JP7797110B2 - X-ray diagnostic apparatus and method for controlling the X-ray diagnostic apparatus - Google Patents

Description

The embodiments disclosed in this specification and the drawings relate to an X-ray diagnostic apparatus and a method for controlling an X-ray diagnostic apparatus .

Long-length imaging is known in which multiple X-ray images are collected by irradiating the subject with X-rays while moving a C-arm or bed along the subject's body axis, and then stitching together the collected X-ray images to generate a long-length image.

In long-length imaging, images are collected by narrowing the X-ray aperture to a slit shape to reduce artifacts caused by differences in the Table To Object Distance (TOD) of the target object. Prior to collecting images for long-length imaging, the user must set the long-length imaging range, including the imaging start and end positions. However, this setting is cumbersome for the user, as it is difficult to grasp the overall image in the slit state.

JP 2010-167263 A

One of the problems that the embodiments disclosed in this specification and drawings attempt to solve is to efficiently perform long-length photography using a simple configuration. However, the problems that the embodiments disclosed in this specification and drawings attempt to solve are not limited to the above problem. Issues corresponding to the various configurations shown in the embodiments described below can also be considered as other problems.

An X-ray diagnostic apparatus according to an embodiment includes an acquisition means, a display control means, and an imaging execution means. The acquisition means acquires a partial image representing a portion of a subject to be X-rayed. The display control means causes a display unit to display a superimposed image in which imaging guide information representing a predetermined position in the imaging range is superimposed on the partial image. The imaging execution means sets the position of the imaging guide information in the superimposed image, and performs X-ray imaging of the subject according to the setting of the position of the imaging guide information.

FIG. 1 is a diagram showing an example of the configuration of an X-ray diagnostic apparatus according to an embodiment. FIG. 2 is a diagram for explaining long length photography according to the embodiment. FIG. 3 is a diagram for explaining a long captured image according to the embodiment. FIG. 4 is a flowchart illustrating an example of a guide information position setting process according to the embodiment. FIG. 5 is a diagram showing an example of a display screen including imaging guide information according to the embodiment. FIG. 6 is a flowchart illustrating an example of the photographing process according to the embodiment. FIG. 7 is a diagram showing an example of a display screen including a live image according to the embodiment. FIG. 8 is a diagram for explaining generation of a long captured image according to the embodiment.

Each embodiment will be described in detail below with reference to the drawings. Note that in the following description, parts with the same reference numerals perform similar operations, and redundant explanations will be omitted where appropriate.

(First embodiment)
FIG. 1 is a diagram showing an example of the configuration of an X-ray diagnostic apparatus 1 according to an embodiment. As shown in FIG. 1 , the X-ray diagnostic apparatus 1 includes an imaging unit 3, a bed 5, a drive unit 7, an operation unit 9, an X-ray high-voltage device 11, a processing circuit 21, a memory circuit 23, a display unit 25, and an input interface 27. The processing circuit 21, the memory circuit 23, and the input interface 27 are built into, for example, a console device 10. The imaging unit 3 includes an X-ray tube 13 that irradiates X-rays onto a subject P, an X-ray diaphragm 15, an iris control unit 16 that controls the drive of the X-ray diaphragm 15, an X-ray detector 17 that detects X-rays, and a holding device 19. The bed 5 is provided with an operation unit 9 for operating the imaging unit 3 and the bed 5. The drive unit 7 includes a drive control unit 70 that controls the drive of the imaging unit 3 and the bed 5, an imaging system movement drive unit 71, and a tabletop movement drive unit 73.

The X-ray high voltage device 11 includes electrical circuits such as a transformer and rectifier, a high voltage generator, and an X-ray control device. The high voltage generator generates the high voltage applied to the X-ray tube 13 and the filament current supplied to the X-ray tube 13. The X-ray control device controls the output voltage according to the X-rays emitted by the X-ray tube 13. The high voltage generator may be a transformer type or an inverter type. The X-ray high voltage device 11 may also be provided in the holding device 19.

The X-ray tube 13 is a vacuum tube that generates X-rays by irradiating thermions from the cathode (filament) toward the anode (target) when high voltage is applied from the X-ray high voltage device 11 and a filament current is supplied. X-rays are generated when thermions collide with the target. One example of an X-ray tube 13 is a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermions. Note that the X-ray tube 13 is not limited to the rotating anode type, and any type of X-ray tube can be used.

The X-ray diaphragm 15 is provided in front of the X-ray emission window in the X-ray tube 13. The X-ray diaphragm 15 has four diaphragm blades made of metal plates such as lead. The diaphragm blades are driven by a drive device (not shown) under the control of the diaphragm control unit 16 according to the region of interest input by the user via the operation unit 9 or input interface 27. The X-ray diaphragm 15 adjusts the region where X-rays are blocked to any size by sliding the diaphragm blades with the drive device. With the adjusted diaphragm blades, the X-ray diaphragm 15 blocks X-rays outside the opening region. In this way, the X-ray diaphragm 15 narrows the X-rays generated by the X-ray tube 13 so that they are irradiated onto the region of interest of the subject P. The diaphragm control unit 16 controls the driving of the X-ray diaphragm 15 according to instructions from the processing circuitry 21.

The X-ray detector 17 detects X-rays generated by the X-ray tube 13. The X-ray detector 17 is, for example, a flat panel detector (FPD). The FPD has multiple semiconductor detection elements. Semiconductor detection elements can be of two types: a direct conversion type, in which X-rays are directly converted into electrical signals, and an indirect conversion type, in which X-rays are converted into light using a phosphor and then the light is converted into electrical signals. Either type may be used for the FPD. The electrical signals generated by the multiple semiconductor detection elements in response to the incidence of X-rays are output to an analog-to-digital converter (A/D converter), not shown. The A/D converter converts the electrical signals into digital data. The A/D converter outputs the digital data to the processing circuitry 21. Note that an image intensifier may also be used as the X-ray detector 17.

