JP6780949B2 - X-ray diagnostic equipment - Google Patents

Description

Embodiments of the present invention relate to an X-ray diagnostic apparatus.

The X-ray diagnostic apparatus is provided with an automatic brightness control (ABC: Automatic Brightness Control) function that automatically adjusts the X-ray dose in order to keep the brightness value of the X-ray image constant. For example, an X-ray diagnostic apparatus sets a predetermined region of interest (ROI) for image data, and X-rays are based on a comparison result between an average pixel value of the set region of interest and a predetermined threshold. Adjust the irradiation conditions. Further, in the X-ray diagnostic apparatus, in order to reduce the exposure dose to the subject, a compensation filter that partially shields the X-rays emitted from the X-ray tube may be used.

Japanese Unexamined Patent Publication No. 2005-118382

An object to be solved by the present invention is to provide an X-ray diagnostic apparatus capable of facilitating the setting of an area of interest while reducing the exposure dose to a subject.

The X-ray diagnostic apparatus of the embodiment includes an X-ray detector, a filter, an adjusting unit, and a control unit. The X-ray detector is irradiated from an X-ray tube that irradiates X-rays, detects X-rays that have passed through the subject, and generates an electric signal. The filter is provided between the X-ray tube and the subject, and has an opening through which the X-rays emitted from the X-ray tube pass. The adjusting unit adjusts the X-ray irradiation condition based on the comparison result between the brightness value in the region of interest corresponding to the opening and the predetermined threshold value in the image generated by using the electric signal. The control unit displays information indicating the position of the region of interest on the display, and when the position of the opening moves with the movement of the filter, the control unit indicates the position of the region of interest corresponding to the opening after the movement. Display information on the display.

FIG. 1 is a diagram showing a configuration example of an X-ray diagnostic apparatus according to the first embodiment. FIG. 2 is a diagram showing a configuration example of an attenuation filter according to the first embodiment. FIG. 3 is a diagram for explaining the operation of the operator during the treatment of intravascular intervention. FIG. 4 is a flowchart showing a processing procedure of ABC control ROI setting display processing by the control function according to the first embodiment. FIG. 5A is a diagram (1) for explaining the first embodiment. FIG. 5B is a diagram (2) for explaining the first embodiment. FIG. 5C is a diagram (3) for explaining the first embodiment. FIG. 5D is a diagram (4) for explaining the first embodiment. FIG. 6A is a diagram (5) for explaining the first embodiment. FIG. 6B is a diagram (6) for explaining the first embodiment. FIG. 6C is a diagram (7) for explaining the first embodiment. FIG. 6D is a diagram (8) for explaining the first embodiment. FIG. 7A is a diagram (1) for explaining the second embodiment. FIG. 7B is a diagram (2) for explaining the second embodiment. FIG. 7C is a diagram (3) for explaining the second embodiment.

Hereinafter, the X-ray diagnostic apparatus according to the embodiment will be described with reference to the drawings. The embodiment is not limited to the following embodiments. In principle, the contents described in one embodiment are similarly applied to other embodiments.

(First Embodiment)
FIG. 1 is a diagram showing a configuration example of the X-ray diagnostic apparatus 100 according to the first embodiment. As shown in FIG. 1, the X-ray diagnostic apparatus 100 according to the first embodiment includes a high voltage generator 11, an X-ray tube 12, a collimator 13, a top plate 14, a C-arm 15, and X-ray. It includes a detector 16. Further, the X-ray diagnostic apparatus 100 according to the first embodiment processes the C-arm rotation / movement mechanism 17, the top plate movement mechanism 18, the C-arm / top plate mechanism control circuit 19, and the aperture control circuit 20. It includes a circuit 21, an input interface 22, and a display 23. Further, the X-ray diagnostic apparatus 100 according to the first embodiment includes an image data generation circuit 24, a storage circuit 25, an image processing circuit 26, a compensation filter 27, and an attenuation filter 28. Then, as shown in FIG. 1, the X-ray diagnostic apparatus 100 connects each circuit to each other and transmits / receives various electric signals between the circuits.

In the X-ray diagnostic apparatus 100 shown in FIG. 1, each processing function is stored in the storage circuit 25 in the form of a program that can be executed by a computer. The C-arm / top plate mechanism control circuit 19, aperture control circuit 20, processing circuit 21, image data generation circuit 24, and image processing circuit 26 correspond to each program by reading and executing the program from the storage circuit 25. It is a processor that realizes the function. In other words, each circuit in the state where each program is read has a function corresponding to the read program.

The word "processor" used in the above description is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an integrated circuit for a specific application (Application Specific Integrated Circuit: ASIC), or a programmable logic device (ASIC). For example, it means a circuit such as a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA). The processor realizes the function by reading and executing the program stored in the storage circuit 25. Instead of storing the program in the storage circuit 25, the program may be directly incorporated in the circuit of the processor. In this case, the processor realizes the function by reading and executing the program embedded in the circuit. It should be noted that each processor of the present embodiment is not limited to the case where each processor is configured as a single circuit, and a plurality of independent circuits may be combined to form one processor to realize its function. Good.

