sensor.

  According to the X-ray imaging apparatus and the control method thereof according to the present invention, when an X-ray imaging sensor is connected, a control command is output according to the progress of the examination, and the waiting time until imaging becomes possible is controlled. In addition, power saving control is also possible.

It is a block circuit block diagram of an X-ray imaging system. It is a block circuit block diagram of a X-ray imaging control part. It is explanatory drawing of a test | inspection screen. It is explanatory drawing of an imaging | photography screen. It is explanatory drawing of an imaging | photography screen. It is explanatory drawing of an imaging | photography screen. It is an operation | movement flowchart figure of command communication control. It is an operation | movement flowchart figure of connection interruption control. It is explanatory drawing of the example of a memory | storage of timeout time. It is explanatory drawing of the display screen which instruct | indicates a connection change. It is explanatory drawing of the display screen which instruct | indicates a connection change. It is an operation | movement flowchart figure of temperature control.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 is a block circuit configuration diagram of an X-ray imaging system. An X-ray imaging apparatus 1 of this embodiment mainly includes an X-ray tube 2, an X-ray generation control unit 3, an X-ray imaging unit 4, and an X-ray imaging. It is comprised from the control part 5. An X-ray imaging unit 4 including an FPD as an X-ray imaging sensor is disposed in front of the X-ray tube 2 via a subject S, and an output of a digital image of the X-ray imaging unit 4 is a connector 6. The X-ray imaging control unit 5 is connected via a control line 7.

  The output of the X-ray imaging control unit 5 is connected to the X-ray tube 2 via the X-ray generation control unit 3, and the X-ray imaging control unit 5 is further connected to the mobile mobile X-ray imaging device via the LAN 8. 9 and connected to the viewer 10. Further, the X-ray imaging control unit 5 is also connected to an external RIS (Radiology Information System) 11 and a PACS (Picture Archiving and Communication System) 12 via the LAN 8. Here, the RIS 11 is a system that progresses and manages radiographing instructions from a doctor, and the PACS 12 is a system that is used in medical care and transmits and receives medical image data over a network.

  The control line 7 includes a signal line and a power supply line, and the signal line is used for transmission of control parameters, shooting timing control, and transfer of a shot image. The control line 7 is configured to be detachable by a connector 6, and when the patient's posture is aligned, the X-ray imaging unit 4 can be temporarily disconnected from the X-ray imaging control unit 5 and reconnected, It is also possible to connect to the mobile X-ray imaging apparatus 9.

  In the first embodiment, X-rays are generated from the X-ray tube 2 in accordance with an instruction from the X-ray generation control unit 3 in accordance with an imaging protocol input from the RIS 11, and X-ray imaging is performed by the X-ray imaging unit 4. An imaging protocol is a unit of X-ray imaging. For example, imaging parts such as the chest, upper arm, lower limb, head, cervical spine, and lumbar region, imaging direction, posture, angle, tube voltage, tube current, irradiation time, tube distance Imaging conditions such as X-ray imaging conditions are defined.

  The image that has been imaged and the accompanying information are output from the X-ray imaging control unit 5 to the PACS 12, and the doctor can observe and diagnose the X-ray image with the image viewer 10. An X-ray engineer who is a user can use an optimum X-ray imaging apparatus among the X-ray imaging apparatus 1 and the mobile X-ray imaging apparatus 9 depending on, for example, the availability of the X-ray imaging room.

  FIG. 2 shows a detailed block circuit configuration diagram of the X-ray imaging control unit 5. The CPU 21 is connected to a RAM 22, an HDD (hard disk drive) 23, a display 24, a mouse 25, and a keyboard 26.

  The CPU 21 executes commands stored in the RAM 22 to perform control of the apparatus, image processing of captured images, and the like. Further, the CPU 21 performs an input to the screen displayed on the display 24 and reflects the result on the display 24. The control program is stored in the HDD 23. The HDD 23 also stores an OS (operating system) necessary for starting the program of the X-ray imaging apparatus and a database necessary for executing the program, and commands in the RAM 22 operate on the OS. . The display 24 displays elements such as images, icons, characters, and the like, and the X-ray technician operates the X-ray imaging apparatus 1 based on the imaging screen displayed on the display 24 using the mouse 25 and the keyboard 26.

  FIG. 3 shows an inspection screen 30 in which the inspection order received from the RIS 11 is displayed on the display 24 in order to perform the X-ray inspection. A message for guiding an operation to be performed by the X-ray technician is displayed in the message area 31, patient information is displayed in the list 32, and the selected protocol is displayed on the imaging protocol display unit 33 indicating the region to be imaged designated by the doctor. indicate.

