WO2016135867A1

WO2016135867A1 - X-ray fluoroscopic imaging apparatus

Info

Publication number: WO2016135867A1
Application number: PCT/JP2015/055288
Authority: WO
Inventors: 祐貴坂本; 清水　達也
Original assignee: 株式会社島津製作所
Priority date: 2015-02-24
Filing date: 2015-02-24
Publication date: 2016-09-01
Also published as: CN107405125A; JPWO2016135867A1; CN107405125B; JP6583649B2

Abstract

This X-ray fluoroscopic imaging apparatus comprises a reference region setting unit 19 with which a reference region is manually set on a display screen. An operator visibly confirms the position of a region of interest of a subject shown on a monitor 17 and, using the reference region setting unit 19, sets a new reference region on the display screen so as to include the region of interest therein. This allows rapid and reliable setting of the reference region that includes the region of interest therein. Additionally, in setting the reference region, burden on the operator is reduced because there is no need for the operator to look at places other than the monitor 17. A luminance value calculation unit 21 calculates an image luminance value on the basis of a luminance value of each pixel positioned within the range of the reference region, and an irradiation condition calculation unit 23 calculates a corrected irradiation condition on the basis of the image luminance value. An X-ray irradiation control unit 13 is capable of acquiring an X-ray image in which the operator can suitably view the region of interest by controlling an X-ray tube 5 on the basis of the corrected irradiation condition.

Description

X-ray fluoroscopic equipment

The present invention relates to an X-ray fluoroscopic apparatus that acquires an X-ray image by irradiating a subject with X-rays, and particularly relates to a technique for determining an X-ray irradiation condition capable of capturing a suitable X-ray image.

In a medical field, an X-ray fluoroscopic apparatus that captures an X-ray image of a subject by irradiating the subject with X-rays is used. As shown in FIG. 6, the conventional X-ray fluoroscopic apparatus 101 includes a top plate 103, an X-ray tube 105, an X-ray detector 107, an image generation unit 109, an image display unit 111, and X-ray irradiation control. Part 113.

The top plate 103 places the subject M in a horizontal posture. The X-ray tube 105 irradiates the subject M with X-rays 105a. The X-ray tube 105 and the X-ray detector 107 are disposed to face each other with the top plate 103 interposed therebetween. The X-ray detector 107 detects the X-ray 105a irradiated to and transmitted through the subject M from the X-ray tube 105, converts it into an electrical signal, and outputs it as an X-ray detection signal. The X-ray tube 105 and the X-ray detector 107 constitute an imaging system.

The image generation unit 109 is provided after the X-ray detector 107 and generates an X-ray image in which an image of the subject M is projected based on the output X-ray detection signal. The X-ray image generated by the image generation unit 109 is displayed on the image display unit 111. The X-ray irradiation control unit 113 is connected to the X-ray tube 105, and controls the tube voltage and tube current of the X-ray tube 105, thereby irradiating the X-ray dose from the X-ray tube 105 and the timing of irradiating X-rays. Control etc. The various conditions under which the X-ray tube 105 irradiates the X-ray 105a controlled by the X-ray irradiation control unit 113 are hereinafter referred to as “X-ray irradiation conditions”.

In such an X-ray fluoroscopic apparatus, the subject is continuously irradiated with a smaller dose of X-rays than in the case of X-ray imaging for capturing a still image, and the generated X-ray image is continuously displayed on the image display unit 111. X-ray fluoroscopy is performed for display and observation. X-ray fluoroscopy is effective in that real-time information of a region of interest can be acquired as an X-ray fluoroscopic image while the surgical procedure is in progress. In X-ray fluoroscopy, when the body thickness of the subject M (subject thickness) increases even if the X-ray irradiation conditions are constant, the X-ray dose that passes through the subject M decreases and the subject thickness decreases. The transmitted X-ray dose increases.