The holding device 19 is a C-arm that supports the X-ray tube 13 and X-ray detector 17. The holding device 19 rotates around the subject P lying on the bed 5 by a motor (not shown). Here, the holding device 19 is supported so that it can rotate about three orthogonal axes, the X, Y, and Z axes, and is rotated around each axis by a drive unit (not shown).

The processing circuitry 21 controls the overall operation of the X-ray diagnostic apparatus 1 in response to electrical signals of input operations output from the operation unit 9 or the input interface 27. For example, the processing circuitry 21 includes, as hardware resources, processors such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), and GPU (Graphics Processing Unit), as well as memories such as ROM (Read Only Memory) and RAM (Random Access Memory).

The various processing functions executed by the processing circuitry 21 are stored in the memory circuitry 23 in the form of programs executable by a computer. The processing circuitry 21 is a processor that realizes the functions corresponding to each program by reading and executing the programs from the memory circuitry 23. In other words, when each program is read, each circuit has the function corresponding to the read program.

Specifically, the processing circuitry 21 executes the operation control function 211, image generation function 212, and display control function 213 using a processor that executes programs loaded into memory. Here, the processing circuitry 21 is an example of a control unit. The processing circuit that realizes the operation control function 211 is an example of an acquisition means. The processing circuit that realizes the operation control function 211 and image generation function 212 is an example of an image capture execution means. The processing circuit that realizes the display control function 213 is an example of a display control means.

Note that the operation control function 211, image generation function 212, and display control function 213 do not necessarily have to be realized by a single processing circuit. A processing circuit may be configured by combining multiple independent processors, and the operation control function 211, image generation function 212, and display control function 213 may be realized by each processor executing a program.

The processing circuit 21 may also be implemented by a processor such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), another complex programmable logic device (CPLD), or a simple programmable logic device (SPLD).

In the operation control function 211, the processing circuitry 21 controls the drive unit 7, X-ray high voltage device 11, aperture control unit 16 (X-ray aperture 15), X-ray detector 17, memory circuitry 23, display unit 25, etc. based on input operations received from the user via the operation unit 9 or input interface 27.

The processing circuitry 21 acquires setting information related to the actual imaging (long-length imaging) and partial images, such as X-ray fluoroscopic images taken for the purpose of aligning the subject P. Here, a partial image is an image representing a portion of the subject P, who is the subject of X-ray imaging in the actual imaging (long-length imaging). The imaging range of the partial image is larger than the acquisition range corresponding to the aperture opening of the X-ray diaphragm 15 that blocks X-rays during the actual imaging of the subject P. Here, "fluoroscopy" refers to moving X-ray images obtained by continuously irradiating the subject with X-rays. On the other hand, "actual imaging (long-length imaging)" refers to still X-ray images obtained by irradiating the subject with X-rays. Here, long-length imaging can be expressed as imaging in which the position of the acquisition range corresponding to the aperture opening of the X-ray diaphragm 15 on the subject P is changed and multiple X-ray images based on that acquisition range are acquired.

Furthermore, based on user operation, the processing circuitry 21 changes the display position of the imaging guide information superimposed on a partial image such as an X-ray image for positioning. Note that in the following description, a partial image on which imaging guide information is superimposed may simply be referred to as a superimposed image. The processing circuitry 21 determines whether at least one of the imaging unit 3 and the bed 5 has been moved in response to user operation, i.e., whether the subject P represented by the partial image has moved. When the processing circuitry 21 determines that the subject P represented by the partial image has moved, it acquires a new partial image after the movement. Furthermore, the processing circuitry 21 performs X-ray imaging of the subject P according to the setting of the position of the imaging guide information in the superimposed image, i.e., the display position of the imaging guide information superimposed on the partial image. Specifically, the processing circuitry 21 sets the start position of long-length imaging (main imaging) according to the setting of the position of the imaging guide information in the superimposed image. Furthermore, the processing circuitry 21 performs X-ray imaging from the set start position.

In the image generation function 212, the processing circuitry 21 generates X-ray image data based on the output from the X-ray detector 17. Specifically, the processing circuitry 21 generates projection data based on the output from the X-ray detector 17. Next, the processing circuitry 21 receives an input signal from the operation unit 9 or the input interface 27, and performs processes such as defective pixel correction, gain correction, and offset correction on the output signal from the X-ray detector 17 to generate X-ray image data. The processing circuitry 21 performs synthesis processing, subtraction processing, and the like using the X-ray image data. The processing circuitry 21 outputs the generated X-ray image data to the display control function 213 or the memory circuitry 23. The processing circuitry 21 may also generate image data for display using the generated X-ray image data, and output this display image to the display unit 25.

For example, the processing circuitry 21 performs a reconstruction process using X-ray image data, in which multiple X-ray images acquired during long-length imaging are stitched together according to their imaging positions to generate long-length imaging image (X-ray image) data. Furthermore, for example, the processing circuitry 21 generates imaging guide information (image) for long-length imaging on the positioning X-ray image based on setting information for the actual imaging and the aperture opening for positioning imaging. In other words, the processing circuitry 21 generates imaging guide information that indicates the long-length imaging range, such as the imaging start position and imaging end position, on the positioning X-ray image. In other words, the imaging guide information is information that indicates a predetermined position within the long-length imaging range. The processing circuitry 21 may also generate a display image using the generated imaging guide information and output this display image to the display unit 25.

