JP2008017965A - X-ray equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set a photography region for long length imaging according to redundantly photographed partial regions. <P>SOLUTION: The X-ray equipment has a photography region setting part 7 for setting the image joint position in a subject at a desired position. A photography control part 11 computes the distance of movement of a two-dimensional X-ray detector according to the set joint position, moves the two-dimensional X-ray detector to each photography position based on the computed quantity of movement, and combines image data captured at respective photography positions to obtain a long length image. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an X-ray imaging apparatus, and more particularly to an X-ray imaging apparatus with improved long image composition technology.

Conventionally, long imaging is performed when an imaging region is the lower limb of the subject or the entire spine.
In this long shooting, when the two-dimensional X-ray detector is a flat-type X-ray detector (FPD), unlike the computed radiography (CR) and film, the shooting area can be captured by a single shooting operation. Since it cannot be obtained, the FPD is moved in the body axis direction of the subject to perform multiple imaging operations, and the captured images obtained by these multiple imaging operations are connected by image processing to create a long image. It was composed. (For example, Patent Document 1)
JP 2005-270277 A

In the above prior art, in order to connect a plurality of photographed images by image processing, it is necessary to use a technique such as pattern matching by image recognition. Therefore, a part of the mutual photographing regions must be photographed in an overlapping manner.
In the prior art described above, no consideration has been given to determining a shooting area for long shooting based on overlapping partial areas.
In addition, it is desired to avoid X-ray exposure as much as possible to a radiosensitive part such as a lens, a mammary gland, and a genital organ in an imaging part.
However. In the above prior art, it has not been considered to control the movement of the FPD so as not to be an overlapping imaging region in a highly radiation sensitive region.

An object of the present invention is to provide an X-ray imaging apparatus in which an imaging area for long imaging can be set by partial areas that are imaged in duplicate.
Another object of the present invention is to provide an X-ray imaging apparatus capable of avoiding setting a region having high radiation sensitivity as an overlapping imaging partial region.

The object is to provide an X-ray source that irradiates the subject with X-rays, a two-dimensional X-ray detector that is arranged opposite to the X-ray source and detects image data from transmitted X-rays of the subject, and the two-dimensional X-ray detector. In an X-ray imaging apparatus having a long image synthesizing unit that moves a line detector in the body axis direction of the subject and synthesizes each imaging data obtained at each imaging position to obtain a long image, A bonding position setting unit that sets an image bonding position in the subject to a desired position; and a movement distance calculation unit that calculates a movement distance of the two-dimensional X-ray detector according to the set bonding position; The long photographing means moves the two-dimensional X-ray detector to each photographing position based on the calculated movement amount, and synthesizes each image data photographed at each photographing position to obtain a long image. Is achieved.
The other object is achieved by the joining position setting means setting a position where it is desired to avoid X-ray irradiation of the subject.

According to the present invention, it is possible to set a shooting area for long shooting based on overlapping partial areas.
In addition, it is possible to avoid setting a portion having high radiation sensitivity as an overlapping imaging partial region.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of the X-ray diagnostic apparatus according to the embodiment.

  As shown in FIG. 1, the X-ray diagnostic apparatus of the present embodiment includes an X-ray tube 2 that irradiates a subject M with X-rays, and a two-dimensional array that is disposed opposite to the X-ray tube 2 with the subject M interposed therebetween. Flat panel X-ray sensor (FPD: Flat Panel Detector) 3, image acquisition device 4 that records the original X-ray image according to the X-ray detection signal output from FPD3, and image processing of the original X-ray image And an image observation device 5 for displaying an X-ray image obtained in this manner. When an X-ray image of the subject M is detected by the FPD3 as a result of X-ray irradiation, the X-ray detection signal is read from the FPD3, and then subjected to image processing and the like. The screen is displayed in real time as an X-ray image.