Therefore, since the brightness (luminance) of the X-ray image displayed on the image display unit 111 changes due to the change in the subject thickness, there are cases where the surgical procedure cannot proceed appropriately. Therefore, in order to keep the brightness of the X-ray image displayed on the image display unit 111 constant, an automatic brightness adjustment mechanism that adjusts the X-ray dose by changing the X-ray irradiation condition according to the subject thickness is proposed. (For example, refer to Patent Document 1).

Here, a configuration in which X-ray irradiation conditions are adjusted by an automatic brightness adjustment mechanism in a conventional apparatus will be described. In the conventional fluoroscopic imaging apparatus 101, an irradiation condition calculation unit 115 is provided after the image generation unit 109. The irradiation condition calculation unit 115 detects the luminance of the X-ray image generated by the image generation unit 109. Next, the irradiation condition calculation unit 115 compares a predetermined value (ideal luminance value) determined in advance with the luminance value of the X-ray image.

Then, based on the X-ray irradiation condition at the time of generating the X-ray image, a corrected X-ray irradiation condition that is an X-ray irradiation condition that can make the luminance value of the X-ray image the ideal luminance value is calculated. The corrected X-ray irradiation conditions calculated by the irradiation condition calculation unit 115 are fed back to the X-ray irradiation control unit 113, and the X-ray tube 105 performs X-ray irradiation based on the corrected X-ray irradiation conditions. As a result of X-ray irradiation based on the corrected X-ray irradiation conditions, the luminance value of the X-ray image generated by the image generation unit 109 becomes an ideal luminance value. By setting the ideal luminance value to a luminance value with high visibility, it is possible to perform automatic luminance adjustment with high visibility for an X-ray image generated intermittently by X-ray fluoroscopy.

As a method of detecting the luminance value of the X-ray image in the conventional apparatus, in addition to the method of calculating the average value of the luminance of the entire X-ray image, the reference region R is previously provided in the vicinity of the center of the image field V of the X-ray image. And calculating the average value of the luminance of the X-ray image in the reference region R. In this case, the area for detecting the brightness is limited to the inside of the reference area R. Therefore, by positioning the region of interest W of the subject M shown in FIG. 7A within the range of the reference region R, the brightness of the X-ray image can be automatically adjusted according to the luminance of the region of interest W. (Refer FIG.7 (b)).

JP 2011-152199 A

However, the conventional example having such a configuration has the following problems.
That is, at the start of fluoroscopy, the position of the region of interest W may be out of the range of the reference region R as shown in FIG. In this case, since the correction X-ray irradiation condition is calculated based on the luminance information of the region other than the region of interest W, the luminance of the region of interest W is not appropriately adjusted. As a result, the visibility of the X-ray image at the site of interest W is reduced. Therefore, in the X-ray fluoroscopic apparatus according to the conventional example, the region of interest W is moved to the inside of the reference region R located at the center of the image visual field V as shown in FIG. Work to align.

However, when positioning is performed by moving hardware such as the imaging system or the top board 103, the distance by which the imaging system is moved even if the positional relationship between the region of interest W and the reference region R displayed on the image display unit 111 is visually confirmed. It is difficult to recognize correctly. Therefore, in order to move the region of interest W into the reference region R, the operation panel for operating the imaging system or the like and the image display unit 111 on which the region of interest W or the like is displayed are alternately watched while the imaging system or the like is finely tuned. The adjustment will be repeated.

When positioning the region of interest W while performing fluoroscopy, the amount of exposure of the subject increases because it takes time to make fine adjustments. On the other hand, when positioning the site of interest W after the fluoroscopy is interrupted, the positional relationship between the site of interest W and the reference region R cannot be confirmed on the image display unit 111 while the fluoroscopy is interrupted. Therefore, at the time of resuming X-ray fluoroscopy, the region of interest W may deviate from the reference region R again. As a result, there is a concern that the work time will be prolonged.

The present invention has been made in view of such circumstances, and X-ray fluoroscopy can quickly adjust the brightness of an X-ray image so as to obtain an X-ray image with high visibility of a region of interest. An object is to provide a photographing apparatus.

