JP2017006334A - X-ray image diagnostic apparatus - Google Patents

Abstract

An object of the present invention is to prevent overheating of an X-ray tube when the opening of an X-ray diaphragm is below a predetermined opening degree under automatic brightness adjustment.
An X-ray diagnostic imaging apparatus according to the present invention includes an X-ray source unit that irradiates a subject with X-rays, a diaphragm having lead blades that form an opening through which the X-rays pass, and a transmission through the subject. And an X-ray detector for detecting the X-ray. In addition, a sensor unit that detects the position information of the lead blades, a determination unit that determines whether or not the threshold value of the opening degree of the opening set in advance using the position information detected by the sensor unit, and a determination result of the determination unit And a controller that stops or cancels the X-ray irradiation.
[Selection] Figure 1

Description

  The present invention relates to an X-ray diagnostic imaging apparatus, and more particularly to an X-ray diagnostic imaging apparatus provided with means for suppressing overheating of an X-ray tube during X-ray fluoroscopic imaging.

  An X-ray diagnostic imaging apparatus controls an X-ray diaphragm to irradiate a region of interest of a subject and detect transmitted X-rays with an X-ray detector in order to reduce the amount of radiation irradiated to the subject. Thus, an X-ray signal of the subject is obtained. The X-ray image diagnostic apparatus displays an X-ray image or a fluoroscopic image on the display unit by processing the X-ray signal in the image processing unit. A fluoroscopic image is a moving image obtained by continuously irradiating a subject with a low-level dose of X-rays and detecting the transmitted X-rays with an X-ray detector.

  Patent Document 1 discloses an X-ray diagnostic imaging apparatus that automatically adjusts the brightness of a fluoroscopic image obtained from an X-ray signal. In this automatic luminance adjustment, the control unit automatically adjusts the contrast or luminance of the fluoroscopic image by changing the X-ray condition by controlling the high voltage generator based on the fluoroscopic image acquired from the image processing unit. Technology.

JP 2000-261724 A

In such an automatic brightness adjustment technique, for example, when the acquired image area is so small that the image processing unit cannot recognize it as an image, it recognizes that the X-ray output is insufficient, and the X-ray irradiation conditions (X-ray irradiation time and tube In some cases, the X-ray irradiation may be continued while the current, the product mAs thereof, the tube voltage, etc.) remain at the maximum values.
The image causing the recognition that the X-ray output is insufficient is acquired, for example, when the opening of the X-ray diaphragm has a very small area due to an erroneous operation by the operator.
If the X-ray output is continued under the maximum X-ray irradiation conditions by automatic brightness adjustment under such an X-ray aperture condition, the temperature of the X-ray tube will rise and the temperature protection circuit will work to regulate the temperature. The device cannot be used until the value falls below.

  An object of the present invention is to prevent overheating of an X-ray tube when the opening of an X-ray diaphragm is not more than a predetermined opening degree under automatic brightness adjustment.

In order to solve the above-mentioned problems, the X-ray diagnostic imaging apparatus of the present invention has means for controlling X-ray irradiation from position information of lead blades constituting the diaphragm.
Specifically, the X-ray diagnostic imaging apparatus of the present invention includes an X-ray source unit that irradiates a subject with X-rays, a diaphragm unit having lead blades that form openings through which the X-rays pass, and the subject. An X-ray detector that detects the transmitted X-ray. In addition, a sensor unit that detects the position information of the lead blades, a determination unit that determines whether or not the threshold value of the opening degree of the opening set in advance using the position information detected by the sensor unit, and a determination result of the determination unit And a controller that stops or cancels the X-ray irradiation.

  The present invention can prevent overheating of the X-ray tube by controlling the X-ray irradiation when the opening of the X-ray diaphragm is not more than a predetermined opening degree under automatic brightness adjustment.