In the display control function 213, the processing circuitry 21 generates an X-ray image for display using the X-ray image data generated by the image generation function 212, and displays this display image on the display 251 of the display unit 25. For example, the processing circuitry 21 generates imaging guide information (image) for display using imaging guide information generated by the image generation function 212, and displays the imaging guide information (image) superimposed on the X-ray image for display on the display 251 of the display unit 25. The processing circuitry 21 may generate the imaging guide information (image) based on setting information related to the actual imaging and the aperture opening for positioning imaging. The processing circuitry 21 may also generate an image indicating the imaging guide information when imaging guide information that has not been visualized is supplied from the image generation function 212. The processing circuitry 21 also changes the display position of the imaging guide information on the X-ray image based on an input operation received from the user via the operation unit 9 or the input interface 27. In addition, the processing circuitry 21 changes the positioning X-ray image on which the imaging guide information is superimposed in response to the acquisition of a new projection image by the operation control function 211.

The memory circuitry 23 is a storage device such as an HDD (Hard Disk Drive), SSD (Solid State Drive), or integrated circuit storage device that stores various information, or a circuit that combines multiple such storage devices. The memory circuitry 23 has, for example, a storage device for primary storage and a storage device for long-term storage. Note that the medical image data that is sequentially stored in the primary storage device is updated, for example, periodically. The memory circuitry 23 also stores, for example, projection data, image data, and programs corresponding to various functions that are read and executed by the processing circuitry 21. In this embodiment, storing or saving various information in the memory circuitry 23 may also be referred to as "recording."

In addition to HDDs and SSDs, the memory circuitry 23 may be a drive that reads and writes various information from portable storage media such as CDs (Compact Discs), DVDs (Digital Versatile Discs), and flash memory, or semiconductor memory elements such as RAM (Random Access Memory). The memory circuitry 23 may also be located in an external storage device connected via a network. Furthermore, if the memory circuitry 23 includes multiple storage devices, some of these may be storage devices connected via a network.

The display unit 25 is composed of a display 251 that displays medical images, etc., an internal circuit that supplies display signals to the display 251, and peripheral circuits such as connectors and cables that connect the display 251 to the internal circuit. The internal circuit generates display data by superimposing additional information such as subject information and projection data generation conditions onto the image data. The internal circuit then performs D/A conversion and TV format conversion on the resulting display data. The internal circuit displays the converted display data on the display 251 as a medical image. In addition, the display unit 25 displays a GUI (Graphical User Interface) and other controls to accept various operations from the user.

The display 251 may be, for example, a liquid crystal display (LCD), a cathode ray tube (CRT), an organic electroluminescence display (OELD), a plasma display, or any other display. The display 251 may be a desktop type, or may be configured as a tablet terminal or the like capable of wireless communication with the processing circuit 21.

The operation unit 9 and input interface 27 each accept various input operations from the user, convert the accepted input operations into electrical signals, and output them to the processing circuit 21. For example, the operation unit 9 and input interface 27 each accept from the user operations for operating at least one of the imaging unit 3 and the bed 5, X-ray conditions related to X-ray generation, conditions related to image processing performed by the image generation function 212, etc. As the operation unit 9 and input interface 27, for example, a mouse, keyboard, trackball, switch, button, joystick, foot switch, touchpad, touch panel display, etc. can be used as appropriate. The operation unit 9 is installed, for example, in an examination room. The input interface 27 is mounted, for example, on a console device 10 installed in an operation room separate from the examination room.

In this embodiment, the operation unit 9 and input interface 27 are not limited to those equipped with physical operation components such as a mouse, keyboard, trackball, switch, button, joystick, touchpad, and touch panel display. For example, examples of the operation unit 9 and input interface 27 also include an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs this electrical signal to the processing circuit 21. The operation unit 9 and input interface 27 may also be configured as a tablet terminal or the like capable of wireless communication with the processing circuit 21.

Figure 2 is a diagram for explaining long-length photography according to the embodiment. Figure 3 is a diagram for explaining long-length photography images (X-ray images) according to the embodiment. Figure 2 illustrates an example of long-length photography in photography direction D1, with respect to photography range R1 from position G1 corresponding to one end of the X-ray diaphragm 15 at the photography start position. Figure 2 also illustrates an example of positioning photography including the photography start position for the main photography (long-length photography).

Long-length imaging involves collecting multiple X-ray images by irradiating the subject P with X-rays while moving at least one of the support device 19 (C-arm) and the bed 5 along the subject's body axis (imaging direction D1 in Figure 2), and stitching the collected X-ray images together to generate a long-length image. In Figure 2, multiple X-ray images corresponding to each imaging range are stitched together to generate a long-length image. In other words, each imaging range is an acquisition range that corresponds to the aperture opening of the X-ray aperture 15, which blocks X-rays during X-ray imaging of the subject P.

X-ray images in long-length imaging are stitched together, for example, based on the target object within the image. Figure 3 shows examples of images (IMG21, IMG22, ...) relating to regions (R11, R12, ...) on the detection surface. For example, a single long-length imaging image IMG2 is generated by stitching together the regions (R21, R22, ...) of each image (IMG21, IMG22, ...) based on the positional information of the target object within each image. Note that long-length imaging images can be generated using known methods, and a detailed description will be omitted. When stitching together multiple X-ray images in this way, images are collected in a slit state with the X-ray aperture narrowed to reduce artifacts caused by differences in TOD (Table To Object Distance) of the target object.