In order to achieve such an object, the present invention has the following configuration.
That is, an X-ray fluoroscopic apparatus according to the present invention includes an X-ray source that irradiates a subject with X-rays, and an X-ray detection unit that detects X-rays irradiated from the X-ray source and transmitted through the subject. , An image generation unit that generates an X-ray image using a detection signal output from the X-ray detection unit, an irradiation control unit that controls an X-ray irradiation condition of the X-ray source, and an X generated by the image generation unit Image display means for displaying a line image, reference area setting means for arbitrarily setting one or more areas in the X-ray image as a reference area on a display screen of the image display means, and within the reference area A luminance value calculating means for extracting a luminance value of each pixel and calculating an image luminance value corresponding to the X-ray image based on the extracted luminance value; and a luminance value of the pixel in the reference region is a predetermined value X-ray irradiation Irradiation condition calculation means for calculating a correction irradiation condition as a condition based on the image luminance value and the predetermined value, and the irradiation control means is configured to apply the correction irradiation condition to the correction irradiation condition calculated by the irradiation condition calculation means. Based on this, the X-ray irradiation conditions of the X-ray source are controlled.

The X-ray fluoroscopic apparatus according to the present invention includes reference area setting means for arbitrarily setting one or more areas in the X-ray image as reference areas on the display screen of the image display means. In this case, the operator visually confirms the display screen of the image display means and confirms the position of the region of interest of the subject. Then, the reference region is arbitrarily set on the display screen so as to include the region of interest inside using the reference region setting means.

Since the operator can easily visually recognize the exact position and shape of the site of interest on the display screen, it is possible to quickly and surely set the reference region that includes the site of interest. Further, when setting the reference area, the operator does not have to move the line of sight other than the display screen of the image display means, so the burden on the operator such as fatigue is further reduced.

The luminance value calculation means extracts the luminance value of each pixel in the reference area, and calculates an image luminance value corresponding to the X-ray image based on the extracted luminance value. The irradiation condition calculation means calculates the corrected irradiation condition based on information on the image luminance value and the predetermined value. The corrected irradiation condition is an X-ray irradiation condition such that the luminance value of the pixel in the reference area becomes a predetermined value. The irradiation control means controls the X-ray irradiation conditions of the X-ray source according to the information on the correction irradiation conditions.

That is, by setting a predetermined value for the luminance value that allows the operator to visually recognize the region of interest appropriately, and setting the reference region so as to accurately include the region of interest, the irradiation condition calculation means can appropriately recognize the region of interest. An X-ray irradiation condition with a brightness that can be calculated can be calculated as a correction irradiation condition. As a result, it is possible to acquire an X-ray image having a luminance that allows the region of interest to be viewed appropriately. Since the X-ray fluoroscopic apparatus according to the present invention includes the reference region setting means, it is possible to quickly and surely set the reference region that includes the region of interest. Therefore, it is possible to quickly and surely acquire an X-ray image that allows the operator to visually recognize the region of interest while reducing the burden on the operator.

In the X-ray fluoroscopic apparatus according to the present invention, the display screen of the image display unit is divided into a plurality of regions, and the reference region setting unit includes one or more of the plurality of regions. Preferably, the reference area is set by selecting as the reference area.

According to the fluoroscopic imaging apparatus according to the present invention, the display screen of the image display means is divided into a plurality of areas, and the reference area setting means selects one or more areas from among the plurality of areas. Set the reference area. The operator visually recognizes the image display means, and manually selects a region that includes the region of interest among a plurality of regions that divide the display screen, whereby a new reference region is set on the display screen. The operator can easily and reliably confirm the region including the region of interest. Accordingly, it is possible to execute the setting of the reference region that includes the region of interest inside more quickly and reliably.

The X-ray fluoroscopic apparatus according to the present invention includes a divided region changing unit that changes at least one of the number and shape of the plurality of regions that divide the display screen of the image display unit, and the divided region changing unit. Divided area storage means for storing the number and shape of the plurality of changed areas, and the image display means reads out information related to the number and shape of the plurality of areas stored in the divided area storage means to display a display screen. Preferably displayed above.

