JP2012223629A - Radiographic apparatus, radiographic method, and radiographic image displaying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a detailed and efficient observation by using two X-ray detectors.SOLUTION: A display control part 81 receives the specification of an oblong region by an operator on an image by the X-ray detector 21a, and a detector moving instruction part 101 converts coordinates in an image coordinate system of the oblong region to coordinates in a physical coordinate system of the X-ray detector 21b. Then, the detector moving instruction part 101 instructs a detector motion control part 34b to move the X-ray detector 21b so as to image the oblong region, and the detector motion control part 34b moves the X-ray detector 21b.

Description

  The present invention provides an X-ray imaging of an X-ray imaging apparatus including a first X-ray detector that detects X-rays transmitted through a subject and a second X-ray detector having a smaller field of view than the first X-ray detector. Regarding technology.

  Some X-ray imaging apparatuses that detect an X-ray that has passed through a subject and photograph the subject by using an X-ray detector include two X-ray detectors (see, for example, Patent Document 1). FIG. 9 is an explanatory diagram for explaining an X-ray imaging apparatus including two X-ray detectors. As shown in the figure, the X-ray imaging apparatus includes two X-ray detectors, that is, X-ray detectors 21a and 21b.

  The X-ray detector 21a is an FPD (Flat Panel Detector), and has a pixel size of 150-200 μm and a visual field of 20 cm-40 cm. FIG. 10 is a diagram illustrating an example of the configuration of the FPD. As shown in the figure, the FPD is converted by a detection element 21-1 that detects X-rays, a photoelectric film 21-2 that converts X-rays detected by the detection element 21-1 into charges, and a photoelectric film 21-2. The charge storage capacitor 21-3 for storing the stored charge and the TFT 21-4 for reading out the charge stored in the charge storage capacitor 21-3 to the signal output line 21-5 based on the signal of the gate driver 22 are arranged on the matrix for each pixel. Arranged and configured.

  In FPD, since the TFT 21-4 cannot be reduced, the pixel size cannot be reduced. Therefore, the pixel size of FPD is limited to 50 μm. However, if the pixel size is 50 μm, an FPD with a side of 40 cm has 16 million pixels, and excessive hardware is required for image memory and image processing. For this reason, it is not realistic to set the pixel size to 50 μm, and the pixel size is 150 to 200 μm.

  The X-ray detector 21b is a detector having a high definition (high resolution) but a narrow visual field as compared with the X-ray detector 21a, and has a pixel size of about 20 μm and a visual field of about 20-30 mm. FIG. 11 is a diagram showing an example of the configuration of such a small-field high-definition X-ray detector. As shown in the figure, this X-ray detector is configured by placing CsI as a scintillator 21-7 on a CCD 21-6 and storing it in a container 21-8. Here, since the CCD 21-6 is made of a single crystal Si material, a large field of view of 40 cm on a side cannot be realized.

  In the X-ray imaging apparatus shown in FIG. 9, imaging is usually performed using the X-ray detector 21a. However, when a lesion or the like that requires detailed observation is found, the X-ray generator 1 generates X-rays. The X-ray detector 21b is inserted into the field of view, and high-definition imaging of the lesion is performed.

  Since the pixel size of the X-ray detector 21b is as small as about 20 μm, it is better to reduce the enlargement ratio of an image photographed using the X-ray detector 21b as much as possible. Here, as shown in FIG. 12, the enlargement ratio is d2 / d1, where d1 is the distance between the X-ray focal point and the region of interest, and d2 is the distance between the X-ray focal point and the X-ray detector. Therefore, in order to reduce the enlargement ratio, it is necessary to make d2 as small as possible, that is, to bring the X-ray detector 21b into close contact with the subject as much as possible. For this reason, as shown in FIG. 9, the X-ray detector 21b is placed at a position closer to the X-ray generator 1 than the X-ray detector 21a.