The figure explaining the whole outline | summary of the X-ray-image diagnostic apparatus with which this invention is applied The figure explaining an example of an aperture blade Functional block diagram of the main configuration of the X-ray diagnostic imaging apparatus of the first embodiment The flowchart figure explaining the process of the X-ray-image diagnostic apparatus of 1st embodiment. The figure explaining the relationship between the positional information which prescribes | regulates the opening degree from the full closure of a lead blade to full open, and X irradiation control The figure explaining the change of the X-ray irradiation prohibition area | region accompanying the change of SID Functional block diagram of the main configuration of the X-ray diagnostic imaging apparatus of the second embodiment The figure explaining the relationship between aperture value, X-ray irradiation area, and SID The flowchart figure explaining the process of the X-ray-image diagnostic apparatus of 2nd embodiment. The figure explaining the change of the threshold value of aperture opening degree accompanying the change of SID The figure which shows an example of the output of the display part in the X-ray image diagnostic apparatus of 1st and 2nd embodiment

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Hereinafter, in all the drawings for explaining the embodiments of the present invention, those having the same function are denoted by the same reference numerals, and repeated explanation thereof is omitted.

As shown in FIG. 1, an X-ray diagnostic imaging apparatus 1 (hereinafter referred to as “X-ray apparatus 1”) mainly includes a top plate 106 on which a subject 100 is placed and an X-ray source unit that irradiates the subject 100 with X-rays. 102, a diaphragm 104 for setting an X-ray irradiation region for the subject 100, a high voltage generator 108 for supplying power to the X-ray source unit 102, and a position facing the X-ray source unit 102. An X-ray detection unit 110 that detects X-rays that have passed through the specimen 100, an image processing unit 112 that performs image processing on the X-ray signal output from the X-ray detection unit 110, and an output from the image processing unit 112 An image storage unit 114 that stores an X-ray image, a display unit 116 that displays an X-ray image, and an overall control unit 123 that controls the above-described components and the like.
In the present embodiment, the X-ray image includes a still image and a moving image (perspective image).

  The X-ray source unit 102 has an X-ray tube that receives power supply from the high voltage generation unit 108 and generates X-rays. The X-ray source unit 102 may include an X-ray filter that selectively transmits X-rays having specific energy.

  The high voltage generator 108 applies a high voltage to the X-ray tube in accordance with an instruction from the main controller 118 described later.

  The diaphragm unit 104 has a plurality of X-ray shielding lead plates that shield X-rays generated from the X-ray source unit 102, and each of the plurality of X-ray shielding lead plates is operated to perform X-rays on the subject 100. Determine the irradiation area.

  FIG. 2 shows an example of the aperture unit 104. The diaphragm 104 has four lead plates for X-ray shielding (hereinafter referred to as “lead blades”) 202, 203, 204, and 205, which are moved to a predetermined position independently or in conjunction with each other ( 2), the aperture 208 of the diaphragm is formed. The lead blades 202 to 205 are remotely operated via a motor (not shown) or the like.

  The degree of opening of the opening 208 formed by the lead blades 202 to 205 (hereinafter “lead blade opening degree”) is, for example, the area of the opening 208 formed by the lead blades 202 to 205 (hereinafter referred to as “throttle opening degree”). And the distance between lead blades.

  The X-ray detection unit 110 is configured by, for example, a plurality of detection elements that detect X-rays arranged in a two-dimensional array, and is incident from the X-ray source unit 102 and transmitted through the subject 100. It is a device that outputs an X-ray signal according to.

  The image processing unit 112 processes the X-ray signal output from the X-ray detection unit 110 and outputs an X-ray image. The processing performed by the image processing unit 112 includes gamma conversion, gradation conversion processing, image enlargement / reduction, and the like.

  The image storage unit 114 stores the X-ray image output from the image processing unit 112. The display unit 116 displays the X-ray image output from the image processing unit 112 or the X-ray image stored in the image storage unit 114.

  The overall control unit 123 includes a main control unit 118 that receives a command from the operation unit 120, and a determination unit 122 and a threshold value management unit 121, or these and a correction unit 701 depending on the embodiment described below. .