The high voltage generator 11 generates a high voltage under the control of the processing circuit 21, and supplies the generated high voltage to the X-ray tube 12. The X-ray tube 12 generates X-rays by using the high voltage supplied from the high voltage generator 11.

Under the control of the aperture control circuit 20, the collimator 13 narrows down the X-rays generated by the X-ray tube 12 so as to selectively irradiate the region of interest (ROI) of the subject P. For example, the collimator 13 has four sliding diaphragm blades. The collimator 13 slides these diaphragm blades under the control of the diaphragm control circuit 20 to narrow down the X-rays generated by the X-ray tube 12 and irradiate the subject P. The top plate 14 is a bed on which the subject P is placed, and is arranged on a bed (not shown). The subject P is not included in the X-ray diagnostic apparatus 100.

The compensation filter 27 is provided between the X-ray tube 12 and the subject P, and attenuates the X-rays applied to the portion to be exposed to radiation reduction. In the X-ray diagnostic apparatus 100, the compensation filter 27 has a plurality of metal plates (also simply referred to as filters) that can be moved independently, and a drive mechanism that controls the rotational movement and horizontal movement of each metal plate. The material of each metal plate is, for example, a copper plate, aluminum, or the like. The material of each metal plate may be other than copper plate or aluminum as long as it can attenuate X-rays. Further, each metal plate has, for example, a rectangular shape, and under the control of the diaphragm control circuit 20, it rotates or moves horizontally via a drive mechanism. That is, the compensation filter 27 narrows down the X-rays generated by the X-ray tube 12 and irradiates the subject P by rotating or horizontally moving each metal plate under the control of the drive mechanism. The number of metal plates provided in the X-ray diagnostic apparatus 100 can be arbitrarily set.

The attenuation filter 28 is provided between the X-ray tube 12 and the subject P, and attenuates the X-rays applied to the portion to be exposed to radiation reduction. FIG. 2 is a diagram showing a configuration example of the attenuation filter 28 according to the first embodiment. As shown in FIG. 2, the attenuation filter 28 has a single metal plate 28a. The metal plate 28a is also simply referred to as a filter. The material of the metal plate 28a is, for example, a copper plate, aluminum, or the like. The material of the metal plate 28a may be other than a copper plate or aluminum as long as it can attenuate X-rays. FIG. 2 shows a case where the metal plate 28a is formed in a rectangular shape, but the shape of the metal plate 28a may be arbitrarily formed. Further, the metal plate 28a may be formed in a tapered shape.

Further, as shown in FIG. 2, the metal plate 28a has an opening 28b through which X-rays emitted from the X-ray tube 12 pass. Although FIG. 2 shows a case where the opening 28b has a rectangular shape, the shape of the opening 28b may be circular or polygonal.

Further, as shown in FIG. 2, the damping filter 28 has a first drive mechanism 28c, a second drive mechanism 28d, and a third drive mechanism 28e. Further, the first drive mechanism 28c and the second drive mechanism 28d are connected, the second drive mechanism 28d and the third drive mechanism 28e are connected, and the third drive mechanism 28e and the metal plate 28a are connected. Be connected. Here, the first drive mechanism 28c supports the second drive mechanism 28d, and under the control of the processing circuit 21, the second drive mechanism 28d is horizontally moved in the ab direction shown in FIG. Further, the second drive mechanism 28d supports the third drive mechanism 28e and horizontally moves the third drive mechanism 28e in the cd direction shown in FIG. 2 under the control of the processing circuit 21. That is, the metal plate 28a horizontally moves in the ab direction shown in FIG. 2 with the horizontal movement of the second drive mechanism 28d, and horizontally moves in the cd direction shown in FIG. 2 with the horizontal movement of the third drive mechanism 28e. ..

Further, FIG. 2 shows a case where the metal plate 28a is located at a position away from the X-ray irradiation range 28f shown by the broken line in FIG. Here, under the control of the processing circuit 21, the metal plate 28a horizontally moves in the d direction shown in FIG. 2 and moves within the X-ray irradiation range 28f to narrow down the X-rays generated by the X-ray tube 12. Irradiate the subject P with. More specifically, the metal plate 28a of the damping filter 28 allows the subject P to be irradiated with the X-rays emitted from the X-ray tube 12 at the opening 28b, and from the X-ray tube 12 around the opening 28b. The subject P is irradiated by reducing the permeability of the irradiated X-rays.

The X-ray detector 16 is irradiated from an X-ray tube 12 that irradiates X-rays, detects X-rays that have passed through the subject P, and generates an electric signal. For example, the X-ray detector 16 has detection elements arranged in a matrix. Each detection element converts X-rays transmitted through the subject P into an electric signal, stores the X-ray, and transmits the stored electric signal to the image data generation circuit 24.

