JP5742734B2 - X-ray equipment - Google Patents

Description

  The present invention relates to an X-ray imaging apparatus that includes an arc-shaped arm generally called a C-shaped arm and performs three-dimensional imaging on a subject.

  For example, in the case of TAE (hepatic artery embolization therapy) of the liver and cardiovascular imaging of the heart, it is necessary to perform imaging from multiple directions in order to obtain a blood vessel image surrounding the front and back of the organ three-dimensionally. In such a case, an X-ray imaging apparatus including a C-type arm that supports an X-ray tube and an X-ray detector such as a flat panel detector or an image intensifier is used (see Patent Document 1). . In such an X-ray imaging apparatus, the C-arm is rotated 180 degrees or more around the rotation axis together with the X-ray tube and the X-ray detector, and the X-ray axis extending from the X-ray tube to the X-ray detector is A three-dimensional image is obtained by performing X-ray imaging while rotating the subject by 180 degrees or more.

  By the way, imaging of a three-dimensional image using such an X-ray imaging apparatus includes, for example, a morphological diagnosis mode in which only the shape of a blood vessel is focused, and a function of imaging information on soft tissue (soft tissue) such as a tumor or an organ. It is roughly divided into diagnostic modes. Here, in the former morphological diagnosis mode, low-exposure and low-invasive high-speed rotation imaging is possible, but in the latter functional diagnosis mode, it is necessary to extract an image from a low contrast state. Low-speed rotation shooting with a large number of shots per hour.

  Generally, since these morphological diagnosis mode and functional diagnosis mode are separate operations, it is necessary to inject a contrast medium every time each diagnosis mode is executed for a subject. There is a problem that the burden on the subject increases.

  For this reason, Patent Document 2 discloses a rotational imaging operation in which X-rays are continuously or intermittently generated from an X-ray tube while the C-arm is rotated and X-ray detection is repeated by an X-ray detector. An X-ray diagnostic apparatus is disclosed that is repeated a plurality of times after the agent injection. In this X-ray diagnostic apparatus, each of a plurality of rotational imaging operations is time-controlled and managed by a time starting from a single contrast agent injection time.

JP 2007-181545 A JP 2010-167254 A

  In the X-ray diagnostic apparatus described in Patent Document 2, in order to perform the next rotational imaging after performing the first rotational imaging, the C-arm is temporarily returned to the origin position after completion of the first rotational imaging. Then, the C-arm is again rotated in the same direction as the first rotation shooting, so that the next rotation shooting is executed. For this reason, a lag time occurs between the first imaging and the next imaging, and there are cases where necessary imaging cannot be performed while the contrast medium flows through an appropriate position.

  The present invention has been made to solve the above problems, and an object thereof is to provide an X-ray imaging apparatus capable of continuously performing a plurality of imaging using a C-shaped arm.

  The invention according to claim 1 detects an X-ray tube and X-rays irradiated from the X-ray tube and passed through the subject in an X-ray imaging apparatus that performs three-dimensional imaging on the subject. An X-ray detector, a C-shaped arm having a substantially C shape that supports the X-ray tube and the X-ray detector, and the C-shaped arm extending from the X-ray tube to the X-ray detector. A rotation mechanism that supports a rotation axis orthogonal to the axis of the line so as to be rotatable, and the C-arm is rotated in the first direction around the rotation axis, thereby performing the first imaging. A rotation control unit that performs second imaging by rotating the C-arm around the rotation axis in a second direction opposite to the first direction; and the first imaging Sometimes the position of the X-ray image taken by the X-ray tube and the X-ray detector is A first image position adjustment unit that changes according to the rotation angle position of the X-ray, and the position of the X-ray image captured by the X-ray tube and the X-ray detector during the second imaging, And a second image position adjusting unit that changes according to the rotation angle position.

  According to a second aspect of the present invention, in the first aspect of the invention, the rotation control unit is configured to perform the first imaging and the second imaging based on a signal from an injector that injects a contrast medium into the subject. Perform shooting.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the rotation control unit rotates the C-arm at a first speed during the first photographing, and the first At the time of photographing 2, the C-arm is rotated at a second speed different from the first speed.