  The main control unit 118 controls the operation of each unit of the X-ray apparatus 1 and performs still shooting and moving image shooting (fluoroscopic shooting). The main control unit 118 has a function (automatic brightness adjustment (ABC) function) for detecting the brightness of the X-ray image output from the image processing unit 112 and controlling the high voltage generation unit 108 during fluoroscopic imaging.

  Each unit constituting the overall control unit 123 can be constituted by a CPU and a memory. The memory stores in advance a program for executing the function of each unit, and the CPU reads and executes the program in the memory. As a result, the operation of each part can be realized. In the description of the processing procedure of each unit to be described later, it will be described as being realized as software, but this embodiment is not limited to software, and the processing of each unit may be realized by hardware such as ASIC or FPGA. Is possible.

The outline of the operation of the X-ray apparatus 1 of the present embodiment relating to the ABC processing at the time of fluoroscopic imaging is as follows.
When fluoroscopic imaging is started, the high voltage generation unit 108 supplies power to the X-ray source unit 102, and X-rays are output to the X-ray irradiation region 207 set by the diaphragm unit 104.
X-ray information transmitted through the subject 100 is received by the X-ray detection unit 110, X-ray signals are transmitted to the image processing unit 112, and the X-ray image or fluoroscopic image stored in the image storage unit 114 by the image processing unit 112 is displayed. To the unit 116.
The main control unit 118 controls the high voltage generation unit 108 and adjusts the X-ray intensity in order to adjust the brightness of the fluoroscopic image output from the image processing unit 112.

  Specifically, during fluoroscopic imaging, the main control unit 118 determines the brightness of the acquired image using a predetermined area at the center of the X-ray image set as a region of interest. By averaging the values of all the pixels in the region of interest and comparing the average value with a preset threshold value, the brightness of the acquired screen can be determined, and an X-ray image with appropriate brightness can be obtained. The X-ray condition is changed by operating the high voltage generation unit 108 until. X-ray conditions are tube voltage, tube current and imaging time, or their product mAs.

  For example, when the X-ray dose received by the X-ray detection unit 110 is small or when the contrast of the image created by the image processing unit 112 is low, it is necessary to change the X-ray condition and output a strong X-ray. . Therefore, the high voltage generator 108 is controlled so as to output X-rays with higher intensity.

  The configuration of the X-ray apparatus 1 described above and the operation of the X-ray apparatus 1 related to ABC processing during fluoroscopic imaging are common to the embodiments described below.

  In the ABC processing, the main control unit 118 also outputs X-rays even when the diaphragm unit 104 is completely closed and there is no signal received by the X-ray detection unit 110 or when the acquired image area is so small that the image processing unit 112 cannot recognize the image. Therefore, X-ray irradiation is continued with the X-ray condition being at the maximum value. If the X-ray output is continuously performed under the maximum condition, the temperature of the X-ray tube is increased, and the apparatus cannot be used until the temperature is reduced to a specified value or less by operating the temperature protection circuit.

  Therefore, the X-ray apparatus 1 of this embodiment controls the X-ray irradiation from the positional information of the lead blades 202 to 205 constituting the diaphragm unit 104 in the ABC processing at the time of fluoroscopic imaging, and prevents the temperature rise of the X-ray tube. Means to do. This control means can take several forms, as in the embodiments described below.

<First embodiment>
The X-ray apparatus 1 of the present embodiment acquires the position information of the lead blades from the sensor unit during fluoroscopic imaging, and stops the X-ray irradiation when the lead blade opening degree is smaller than a predetermined lead blade opening degree. If large, X-ray irradiation is performed.
In order to realize such control, as shown in FIG. 3, each of the lead blades 202 to 205 is provided with a position detection sensor unit 124 such as a position detection encoder or potentiometer, and the position detection sensor unit 124. Transmits the position information of these lead blades to the main control unit 118.

  In addition to the main control unit 118, the overall control unit 123 includes a determination unit 122 that determines the lead blade opening degree during fluoroscopic imaging and a threshold management unit 121 that manages a threshold value of the lead blade opening degree.