The C-arm 15 holds an X-ray tube 12, a collimator 13, a compensation filter 27, an attenuation filter 28, and an X-ray detector 16. The X-ray tube 12, the collimator 13, and the X-ray detector 16 are arranged so as to face each other with the subject P sandwiched by the C arm 15. In FIG. 1, a case where the X-ray diagnostic apparatus 100 is a single plane is described as an example, but the embodiment is not limited to this, and may be a biplane case.

The C-arm rotation / movement mechanism 17 is a mechanism for rotating and moving the C-arm 15, and the top plate moving mechanism 18 is a mechanism for moving the top plate 14. The C-arm / top plate mechanism control circuit 19 controls the C-arm rotation / movement mechanism 17 and the top plate movement mechanism 18 under the control of the processing circuit 21 to rotate and move the C-arm 15 and the top plate 14. Adjust the movement. The diaphragm control circuit 20 controls the irradiation range of X-rays irradiated to the subject P by adjusting the opening degree of the diaphragm blades of the collimator 13 under the control of the processing circuit 21. Further, the diaphragm control circuit 20 controls the irradiation range of X-rays irradiated to the subject P by rotating or horizontally moving the metal plate of the compensation filter 27 under the control of the processing circuit 21. .. Further, the diaphragm control circuit 20 controls the irradiation range of X-rays irradiated to the subject P by adjusting the position of the metal plate 28a included in the attenuation filter 28 under the control of the processing circuit 21.

The image data generation circuit 24 generates image data (X-ray image) using an electric signal converted from X-rays by the X-ray detector 16, and stores the generated image data in the storage circuit 25. For example, the image data generation circuit 24 generates image data by performing current / voltage conversion, A (Analog) / D (Digital) conversion, and parallel / serial conversion on the electric signal received from the X-ray detector 16. To do. As an example, the image data generation circuit 24 generates image data (mask image) captured without the contrast medium injected and image data (contrast image) captured with the contrast medium injected. To do. Then, the image data generation circuit 24 stores the generated mask image and contrast image in the storage circuit 25. Here, the image data generation circuit 24 can also generate a plurality of contrast images captured while changing the concentration of the contrast medium injected into the same subject and store them in the storage circuit 25.

The storage circuit 25 receives and stores the image data generated by the image data generation circuit 24. For example, the storage circuit 25 stores image data of the subject P before and after the contrast medium is administered. Further, the storage circuit 25 stores programs corresponding to various functions read and executed by each circuit shown in FIG. As an example, the storage circuit 25 stores a program corresponding to the adjustment function 211 and a program corresponding to the control function 212 read and executed by the processing circuit 21.

The image processing circuit 26 performs various image processing on the image data stored in the storage circuit 25. For example, the image processing circuit 26 reads out the mask image and the contrast image stored in the storage circuit 25 and performs subtraction (Log sub) to generate a difference image. Here, the image processing circuit 26 can also generate a plurality of difference images by subtracting each of a plurality of contrast images and mask images captured in a state where contrast media having different densities are injected.

The input interface 22 is realized by a trackball, a switch button, a mouse, a keyboard, or the like for setting a predetermined area (for example, a catheter area) or the like. The input interface 22 is connected to the processing circuit 21, converts the input operation received from the operator into an electric signal, and outputs the input operation to the processing circuit 21. The operator is, for example, an operator such as a doctor.

The display 23 displays a GUI (Graphical User Interface) for receiving an operator's instruction, image data generated by the image data generation circuit 24, a difference image generated by the image processing circuit 26, and the like.

The processing circuit 21 controls the operation of the entire X-ray diagnostic apparatus 100. The processing circuit 21 executes various processes by reading a program corresponding to various processing functions for controlling the entire device from the storage circuit 25 and executing the program. For example, the processing circuit 21 controls the high voltage generator 11 according to the instruction of the operator transferred from the input interface 22, and adjusts the voltage supplied to the X-ray tube 12 to irradiate the subject P. X-ray dose and ON / OFF are controlled. Further, for example, the processing circuit 21 controls the C-arm / top plate mechanism control circuit 19 according to the instruction of the operator, and adjusts the rotation and movement of the C-arm 15 and the movement of the top plate 14. Further, for example, the processing circuit 21 controls the diaphragm control circuit 20 according to the instruction of the operator and adjusts the opening degree of the diaphragm blades of the collimator 13 to irradiate the subject P with X-rays. Control the range.

Further, the processing circuit 21 controls the image data generation processing by the image data generation circuit 24, the image processing by the image processing circuit 26, the analysis processing, and the like according to the instruction of the operator. Further, the processing circuit 21 controls the GUI for receiving the operator's instruction, the image stored in the storage circuit 25, and the like to be displayed on the display 23.