  The invention according to claim 4 is the image composition according to claim 3, wherein the X-ray image obtained at the time of the first imaging and the X-ray image obtained at the time of the second imaging are synthesized. A part.

  According to the first aspect of the present invention, it is possible to continuously execute a plurality of shootings by changing the rotation direction of the C-arm between the first shooting and the second shooting. At this time, even when the rotation direction of the C-arm is different between the first imaging and the second imaging, the position error of the X-ray image caused by the rotation direction of the C-arm can be corrected appropriately. It becomes possible.

  According to the second aspect of the present invention, after the contrast medium is injected from the injector into the subject, the first imaging and the second imaging are executed in accordance with the timing when the contrast medium reaches the imaging area. It becomes possible.

  According to the third aspect of the present invention, it is possible to continuously execute photographing under a plurality of conditions having different rotational speeds.

  According to the invention described in claim 4, an image having more information is used for diagnosis by superimposing the X-ray image obtained by the first imaging and the X-ray image obtained by the second imaging. It becomes possible to do.

1 is a perspective view showing an outline of an X-ray imaging apparatus according to the present invention. It is a block diagram which shows the control system etc. of the X-ray imaging apparatus which concerns on this invention.

  FIG. 1 is a perspective view showing an outline of an X-ray imaging apparatus according to the present invention. FIG. 2 is a block diagram showing a control system and the like of the X-ray imaging apparatus according to the present invention.

  This X-ray imaging apparatus performs X-ray fluoroscopy or X-ray imaging (collectively referred to as “X-ray imaging”) with respect to a subject 21 placed on a table 22. As shown in FIG. 1, the X-ray imaging apparatus includes an X-ray tube 11 and a flat panel detector as an X-ray detector that detects X-rays irradiated from the X-ray tube 11 and passing through a subject 21. 12, a substantially C-shaped C-shaped arm 13 that supports the X-ray tube 11 and the flat panel detector 12, a support portion 14 that slidably supports the C-shaped arm 13, and the support portion 14 that rotates. And a suspension arm 16 that suspends the rotation mechanism 15 from a fixing portion 18 fixed to the ceiling.

  An arcuate guide portion 17 is formed on the C-shaped arm 13, and the support portion 14 is engaged with the guide portion 17 to support the C-shaped arm 13 so as to be slidable. The C-shaped arm 13 is in a state in which the X-ray tube 11 and the flat panel detector 12 are aligned with the X-ray axis extending from the X-ray tube 11 to the flat panel detector 12 being the diameter of the arc forming the guide portion 17. I support it. The rotating mechanism 15 also has a rotating shaft that faces the direction orthogonal to the X-ray axis extending from the X-ray tube 11 to the flat panel detector 12 (horizontal direction in this embodiment) together with the C-shaped arm 13 and the like. It is rotatably supported at the center.

  2, the X-ray imaging apparatus controls a control unit 30, an input unit 45 such as a keyboard, a display unit 46 such as a CRT, a tube voltage applied to the X-ray tube 11, and the like. And an X-ray tube control unit 44. The control unit 30 includes a motor 41 as a drive unit for sliding the C-type arm 13 with respect to the support unit 14 and a drive unit for rotating the C-type arm 13 around a rotation axis facing the horizontal direction. The motor 42 is connected. Further, the control unit 30 is also connected to an injector 50 for injecting a contrast medium into the body of the subject 21 via an injection needle attached to the subject 21.

  The controller 30 is for rotating the C-arm 13 in the first and second directions to execute the first and second imaging. Further, the control unit 30 performs image processing on the X-ray image captured by the flat panel detector 12 and displays the image on the display unit 46, and the rotation angle position for each rotation direction of the C-arm 13. A pair of tables 35 and 36 in which data indicating the relationship with the photographing position error is recorded are provided. Then, the image processing unit 31 includes a first image position adjusting unit 32 that changes the position of the X-ray image according to the rotational angle position of the C-shaped arm 13 during first imaging described later, and a second imaging described later. Sometimes, the second image position adjustment unit 33 that changes the position of the X-ray image according to the rotational angle position of the C-arm 13, the X-ray image obtained at the first imaging, and the obtained at the second imaging An image composition unit 34 that composes the X-ray image is provided.