Under these circumstances, the user must set the long-length imaging range before collecting long-length images. However, this setting is cumbersome for the user, as it is difficult to grasp the overall image in the slit state. In response to this, the X-ray diagnostic device 1 according to this embodiment is configured to display imaging guide information superimposed on the positioning X-ray image during positioning imaging.

Figure 4 is a flowchart showing an example of a guide information position setting process according to an embodiment. Here, an example is shown in which imaging guide information is superimposed on an LIH (Last Image Hold) display image of a fluoroscopic image. The LIH display image is a captured image (still image) of a fluoroscopic image acquired during positioning imaging. Note that while an LIH display image is used as an example here, imaging guide information may be superimposed on a fluoroscopic image instead of the LIH display image, or imaging guide information may be superimposed on a still image or video captured by an optical camera. Here, the various images on which imaging guide information is superimposed are examples of partial images representing a portion of the subject P who is the subject of X-ray imaging. Note that in the following description, the LIH display image of a fluoroscopic image may also be referred to simply as LIH.

The flow in Figure 4 is performed prior to long-length photography. The flow in Figure 4 is initiated in response to a user operation, for example, from the operation unit 9 or the input interface 27.

The operation control function 211 acquires setting information for the actual imaging (step S101). The setting information for the actual imaging includes the aperture opening of the X-ray aperture 15 for the actual imaging, the direction and speed of movement of the X-ray tube 13 and X-ray detector 17, etc. The setting information for the actual imaging also includes stroke information for long-length imaging. The stroke information is the stroke length that defines the long-length imaging range (the length between the imaging start position and the imaging end position).

The stroke length can also be expressed as the length of the imaging range in the imaging direction for long-length imaging. The stroke length is set to a distance depending on the body shape of the subject P, the region to be imaged, etc., such as 100 cm for imaging the entire spine.

The stroke length is assumed to be predetermined for each body shape and imaging region of the subject P and stored in the memory circuitry 23, etc. In this case, the operation control function 211 acquires the stroke length from the memory circuitry 23, etc., in accordance with the subject information, etc., input by the user.

The operation control function 211 may modify the stroke length obtained from the memory circuitry 23 or the like in response to a user input operation via the operation unit 9 or the input interface 27. The stroke length may also be input directly by the user via, for example, the operation unit 9 or the input interface 27.

The operation control function 211 drives the X-ray aperture 15 so that the aperture opening for positioning is larger than the aperture opening during actual imaging (step S102). Note that the aperture opening for positioning is assumed to be predetermined and stored in the memory circuitry 23, for example.

After the X-ray aperture reaches the aperture opening for positioning, the operation control function 211 starts acquiring X-ray image data (step S103). At this time, the image generation function 212 generates X-ray image data based on the output from the X-ray detector 17 and temporarily saves, i.e., temporarily stores, it in the memory circuitry 23.

The display control function 213 superimposes and displays the shooting guide information on the LIH (step S104). At this time, the image generation function 212 generates the shooting guide information based on the actual shooting setting information acquired by the operation control function 211 and the aperture opening for positioning. In addition, the display control function 213 displays the LIH with the shooting guide information superimposed on it on the display 251.

Figure 5 is a diagram showing an example of a display screen 300 including imaging guide information 330 according to an embodiment. Figure 5 illustrates an example of a display screen 300 including subject information 301, current acquisition conditions 303, information about the actual imaging 305, and a positioning image 310.

The current acquisition conditions 303 include, for example, fluoroscopy conditions. The information 305 related to the current imaging includes, for example, the protocol name for long-length imaging and typical reconstruction conditions. Typical reconstruction conditions may include, for example, the stitching mode and blend width (width of the overlap area) for generating a long-length imaging image. Here, the positioning image 310 is the LIH 311 of the fluoroscopic image on which imaging guide information 330 is superimposed. In the example shown in Figure 5, the imaging guide information 330 has guides 331, 333, 335, and 337.

Guide 331 is a display that indicates imaging start position information. In Figure 5, guide 331 is a display that guides the imaging start position for the long-length image. Guide 333 indicates a position that is determined based on guide 331 and the aperture opening (irradiation range) of the X-ray aperture 15. In other words, guides 331 and 333 indicate the image range of the first long-length image. Furthermore, during actual imaging, X-ray imaging is performed sequentially for each image range indicated by guides 331 and 333.

The guide 335 is a display that indicates the shooting direction. In the example of Figure 5, the guide 335 is an image of an arrow that indicates the long-length shooting direction.

The guide 337 is a display showing imaging range information. The imaging range information is, for example, information for explicitly showing on the LIH the range that will not be imaged by the actual imaging. In the example of Figure 5, the guide 337 is a mask image (hatched in Figure 5) that shows the range that will not be imaged by the actual imaging by masking the LIH 311. In other words, the guide 337 is an image for applying semi-transparent masking (masking) to the LIH 311. Note that semi-transparent masking can also be expressed as a process for displaying positions on the LIH that are not imaged because X-rays are blocked by the X-ray aperture 15 with a lower illuminance (pixel value) on the image than positions on the LIH that are imaged. Note that the imaging range information may also be information for explicitly showing on the LIH the range that will be imaged by the actual imaging.

After the display screen 300 is displayed, the operation control function 211 sets the imaging start position (step S105). First, while looking at the display screen 300, the user moves at least one of the imaging unit 3 and the bed 5 to adjust the desired imaging start range so that it fits between the two lines (guides 331, 333). In response to an instruction from the operation unit 9 or input interface 27 in response to the user's operation after adjustment is complete, the operation control function 211 sets the current position of the guide 331 as the imaging start position. Then, the flow in Figure 4 ends.