Further, the processing circuit 21 executes the adjustment function 211 and the control function 212. Here, for example, each processing function executed by the adjustment function 211 and the control function 212, which are components of the processing circuit 21 shown in FIG. 1, is recorded in the storage circuit 25 in the form of a program that can be executed by a computer. There is. The processing circuit 21 is a processor that realizes a function corresponding to each program by reading each program from the storage circuit 25 and executing the program. In other words, the processing circuit 21 in the state where each program is read has each function shown in the processing circuit 21 of FIG. Each processing function executed by the processing circuit 21 will be described later.

The example of the configuration of the X-ray diagnostic apparatus 100 has been described above. Under such a configuration, the X-ray diagnostic apparatus 100 according to the present embodiment is used for intravascular intervention treatment for a stenotic site generated in a blood vessel due to, for example, a thrombus. FIG. 3 is a diagram for explaining the operation of the operator during the treatment of intravascular intervention.

As shown in FIG. 3, when performing intravascular intervention treatment on the subject P placed on the top plate 14, the operator refers to the X-ray image displayed on the display 23 and refers to the treatment site. To confirm. Here, the X-ray diagnostic apparatus 100 has an automatic brightness control (ABC: Automatic Brightness Control) function in order to keep the brightness value of the X-ray image constant. This ABC function is realized by the processing circuit 21 executing the adjustment function 211 when a setting for enabling the ABC function is received from the operator via the input interface 22.

More specifically, the adjustment function 211 sets a predetermined region of interest for the image data generated by the image data generation circuit 24, and compares the average pixel value of the set region of interest with the predetermined threshold value. Based on this, the ABC function is executed by adjusting the X-ray irradiation conditions such as the tube voltage, the tube current, and the pulse width. Here, the adjustment function 211 adjusts the X-ray irradiation conditions so that the average image brightness in the region of interest is substantially constant, for example. The area of interest set when the ABC function is executed is also referred to as an ABC control ROI.

Further, at the time of intravascular intervention treatment, a compensation filter 27 or an attenuation filter 28 may be used in order to reduce the exposure dose to the subject P. Here, a case where the metal plate 28a of the attenuation filter 28 is inserted in the field of view will be described. For example, the operator operates the GUI on the display 23, the buttons on the input interface 22, and the like to move the metal plate 28a of the attenuation filter 28 into the field of view. Further, the operator can move the position of the metal plate 28a of the damping filter 28 by operating the lever on the input interface 22. For example, the operator moves the metal plate 28a so that the opening 28b is located at the position of the region of interest set when executing the ABC function.

Here, in the conventional technique, when the operator moves the position of the metal plate 28a of the attenuation filter 28, the metal plate 28a in the field of view while observing the shadow of the metal plate 28a in the X-ray image displayed on the display 23. The positional relationship of is confirmed. The operation of moving the metal plate 28a while observing the shadow of the metal plate 28a is troublesome for the operator. Therefore, in the conventional technique, when the ABC function is executed while using the attenuation filter 28, the operation of setting the region of interest for the operator becomes complicated.

For this reason, in the X-ray diagnostic apparatus 100 according to the first embodiment, the processing circuit 21 executes the control function 212 to facilitate the setting of the region of interest while reducing the exposure dose to the subject P. To. The control function 212 will be described in detail below.

FIG. 4 is a flowchart showing a processing procedure of ABC control ROI setting display processing by the control function 212 according to the first embodiment. Steps S1 to S11 shown in FIG. 4 are steps corresponding to the control function 212. This is a step in which the control function 212 is realized by the processing circuit 21 calling and executing a predetermined program corresponding to the control function 212 from the storage circuit 25. In the example shown in FIG. 4, a case where the metal plate 28a of the attenuation filter 28 is inserted into the field of view when executing the ABC function will be described.

In step S1, the control function 212 acquires the position of the metal plate 28a of the damping filter 28. For example, the control function 212 acquires the position of the metal plate 28a from the aperture control circuit 20. More specifically, the control function 212 acquires the positions of the four vertices of the metal plate 28a. Alternatively, the control function 212 acquires the position of the center of gravity of the metal plate 28a.

Then, in step S2, the control function 212 calculates the position and region of the ABC control ROI on the display 23 based on the position of the metal plate 28a acquired in step S1. For example, the control function 212 obtains the position of the opening 28b from the acquired position of the metal plate 28a. The control function 212 holds information in which the position of the metal plate 28a is associated with the position on the display 23, and the position and area on the display 23 corresponding to the obtained position of the opening 28b are set on the display 23. It is obtained as the position and region of the ABC control ROI of.

In step S3, the control function 212 sets the ABC control ROI based on the position and area of the ABC control ROI on the display 23 obtained in step S2. In other words, the control function 212 sets the position and region corresponding to the opening 28b obtained in step S2 in the ABC control ROI. Here, when the control function 212 sets the ROI using the generated X-ray image and performs ABC control, the number of target pixels increases. Therefore, the control function 212 compresses the X-ray image generated by using the electric signal, and sets the ABC control ROI in the compressed X-ray image. For example, the control function 212 compresses the generated X-ray image into an X-ray image of 32 pixels × 32 pixels, and sets the position and region corresponding to the opening 28b in the ABC control ROI in the compressed X-ray image. ..