  The X-ray tube 2 is configured such that the high voltage generator 12 emits X-rays according to the set irradiation conditions under the control of the imaging controller 11. A movable X-ray diaphragm 1 capable of irradiating light is disposed in front of the X-ray tube 2 to limit the X-ray irradiation area to the effective field of view of the FPD. The imaging control unit 11 controls the operation of the imaging control unit 11 according to a command signal sent from the imaging control unit 11 by an operation input from the input unit 10 including a keyboard and a mouse, and also applies irradiation conditions (X-ray tube). 2 conditions such as tube voltage, tube current, imaging timing, X-ray aperture position).

  The FPD 3 is a sensor configured to detect an X-ray transmission signal of the subject M generated by X-ray irradiation by the X-ray tube 2 and to convert it into an electric signal as an X-ray detection signal and output the X-ray detection signal. Is a two-dimensional array type sensor arranged vertically and horizontally. Details of this two-dimensional array type sensor are described in Japanese Patent No. 3277866. The X-ray detection signal thus extracted from the X-ray sensor and digitized is stored as an image in the image data collection processing unit 13 corresponding to the XY matrix of the two-dimensional X-ray detection element included in the image acquisition device 4.

Next, a procedure for performing long imaging of the spine and chest with the above-described X-ray imaging apparatus will be described.
Step 1: At the normal imaging system stage where the X-ray tube 2 and the FPD 3 are arranged opposite to each other, the irradiation lamp of the X-ray diaphragm device 1 is turned on, and light is irradiated corresponding to the entire imaging area of the subject M Adjust the X-ray diaphragm device so that.
The position of the X-ray aperture at this time is recorded in the imaging area setting unit 7.

  Step 2: Next, specify the area where you want to avoid double X-ray exposure. In this method, the irradiation lamp of the X-ray diaphragm device 1 is turned on, and the X-ray diaphragm is controlled to be narrowed up and down to irradiate the X-ray irradiation area that the operator wants to avoid double exposure with light. For example, a region such as a lens, a mammary gland, and a genital organ is selected. In the double exposure prohibited area designated by light, the position information of the X-ray aperture is converted into coordinates on the entire field of view for each time and recorded in the imaging area setting unit 7.

  Step 3: The FPD 3 is arranged at the first photographing position so that the upper end of the FPD 3 coincides with the upper end of the photographing region of interest.

  Step 4: Next, calculate the FPD travel distance. For example, using a FPD with a height of 30 cm and a width of 40 cm, creating a long image with a detection area distance of 30 cm in the long direction and a distance of 5 cm in the long direction of the overlapping shooting area for image joining, and a shooting interest area of 80 cm in the subject M Consider the case. The overlapping image capturing area for image joining in the detection area 30 cm of FPD3 is examined. When the overlapping image capturing area for image joining and the double exposure prohibited area do not overlap, 30 cm is the first irradiation area.

  Step 5: The imaging region setting unit 7 moves the diaphragm on the lower side of the aperture device 1 through the imaging control unit 11 to restrict the X-ray from the X-ray tube 2 to be irradiated only to the corresponding region of the FPD. To do.

  Step 6: After that, the irradiation condition setting unit irradiates from the X-ray tube based on the input conditions from the input unit and performs the first imaging. At this time, the image data collection processing unit takes in the FPD detection signal and stores it in the image memory as the first image data.

  Step 7: In the subsequent step 2, the image area setting unit 8 first determines whether or not the long shooting has been completed. If the FPD has already moved the full distance, the shooting will end. If the entire moving distance has not been moved, proceed to the next step. In this case, it is 80cm, so proceed next.

  Step 8: Here, the movement amount calculation unit moves down by 25 cm because the distance in the long direction of the FPD detection area is 30 cm, and the distance in the long direction of the overlapping distance for image joining is 5 cm. The shooting position candidates of Then, the shooting area setting unit determines whether or not the long shooting is finished at this time. If the process is not completed, an overlapping area for image joining in the 25 cm FPD detection area is examined. If the overlapping image capturing area for image joining and the double exposure prohibited area do not overlap, the second irradiation area movement amount is 25 cm. If an exposure restriction area such as a mammary gland is included in the overlapping area for image joining, the movement distance of the FPD is limited to the range immediately before the exposure restriction area.