US Pat. No. 6,285,739

  In an X-ray imaging apparatus including two X-ray detectors, when a lesion is found during observation of an image captured by the X-ray detector 21a, the operator operates the X-ray detector 21b to detect the lesion. It is necessary to be able to shoot as easily as possible. However, there is a problem that it is not easy to operate the X-ray detector 21b so that the visual field of the X-ray detector 21b accurately matches the lesioned part. Further, there are cases where the lesioned part cannot be observed accurately only by separately observing the image of the lesioned part taken by the X-ray detector 21b and the peripheral image taken by the X-ray detector 21a.

  The present invention has been made to solve the above-described problems caused by the prior art, and enables an operator to efficiently perform detailed observation of a lesioned part or the like using two X-ray detectors. An object is to provide an X-ray imaging apparatus, an X-ray imaging method, and an X-ray image display method.

  In order to solve the above-described problems and achieve the object, the present invention provides a first X-ray detector for detecting X-rays transmitted through a subject, and a second X-ray having a smaller field of view than the first X-ray detector. An X-ray imaging apparatus for displaying a first image and a second image respectively captured using a line detector, wherein the second image accepts designation of an imaging region of a second image on the first image Image capturing area designation receiving means and second X-ray detector moving means for moving the second X-ray detector to a position for capturing the imaging area of the second image received by the second image capturing area receiving means And a second image photographed using the second X-ray detector moved by the second X-ray detector moving means, the second image photographed via the second image photographing area designation receiving means. An image display hand that overlaps and displays the shooting area specified above. Characterized by comprising and.

  In addition, the present invention was imaged using a first X-ray detector that detects X-rays transmitted through the subject and a second X-ray detector that has a smaller field of view than the first X-ray detector. An X-ray imaging apparatus for displaying a first image and a second image, the second image imaging area designation receiving means for accepting designation of an imaging area of a second image on the first image, and the first And image display means for displaying the second image so as to overlap the imaging area designated on the first image via a two-image imaging area designation receiving means.

  The present invention also provides a first X-ray detector that detects X-rays transmitted through a subject and a second X-ray detector that has a field of view smaller than that of the first X-ray detector. An X-ray imaging method by an X-ray imaging apparatus for displaying one image and a second image, wherein a second image imaging area designation receiving step for accepting designation of an imaging area of a second image on the first image A second X-ray detector moving step of moving the second X-ray detector to a position where the imaging region of the second image received by the second image imaging region receiving step is imaged, and the second X The second image photographed using the second X-ray detector moved by the line detector moving step is designated on the first image via the second image photographing region designation receiving step. Image display that overlaps the shooting area And a step, the first image is a real-time image according to the first detector, the second image is characterized in that by the second detector is a real-time image.

  In addition, the present invention was imaged using a first X-ray detector that detects X-rays transmitted through the subject and a second X-ray detector that has a smaller field of view than the first X-ray detector. An X-ray image display method by an X-ray imaging apparatus for displaying a first image and a second image, wherein the second image imaging area designation accepts designation of an imaging area of a second image on the first image Including an accepting step, and an image display step for displaying the second image in an overlapping manner on the photographing region designated on the first image through the second image photographing region designation accepting step, The first image is a real-time image by the first detector, and the second image is a real-time image by the second detector.

  According to the present invention, the operator can easily specify the imaging region of the second image on the first image.

  According to the present invention, the surgeon can observe the second image while comparing with surrounding images.

It is a functional block diagram which shows the structure of the X-ray imaging apparatus which concerns on a present Example. It is a figure which shows the structure relevant to imaging | photography using the X-ray detector 21b among the structures of the X-ray imaging apparatus shown in FIG. It is explanatory drawing for demonstrating designation | designated of the imaging | photography area | region using the pointing device 83 on the monitor 82a. It is a figure which shows an example of the moving mechanism of the X-ray detector 21b of the X-ray detector moving mechanisms 31. FIG. It is explanatory drawing for demonstrating the display method on the monitor 82a by the X-ray detector 21b. It is explanatory drawing for demonstrating the enlarged display of the image image | photographed using the X-ray detector 21b. It is explanatory drawing for demonstrating the optimal gradation conversion of each of two images made to overlap. It is a flowchart which shows the process sequence of the small visual field high-definition image display process by the X-ray imaging apparatus which concerns on a present Example. It is explanatory drawing for demonstrating the X-ray imaging apparatus provided with two X-ray detectors. It is a figure which shows an example of a structure of FPD. It is a figure which shows an example of a structure of a small visual field high-definition X-ray detector. It is a figure which shows the definition of an expansion rate.