  In this X-ray imaging apparatus, X-rays are irradiated from the X-ray tube 11 toward the subject 21 on the table 22, and the X-rays passing through the subject 21 are detected by the flat panel detector 12. X-rays are subjected to image processing by the image processing unit 31 in the control unit 30, and an X-ray image is displayed on the display unit 46 using a video signal obtained by the image processing.

  In the X-ray imaging apparatus according to the present invention, as will be described later, the C-arm 13 is rotated in the first direction to perform the first imaging, and then rotated in the second direction to obtain the second It is the structure which performs imaging | photography. Here, when the C-arm 13 is rotated, ideally, the X-ray tube 11 and the flat panel detector 12 move in the same plane facing the direction orthogonal to the rotation axis. Due to the mechanical error such as the above, the locus slightly deviated from the same plane is moved, so that the position of the X-ray image taken by the X-ray tube 11 and the flat panel detector 12 is displaced.

  For this reason, in the X-ray imaging apparatus using the C-shaped arm 13, the position of the X-ray image captured by the X-ray tube 11 and the flat panel detector 12 is changed according to the rotational angle position of the C-shaped arm 13. There is a need. The positional deviations of the X-ray images differ from each other depending on the rotation direction of the C-arm 13. Therefore, in the X-ray imaging apparatus according to the present invention, the position adjustment for adjusting the position of the X-ray image between the case where the C-arm 13 is rotated in the first direction and the case where it is rotated in the second direction. The actions are performed individually.

  That is, the table 35 records data indicating the relationship between the rotational angle position of the C-type arm 13 and the photographing position error at that time when the C-type arm 13 is rotated in the first direction. Similarly, the table 36 records data indicating the relationship between the rotational angle position of the C-type arm 13 and the photographing position error at that time when the C-type arm 13 is rotated in the second direction. . These data are obtained in advance by photographing a phantom or the like with the C-arm 13 rotated, and experimentally measuring the relationship between the rotational angle position of the C-arm 13 and the position of the photographed X-ray image. Is required.

  Next, an operation when X-ray imaging is performed by the above-described X-ray imaging apparatus will be described. In the following embodiments, a case where blood vessel contrast and tumor contrast are sequentially performed in order to perform TAE (hepatic artery embolization therapy) of the liver will be described.

  When X-ray imaging is performed, an injector 50 is set for the subject 21, and the injector 50 can inject a contrast medium into the body of the subject 21. In this state, imaging by the X-ray imaging apparatus is started.

  In this case, first, the motor 41 is driven by a command from the control unit 30 and the C-type arm 13 is slid with respect to the support unit 14 to place the C-type arm 13 in a place suitable for X-ray imaging. Deploy. In this state, the motor 42 is driven by a command from the control unit 30, and the C-arm 13 rotates in the first direction (for example, clockwise direction). In this X-ray imaging, the C-arm 13 is first rotated at high speed to perform X-ray imaging in the morphological diagnosis mode in order to perform blood vessel imaging. Therefore, the rotational speed at this time is relatively high. 1 speed.

  When a predetermined time elapses after receiving a signal from the injector 50, a first X-ray image of the contrast agent flowing into the blood vessel is obtained while rotating the C-arm 13 in the first direction at the first speed. Perform shooting. At this time, the X-ray image taken by the flat panel detector 4 is transmitted to the image processing unit 31 in the control unit 30. At this time, the first image position adjustment unit 32 in the image processing unit 31 rotates the position of the C-shaped arm 13 with the position of the X-ray image captured by the X-ray tube 11 and the flat panel detector 12 during the first imaging. By adjusting according to the angular position, the positional deviation of the X-ray image is corrected. Then, a three-dimensional image of the blood vessel is created by reconstructing the X-ray image captured by the image processing unit 31. This three-dimensional image is displayed on the display unit 46.

  When the first photographing is finished, the control unit 30 transmits a command to the motor 42 to rotate the C-arm 13 in a second direction (counterclockwise direction) opposite to the first direction. In this X-ray imaging, in order to perform imaging of a darkly stained tumor following the first imaging, the C-arm 13 is rotated at a low speed and X-ray imaging is performed in the function diagnosis mode. The rotation speed is a relatively low second speed.