After the flow in Figure 4 is completed, the actual imaging is performed. In this imaging, by moving at least one of the support device 19 (C-arm) and the bed 5 in the direction of the subject P's body axis, long-length imaging can be started from the imaging start position specified by the user in the guide information position setting process according to this embodiment. In other words, the imaging range for long-length imaging according to this embodiment is a range set based on the preset stroke information and the position of the imaging guide information set in the superimposed image.

In the example shown in FIG. 5, the start position information is displayed at the center of the image of the LIH 311, but this is not limited to this. For example, the display control function 213 may display the information according to the position where actual acquisition will take place, such as when acquisition begins after the acceleration operation is completed. For example, when moving the bed 5 toward the head to start long-length imaging, the start position information will be displayed at the top of the display screen 300 in the example shown in FIG. 5.

In this embodiment, the case where the imaging guide information 330 is displayed superimposed on the LIH 311 has been described as an example, but this is not limited to this. The image on which the imaging guide information 330 is superimposed is not limited to the LIH of a fluoroscopic image, but may also be a photographed image or an image obtained by a visible light camera, etc.

In addition, shooting guide information for two or more shooting positions may be superimposed on the positioning image.

In addition, as imaging guide information, the overlap area between adjacent imaging positions during actual imaging, which is reserved for long-length stitching (reconstruction), can also be superimposed on the positioning image.

Note that there are no restrictions on the opening (vertical blades, horizontal blades) of the X-ray diaphragm 15 or the size of the collimator when acquiring the fluoroscopic image LIH on which the imaging guide information is superimposed. Therefore, the positioning diaphragm opening may be fully open, or the shape of the opening may be, for example, a rectangle that is long in the imaging direction D1 (the body axis direction of the subject P), or a predetermined opening determined in advance by the user may be used. In either case, the slit width for the actual imaging is converted to a size on the detection surface of the X-ray detector 17 and superimposed display is performed.

In this embodiment, a case has been described in which a stroke length is set and a long shooting range is set in response to a user's specification of the shooting start position, but this is not limited to this. There may be cases in which the stroke length is not used when setting a long shooting range.

For example, the position of the end of the subject P's body axis direction that can be imaged by the X-ray diagnostic device 1 can be used as the imaging end position. Even in this case, a long imaging range can be set according to the user's specification of the imaging start position. For example, when imaging the lower limbs, if imaging starts from the head side, the position of the end of the subject P's body axis direction is the end of the lower limb opposite the head. In such a case, the position of the end of the subject P's body axis direction can be determined by the end position of the bed 5.

Note that, although this embodiment has been described as an example in which shooting guide information that guides the shooting start position is displayed on the LIH, this is not limited to this. According to the technology of this embodiment, shooting guide information that guides the shooting end position can also be displayed on the LIH.

For example, the stroke length may be set, and the long-length imaging range may be set in response to the user's specification of the imaging end position. In this case, during the actual imaging, by moving at least one of the support device 19 (C-arm) and the bed 5 in the direction of the subject P's body axis, long-length imaging can be started from the imaging start position defined by the imaging end position specified by the user and the stroke length setting. In other words, the stroke information may be selected and set from among predetermined positions, such as the stroke length set numerically, the extreme end (start position, end position), or intermediate portion of the range in which long-length imaging is possible.

Note that, according to this embodiment, it is also possible to display shooting guide information on the LIH that guides users to positions other than the shooting start position and shooting end position. For example, there may be an intermediate shooting position that is halfway between the shooting start position and shooting end position. In other words, the user can specify the intermediate shooting position using the guide information display according to this embodiment.

For example, if a stroke length is set, a long imaging range is set that extends from the imaging intermediate position to both sides in the body axis direction of the subject P by half the stroke length in response to the user's specification of the imaging intermediate position. Similarly, for example, the end positions in the body axis direction of the subject P that can be imaged by the X-ray diagnostic device 1 can also be used as the imaging intermediate position.

Note that the user can also specify both the shooting start position and shooting end position using the guide information display according to this embodiment. In other words, in the position setting process of the guide information according to this embodiment, the long shooting range may be set according to the user's specification of the shooting start position and shooting end position.

As described above, the X-ray diagnostic apparatus 1 according to the embodiment generates imaging guide information indicating the range on the LIH to be imaged by the actual imaging based on setting information related to the actual imaging and the aperture opening for positioning, and displays the generated imaging guide information superimposed on the LIH for positioning. This configuration allows the user to perform positioning with a wide aperture opening. Furthermore, during positioning, the user can easily grasp which position on the positioning image will be imaged. In other words, according to the technology according to the embodiment, the long imaging range can be easily set by displaying the imaging guide information during positioning imaging performed prior to the actual imaging. Therefore, according to the technology according to the embodiment, long imaging can be performed efficiently with a simple configuration.

Second Embodiment
Next, an X-ray diagnostic apparatus 1 according to a second embodiment will be described, focusing mainly on the differences from the first embodiment.

In this embodiment, long-length photography is performed after the position of the shooting guide information is set in the guide information position setting process according to the first embodiment.

Figure 6 is a flowchart showing an example of the imaging process according to the embodiment.

Prior to the actual shooting process (steps S202 to S210), a process for setting the position of the shooting guide information is carried out (step S201). The process for setting the position of the shooting guide information was explained in the first embodiment with reference to FIG. 4, so a detailed explanation will be omitted here.

Then, the operation control function 211 determines whether to start actual shooting (long-length shooting) based on, for example, an instruction from the operation unit 9 or input interface 27 in response to a user operation (step S202). As an example, it is determined that actual shooting will start when the user starts pressing a button to instruct shooting. If it is not determined that actual shooting will start (step S202: No), the flow in FIG. 6 returns to the processing of step S201. On the other hand, if it is determined that actual shooting will start (step S202: Yes), the flow in FIG. 6 proceeds to the processing of step S203.