  Exemplary embodiments of an X-ray imaging apparatus, an X-ray imaging method, and an X-ray image display method according to the present invention will be described below in detail with reference to the accompanying drawings.

  First, the configuration of the X-ray imaging apparatus according to the present embodiment will be described. FIG. 1 is a functional block diagram illustrating the configuration of the X-ray imaging apparatus according to the present embodiment. As shown in the figure, the X-ray imaging apparatus includes an X-ray generation unit 1, an X-ray detection unit 2, a mechanism unit 3, a high voltage generation unit 4, a C arm 5, a top plate 6, The image processing unit 7 includes a display unit 8, an operation unit 9, and a system control unit 10.

  The X-ray generation unit 1 is an apparatus that generates X-rays to be irradiated on a subject on the top 6, and an X-ray tube 11 that generates X-rays using a high voltage supplied from the high voltage generation unit 4. And an X-ray diaphragm 12 that controls the irradiation field by shielding a part of the X-rays generated by the X-ray tube 11.

  The X-ray detection unit 2 is an apparatus that detects X-rays that have passed through the subject and generates image data. The X-ray detector 21a is a flat detector that is normally used when imaging a subject, X-ray detector 21b used for detailed observation of a lesion, etc., with a small field of view and finer resolution than the line detector 21a, a gate driver 22 for extracting charges from the X-ray detector 21a, and charges detected by the X-ray detector 21a Is converted into a voltage, and an A / D converter 24 that converts the voltage converted by the charge / voltage converter 23 into a digital value.

  The mechanism unit 3 is a device that moves the X-ray detectors 21a and 21b, the C arm 5 and the top plate 6, and includes an X-ray detector moving mechanism 31 that moves the X-ray detectors 21a and 21b, and a C arm 5. A C-arm rotating / moving mechanism 32 that rotates or moves, a top-plate moving mechanism 33 that moves the top 6, an X-ray detector moving mechanism 31, and a C-arm rotation based on instructions from the system control unit 10. And a mechanism control unit 34 for controlling the moving / moving mechanism 32 and the top plate moving mechanism 33.

  The high voltage generation unit 4 is a device that supplies a high voltage necessary for the X-ray generation unit 1 to generate X-rays, and controls the generation of the high voltage based on an instruction from the system control unit 10 to generate X-rays. An X-ray control unit 41 that controls generation and a high voltage generator 42 that generates high voltage are included.

  The C arm 5 is an arm that holds the X-ray generator 1 and the X-ray detectors 21a and 21b, and the top plate 6 is a plate on which the subject is placed. The image processing unit 7 is a processing unit that processes the image data generated by the X-ray detection unit 2, and includes an image calculation circuit 71 that performs reconstruction calculation, subtraction calculation, and the like, and an image data storage circuit 72 that stores image data. And have.

  The display unit 8 is a device that displays an image stored in the image data storage circuit 72, and includes a display control unit 81 that controls display on the monitor 82 and a monitor 82 that displays an image. The operation unit 9 is a console that receives an operation by the operator, and the system control unit 10 is a device that controls the entire X-ray diagnostic apparatus based on the operation of the operator.

  Next, imaging using the X-ray detector 21b will be described. FIG. 2 is a diagram showing a configuration related to imaging using the X-ray detector 21b in the configuration of the X-ray imaging apparatus shown in FIG. In FIG. 2, it is assumed that the monitor 82 includes a monitor 82a and a monitor 82b, and an image of the subject imaged using the X-ray detector 21a is displayed on the monitor 82a.