  In addition to controlling the operation of each part of the X-ray apparatus 1, the main control unit 118 monitors the position detection sensor unit 124 and converts the obtained position information into a scale that matches the threshold used by the determination unit 122. Is notified to the determination unit 122. Here, the area of the opening 208 (aperture aperture) is used as a scale.

  The state in which the opening 208 is completely open is referred to as “fully open”, and the state in which the opening 208 is completely closed is referred to as “fully closed”. Expressing “fully open” and “fully closed” in terms of the area of the opening 208 is referred to as “fully open” when the area of the opening 208 has the maximum value, and there is no area of the opening 208 or the area value is “zero”. Is called “fully closed”. When fully closed, the opening 208 may not be formed by four lead blades, and the opening 208 is not formed by closing any one of the lead blades 202 and 205 or the lead blades 203 and 204 facing each other. It may be the case.

The threshold management unit 121 receives an instruction from the main control unit 118 and manages the threshold value of the opening degree used by the determination unit 122 by setting or appropriately correcting the threshold value.
In the present embodiment, the threshold management unit 121 sets a predetermined aperture opening degree as a threshold in advance. For example, the threshold value management unit 121 sets the aperture value (hereinafter referred to as “minimum aperture value”) that determines the X-ray irradiation range 207 in which the acquired fluoroscopic image does not have information necessary for diagnosis as a threshold value. To do. Such a threshold value of the aperture opening degree is, for example, a very small area that forms a small gap without the lead blades 202 to 205 being completely closed.

  The determination unit 122 compares the aperture opening degree calculated from the position information of the lead blades 202 to 205 acquired from the main control unit 118 with the threshold value of the lead blade opening degree set by the threshold value management unit 121 to make a determination.

  The operation of the X-ray control process at the time of fluoroscopic imaging accompanied with the ABC process in this embodiment will be described with reference to FIG.

<Step S301>
While X-rays are irradiated and fluoroscopic imaging is being performed, the operator moves the lead blades 202 to 205 to a position where the aperture aperture degree for obtaining the target image range is obtained by remote control. The position detection sensor unit 124 notifies the main control unit 118 of the position information of these lead blades. In the present embodiment, an encoder that detects the amount of movement is used as an example of the position detection sensor unit 124.

<Step S302>
The main control unit 118 monitors the position information of the lead blades 202, 203, 204, and 205 notified from the position detection sensor unit 124, calculates the aperture opening degree from the position information, and calculates the calculated aperture opening degree. The determination unit 122 is notified. In the present embodiment, the main control unit 118 calculates the aperture opening degree from the movement amount of each of the lead blades 202 to 205 notified from the encoder.
The determination unit 122 compares the notified aperture opening degree with the threshold set in advance by the threshold management unit 121.

<Step S303>
If the determination unit 122 determines that the notified aperture opening degree is larger than the set threshold value, the determination unit 122 returns to step S302 described above. When it is determined that the notified aperture opening degree is equal to or less than the set threshold value, it is notified to the main control unit 118. The cause determined to be less than or equal to the threshold value may occur due to an erroneous operation of the diaphragm blades 202 to 205 by the operator, for example.

<Step S304>
Receiving the notification from the determination unit 122, the main control unit 118 sends a notification of X-ray irradiation stop to the high voltage generation unit 108. Receiving the notification, the high voltage generation unit 108 stops the power supply to the X-ray source unit 102 and stops the X-ray irradiation. Thereby, since the fluoroscopic image is not displayed, the operator notices an erroneous operation of the lead blade and can correct the position of the lead blades 202 to 205 to an appropriate position.

<Step S305>
Even after the X-ray irradiation is stopped, when the instruction from the operator is in the fluoroscopic imaging state, the lead blade position detection sensor unit 124 notifies the main control unit 118 of the position information of these lead blades.