Further, the control function 212 sets the ABC control ROI on the center side of the opening 28b from the opening 28b. The control function 212 notifies the adjustment function 211 of the set ABC control ROI. As a result, the adjustment function 211 adjusts the X-ray irradiation condition based on the comparison result between the brightness value in the region of interest corresponding to the opening 28b and the predetermined threshold value in the image generated by using the electric signal. In such a case, the adjustment function 211 adjusts the X-ray irradiation condition based on the comparison result between the brightness value in the ABC control ROI corresponding to the opening 28b and the predetermined threshold value in the compressed X-ray image.

In step S4, the control function 212 displays the ABC control ROI set in step S3 on the display 23. In other words, the control function 212 causes the display 23 to display information indicating the position of the ABC control ROI. For example, the control function 212 sets the ABC control ROI on the display 23 based on the position and area of the ABC control ROI on the display 23 obtained in step S2. Here, the control function 212 sets the ABC control ROI on the center side of the opening 28b from the opening 28b in the X-ray image displayed on the display 23.

In step S5, the control function 212 determines whether or not the movement of the position of the metal plate 28a of the damping filter 28 has been accepted. Here, when the control function 212 determines that the movement of the position of the metal plate 28a of the damping filter 28 has been accepted (step S5, Yes), the process proceeds to step S1 and the processes from step S2 to step S4 are executed again. To do. That is, when the position of the opening 28b moves with the movement of the filter, the control function 212 causes the display 23 to display information indicating the position of the ABC control ROI corresponding to the moved opening 28b.

On the other hand, when the control function 212 does not determine that the movement of the position of the metal plate 28a of the damping filter 28 has been accepted (steps S5 and No), the process proceeds to step S6. By the way, the operator may change the SID (Source to image-receptor distance) or the FOV (Field Of View) in order to make the treatment site easier to see, for example. Therefore, in steps S6 and subsequent steps, the processing when the SID and FOV are changed will be described with reference to FIGS. 5A to 6D. It should be noted that FIGS. 5A to 6D are diagrams for explaining the first embodiment.

In step S6, the control function 212 determines whether or not the SID change has been accepted. Here, when the control function 212 determines that the change of the SID has been accepted (step S6, Yes), the control function 212 proceeds to step S7. For example, in the control function 212, as shown in FIG. 5A, when the X-ray detector 16 whose distance from the X-ray tube 12 is at the position a moves to the position where the distance from the X-ray tube 12 is b. It is determined that the change in SID has been accepted. On the other hand, if the control function 212 does not determine that the change in SID has been accepted (steps S6 and No), the process proceeds to step S9.

In step S7, the control function 212 sets the ABC control ROI. For example, the control function 212 sets the ABC control ROI according to the size of the opening 28b projected on the X-ray detector 16 when the distance between the X-ray tube 12 and the X-ray detector 16 is changed. Set to X-ray image. In other words, the control function 212 sets the ABC control ROI corresponding to the opening 28b projected on the X-ray detector 16 after the SID change. Hereinafter, the process of setting the ABC control ROI in step S7 will be described.

When the control function 212 determines that the change of the SID has been accepted, the control function 212 acquires the current SID from the C-arm rotation / movement mechanism 17. In the example shown in FIG. 5A, the control function 212 acquires from the C-arm rotation / movement mechanism 17 that the changed SID is b. Since the control function 212 has acquired the SID at the time of the previous setting, it holds that the SID before the change is a. As a result, the control function 212 calculates that the SID has been changed from a to b. Further, the control function 212 requires that the SID ratio before and after the change is b / a.

Further, in FIG. 5A, the irradiation range of X-rays passing through the opening 28b is shown by a broken line. The X-ray irradiation range shown by the broken line corresponds to the opening 28b projected on the X-ray detector 16. Further, the upper figure of FIG. 5B illustrates the opening 28b projected on the X-ray detector 16 before the SID change, and the lower figure of FIG. 5B shows the opening 28b projected on the X-ray detector 16 after the SID change. It is shown in the figure. Here, the size of the opening 28b projected on the X-ray detector 16 after the SID change is before and after the change with respect to the size of the opening 28b projected on the X-ray detector 16 before the SID change. Expressed as a SID ratio.

Subsequently, the control function 212 sets the ABC control ROI in the X-ray image by internal processing using the SID ratio before and after the change. Here, when the control function 212 sets the ROI using the generated X-ray image and performs ABC control, the number of target pixels increases. Therefore, the control function 212 compresses the X-ray image generated by using the electric signal, and sets the ABC control ROI in the compressed X-ray image.