  In imaging using the X-ray detector 21b, the display control unit 81 receives an imaging area designated by the surgeon using the pointing device 83 for the image of the subject displayed on the monitor 82a. FIG. 3 is an explanatory diagram for describing designation of an imaging region using the pointing device 83 on the monitor 82a. As shown in the figure, the surgeon designates an imaging region by the X-ray detector 21b by moving a rectangle 85 on the image 84 by the X-ray detector 21a by using a pointing device 83 such as a mouse. .

  Then, the system control unit 10 instructs the detector operation control unit 34b to move the X-ray detector 21b to a position where the imaging region received by the display control unit 81 can be imaged. Specifically, the system control unit 10 includes a detector movement instruction unit 101, and the detector movement instruction unit 101 determines the coordinates in the screen coordinate system of the imaging region designated on the monitor 82a of the X-ray detector 21b. The coordinates are converted into coordinates in the physical coordinate system, and the detector operation control unit 34b is instructed to move the X-ray detector 21b. Then, the detector operation control unit 34b controls the X-ray detector moving mechanism 31 to move the X-ray detector 21b. The detector operation control unit 34b is a part of the mechanism control unit 34.

  FIG. 4 is a diagram illustrating an example of the moving mechanism of the X-ray detector 21 b in the X-ray detector moving mechanism 31. As shown in the figure, this moving mechanism includes an X-direction drive mechanism 31a that moves the X-ray detector 21b in the X direction relative to the X-ray detector 21a, and a Y-direction drive mechanism 31b that moves in the Y direction. Is provided.

  When the X-ray detector 21b moves to a position where the imaging region designated by the operator can be imaged on the monitor 82a, the display control unit 81 is generated based on the X-rays detected by the X-ray detector 21b. The image signal is received and displayed on the imaging region designated by the operator on the monitor 82a.

  FIG. 5 is an explanatory diagram for explaining a method of displaying an image on the monitor 82a by the X-ray detector 21b. As shown in the figure, the display control unit 81 designates an image 86 by the X-ray detector 21b and an image of the container portion of the X-ray detector 21b on the image 84 by the X-ray detector 21a. Overlapping display in the shooting area.

  As described above, the detector movement instruction unit 101 converts the coordinates in the screen coordinate system of the imaging region designated on the monitor 82a into coordinates in the physical coordinate system, and the detector operation control unit 34b transmits the X-ray detector 21b. The movement is instructed, and the detector operation control unit 34b controls the X-ray detector moving mechanism 31 to move the X-ray detector 21b, so that the surgeon displays the lesioned part and the like with a simple operation in high definition. be able to.

  Further, the display control unit 81 displays the image 86 by the X-ray detector 21b so as to overlap the imaging region designated by the operator on the image 84 by the X-ray detector 21a, so that the operator The lesioned part can be observed in detail while comparing with the surrounding area.

  Here, although the image 84 by the X-ray detector 21a is an image immediately before the X-ray detector 21b moves, a real-time image by the X-ray detector 21a is displayed as the image 84 by the X-ray detector 21a. You can also. The image 86 obtained by the X-ray detector 21b can be a one-shot image or a real-time image.

  In addition, in FIG. 5, the case where an image captured using the X-ray detector 21b is displayed as it is has been described. However, since the X-ray detector 21b has a higher definition than the X-ray detector 21a, The enlarged image can also be displayed. FIG. 6 is an explanatory diagram for explaining an enlarged display of an image photographed using the X-ray detector 21b. As shown in the figure, in the enlarged display, when the operator gives an instruction, the display control unit 81 displays an enlarged image 87 of the image 86 (see FIG. 5) by the X-ray detector 21b as an image by the X-ray detector 21a. 84 is overlapped and displayed. Thus, the display control unit 81 enlarges and displays the image by the X-ray detector 21b, so that the surgeon can accurately observe details such as a lesioned part.