<Step S306>
The main control unit 118 monitors the position information of the lead blades 202, 203, 204, and 205 notified from the sensor unit 124, calculates the aperture opening degree from the position information, and notifies the determination unit 122 of it. The determination unit 122 compares the notified aperture opening degree with the threshold set by the threshold management unit 121 (similar to step S302).

<Step S307>
If the determination unit 122 determines that the notified aperture opening degree is equal to or less than the set threshold, the process returns to step S306 described above. When it is determined that the notified aperture opening degree is larger than the set threshold value, it is notified to the main control unit 118. For example, if the operator has not yet noticed an erroneous operation of the aperture blade, the process returns to step S306 described above, and the X-ray irradiation stop state is maintained. On the other hand, when the operator notices an erroneous operation of the lead blades and corrects the positions of the lead blades 202 to 205 to an appropriate position, thereby increasing the aperture opening degree, the operator is notified.

<Step S308>
Receiving the notification, the main control unit 118 notifies the cancellation of the X-ray irradiation stop signal sent to the high voltage generation unit 108. Receiving the notification, the high voltage generation unit 108 resumes the supply of power to the X-ray source unit 102 and X-ray irradiation is started.

  According to the present embodiment, during fluoroscopic imaging, the X-ray irradiation is stopped when the lead blades 202 to 205 are moved to a position where the minimum aperture value is formed, for example, due to an erroneous operation by the operator. It is possible to prevent the photographing of a fluoroscopic image in which information necessary for the display cannot be displayed. In addition, unnecessary X-ray output can be stopped in the ABC process to reduce the risk of X-ray tube overheating. Furthermore, unnecessary X-ray exposure given to the subject can be suppressed.

  In the present embodiment, the minimum value of the aperture opening degree is given as an example of the predetermined aperture opening degree (threshold value). However, the user may set an arbitrary range of aperture opening degree as the predetermined aperture opening degree in advance. . Specifically, X-ray irradiation is started when the operator obtains an image that exceeds the preset X-ray irradiation area 207 with an emphasis on reducing exposure of the subject, and the preset X-ray irradiation area 207 is started. A threshold value of the aperture opening degree may be set so that X-ray irradiation is stopped when the following image is acquired. For example, when fluoroscopic imaging is started, the irradiation range is narrowed by operating the diaphragm so that the target X-ray irradiation region 207 (image range) is reached after the irradiation range is set to the widest state. Second, a method of operating to expand the X-ray irradiation range from the state in which the aperture is closed after the X-ray irradiation center position is determined by a laser or the like to the target X-ray irradiation region 207 (image range). A street is conceivable. When the aperture opening degree for obtaining the target X-ray irradiation region 207 is set as a threshold value, in the former case, if the size is the same as or smaller than the size of the target X-ray irradiation region 207, X-ray irradiation can be prohibited. In this case, X-ray irradiation can be prohibited until the target X-ray irradiation area 207 is wide, and exposure can be reduced.

<Variation 1 of the first embodiment>
In the present embodiment, the aperture opening degree (area) is used as the threshold value for the degree of opening of the lead blades, but the present invention is not limited to this. As shown in FIG. 5, the position information of the lead blades 202 to 205 that can define the degree of opening (condition) of the lead blades from fully closed to fully open of the lead blades 202 to 205 may be used as a threshold value. Such position information includes a movement amount, position coordinates, and the like. Further, by using the threshold value of such position information, the X-ray irradiation control is performed at the time of the threshold value and when the X-ray irradiation is closer to the fully closed state than the threshold value. You may set so that line irradiation may be started.

<Modification 2 of the first embodiment>
In the present embodiment, the position detection sensor unit 124 is described as an encoder that detects the amount of movement, but a sensor that can detect position coordinates may be used. In this case, for example, the plurality of sensors are arranged at positions where the lead blades 202 to 205 form a minimum aperture value. Thereby, when these lead blades move to a position narrower than the minimum aperture, the sensor sends the position information to the main control unit 118 (step S301), and the main control unit performs X-ray irradiation. Notification to stop is made (step S304). If these lead blades move to a position wider than the minimum aperture, the sensor sends the position information to the main control unit 118 (step S305), and the main control unit 118 performs X-ray irradiation. The cancellation is notified (step S308). Therefore, in this case, the steps of comparing and determining the threshold values (step S302, step S303, step S306, and step S307) can be omitted.