For example, as shown in FIG. 5C, the control function 212 compresses the generated X-ray image into a 32 pixel × 32 pixel X-ray image. The upper figure of FIG. 5C shows the ABC control ROI before the SID change set in the compressed X-ray image, and the lower figure of FIG. 5C shows the ABC control ROI after the SID change set in the compressed X-ray image. The control function 212 sets the ABC control ROI shown in the lower figure of FIG. 5C by using the SID ratio before and after the change with respect to the ABC control ROI set in the upper figure of FIG. 5C. That is, the control function 212 sets the ABC control ROI shown in the lower figure of FIG. 5C by multiplying the ABC control ROI shown in the upper figure of FIG. 5C by b / a. Further, the control function 212 notifies the adjustment function 211 of the ABC control ROI after the SID change. As a result, the adjustment function 211 adjusts the X-ray irradiation condition based on the comparison result between the brightness value in the ABC control ROI after the SID change and the predetermined threshold value. In such a case, the adjustment function 211 adjusts the X-ray irradiation condition based on the comparison result between the brightness value in the ABC control ROI and the predetermined threshold value in the compressed X-ray image.

In step S8, the control function 212 causes the display 23 to display information indicating the position of the set ABC control ROI. FIG. 5D shows an example of information indicating the ABC control ROI displayed on the display 23. The upper figure of FIG. 5D shows the information showing the position of the ABC control ROI before the SID change, and the lower figure of FIG. 5D shows the information showing the position of the ABC control ROI after the SID change.

Here, the control function 212 sets the ABC control ROI on the center side of the opening 28b from the opening 28b in the X-ray image displayed on the display 23. As an example, the control function 212 displays information indicating the position of the ABC control ROI before the SID change with a solid line, as shown in the upper diagram of FIG. 5D. Similarly, as shown in the lower figure of FIG. 5D, the control function 212 displays information indicating the position of the ABC control ROI after the SID change with a solid line. When displaying the information indicating the position of the ABC control ROI, the control function 212 may further display the information corresponding to the opening 28b on the display 23 outside the ABC control ROI. For example, the control function 212 displays the information corresponding to the opening 28b in a display form different from the ABC control ROI.

In step S9, the control function 212 determines whether or not the FOV change has been accepted. For example, the control function 212 determines whether or not an instruction to change the FOV has been received from the operator via the input interface 22. Here, when the control function 212 determines that the change of the FOV has been accepted (step S9, Yes), the control function 212 proceeds to step S10. For example, as shown in FIG. 6A, the control function 212 determines that the change in FOV has been accepted when the effective field of view of the X-ray detector 16 is changed from the range indicated by FOV-A to the range indicated by FOV-B. To do. On the other hand, if the control function 212 does not determine that the change in the FOV has been accepted (steps S9 and No), the process proceeds to step S11.

In step S10, the control function 212 displays the ABC control ROI according to the magnitude of the FOV. Hereinafter, the process of displaying the ABC control ROI according to the magnitude of the FOV in step S10 will be described. Here, the control function 212 does not change the size of the ABC control ROI set in the X-ray image when the effective field of view of the X-ray detector 16 is changed. For example, the upper figure of FIG. 6B illustrates the opening 28b projected on the X-ray detector 16 before the FOV change, and the lower figure of FIG. 6B shows the opening 28b projected on the X-ray detector 16 after the FOV change. It is shown in the figure. Here, the effective field of view of the X-ray detector 16 after the FOV change is narrowed because the shaded portion in the lower figure of FIG. 6B is out of the field of view, but the size of the opening 28b projected on the X-ray detector 16 after the FOV change is large. The size of the opening 28b projected on the X-ray detector 16 before the FOV change is the same.

Further, since the size of the opening 28b projected on the X-ray detector 16 is the same before and after the FOV change, as shown in FIG. 6C, the ABC control ROI set in the compressed X-ray image is also before and after the FOV change. Is the same. The upper figure of FIG. 6C shows the ABC control ROI before the FOV change set in the compressed X-ray image, and the lower figure of FIG. 6C shows the ABC control ROI after the FOV change set in the compressed X-ray image.

Further, the control function 212 causes the display 23 to display information indicating the position of the ABC control ROI. FIG. 6D shows an example of information indicating the ABC control ROI displayed on the display 23. The upper figure of FIG. 6D shows the information showing the position of the ABC control ROI before the FOV change, and the lower figure of FIG. 6D shows the information showing the position of the ABC control ROI after the FOV change.

Here, the control function 212 sets the ABC control ROI on the center side of the opening 28b from the opening 28b in the X-ray image displayed on the display 23. As an example, the control function 212 displays information indicating the position of the ABC control ROI before the FOV change with a solid line, as shown in the upper diagram of FIG. 6D. Similarly, the control function 212 displays information indicating the position of the ABC control ROI after the FOV change with a solid line, as shown in the lower figure of FIG. 6D. Further, the control function 212 causes the display 23 to display information indicating the position of the ABC control ROI according to the size of the effective field of view after the change. For example, when the effective field of view is narrowed, the control function 212 enlarges and displays the information indicating the position of the ABC control ROI after the FOV is changed, as shown in the lower figure of FIG. 6D. When the effective field of view is widened, the control function 212 reduces and displays the information indicating the position of the ABC control ROI after the FOV is changed. When displaying the information indicating the position of the ABC control ROI, the control function 212 may further display the information corresponding to the opening 28b on the display 23 outside the ABC control ROI. For example, the control function 212 displays the information corresponding to the opening 28b in a display form different from the ABC control ROI.