  Further, since the sensitivity of the X-ray detector 21b is different from that of the X-ray detector 21a, an image obtained using the X-ray detector 21b and an image obtained using the X-ray detector 21a are not shown in FIG. The frequency distribution of pixel values is different. For this reason, the display control unit 81 associates the gradation of the image by the X-ray detector 21b with a pixel value different from the gradation of the image by the X-ray detector 21a so that each image has the optimum gradation. Perform gradation processing. As described above, the display control unit 81 performs the gradation processing for achieving the optimum gradation for each of the image by the X-ray detector 21b and the image by the X-ray detector 21a, thereby displaying both images clearly. Can do.

  Next, a processing procedure of small-field high-definition image display processing by the X-ray imaging apparatus according to the present embodiment will be described. FIG. 8 is a flowchart illustrating a processing procedure of a small-field high-definition image display process performed by the X-ray imaging apparatus according to the present embodiment.

  As shown in the figure, in this small-field high-definition image display process, the display control unit 81 displays an image photographed using the X-ray detector 21a on the monitor 82a, and uses the X-ray detector 21b. Designation of a rectangular area to be photographed is received from the operator (step S1).

  Then, the detector movement instruction unit 101 converts the coordinates in the screen coordinate system of the rectangular area designated by the operator into the coordinates in the physical coordinate system of the X-ray detector 21b (step S2), so that the rectangular area can be imaged. Then, the detector operation control unit 34b is instructed to move the X-ray detector 21b (step S3).

  Then, the detector operation control unit 34b moves the X-ray detector 21b (step S4), and when the X-ray detector 21b moves to a position for imaging a rectangular area designated by the operator, the X-ray detector 21b. Start shooting using.

  Then, the display control unit 81 performs gradation conversion so that the pixel value based on the X-ray detected by the X-ray detector 21b is optimized with respect to the sensitivity of the X-ray detector 21b (step S5), and the X-ray detector. An image captured using the X-ray detector 21b is displayed in a rectangular area designated by the operator on the image 21a (step S6).

  As described above, in this embodiment, the display control unit 81 accepts designation of a rectangular area on the image by the X-ray detector 21a, and the detector movement instruction unit 101 uses the screen coordinate system of the rectangular area. Are converted into coordinates in the physical coordinate system of the X-ray detector 21b. The detector movement instructing unit 101 instructs the detector operation control unit 34b to move the X-ray detector 21b so that a rectangular area can be imaged, and the detector operation control unit 34b moves the X-ray detector 21b. Therefore, the surgeon can display a high-definition image such as a lesion on the monitor 82a with a simple operation.

  In the present embodiment, the display control unit 81 overshoots an image captured using the X-ray detector 21b over a rectangular area designated by the operator on the image captured using the X-ray detector 21a. Since the display is wrapped, the surgeon can observe details such as a lesioned part in comparison with surrounding images.

  In the present embodiment, the display control unit 81 enlarges and displays an image captured using the X-ray detector 21b based on an instruction from the operator. It can be observed in more detail.

  In the present embodiment, the display control unit 81 performs gradation conversion so that the pixel value based on the X-ray detected by the X-ray detector 21b is optimized with respect to the sensitivity of the X-ray detector 21b. Even when the sensitivities of the X-ray detectors 21a and 21b are different from each other, it is possible to display the images by the respective X-ray detectors clearly.

  In the present embodiment, the case where the X-ray detector 21b is higher in definition than the X-ray detector 21a has been described. However, the present invention is not limited to this, for example, the X-ray detector The present invention can be similarly applied when the features of the X-ray detector 21a and the X-ray detector 21b are different, such as the X-ray detector 21a having a greatly different X-ray detection range than the X-ray detector 21a.

  As described above, the present invention is useful when imaging a patient or the like using X-rays, and is particularly suitable for operating and observing two X-ray detectors having different characteristics.