The operation control function 211 drives the X-ray aperture 15 to the aperture opening for the actual imaging (step S203), for example, in the same manner as the processing of step S102 in FIG. 4. Note that the aperture opening for the actual imaging is assumed to be predetermined and stored in the memory circuitry 23, for example.

After the X-ray aperture reaches the aperture opening for actual imaging, the operation control function 211 begins acquiring X-ray image data (step S204). At this time, the image generation function 212 generates X-ray image data based on the output from the X-ray detector 17 and temporarily stores the data in the memory circuitry 23. Furthermore, each time the image generation function 212 acquires X-ray image data, it sequentially generates long-length images by temporarily reconstructing the acquired data and stitching it together with previously acquired images. In other words, during long-length imaging, each time the image generation function 212 acquires an X-ray image at each position in the acquisition range of the subject P corresponding to the aperture opening of the X-ray aperture 15, it sequentially generates a long-length image based on the acquired X-ray image. The image generation function 212 temporarily stores the sequentially generated long-length images in the memory circuitry 23 (step S205). Furthermore, the display control function 213 displays the live image generated in the processing of step S205, i.e., the temporarily reconstructed long-length image, on the display 251 (step S206).

Figure 7 is a diagram showing an example of a display screen 400 including a live image 410 according to an embodiment. Figure 7 illustrates an example of a display screen 400 including subject information 401, a protocol selection screen 403, reconstruction conditions 405, a reconstruction condition change screen 407, and a live image 410.

The protocol selection screen 403 is an operation screen for selecting, for example, a preset long-length imaging protocol. The reconstruction conditions 405 may include, for example, a stitching mode and blend width (width of the overlap area) for generating a long-length imaging image according to the selected protocol. The reconstruction condition change screen 407 is an operation screen for changing the settings of the reconstruction conditions 405, such as the stitching mode and blend width.

The live image 410 is a long-length photographed image generated by temporary reconstruction in which newly acquired photographed images are added sequentially along the photographing direction D1 without changing the size of the long-length photographed images (photographed images) that have already been generated. Therefore, the size of the long-length photographed image generated by temporary reconstruction increases by the size of the photographed image at each position each time photographing is performed at each position.

In the example shown in Figure 7, newly acquired captured images are pasted, for example, at the positions indicated by the dashed frame. Note that in the example shown in Figure 7, each captured image is indicated by a solid frame to illustrate how newly acquired captured images are added sequentially along the capturing direction D1. In other words, the solid and dashed frame in the live image 410 in Figure 7 are not included in the live image 410.

The size of each captured image in the temporary reconstruction is assumed to be predetermined and stored in the memory circuitry 23, etc. In this case, the size of each captured image is determined, for example, based on the longitudinal length of the bed 5 of the long imaging range set in the guide information position setting process in step S201 and the aperture opening of the X-ray diaphragm 15 during the actual imaging. The size of each captured image may also be determined based on the longitudinal length of the bed 5 that can be imaged by the X-ray diagnostic device 1 and the aperture opening of the X-ray diaphragm 15 during the actual imaging. For example, the size of each captured image becomes smaller as the longitudinal length of the bed 5 increases with respect to the long imaging range expected before the long imaging is completed.

Note that the display screen 400 may be displayed as a display screen including subject information 301, current acquisition conditions 303, information about the actual imaging 305, and live images 410, similar to the display screen 300 in Figure 5. In this case, the current acquisition conditions 303 include, for example, information about the sequence of long-length imaging. Furthermore, the information about the actual imaging 305 includes, for example, the protocol name for long-length imaging and typical reconstruction conditions. Typical reconstruction conditions may include, for example, the stitching mode and blend width (width of the overlap area) for generating the long-length imaging image.

The operation control function 211 determines whether to end the actual imaging (step S207). As an example, it is determined that the actual imaging is to end when the user finishes pressing the button that instructs imaging, that is, when the user releases the button that began to be pressed in the processing of step S202. In other words, the operation control function 211 accepts an operation to stop X-ray imaging until collection of X-ray images in the long imaging range according to the position setting of the imaging guide information is completed. As an example, it is determined that the actual imaging is to end when imaging is completed up to the imaging end position set in the guide information position setting processing of step S201. If it is not determined that the actual imaging is to end (step S207: No), the flow of FIG. 6 returns to the processing of step S204.

On the other hand, when it is determined that the actual imaging should be terminated (step S207: Yes), the image generation function 212 acquires all projection image data obtained during the actual imaging and temporarily reconstructed X-ray image data (step S208). The temporarily reconstructed X-ray image data acquired here is image data based on the long images generated and stored until an operation to stop the X-ray imaging is performed or until imaging of the imaging range corresponding to the position setting of the imaging guide information in the superimposed image is completed. The image generation function 212 also generates long imaging image data by actual reconstruction, which stitches together all X-ray images (images) obtained during the actual imaging, and saves, i.e., stores, the data in the memory circuitry 23 (step S209). The display control function 213 also displays the long imaging image reconstructed in step S209 on the display 251 (step S210). The flow in FIG. 6 then ends.

Figure 8 is a diagram for explaining the generation of long-length captured images 500 and 600 according to an embodiment. Figure 8 illustrates an example of a live image (long-length captured image 500) at the end of the actual capture, and a long-length captured image 600 generated by the actual reconstruction.