In step S11, the control function 212 determines whether or not the end of the ABC control ROI setting display process has been accepted. Here, when the control function 212 determines that the end of the ABC control ROI setting display process has been accepted (step S11, Yes), the process ends. On the other hand, when the control function 212 does not determine that the end of the ABC control ROI setting display process has been accepted (steps S11, No), the process proceeds to step S1.

As described above, the control function 212 according to the first embodiment displays information indicating the position of the ABC control ROI on the display 23, and moves when the position of the opening 28b moves with the movement of the metal plate 28a. Information indicating the position of the ABC control ROI corresponding to the later opening 28b is displayed on the display 23. Thereby, according to the first embodiment, it is possible to easily set the region of interest while reducing the exposure dose to the subject.

Further, in the first embodiment described above, the ABC control ROI is set following the movement of the metal plate 28a. Therefore, the brightness of the X-ray image at the opening 28b of the attenuation filter 28 can be appropriately maintained at the brightness value. As a result, it becomes possible to improve the image quality of the X-ray image.

(Second Embodiment)
In the first embodiment, the case where the attenuation filter 28 is inserted in the field of view when executing the ABC function has been described. By the way, when executing the ABC function, the compensation filter 27 may be inserted in the field of view. Further, an opening may be formed in the compensation filter 27 included in the X-ray diagnostic apparatus 100. Therefore, in the second embodiment, the case where the compensation filter 27 having an opening is inserted into the field of view instead of the attenuation filter 28 will be described when the ABC function is executed.

The overall configuration of the X-ray diagnostic apparatus 100 according to the second embodiment is the same as the configuration example shown in FIG. 1, except that the configuration of the metal plate included in the compensation filter 27 is different. Therefore, the description of the same configuration as in FIG. 1 will be omitted. 7A to 7C are diagrams for explaining the second embodiment.

FIG. 7A describes a case where the compensation filter 27 has two metal plates. As shown in FIG. 7A, the compensation filter 27 has a metal plate 27a and a metal plate 27b that can be moved independently. Although not shown in FIG. 7A, the compensation filter 27 has a drive mechanism for controlling the rotational movement and horizontal movement of each metal plate.

Further, similarly to the metal plate according to the first embodiment, the material of the metal plate 27a and the metal plate 27b is, for example, a copper plate, aluminum, or the like. The material of the metal plate 27a and the metal plate 27b may be other than a copper plate or aluminum as long as it can attenuate X-rays. Further, the metal plate 27a and the metal plate 27b are, for example, rectangular in shape, and have a notch in a part of the rectangle. The metal plate 27a and the metal plate 27b rotate or move horizontally via a drive mechanism under the control of the aperture control circuit 20.

Then, when the operator operates the metal plate 27a and the metal plate 27b via the input interface 22, the metal plate 27a and the metal plate 27b move under the control of the throttle control circuit 20. Here, for example, as shown in FIG. 7B, the operator operates the metal plate 27a and the metal plate 27b so as to surround the region of interest 27c. Alternatively, the operator moves the metal plate 27a and the metal plate 27b so as to surround the region of interest 27c, as shown in FIG. 7C.

After the metal plate 27a and the metal plate 27b move so as to surround the region of interest 27c, the aperture control circuit 20 determines the positional relationship between the metal plate 27a and the metal plate 27b by receiving an instruction from the operator to set the region of interest. In the held state, it is controlled to move as one metal plate having an opening.

Further, the control function 212 according to the second embodiment executes the same function as the control function 212 according to the first embodiment. For example, the control function 212 according to the second embodiment sets the region of interest 27c as the ABC control ROI by receiving an instruction to set the region of interest as the region of interest from the operator. Here, the control function 212 sets the ABC control ROI on the center side of the opening from the opening in the X-ray image displayed on the display 23.

Further, the control function 212 notifies the adjustment function 211 of the set ABC control ROI. As a result, the adjustment function 211 adjusts the X-ray irradiation condition based on the comparison result between the brightness value in the set ABC control ROI and the predetermined threshold value. In such a case, the adjustment function 211 adjusts the X-ray irradiation condition based on the comparison result between the brightness value in the ABC control ROI and the predetermined threshold value in the compressed X-ray image.

Further, the control function 212 causes the display 23 to display information indicating the position of the ABC control ROI. Then, when the position of the opening moves with the movement of the metal plates 27a and 27b, the control function 212 according to the second embodiment displays information indicating the position of the ABC control ROI corresponding to the moved opening. Display on 23. Thereby, according to the second embodiment, it is possible to easily set the region of interest while reducing the exposure dose to the subject.