  In the control program executed by the CPU 21, even if the X-ray engineer performs a detach operation or an attach operation on the FPD of the X-ray imaging unit 4 on the inspection screen 30, it is not displayed on the screen. When the “next” button 34 is pressed by the X-ray engineer to start the inspection on the screen, the control program executed by the CPU 21 transitions to a screen for executing the X-ray inspection.

  FIG. 4 shows an X-ray examination imaging screen 40 displayed on the display 24. In order to execute X-ray imaging, the status display unit 41 displays whether the FPD is in a detached state or an attached state. The shooting protocol display unit 42 displays the selected shooting protocol together with a green button to indicate that the protocol is to be shot. The message display unit 43 displays “READY” by the control program when the FPD noise is reduced and the camera is ready for shooting, and changes the background color to green to indicate that shooting is possible.

  The imaging screen 40 shown in FIG. 5 shows an example in which the control program executed by the CPU 21 detects that the X-ray technician has removed the FPD control line 7 as a detached state in the imaging ready state of FIG. Yes. The control program overwrites the X mark on the state display unit 41 that has detected the FPD detachment, and displays that it is in the OFF state. Further, the message display unit 43 is changed to a display “Please confirm the connection state of the FPD”, and at this time, the photographing protocol display unit 42 maintains the display being selected.

  FIG. 6 shows a photographing screen 40 in which the control line 7 is connected and the FPD attached state is detected from the state of FIG. When it is detected that the selected FPD has been attached, the FPD status display unit 41 is turned ON, and a control command corresponding to the display on the imaging protocol display unit 42 is transmitted to the FPD to wait for X-ray imaging. Transition. In order to remove the dark current noise, the switch TFT is refreshed for a predetermined time, and “Please wait for a while” is displayed on the message display unit 43 until X-ray imaging becomes possible.

  For example, in the case of the present embodiment, when 10 seconds have elapsed from the start of energization and when it is detected that the dark current noise of the FPD has decreased, the state is returned to the photographing enabled state of FIG. Looking at the display on the imaging screen 40, the X-ray engineer presses the X-ray irradiation switch to irradiate the subject S with the X-ray, and images the subject S.

  The control program for driving the FPD measures the timeout time received by the control command from the start of energization. If X-ray imaging is not executed, the energization of bias application to the FPD is stopped to save power, and the bias application is performed. To release. This time-out process can also be realized by measuring time with a program executed by the X-ray imaging control unit 5 and transmitting an energization stop command to the FPD.

  FIG. 7 is an operation flowchart when an FPD status notification is received. First, when the control program executed by the CPU 21 receives a status notification event from the FPD, the process proceeds to step S100 to start processing. In step S101, the CPU 21 receives an FPD status status code I = 0-3. In step S102, the current bias application timeout period is read from the memory. In addition, the SLEEP state etc. which are demonstrated in FIG. 7 have shown the state like following Table 1. FIG.

Table 1
CPU bias application state SLEEP ON OFF Immediately after the connector is connected. Power saving state IDLE ON ON Preparing for shooting drive (temporary transition)
READY ON ON Shooting is possible OFF OFF OFF Power OFF Connector is not connected

  In step S103, the process branches according to the notified status state code I. If I = 1, the process proceeds to step S104, the system state is set to the SLEEP state, and a control command for applying a bias to the FPD is transmitted. If the status status code is I = 2, the process advances to step S105 to set the system status to IDLE. When I = 3, the process proceeds to step S106, and the system state is set to the ready state where photographing is possible. When I = 0, the process proceeds to step S107 and is set to the OFF state.

  In step S108, a bias application control command is transmitted, and then in step S109, the system state is changed. In step S110, the status process is terminated.

  FIG. 8 shows an interrupt process (Interrupt Sub Routine) when an attach operation to the FPD is detected, and the bias application time-out time in step S102 of FIG. 7 is changed according to the system state. When the control program executed by the CPU 21 detects reconnection due to the attach operation, connection detection interrupt processing in step S200 is performed. In step S201, interrupts are prohibited so that multiple interrupt processing is not executed.

  Then, it progresses to step S202 and it is determined whether FPD is an attached state. If it is in the attached state, the process proceeds to step S203, and it is determined whether the inspection is in progress. If it is determined in step S203 that the state N = 1 when no patient information is input, the process proceeds to step S204, where the bias application time-out time is read from the memory N1, and for example, the time-out time is set to zero.