Prior to the actual reconstruction, the image generation function 212 acquires the image size L1 of the temporarily reconstructed X-ray image and the predetermined image size L2 of the long-length image. The image size L1 of the temporarily reconstructed X-ray image is acquired based on the temporarily reconstructed X-ray image data stored in the memory circuitry 23 or the like. The image size L2 of the long-length image generated by the actual reconstruction is, for example, predetermined and stored in the memory circuitry 23 or the like. Here, each image size L1, L2 is the number of pixels of each image. More specifically, each image size L1, L2 is the number of pixels in the long-length imaging direction of each image, i.e., the stitching direction.

The image generation function 212 obtains the number of pixels of the X-ray detector 17 per pixel of the live image based on the image size L1 of the provisionally reconstructed X-ray image, i.e., the live image obtained by provisional reconstruction. The image generation function 212 also determines the size of each X-ray image to be stitched together in the actual reconstruction based on the number of pixels of the X-ray detector 17 per pixel of the live image and the size ratio between the two image sizes L1 and L2. The image generation function 212 then performs actual reconstruction, stitching together all of the X-ray images obtained in the actual imaging. In this way, the image generation function 212 performs actual reconstruction, generating a long image of a predetermined image size based on the X-ray images collected in the X-ray imaging, based on the image size of the X-ray image generated by provisional reconstruction.

Note that, while the example shown is one in which the processing related to the actual reconstruction (steps S208 to S210) is performed as a series of steps in conjunction with the processing of the actual image capture (steps S202 to S207), this is not limiting. The processing related to the actual reconstruction may also be performed as post-processing.

Note that the processing related to the actual reconstruction (steps S208 to S210) does not necessarily have to be performed. In other words, in the temporary reconstruction performed during long-length photography, the captured images from each position are stitched together in the same way as in the actual reconstruction, so the live image generated using the captured image from the last shooting position can also be treated as the long-length captured image generated by the actual photography. In this case, the long-length captured image generated by the temporary reconstruction can be converted to an image size suitable for display.

Note that while the example given above illustrates a case in which the same stitching as in the actual reconstruction is performed in the temporary reconstruction, this is not limiting. For example, temporary reconstruction can also be a process in which captured images at each position are displayed side-by-side in the shooting direction, without considering factors such as blend width. In this case, the long captured image is generated in the process related to the actual reconstruction, taking the blend width into consideration. Of course, the process related to the actual reconstruction may also perform reconstruction for determining the image size and reconstruction for generating the long captured image. Even with these configurations, the user can easily check the shooting position even during long-length shooting. In other words, the user can easily check up to which position on the subject imaging has been completed, and can easily determine when to release the button that instructs imaging and end imaging.

Note that image quality improvement processes such as noise reduction may be applied to the long-length captured image generated by the main reconstruction. Furthermore, for example, if main reconstruction is not performed, image quality improvement processes such as noise reduction may be applied to the long-length captured image generated by the temporary reconstruction.

Note that while the example given above shows a case where the live image generated in the processing of step S205 during long-length photography, i.e., the provisionally reconstructed long-length photography image, is displayed on the display 251, this is not limiting. For example, the display control function 213 may sequentially display the photographed images from each position at the same position on the display screen during long-length photography. In this display mode, unlike the live monitor mode in which live images are displayed, the size of the image displayed at each point in time remains constant from the start to the end of long-length photography. Note that photographed images such as live images may not be displayed during long-length photography, for example, depending on the user's settings.

In this way, the image generation function 212 obtains the number of pixels of the X-ray detector 17 corresponding to the imaging range of the long-length imaging based on the provisionally reconstructed X-ray image. The image generation function 212 also generates the actual reconstructed image (long-length imaging image 600) based on a live image stitched together based on the target object in the image, i.e., a provisionally reconstructed image that takes into account the width of the overlapping area in the stitching. This not only enables efficient long-length imaging with a simple configuration, but also makes it easy to grasp the range generated as a long-length imaging image by actual imaging with the X-ray aperture 15 narrowed, i.e., the range to be imaged. Furthermore, a long-length imaging image that matches the predetermined image size L2 can be generated with higher accuracy than when the image size is estimated from the encoder of the imaging unit 3 or the bed 5. In other words, the technology according to this embodiment can prevent the occurrence of blank areas in the long-length imaging image that do not include the imaging image. Therefore, it is possible to prevent degradation in the image quality of the long-length imaging image generated by actual imaging with the X-ray aperture 15 narrowed.

In the first embodiment, a case where long-length imaging is performed as the main imaging is described as an example, but this is not limited to this. The technology according to the first embodiment can also be applied to bone mineral density (BMD) measurement.

BMD measurement may be performed using the X-ray diagnostic device 1, but the size of the BMD measurement target, such as the femur, is often smaller than the detector size of the X-ray detector 17 of the X-ray diagnostic device 1. For this reason, from the perspective of analytical accuracy, images are collected during BMD measurement with the X-ray aperture 15 narrowed, as with the long-length imaging described above. Even during BMD measurement, the user must set the imaging range prior to image collection.

In this situation, for example, during BMD measurement, the user changes the display position of the imaging guide information on the display screen 300 so that the range they want to capture falls between the two lines (guides 331, 333). In other words, the user adjusts the display position of the imaging guide information on the LIH image. Note that if the display position of the imaging start position information is changed, the size of the imaging range information also changes.

In BMD measurement, the imaging start position information may be, for example, an image of a rectangular frame. In this case, the user adjusts the size and position of the frame so that the area they want to image fits within the frame.

In addition, during BMD measurement, the operation control function 211 responds to instructions from the operation unit 9 or input interface 27 in response to user operation after adjustment is complete and sets the position of the guide 331 at that time as the imaging start position. In other words, the operation control function 211 can also set the imaging range (imaging field of view) for bone density measurement as the main imaging in accordance with the display position of the imaging guide information on the LIH image.