The control function 212 sets the ABC control ROI according to the size of the opening projected on the X-ray detector 16 when the distance between the X-ray tube 12 and the X-ray detector 16 is changed. Set to line image. Further, the control function 212 does not change the ABC control ROI set in the X-ray image when the effective field of view of the X-ray detector 16 is changed, and ABC control according to the size of the changed effective field of view. Information indicating the position of the ROI is displayed on the display 23.

Further, in the second embodiment described above, the ABC control ROI is set following the movement of the metal plates 27a and 27b. Therefore, the brightness of the X-ray image at the opening of the compensation filter 27 can be appropriately maintained at the brightness value. As a result, it becomes possible to improve the image quality of the X-ray image.

(Other embodiments)
The embodiment is not limited to the above-described embodiment.

In the above-described embodiment, the compensation filter 27 has been described as having a plurality of independently movable metal plates, but the embodiment is not limited to this. For example, the metal plate included in the compensation filter 27 may be formed of a single plate. Further, when the metal plate of the compensation filter 27 is formed of a single plate, an opening may be formed in the metal plate.

Further, in the above-described embodiment, the metal plate 28a included in the damping filter 28 has been described as horizontally moving, but the embodiment is not limited to this. For example, the metal plate 28a included in the damping filter 28 may be rotationally moved.

In the example shown in FIG. 1, the compensation filter 27 is shown as being provided between the collimator 13 and the attenuation filter 28, but the embodiment is not limited to this. For example, the position where the compensation filter 27 and the attenuation filter 28 are provided can be arbitrarily changed as long as it is between the X-ray tube 12 and the subject P.

Further, in the above-described embodiment, the X-ray diagnostic apparatus 100 has been described as having the compensation filter 27 and the attenuation filter 28, but the embodiment is not limited to this. For example, the X-ray diagnostic apparatus 100 may have either the attenuation filter 28 described in the first embodiment or the compensation filter 27 described in the second embodiment.

Further, in the above-described embodiment, the case where the intravascular intervention treatment is performed has been described as an example, but the embodiment is not limited to this. That is, the above-described embodiment is applicable when the compensation filter 27 or the attenuation filter 28 having an opening is inserted into the field of view when the ABC function is executed in the X-ray diagnostic apparatus 100.

In the description of the above-described embodiment, each component of each of the illustrated devices is a functional concept, and does not necessarily have to be physically configured as shown in the figure. That is, the specific form of distribution / integration of each device is not limited to the one shown in the figure, and all or part of the device is functionally or physically distributed in arbitrary units according to various loads and usage conditions. It can be integrated and configured. Further, each processing function performed by each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

Further, the control method described in the above embodiment can be realized by executing a control program prepared in advance on a computer such as a personal computer or a workstation. This control program can be distributed via a network such as the Internet. Further, this control program can also be executed by being recorded on a computer-readable recording medium such as a hard disk, flexible disk (FD), CD-ROM, MO, or DVD, and being read from the recording medium by the computer.

According to at least one embodiment described above, it is possible to easily set the region of interest while reducing the exposure dose to the subject.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention as well as the invention described in the claims and the equivalent scope thereof.

16 X-ray detector 21 Processing circuit 28 Attenuation filter 100 X-ray diagnostic device 211 Adjustment function 212 Control function

Claims (4)

An X-ray detector that is irradiated from an X-ray tube that irradiates X-rays, detects X-rays that have passed through the subject, and generates an electrical signal.
A compensating filter provided between the X-ray tube and the subject and provided with a plurality of movable filters for attenuating X-rays emitted from the X-ray tube to a site to be exposed to radiation.
Wherein said X-ray tube is provided between the subject and have a opening for passing the X-rays irradiated from the X-ray tube, the transmittance attenuates the X-rays irradiated to the portion other than the opening Attenuation filter to make
An adjustment unit that adjusts the X-ray irradiation conditions based on the comparison result between the brightness value in the region of interest corresponding to the opening and a predetermined threshold value in the image generated by using the electric signal.
Information indicating the position of the region of interest is displayed on the display, and when the position of the opening moves with the movement of the attenuation filter, information indicating the position of the region of interest corresponding to the opening after the movement is displayed. The control unit to be displayed on the X-ray image displayed in
With
When the distance between the X-ray tube and the X-ray detector is changed, the control unit of the opening projected onto the X-ray detector based on the ratio of the distances before and after the change . An X-ray diagnostic apparatus that sets an area of interest changed according to the size on the image and displays information indicating the position of the set area of interest on the X-ray image . When the effective field of view of the X-ray detector is changed, the control unit does not change the area of interest set in the image, and the position of the area of interest according to the size of the changed effective field of view. The X-ray diagnostic apparatus according to claim 1, wherein the information indicating the above is displayed on the X-ray image . The X-ray diagnostic apparatus according to claim 1 or 2, wherein the control unit sets the region of interest from the opening to the center side of the opening in the image. The X-ray diagnostic apparatus according to any one of claims 1 to 3, wherein the control unit compresses an image generated by using the electric signal and sets the region of interest in the compressed image.

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