  In the present embodiment, a contact point such as a relay may be mounted in the aperture unit 104 to acquire the position information of the lead blade.

  In the present embodiment, the case where the position detection sensor unit 124 is arranged in the diaphragm unit 104 has been described. However, the present invention is not limited to this, and if the position information of the lead blades 202 to 205 can be acquired, You may arrange | position to a structure part.

  When the lead blade is remotely operated by an electric motor, a remote operation control unit may monitor a signal for operating the electric motor. For example, when the diaphragm blades are driven by a pulse motor, the position information of the lead blades can be estimated by counting the number of transmitted pulses. In this case, the threshold value of the lead blade may be determined based on the estimated blade position information.

<Modification 3 of the first embodiment>
In the present embodiment, the threshold value of the aperture opening degree set by the threshold value management unit 121 may be “zero” (see step S302). In this case, the determination unit 122 determines whether the notified aperture opening degree is “zero”. The main control unit 118 stops the X-ray irradiation when the aperture opening degree is “zero”, that is, when the lead blades 202 to 205 are fully closed, and starts the X-ray irradiation when the lead blades 202 to 205 are not fully closed.

  When the lead blades 202 to 205 are fully closed, X-rays are not likely to be exposed to the subject, but it is possible to prevent taking a fluoroscopic image that cannot display information necessary for diagnosis, and unnecessary X-ray output in ABC It is advantageous that the risk of overheating of the X-ray tube can be reduced by stopping the operation.

  When it is determined whether or not X-ray irradiation is stopped based on whether or not it is fully closed, a micro switch may be used as the position detection sensor unit 124. In this case, the microswitch has at least two microswitches disposed on the pair of lead blades 202 and 205 and the pair of lead blades 204 and 203, respectively, and the paired lead blades are closed. Sometimes set to switch on and switch off when opened. Thereby, when these lead blades are closed, the macro switch sends information on the aperture blade fully closed state as position information to the main control unit 118 (step S301), and the main control unit 118 notifies the X-ray irradiation stop ( Step S304). When these lead blades are opened, the macro switch sends information indicating that the diaphragm blades are not fully closed as position information to the main control unit 118 (step S305), and the main control unit 118 cancels the stop of the X-ray irradiation. Notification is made (step S308). Therefore, in this case, step S302, step S303, step S306, and S307 for performing threshold comparison and the like can be omitted.

<Second embodiment>
In the X-ray apparatus 1 of the present embodiment, the X-ray irradiation region 207 changes when the distance between the focal point 209 where X-rays are generated and the X-ray detection unit 110 (hereinafter referred to as “SID (Source Image Receptor Distance)”) changes. Therefore, the threshold value of the lead blade opening degree is adjusted corresponding to the case where the SID changes.
That is, the X-ray apparatus 1 of the present embodiment is different from the X-ray apparatus 1 of the first embodiment in that the X-ray apparatus 1 of the present embodiment further includes means for correcting the threshold value of the degree of opening of the lead blade using SID.

  The reason for the necessity of correction will be briefly described. For example, in the region of interest, a range in which X-ray irradiation is started outside an arbitrary range and X-ray irradiation is stopped within the range (hereinafter referred to as “X-ray irradiation prohibited region”) is set in advance. As shown in FIG. 6, when the aperture opening degree threshold (Cth1) is set in advance with reference to the X-ray irradiation prohibited area 601a, the position of the X-ray detection unit 110 is changed from SID1 (X-ray detection unit 110a) to SID2. When moving to (X-ray detection unit 110b), the X-ray irradiation prohibited area 601a determined by Cth1 becomes larger (the reference becomes wider) to the X-ray irradiation prohibited area 602b. Therefore, it is necessary to correct the preset threshold value Cth1.