In addition, in long-length photography, as with BMD measurement, the display position of the photography guide information 330 on the image of the LIH 311 may be adjustable. In this case, the user can set the photography start position for long-length photography by changing the display position of the photography guide information on the display screen 300.

Furthermore, during BMD measurement, the user may move at least one of the imaging unit 3 and the bed 5 while looking at the display screen 300, thereby adjusting the area to be imaged so that it fits between the two lines (guides 331, 333) or frames.

In this way, the technology according to the first embodiment enables efficient BMD measurement with a simple configuration.

In the X-ray diagnostic apparatus 1 according to each of the above-described embodiments, X-ray images may be acquired with the subject P in an upright position or with the subject P in a supine position.

At least one of the embodiments described above enables efficient long-length photography with a simple configuration.

While several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments may be embodied in a variety of other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are intended to fall within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as set forth in the claims.

REFERENCE SIGNS LIST 1 X-ray diagnostic device 3 Imaging unit 5 Bed 7 Drive unit 9 Operation unit 10 Console device 11 X-ray high voltage device 13 X-ray tube 15 X-ray aperture 16 Aperture control unit 17 X-ray detector 19 Holding device 21 Processing circuit (control unit)
23 Memory circuit (memory)
25 Display unit 27 Input interface 70 Drive control unit 71 Imaging system movement drive unit 73 Top plate movement drive unit 211 Operation control function (acquisition means, imaging execution means)
212 Image generation function (photography execution means)
213 Display control function (display control means)
251 Display

Claims (8)

1. An X-ray diagnostic apparatus for performing long-length photography of a subject by changing a position of an acquisition range corresponding to an aperture opening of an X-ray aperture and acquiring a plurality of X-ray images based on the acquisition range,
an acquisition means for acquiring a first partial X-ray image representing a part of the subject, for setting a first acquisition range defined based on an imaging start position of the long length imaging and the aperture opening ;
a display control means for causing a display unit to display a first superimposed image in which first guide information representing the first acquisition range is superimposed on the first X-ray partial image;
a photography execution means for setting conditions for long-length photography and executing the long-length photography,
the acquiring means further acquires a second partial X-ray image representing a part of the subject for setting a second acquisition range defined based on an imaging end position of the long length imaging and the aperture opening;
the display control means causes the display unit to display a second superimposed image in which second guide information representing the second acquisition range is superimposed on the second X-ray partial image;
the photographing execution means sets conditions for the long photographing including a third collection range defined based on a photographing position between the photographing start position represented by the first guide information set in the first superimposed image and the photographing end position represented by the second guide information set in the second superimposed image , both of which are acquired by a user's operation, and the aperture opening, based on a setting of a superimposition position of the first guide information in the first superimposed image and a setting of a superimposition position of the second guide information in the second superimposed image ;
X-ray diagnostic equipment. the display control means further performs one of superimposing a display indicating a direction of long-length imaging of the subject , masking a collection range, and masking a region other than the collection range on at least one of the first superimposed image and the second superimposed image.
2. The X-ray diagnostic apparatus according to claim 1. the imaging execution means sequentially generates long images based on the acquired X-ray images each time the X-ray images are acquired;
the display control means causes the generated long image to be displayed on the display unit.
3. The X-ray diagnostic apparatus according to claim 1. the imaging execution means accepts an operation to stop the long length imaging until the collection of the X-ray images under the setting of the long length imaging conditions is completed.
The X-ray diagnostic apparatus according to any one of claims 1 to 3. the photographing execution means, in response to an operation to stop the long photographing, records image data based on the long image generated up until the operation is performed;
The X-ray diagnostic apparatus according to any one of claims 1 to 4. the acquiring means determines whether or not the subject represented by the first X-ray partial image or the second X-ray partial image has moved, and when determining that the subject has moved, acquires a new X-ray partial image after the movement;
the display control means causes the display unit to display a superimposed image in which the acquisition range is superimposed on the X-ray partial image after the movement.
The X-ray diagnostic apparatus according to any one of claims 1 to 5. an imaging range of the first X-ray partial image and the second X-ray partial image is larger than an acquisition range corresponding to an aperture opening of an X-ray aperture that blocks X-rays in the long-length imaging;
The X-ray diagnostic apparatus according to any one of claims 1 to 6. 1. A control method for an X-ray diagnostic apparatus for performing long-length photography of a subject by changing a position of an acquisition range corresponding to an aperture opening of an X-ray aperture, and acquiring a plurality of X-ray images based on the acquisition range, the method comprising:
acquiring a first partial X-ray image representing a part of the subject for setting a first acquisition range defined based on an imaging start position of the long length imaging and the aperture opening ;
displaying a first superimposed image on a display unit, the first superimposed image being obtained by superimposing first guide information representing the first acquisition range on the first X-ray partial image;
further acquiring a second partial X-ray image representing a part of the subject for setting a second acquisition range defined based on the imaging end position of the long length imaging and the aperture opening;
displaying a second superimposed image on the display unit, the second superimposed image being obtained by superimposing second guide information representing the second acquisition range on the second X-ray partial image;
based on a setting of a superimposition position of the first guide information on the first superimposed image and a setting of a superimposition position of the second guide information on the second superimposed image, both of which are acquired by a user's operation, set a condition for the long length photography including a third collection range that is defined based on a photography position between the photography start position represented by the first guide information set on the first superimposed image and the photography end position represented by the second guide information set on the second superimposed image, and the aperture;
Perform the long-length photography.
A method for controlling an X-ray diagnostic apparatus.