JP5505284B2 - Exposure dose calculation device - Google Patents

Description

  The present invention relates to an exposure dose calculation apparatus that calculates an exposure dose by a surface dose simple conversion method.

  In an X-ray inspection apparatus such as an X-ray imaging apparatus or an X-ray fluoroscopic apparatus, it is necessary to manage the X-ray exposure dose of the subject. For this reason, conventionally, the X-ray dose was measured by attaching a dosimeter to the X-ray inspection apparatus. On the other hand, in recent years, a simple surface dose conversion method has been used. This surface dose simple conversion method is a method for calculating the exposure dose of a subject when the subject is irradiated with X-rays from the X-ray conditions and the distance between the X-ray focal point incidence surfaces (FSD / focus-surface distance). And is also referred to as NDD (Non Dosimetry Dosimetry) method.

  In Patent Document 1, a histogram of transmitted X-ray image data is created, and the FSD estimation means for estimating the FSD value from the feature quantity related to the body thickness of the histogram, and the FSD value obtained by the FSD estimation means are used. An X-ray diagnostic apparatus capable of obtaining a high-accuracy exposure dose without using a dosimeter by providing surface dose calculation means for calculating the surface incident dose of the subject based on a predetermined surface dose conversion formula Has been proposed.

  In Patent Document 2, the dose is determined based on the X-ray conditions set by the X-ray condition setting unit, the positional information on the subject from the X-ray generation unit, and the irradiation angle of the X-rays irradiated on the subject. The X-ray irradiation field is sequentially subdivided into a plurality of areas as in the first stage and the second stage by the distribution calculation unit, and for each of these subdivisions, the respective X-ray irradiation doses for each subdivided area are obtained. By combining the X-ray irradiation dose and obtaining the dose distribution of the entire X-ray irradiation field and displaying it on the display unit, it is possible to obtain the dose distribution of the entire X-ray irradiation field with high accuracy without impairing real-time properties. An exposure dose calculation method has been proposed.

JP 2009-142497 A JP 2008-132147 A

  The method of calculating the exposure dose using such a simple surface dose conversion method is effective in managing the exposure dose to the subject. On the other hand, there are many X-ray inspection apparatuses that are currently in operation that do not have a mechanism for calculating an exposure dose. In such an X-ray inspection apparatus, in order to add an exposure dose calculation system that calculates the exposure dose using the surface dose simple conversion method, control software and hardware for controlling the apparatus are updated. Is required. However, such software and hardware updates are not practical unless the X-ray inspection apparatus is up-to-date. For this reason, conventionally, there has been a problem that X-ray inspection may be performed without managing the exposure dose.

  The present invention has been made to solve the above-described problem, and has a function of calculating an exposure dose without changing the configuration of a conventional X-ray inspection apparatus that does not include a mechanism for calculating the exposure dose. An object of the present invention is to provide an exposure dose calculation device that can be added.

  The invention according to claim 1 is an exposure dose calculation device that calculates an exposure dose by a surface dose simple conversion method, and an imaging unit for imaging a display unit that displays an X-ray condition in an X-ray inspection device; In the OCR processing unit for recognizing the X-ray condition displayed on the display unit by performing OCR processing on the image of the display unit displaying the X-ray condition captured by the imaging unit, and the OCR processing unit And a dose calculation unit that calculates an exposure dose based on the recognized X-ray condition.

  According to a second aspect of the present invention, in the first aspect of the present invention, in the image of the display unit that displays the X-ray conditions imaged by the imaging unit, a processing region that specifies an OCR processing region in which the OCR processing is to be performed A designation part is provided.

  According to a third aspect of the present invention, in the second aspect of the present invention, the processing area designating unit designates an area set by the operator operating the input means as an OCR processing area.

  The invention according to claim 4 is the invention according to claim 2, wherein the X-ray condition includes at least one of a tube voltage of the X-ray tube, a tube current of the X-ray tube, and an X-ray irradiation time. The processing region designating unit displays character arrangement information indicating a unit of the tube voltage of the X-ray tube, the tube current of the X-ray tube or the X-ray irradiation time in the image of the display unit that displays the X-ray condition imaged by the imaging unit. By using this, the OCR processing area where the OCR processing is to be executed is designated.

  According to the first aspect of the present invention, the exposure dose can be calculated using the X-ray condition displayed on the display unit of the X-ray inspection apparatus. For this reason, it is possible to add a function for calculating the exposure dose to a conventional X-ray inspection apparatus that does not include a mechanism for calculating the exposure dose without changing the configuration.