Differences from the first embodiment will be described.
As shown in FIG. 7, the diaphragm unit 104 of this embodiment includes a sensor unit 702 for distance measurement using ultrasonic waves or infrared reflection in addition to the position detection sensor unit 124. As shown in FIG. 8, the distance measurement sensor unit notifies the main control unit 118 of SID information that is the distance between the focal point 209 where X-rays are generated and the X-ray detection unit 110.

  In the present embodiment, as will be described below, the threshold management unit 121 sets the aperture opening degree based on the X-ray irradiation prohibited area 601 as the initial value of the threshold.

  The operation of the processing for correcting the aperture opening degree threshold when the SID is changed will be described with reference to FIG.

<Step S1000>
When the threshold value of the X-ray irradiation prohibited area 601 is determined (Ath1 of the X-ray irradiation prohibited area 601a), the threshold management unit 121 calculates and sets the initial value Cth1 of the aperture opening degree threshold based on Equation 3 described later.
In general, the relationship between the distance (DFC) between the focal point 209 where the X-rays are generated and the diaphragm 104 (DFC), the aperture opening degree (C) of the lead blades 202 to 205, the X-ray irradiation region 207 (A), and the SID is expressed by the following equation. (See FIG. 8). The DFC is fixed by the device.

  (C / 2) / DFC = (A / 2) / SID (Formula 1)

  Therefore, C is calculated from the following equation.

  C = (A × DFC) / SID (Formula 2)

  Next, assuming that the threshold value of the X-ray irradiation prohibited area 601 is Ath1 (X-ray irradiation prohibited area 601a), the initial value (Cth1) of the aperture opening degree threshold value based on Ath1 is calculated by the following equation.

  Cth1 = (Ath1 × DFC) / SID1 (Formula 3)

  As an example of the threshold value (Ath1) of the X-ray irradiation prohibited area 601, for example, the maximum value of the X-ray irradiation area 207 that does not have the information necessary for the examination, or the X-ray apparatus 1 is set in advance for ABC. For example, a region formed inside the region of interest that is separated from the outer periphery of the region of interest by an arbitrary distance.

<Step S1001>.
The distance measurement sensor unit 702 notifies the main control unit 118 of SID distance information. For example, as shown in FIG. 10, when the X-ray detection unit 110 moves from the SID1 position (X-ray detection unit 110a) to the SID2 position (X-ray detection unit 110b), the SID measurement sensor unit 702 Information of SID2 is notified to the main control unit 118 as information.

<Step S1002>
The main control unit 118 notifies the correction unit 701 of the acquired SID distance information (SID2), Ath1 information determined by Cth1, and DFC information that is a fixed value.

<Step S1003>
The correction unit 701 corrects the threshold value using Expression (2).
Specifically, the correction unit 701 calculates a corrected threshold value (Cth2) based on the Ath1 information, the SID2 information, and the DFC information acquired from the main control unit 118 as shown in the following equation. .

  Cth2 = (Ath1 × DFC) / SID2 (Formula 4)

The correction unit 701 notifies the threshold value management unit 121 of the corrected threshold value (Cth2).
<Step S1004>
The threshold management unit 121 receives the corrected threshold (Cth2) and sets it as a new threshold.

  The determination unit 122 compares the updated threshold value with the aperture opening degree notified from the main control unit 118 (see step S302 and step 306).

  With the updated aperture opening degree threshold Cth2, the threshold (Ath1) of the X-ray irradiation prohibited area 601 can be maintained even when the SID increases from SID1 to SID2, and within the range exceeding the X-ray irradiation prohibited area 601a (Ath1). X-ray irradiation does not stop.

  According to the present embodiment, even if the SID is changed, the threshold value of the aperture opening degree can be corrected by acquiring the SID information, and X-ray irradiation can be appropriately controlled by the corrected threshold value.

  In the present embodiment, the case where the distance measurement sensor unit 702 is arranged in the diaphragm unit 104 has been described. However, the present invention is not limited to this, and if the SID can be measured, the distance measurement sensor unit is included in the other components of the X-ray apparatus 1. 702 may be arranged.