  Returning to FIG. 7 for explaining step S204, the timeout time in step S102 is set to 0 by the control program, so that the command communicated in step S107 can instruct to omit the bias application. That is, when there is no control of FIG. 8, a bias is applied to the FPD without depending on the system state. However, when the FPD is simply reconnected, not for preparing for shooting, it is not necessary to output a control command, but a bias is applied to reduce the sensitivity.

  In step S205, the same event as that when the control command is received is generated from the FPD, and then the process proceeds to step S206 to permit the interrupt, and the process proceeds to step S207 to end the interrupt process.

  FIG. 9 shows the timeout time (minutes) stored in the HDD 23, the column 800 corresponds to the system state, and the column 801 shows the bias application timeout time when the test is not performed. When the inspection is started, the timeout time is read with reference to the column 802.

  On the other hand, if it is not in the attached state in step S202, the process proceeds to step S208, a detach operation is executed, and the process proceeds to step S205.

  Further, when the examination is not started in step S203, if it is determined that the patient information is input and the state N = 2 when the imaging protocol is not input, the process proceeds to step S209. In this case, the bias application time-out time is read from the memory N2 and set to 2 minutes, for example. Thereby, the operation can be set as a system state where the priority immediately starts photographing.

  Similarly, if it is determined in step S203 that patient information is input and the state N = 3 when the imaging protocol is input, the process proceeds to step S210, and the bias application time-out time is read from the memory N3, for example, 10 minutes. Set to. Thereby, it is possible to set a system state in which it is difficult to time out the bias application of the FPD during the execution of imaging of the patient.

  Therefore, in this embodiment, in order to shorten the waiting time until the photographing is possible when the connection of the FPD is detected, whether to apply a bias to the FPD according to the examination progress state, and further, the timeout time is set. It becomes possible to decide.

  In the second embodiment, the control line 7 shown in FIG. 1 is not connected by a cable, that is, configured by wireless communication using a wireless LAN instead of a signal line. At the same time, by mounting a battery in the FPD instead of the power line, the FPD and the X-ray imaging control unit 5 can be logically connected.

  In the first embodiment, it is possible to detect when the X-ray imaging unit 4 including the FPD is once removed from the control of the X-ray imaging control unit 5 or reconnected by the connector 6. However, in the case of wireless communication, if the connection destination is automatically switched according to the signal strength instead of the detach operation and the attach operation by the connector 6, there is a possibility that an error in the connection destination may occur. It is necessary to explicitly instruct the photographing apparatus 1.

  For example, the control line 7 is temporarily removed during the examination, the posture of the subject S is aligned, and the temporary detaching and attaching operations for connecting the control line 7 again are unnecessary because there is no physical connection. Become. However, when the X-ray imaging unit 4 having FPD is shared and used for the mobile X-ray imaging apparatus 9, it is necessary to give a release instruction to the X-ray imaging control unit 5.

  This is because the mobile X-ray imaging apparatus 9 continues the logical connection with the X-ray imaging control unit 5 and cannot receive a control command. If another connection request is automatically detected and the connection is released, there is a possibility that the logical connection may be lost due to a false detection even if it should not be released. Therefore, there is a problem that synchronization cannot be established between the X-ray imaging apparatus 1 and the X-ray imaging apparatus 9 during imaging.

  Therefore, the control program executed by the CPU 21 pushes the state display unit 41 indicating the state of the FPD in FIG. 6 in order to release the logical connection. As a result, the screen transitions to the display screen 50 in FIG. 10, the connection target is scanned, and the FPD name, wireless LAN signal strength, presence / absence of existing logical connection, and encryption method are displayed in the table 51 in FIG.

  After the connection confirmation display screen 50 shown in FIG. 10 is displayed, if “release” is selected by the instruction button 52 by the X-ray technician, a control command for releasing the programmed logical connection is transmitted to the FPD. Further, in order to display the connection state, the instruction button 52 is overwritten with a cross mark as in the state display unit 41 shown in FIG. When the X-ray engineer selects the “OK” button 53 without operating the instruction button 52, the CPU 21 returns to the original screen while maintaining the logical connection.

  When the control program executed by the CPU 21 confirms that the above-described logical connection is released, the CPU 21 displays “None” as the connection in Table 51. When a target FPD is selected on the display screen 50 and a connection is established with the selected FPD, “connection” is selected with the instruction button 52.