  According to the second aspect of the present invention, it is possible to execute the OCR processing quickly and accurately by designating the OCR processing area where the OCR processing is to be executed.

  According to the third aspect of the present invention, the OCR processing area can be set accurately by designating the area set by the operator operating the input means as the OCR processing area, and the OCR processing can be performed quickly and accurately. Can be executed.

  According to the invention described in claim 4, by specifying the OCR processing area using the arrangement information in the character representing the unit of the tube voltage of the X-ray tube, the tube current of the X-ray tube or the X-ray irradiation time, It is possible to automatically set the OCR processing area.

1 is a schematic diagram showing an exposure dose calculation apparatus 10 according to a first embodiment of the present invention together with an X-ray inspection apparatus. 4 is a schematic diagram showing an image of the display unit 8 taken by a camera 11. FIG. 4 is a schematic diagram showing an image of the display unit 8 taken by a camera 11. FIG. It is a schematic diagram which shows the exposure dose calculating apparatus 10 which concerns on other embodiment of this invention with a X-ray inspection apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an exposure dose calculation apparatus 10 according to a first embodiment of the present invention together with an X-ray inspection apparatus.

  An X-ray inspection apparatus to which an exposure dose calculation apparatus 10 according to the present invention is applied is a table 3 on which a patient 4 is placed, an X-ray tube 1, and a high voltage for controlling a tube voltage applied to the X-ray tube 1 and the like. The generation unit 6, the flat panel detector 2 as an X-ray detector, the image processing unit 7, the control unit 5 for controlling the entire apparatus, the X-ray conditions at the time of X-ray inspection and the captured image at the time of X-ray inspection And a display unit 8 for displaying. In this X-ray inspection apparatus, X-rays are irradiated from the X-ray tube 1 toward the patient 4 on the table 3, the X-rays passing through the patient 4 are detected by the flat panel detector 2, and detected by the image processing unit 7. The X-rays thus processed are subjected to image processing, and the image-processed X-ray images are displayed on the display unit 8.

  Further, the exposure dose calculation device 10 according to the present invention calculates the exposure dose by the surface dose simple conversion method, and images the X-ray condition displayed on the display unit 8 in the X-ray inspection device by the camera 11, The image is subjected to OCR (Optical Character Recognition / Optical Character Recognition) processing to recognize an X-ray condition, and an exposure dose is calculated based on the X-ray condition.

  That is, the exposure dose calculation apparatus 10 according to the present invention executes a camera 11 as an imaging unit for imaging the display unit 8 in the X-ray inspection apparatus, and an OCR process on the image of the display unit 8 captured by the camera 11. OCR processing is performed on the OCR processing area specified by the processing area specifying section 12 among the images of the processing area specifying section 12 that specifies the power OCR processing area and the display section 10 that displays the X-ray conditions captured by the camera 11. An OCR processing unit 13 that recognizes the X-ray condition displayed on the display unit 8 by executing, a dose calculation unit 14 that calculates an exposure dose based on the X-ray condition recognized by the OCR processing unit 13, and a camera 11, an X-ray condition display unit 15 that displays an X-ray condition image captured by the display unit 8, an X-ray condition recognized by the OCR processing unit 13, and the like. And an input section consisting of the board 16 and the mouse 17 or the like.

  When the exposure dose calculation apparatus 10 according to the present invention calculates the exposure dose, first, the camera 11 takes an image of the X-ray condition displayed on the display unit 8 in the X-ray inspection apparatus. That is, when X-ray imaging is performed in a general X-ray inspection apparatus, the tube voltage of the X-ray tube 1 during X-ray imaging, the tube current of the X-ray tube 1, the X-ray irradiation time by the X-ray tube 1, etc. Are displayed on the display unit 8. When performing X-ray fluoroscopy in the X-ray inspection apparatus, X-rays such as a tube voltage of the X-ray tube 1 at the time of X-ray fluoroscopy, a tube current of the X-ray tube 1 and a display indicating that fluoroscopy is being performed The condition is displayed on the display unit 8. The exposure dose calculation apparatus 10 according to the present invention is configured to capture these X-ray conditions with the camera 11.