  Step 9: The imaging area setting unit acquires information on the final movement calculation distance calculated by the movement amount calculation unit as in the previous step, and controls the position of the aperture device and the position of the FPD through the imaging control unit. The X-ray aperture is limited within the FPD field of view.

  Step 10: The irradiation condition setting unit performs imaging by irradiating from the X-ray tube based on the input conditions from the input unit. At this time, the image data collection processing unit 13 captures the FPD detection signal and stores the second image data in the image data 17.

  Step 11: Return to Step 8. When the sum of the shooting distances reaches the entire field of view, the shooting plan ends.

  Step 12: When all the X-rays are completed, the long image composition unit takes out each image data stored in the image memory, and sets a common image connection overlapping photographing region from adjacent image data, that is, two image data. Composite image data that is detected and connected using the same part is generated.

  Step 13: The composite image data is stored in the image memory, and the display control unit extracts it from the image memory and displays it on a display device or prints it on a film and outputs it.

  According to such an X-ray imaging apparatus, from the first fixed position in which the FPD is determined in the conventional manner to the second fixed position mechanically determined based on the size of the FPD in the long imaging direction as in the past. Instead of moving, the FPD movement amount is calculated by the movement amount calculation unit based on the imaging region of interest of the subject M, and the FPD is moved to this calculated position. It is possible to prevent the area from overlapping an area important for diagnosis or from overlapping an area where exposure is desired to be limited. Long images with high image quality can be obtained with low exposure.

  In this embodiment, the distance in the longitudinal direction of the overlapping image capturing region for common image joining is 5 cm. However, unnecessary X-ray irradiation can be reduced by further reducing the distance.

As described above, according to the present embodiment, it is possible to control the movement distance of the FPD for long imaging so that an area where X-ray exposure is avoided as much as possible does not overlap with the overlapping imaging area for image connection.
Moreover, since the overlapping region for image joining is moved so as to avoid the region of interest, diagnosis can be performed without degrading the resolution of the region of interest.
Furthermore, since it is possible to avoid setting the overlapping region for image joining to a region having high radiation sensitivity, the influence of exposure can be reduced.

1 is a block diagram showing the overall configuration of an X-ray diagnostic apparatus according to the present invention. FIG. 2 is a flowchart in a case where an imaging region of interest of the digital long imaging apparatus of the X-ray diagnostic apparatus of FIG. 1 is limited. The figure which shows this embodiment.

Explanation of symbols

1 X-ray diaphragm 2 X-ray tube 3 FPD (X-ray sensor)
4 Image collection device 5 Image observation device 7 Imaging region setting unit 8 Irradiation condition setting unit 11 Imaging control unit 12 High voltage generation unit

Claims (2)

An X-ray source that irradiates a subject with X-rays, a two-dimensional X-ray detector that is disposed opposite to the X-ray source and detects image data from transmitted X-rays of the subject, and the two-dimensional X-ray detector In an X-ray imaging apparatus having a long image synthesizing unit that moves in the body axis direction of the subject and synthesizes each imaging data obtained at each imaging position to obtain a long image,
A joining position setting means for setting an image joining position in the subject to a desired position;
A moving distance calculating means for calculating a moving distance of the two-dimensional X-ray detector according to the set joining position;
The long photographing unit moves the two-dimensional X-ray detector to each photographing position based on the calculated movement amount, and synthesizes each image data photographed at each photographing position to form a long image. An X-ray imaging apparatus characterized by being obtained.   The X-ray imaging apparatus according to claim 1, wherein the joining position setting unit sets a position where it is desired to avoid X-ray irradiation of the subject.

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