  Further, a wireless connection change button is added on the FPD, and the FPD can be selected on the screen of the mobile X-ray imaging apparatus 9 with the X-ray technician pressing the instruction button 52 to change the connection. At this time, the control program executed by the CPU 21 displays the information of the FPD received by scanning the wireless moving body as shown in FIG.

  Thus, even in the case of a wireless communication configuration, a logical connection is formed by communicating a command when a connection is changed. Then, as a condition for enabling the FPD to be photographed, the command communication content is similarly changed according to the inspection input and executed.

  In the third embodiment, a temperature sensor (not shown) is added to the FPD in order to acquire the internal temperature of the switch TFT provided in the X-ray imaging unit 4 in FIG. FIG. 12 is a flowchart when the attached state is detected in step S202 of FIG.

  Since the FPD has a characteristic that the image quality varies depending on the internal temperature, an error may occur at a temperature immediately after bias application unless correction using nonlinear correction data is performed.

  In contrast, in the third embodiment, control is performed to stabilize the image quality by acquiring the temperature of the FPD after power-on and accelerating to a steady temperature that can be corrected by linear data. In addition, when the frequency of use increases and cooling of the internal temperature is required, control for reducing the voltage application time is required.

  The control program executed by the CPU 21 acquires the current temperature information T in step S301, and compares it with the threshold value of the upper limit TH set in advance in step S302. When the temperature is higher than the upper limit value TH, the process proceeds to step S303, and the cooling sequence is executed. In this cooling sequence, the bias application of the FPD is stopped, the rotation speed of the cooling fan is increased, and at the same time the timeout period N of bias application is shortened. The method for shortening the timeout time N is performed by changing the table shown in FIG. 9 to a cooling table, and then the process ends in step S304.

  Further, in the case of immediately after power-on in a low temperature environment, the process proceeds to step S305 in the determination of step S302. Run. In the heating sequence, for example, bias is forcibly applied, and the timeout time N is set longer than the normal state, thereby raising the internal temperature of the FPD.

  For example, in the second embodiment, the bias application is stopped when the X-ray inspection is not started. However, in the third embodiment, when the time-out time N1 is changed to 5 minutes, the temperature is not stable and low. Acceleration is possible. By this control, the FPD is raised to a predetermined temperature at an early stage, and an effect of stabilizing the corrected image quality is obtained.

  If it is determined that the temperature of the FPD is in a steady state and the process exits step S305, the process proceeds to step S304 without executing the temperature control and exits from this subroutine. That is, since the control of FIG. 8 is executed when the temperature reaches a steady state, the timeout time N1 is set to 0, and control is performed to avoid unnecessary power consumption.

  As described above, in the third embodiment, the control command can be optimized by determining the control parameter according to the temperature of the FPD.

DESCRIPTION OF SYMBOLS 1 X-ray imaging apparatus 2 X-ray tube 3 X-ray generation control part 4 X-ray imaging unit 6 Connector 7 Control line 9 Mobile X-ray imaging apparatus 10 Viewer 11 RIS
12 PACS
21 CPU
22 RAM
23 HDD
24 display 25 mouse 26 keyboard 30 inspection screen 40 shooting screen 50 display screen

Claims (5)

An X-ray imaging apparatus having an X- ray imaging sensor that captures an X- ray image as a digital image,
Measuring means for measuring the timeout time to stop the bias application to the X-ray image sensor,
Detection means for detecting the progress of the inspection;
Control means for performing control to not apply the bias regardless of whether the time-out time elapses when it is detected by the detection means for detecting the inspection progress state; and
An X-ray imaging apparatus comprising: Means for detecting a connection state of the X-ray imaging sensor;
2. The control unit according to claim 1, further comprising a setting unit configured to set the timeout period, wherein a bias is applied when the connection of the X-ray imaging sensor is detected, and the bias application is stopped at the timeout. The X-ray imaging apparatus described. The X-ray imaging apparatus according to claim 2 , wherein the timeout time is set depending on whether patient information or imaging conditions are input. Obtaining means for obtaining an internal temperature of the X-ray imaging sensor;
The X-ray imaging apparatus according to claim 2, wherein the setting unit sets a timeout period of the bias application based on a comparison between the internal temperature and a threshold value. In an X-ray imaging apparatus having an X- ray imaging sensor that captures an X- ray image as a digital image,
Setting a bias application timeout period for the X-ray imaging sensor by inputting imaging conditions;
Measuring the bias application time;
A control step for performing control not to apply the bias regardless of whether the time-out period elapses when it is detected that the inspection is not being performed by the detection unit that detects the inspection progress state;
An X-ray imaging method comprising:

Images