  When a predetermined time elapses after receiving a signal from the injector 50, an X-ray image of the contrast agent flowing into the tumor from the capillary tube is photographed while rotating the C-arm 13 in the second direction at the second speed. Second imaging is performed. At this time, the X-ray image captured by the flat panel detector 12 is transmitted to the image processing unit 31 in the control unit 30. At this time, the second image position adjustment unit 33 in the image processing unit 31 rotates the position of the C-shaped arm 13 based on the position of the X-ray image captured by the X-ray tube 11 and the flat panel detector 12 during the second imaging. By adjusting according to the angular position, the positional deviation of the X-ray image is corrected. Then, by reconstructing the X-ray image photographed by the image processing unit 31, a three-dimensional image of a dark dyed image is created. This three-dimensional image is displayed on the display unit 46.

  Next, the image synthesizing unit 34 synthesizes the three-dimensional image of the blood vessel created by the first imaging and the three-dimensional image of the deeply dyed image created by the second imaging. At this time, since the three-dimensional positional relationship between the two images is kept constant, an accurate composite image can be created. This composite image is also displayed on the display unit 46.

  In the above-described embodiment, since blood vessel contrast and tumor contrast are sequentially performed, the C-arm 13 is first rotated at a high speed to perform the first imaging, and then rotated at a low speed. The second shooting is executed. However, for example, when it takes time for the contrast medium to reach the portal vein, such as when imaging the portal vein after imaging the organ, the C-arm 13 is first rotated at a low speed. After executing the first imaging, the C-arm 13 may be rotated at a high speed to execute the second imaging.

  In the above-described embodiment, the C-arm 13 is rotated at a relatively high first speed during the first shooting, and the C-arm 13 is different from the first speed during the second shooting. It is rotated at a relatively low second speed. However, when the tumor site is photographed multiple times in succession and it is determined whether the tumor is malignant or benign, the same part may be photographed continuously at the same speed. .

DESCRIPTION OF SYMBOLS 11 X-ray tube 12 Flat panel detector 13 C type arm 14 Support part 15 Rotation mechanism 16 Suspended arm 18 Fixed part 21 Subject 22 Table 30 Control part 31 Image processing part 32 1st image position adjustment part 33 2nd image position adjustment Section 34 Image composition section 35 Table 36 Table 41 Motor 42 Motor 45 Input section 46 Image display section

Claims (4)

In an X-ray imaging apparatus that performs three-dimensional imaging on a subject,
An X-ray tube;
An X-ray detector for detecting X-rays irradiated from the X-ray tube and passing through the subject;
A C-shaped arm having a substantially C-shape for supporting the X-ray tube and the X-ray detector;
A rotation mechanism that supports the C-arm so as to be rotatable about a rotation axis orthogonal to an X-ray axis extending from the X-ray tube to the X-ray detector;
By rotating the C-arm in the first direction around the rotation axis, the first photographing is performed, and the C-arm is reversed from the first direction around the rotation axis. A rotation control unit that performs second imaging by rotating in a second direction facing the direction;
A first image position adjustment unit that changes a position of an X-ray image captured by the X-ray tube and the X-ray detector at the time of the first imaging according to a rotation angle position of the C-arm;
A second image position adjustment unit that changes a position of an X-ray image captured by the X-ray tube and the X-ray detector at the time of the second imaging according to a rotation angle position of the C-arm;
An X-ray imaging apparatus comprising: The X-ray imaging apparatus according to claim 1,
The rotation control unit is an X-ray imaging apparatus that performs the first imaging and the second imaging based on a signal from an injector that injects a contrast medium into the subject. The X-ray imaging apparatus according to claim 1 or 2,
The rotation control unit rotates the C-arm at a first speed during the first shooting, and rotates the C-arm at a second speed different from the first speed during the second shooting. A rotating X-ray imaging device. The X-ray imaging apparatus according to claim 3,
An X-ray imaging apparatus including an image composition unit that synthesizes an X-ray image obtained at the time of the first imaging and an X-ray image obtained at the time of the second imaging.

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