  FIG. 2 is a schematic diagram showing an image of the display unit 8 photographed by the camera 11. Here, FIG. 2A shows an image of the display unit 8 taken by the camera 11 when X-ray imaging is executed, and FIG. 2B is taken by the camera 11 when X-ray fluoroscopy is executed. The image of the display unit 8 is shown.

  When performing X-ray imaging, as shown in FIG. 2A, the display unit 8 displays 100 kV as the tube voltage, 200 mA as the tube current, and 25 ms as the X-ray irradiation time. Has been made. In response to this, the processing area designating unit 12 designates an OCR processing area in which the OCR processing is to be executed. At this time, an image of the X-ray condition in the display unit 8 photographed by the camera 11 is displayed on the X-ray condition display unit 15. Then, when the operator operates the input unit such as the mouse 17, the tube voltage display area 21, the tube current display area 22, and the X-ray irradiation time display area 23 are respectively designated.

  The tube voltage display area 21, the tube current display area 22, and the X-ray irradiation time display area 23 are specified by setting the display position of the tube voltage, tube current, and X-ray irradiation time on the display unit 8. As long as it is not changed, it is sufficient to execute it only once.

  If a tube voltage display area 21, a tube current display area 22, and an X-ray irradiation time display area 23 are designated, the OCR processing unit 13 performs OCR on the images in these areas 21, 22, and 23. Process. The OCR processing unit 13 executes optical character recognition for the regions 21, 22, and 23, recognizes the character strings displayed in the regions 21, 22, and 23, and transmits them to the exposure dose calculation unit 14. The exposure dose calculation apparatus 10 obtains information on the tube voltage of the X-ray tube 1 at the time of X-ray imaging, the tube current of the X-ray tube 1 and the X-ray irradiation time by the X-ray tube 1 from these character strings. And the dose calculation apparatus 10 calculates an exposure dose by the surface dose simple conversion method from those tube voltage, tube current, and X-ray irradiation time.

  In this case, FSD (Focus-Surface Distance) data that is the distance from the focal point of the X-ray tube 1 to the body surface of the patient 4 is required. The SFD data may be input by the operator operating the input unit such as the keyboard 16 before executing the X-ray inspection. Further, the FSD data may be calculated by the operator operating the input unit such as the keyboard 16 to input the examination site and measuring the body thickness from the examination site. The FSD data may be a value unique to each X-ray inspection apparatus.

  By adopting such a configuration, it becomes possible to calculate the exposure dose by a simple surface dose conversion method using the X-ray conditions displayed on the display unit 8 of the X-ray inspection apparatus. For this reason, it becomes possible to add the function which calculates an exposure dose, without adding a change with respect to the conventional X-ray inspection apparatus which is not provided with the mechanism which calculates an exposure dose.

  In the case of performing X-ray imaging, as shown in FIG. 2A, the tube voltage of the X-ray tube 1 during X-ray imaging, X from the character strings displayed in the areas 21, 22, and 23, respectively. Information on the tube current of the tube 1 and the X-ray irradiation time by the X-ray tube 1 is obtained. On the other hand, when performing X-ray fluoroscopy, information about the X-ray irradiation time is not displayed on the display unit 8. In this case, the fluoroscopic time may be recognized using a mark indicating the fluoroscopic state displayed on the display unit 8.

  That is, as shown in FIG. 2B, during X-ray fluoroscopy, the display unit 1 displays 100 FkV as the tube voltage and 2.5 mA as the tube current, as in the case of X-ray imaging. In addition, a mark such as a black circle indicating the X-ray fluoroscope is displayed on the display unit 8 during X-ray fluoroscopy. Therefore, the tube voltage and the tube current are recognized based on the tube voltage display region 24 and the tube current display region 25, and the time when the mark such as the black circle is displayed on the display region 26 indicating the fluoroscopic state is determined. By recognizing, the dose calculation unit 14 may recognize the fluoroscopy time and calculate the exposure dose.

  In the above-described embodiment, the processing area designating unit 12 designates the areas 21, 22, 23, 24, 25, and 26 set by the operator by operating the input unit such as the mouse 17 as the OCR processing area. ing. On the other hand, the processing area designating unit 12 uses characters representing units such as the tube voltage of the X-ray tube 1, the tube current of the X-ray tube 1 and the X-ray irradiation time in the image of the display unit 8 taken by the camera 11. By using the arrangement information, the OCR processing area where the OCR processing should be executed may be designated.