  In the present embodiment, the case of dealing with a change in SID has been described, but it is possible to deal with a change in FFD (Focal Film Distance) and the like in the same manner.

  The first embodiment and the second embodiment may be used alone or in combination.

<Display Embodiment>
In the X-ray apparatus 1 of the first embodiment and the second embodiment, a function of outputting the display of X-ray irradiation stop information (see FIG. 11) can be further added to the display unit 116 that displays an X-ray image.
Specifically, in step S304 in which X-ray irradiation is stopped, the main control unit 118 notifies the display unit 116 of information on stopping X-ray irradiation, and the display unit 116 outputs the information. In step S308 for canceling the X-ray irradiation stop, the main control unit 118 notifies the display unit 116 of the X-ray irradiation stop cancellation information, and the display unit 116 erases the X-ray irradiation stop display.

  By telling the operator to stop X-ray irradiation, it is possible to avoid an operator's misunderstanding that X-ray fluoroscopic imaging has not started.

  In addition, as shown in FIG. 11, information for prompting the operation of the lead blade (X-ray movable diaphragm) can be further displayed. In this case, the operator can recognize the lead blade erroneous operation at an early stage.

DESCRIPTION OF SYMBOLS 100 ... Subject, 102 ... X-ray source part, 208 ... Opening part, 202, 203, 204, 205 ... Lead blade, 104 ... Aperture part, 110 ... X-ray detection part DESCRIPTION OF SYMBOLS 1 ... X-ray image diagnostic apparatus 124 ... Position detection sensor part (sensor part which detects position information) 122 ... Judgment part 118 ... Main control part (control part), 209 ... Focus where X-rays are generated, 702 ... Sensor unit for distance measurement (sensor unit for measuring SID), 701 ... Correction unit, 116 ... Display unit

Claims (7)

An X-ray source that irradiates the subject with X-rays, a diaphragm having lead blades that form an opening through which the X-rays pass, and an X-ray detector that detects the X-rays transmitted through the subject. An X-ray diagnostic imaging apparatus comprising:
A sensor unit for detecting position information of the lead blade;
A determination unit that determines whether the opening degree of the opening is equal to or less than a preset threshold using the position information detected by the sensor unit;
An X-ray diagnostic imaging apparatus comprising: a control unit that stops or releases the X-ray irradiation based on a determination result of the determination unit. The X-ray diagnostic imaging apparatus according to claim 1,
The X-ray diagnostic imaging apparatus, wherein when the degree of opening of the opening is equal to or less than a threshold, the control unit stops the X-ray irradiation. The X-ray diagnostic imaging apparatus according to claim 1 or 2,
An X-ray diagnostic imaging apparatus, wherein an opening degree of the opening is an area of the opening. The X-ray diagnostic imaging apparatus according to any one of claims 1 to 3,
The threshold value is an area of the opening that determines an X-ray irradiation region that does not have information necessary for diagnosis, or an area of the opening that determines an arbitrary range in which the X-ray irradiation is stopped within the region of interest. An X-ray diagnostic imaging apparatus characterized by The X-ray diagnostic imaging apparatus according to any one of claims 1 to 4,
A sensor unit for measuring a distance (SID) between the X-ray focal point of the X-ray source unit and the X-ray detection unit;
An X-ray diagnostic imaging apparatus, further comprising a correction unit that corrects the threshold value of the degree of opening corresponding to the SID. The X-ray diagnostic imaging apparatus according to claim 2,
The threshold is zero;
The X-ray diagnostic imaging apparatus, wherein when the opening degree of the opening is zero, the control unit stops the X-ray irradiation. The X-ray diagnostic imaging apparatus according to any one of claims 1 to 6,
An X-ray diagnostic imaging apparatus, further comprising: a display unit that displays X-ray irradiation stop information and / or information that prompts the operation of the diaphragm when the X-ray irradiation is stopped.

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