DESCRIPTION OF SYMBOLS 1 X-ray generation part 2 X-ray detection part 3 Mechanism part 4 High voltage generation part 5 C arm 6 Top plate 7 Image processing part 8 Display part 9 Operation part 10 System control part 11 X-ray tube 12 X-ray restrictor 21a, 21b X-ray detector 21-1 Detection element 21-2 Photoelectric film 21-3 Charge storage capacitor 21-4 TFT
21-5 Signal output line 21-6 CCD
21-7 Scintillator 21-8 Container 22 Gate driver 23 Charge / voltage converter 24 A / D converter 31 X-ray detector moving mechanism 31a X-direction driving mechanism 31b Y-direction driving mechanism 32 C-arm rotating / moving mechanism 33 Plate moving mechanism 34 Mechanism control unit 34a, 34b Detector operation control unit 41 X-ray control unit 42 High voltage generator 71 Image arithmetic circuit 72 Image data storage circuit 81 Display control unit 82, 82a, 82b Monitor 83 Pointing device 84 X-ray Image by detector 21a 85 Rectangle 86 Image by X-ray detector 21b 87 Enlarged image 101 Detector movement instruction section

Claims (7)

A first image and a second image captured using a first X-ray detector that detects X-rays that have passed through the subject and a second X-ray detector that has a smaller field of view than the first X-ray detector, respectively. An X-ray imaging apparatus that displays an image of
Second image shooting area designation receiving means for receiving designation of the shooting area of the second image on the first image;
Second X-ray detector moving means for moving the second X-ray detector to a position for imaging the imaging area of the second image received by the second image imaging area receiving means;
A second image photographed using the second X-ray detector moved by the second X-ray detector moving means is displayed on the first image via the second image photographing area designation receiving means. An X-ray imaging apparatus, comprising: an image display unit configured to overlap and display the designated imaging region.   When the sensitivity of the first X-ray detector is different from the sensitivity of the second X-ray detector, the image display means performs the first display based on the sensitivity of the second X-ray detector with respect to the second image. The X-ray imaging apparatus according to claim 1, wherein the display is performed after gradation conversion different from gradation conversion of an image.   The X-ray imaging apparatus according to claim 1, wherein the second X-ray detector has a higher resolution than the first X-ray detector. A first image and a first image captured using a first X-ray detector that detects X-rays transmitted through the subject and a second X-ray detector having a smaller field of view than the first X-ray detector, respectively. An X-ray imaging apparatus displaying a second image,
Second image shooting area designation receiving means for receiving designation of the shooting area of the second image on the first image;
Image display means for displaying the second image in an overlapping manner on the shooting area designated on the first image via the second image shooting area designation receiving means. X-ray imaging device. The first image is a real-time image by the first detector;
The X-ray imaging apparatus according to claim 1, wherein the second image is a real-time image obtained by the second detector. A first image and a second image captured using a first X-ray detector that detects X-rays that have passed through the subject and a second X-ray detector that has a smaller field of view than the first X-ray detector, respectively. An X-ray imaging method using an X-ray imaging apparatus displaying an image of
A second image photographing region designation receiving step for accepting designation of a photographing region of the second image on the first image;
A second X-ray detector moving step of moving the second X-ray detector to a position for imaging the imaging region of the second image received by the second image imaging region receiving step;
A second image captured using the second X-ray detector moved by the second X-ray detector moving step is displayed on the first image via the second image capturing area designation receiving step. An image display step that overlaps and displays the designated shooting area,
The first image is a real-time image by the first detector;
The X-ray imaging method, wherein the second image is a real-time image obtained by the second detector. A first image and a first image captured using a first X-ray detector that detects X-rays transmitted through the subject and a second X-ray detector having a smaller field of view than the first X-ray detector, respectively. An X-ray image display method by an X-ray imaging apparatus for displaying two images,
A second image photographing region designation receiving step for accepting designation of a photographing region of the second image on the first image;
An image display step of overlapping and displaying the second image on the imaging region designated on the first image through the second image photographing region designation receiving step,
The first image is a real-time image by the first detector;
The X-ray image display method, wherein the second image is a real-time image obtained by the second detector.

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