  FIG. 3 is a schematic diagram showing an image of the display unit 8 taken by the camera 11 when such an embodiment is applied. 2A, FIG. 3A shows an image of the display unit 8 taken by the camera 11 when X-ray imaging is performed, and FIG. 3B shows a case where X-ray fluoroscopy is executed. The image of the display part 8 image | photographed with the camera 11 is shown.

  For example, at the time of X-ray imaging, the image of the display unit 8 imaged by the camera 11 is subjected to image processing, whereby a kV character region 31 representing a unit of tube voltage is obtained as shown in FIG. The arrangement, the arrangement of the mA character region 32 representing the unit of the tube current, and the arrangement of the ms character region representing the X-ray irradiation time are recognized. Then, based on the arrangement information of these areas 31, 32, and 33, the processing area specifying unit 12 displays the area immediately before these areas 31, 32, and 33 as the tube voltage display area 21 and the tube current display, respectively. The area 22 and the X-ray irradiation time display area 23 are designated.

  When the tube voltage display area 21, the tube current display area 22, and the X-ray irradiation time display area 23 are designated in this way, the OCR processing unit 13 performs these areas as in the above-described embodiment. After performing OCR processing on the images 21, 22, and 23, information on the tube voltage, tube current, and X-ray irradiation time is transmitted to the dose calculation device 10, and the exposure dose is calculated by the surface dose simple conversion method.

  In the case of the X-ray fluoroscopy shown in FIG. 3B, the arrangement of the FkV character region 34 representing the unit of the tube voltage and the arrangement of the mA character region 35 representing the unit of the tube current are recognized. Although it is possible, there is no unit for a mark such as a black circle indicating a fluoroscopic state. In this case, the display area 26 indicating the fluoroscopic state may be specified from the arrangement information of the area 36 indicating the characters “perspective”.

  Next, still another embodiment of the present invention will be described. FIG. 4 is a schematic diagram showing an exposure dose calculation apparatus 10 according to still another embodiment of the present invention together with an X-ray inspection apparatus. In addition, about the member same as embodiment shown in FIG. 1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  In the embodiment shown in FIG. 1, FSD data is set by an operator operating an input unit such as a keyboard 16. On the other hand, in the embodiment shown in FIG. 4, an ultrasonic distance meter 9 is attached to the X-ray tube 1, and FSD data is obtained based on the signal of the ultrasonic distance meter 9. Yes. When such a configuration is adopted, FSD data can be obtained automatically, so that the operator's operation can be omitted.

DESCRIPTION OF SYMBOLS 1 X-ray tube 2 Flat panel detector 3 Table 4 Patient 5 Control part 6 High voltage generation part 7 Image processing part 8 Display part 9 Ultrasonic distance meter 10 Exposure dose calculating device 11 Camera 12 Processing area designation part 13 OCR processing part 14 Dose Calculation unit 15 X-ray condition display unit 16 Keyboard 17 Mouse 21 Tube voltage display area 22 Tube current display area 23 X-ray irradiation time display area 24 Tube voltage display area 25 Tube current display area 26 Display showing the fluoroscopic state region

Claims (4)

An exposure dose calculation device that calculates an exposure dose by a surface dose simple conversion method,
An imaging unit for imaging a display unit for displaying X-ray conditions in the X-ray inspection apparatus;
An OCR processing unit that recognizes an X-ray condition displayed on the display unit by performing an OCR process on an image of a display unit that displays the X-ray condition captured by the imaging unit;
A dose calculation unit that calculates an exposure dose based on the X-ray condition recognized in the OCR processing unit;
An apparatus for calculating an exposure dose. The exposure dose calculation apparatus according to claim 1,
An exposure dose calculation apparatus comprising a processing region designating unit that designates an OCR processing region in which an OCR process is to be performed in an image of a display unit that displays an X-ray condition photographed by the photographing unit. In the exposure dose calculation apparatus according to claim 2,
The treatment area designating unit designates an area set by an operator by operating an input means as an OCR process area. In the exposure dose calculation apparatus according to claim 2,
The X-ray condition includes at least one of an X-ray tube voltage, an X-ray tube current, or an X-ray irradiation time,
The processing area designating unit is a character arrangement information representing a unit of an X-ray tube voltage, an X-ray tube current, and an X-ray irradiation time in an image of a display unit that displays an X-ray condition imaged by the imaging unit. An exposure dose calculation device that designates an OCR processing region in which OCR processing is to be performed by using the OCR.

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