According to the X-ray fluoroscopic apparatus according to the present invention, at least one of the number and the shape of the area dividing the display screen of the image display means can be changed by the divided area changing means. Therefore, the number and shape of the divided regions can be changed according to the size and shape of the region of interest, and the divided region set as the reference region can more suitably include the region of interest. Further, the changed number and shape of the divided areas are stored in the divided area storage means, and the image display means reads out information on the number and shapes of the areas stored in the divided area storage means and displays them on the display screen. In this case, information on the number and shape of the changed divided areas is stored and can be read out. Accordingly, since it is not necessary to change the number of divided areas and the information of the shape again after the change once, it is possible to avoid a complicated work process.

In the X-ray fluoroscopic apparatus according to the present invention, it is preferable that the reference area setting means sets the reference area by drawing an arbitrary area on the display screen of the image display means as the reference area. .

According to the X-ray fluoroscopic apparatus according to the present invention, the reference area setting means sets the reference area by drawing an arbitrary area on the display screen of the image display means as the reference area. In such a configuration, the operator visually recognizes the image display means, and draws a region including the region of interest on the display screen, whereby a new reference region is set. In this case, the operator can set a reference area having an arbitrary shape at an arbitrary position. Therefore, a reference region having a suitable shape can be newly set so as to exclude a region other than the region of interest as much as possible according to the position / shape of the region of interest. As a result, the image luminance value calculated by the luminance value calculating means is closer to the luminance value of the region of interest, and thus an X-ray image with higher visibility of the region of interest can be generated.

Further, in the X-ray fluoroscopic apparatus according to the present invention, the luminance value calculation means calculates the luminance value included between a predetermined upper limit value and a predetermined lower limit value among the luminance values of the pixels in the reference region. It is preferable to extract and calculate an image luminance value corresponding to the X-ray image based on the extracted luminance value.

According to the X-ray fluoroscopic apparatus according to the present invention, the luminance value calculating means extracts a luminance value included between a predetermined upper limit value and a predetermined lower limit value among the luminance values of the pixels in the reference region. That is, extreme numerical brightness values such as a brightness value exceeding the upper limit value and a brightness value falling below the lower limit value are excluded from the extraction target of the brightness value calculating means. Therefore, even when an X-ray image having an extreme luminance value such as a metal piece is reflected in the reference region, it is possible to avoid an X-ray image showing an extremely high luminance value from affecting the image luminance value. As a result, a situation in which the brightness of the X-ray image rapidly changes due to an X-ray image having an excessively high brightness value such as a metal piece being reflected in the reference region can be suitably avoided.

The X-ray fluoroscopic apparatus according to the present invention preferably includes a luminance adjustment switching unit that fixes the corrected irradiation condition calculated by the irradiation condition calculation unit to the corrected irradiation condition calculated most recently.

According to the X-ray fluoroscopic apparatus according to the present invention, the brightness adjustment switching unit fixes the correction irradiation condition calculated by the irradiation condition calculation unit to the correction irradiation condition calculated most recently. In such a configuration, since the automatic brightness adjustment function is turned off by the brightness adjustment switching means, the corrected irradiation condition is fixed under the most recently calculated condition and is no longer updated.

The operator uses the reference area setting means to set the reference area range on the display screen according to the position of the region of interest. Then, after the brightness of the X-ray image in the region of interest is adjusted to a brightness value that can be suitably viewed in accordance with the corrected irradiation condition, the brightness adjustment switching unit switches the automatic brightness adjustment function to an off state. In this case, since the correction irradiation condition is fixed, the brightness of the X-ray fluoroscopic image is always maintained at a brightness value at which the region of interest can be suitably viewed. Therefore, after suitably adjusting the brightness of the X-ray image in the region of interest, the brightness of the X-ray image changes abruptly due to an X-ray image having an excessively high brightness value, such as a metal piece, appearing in the reference region. The situation can be suitably avoided.

In the X-ray fluoroscopic apparatus according to the present invention, it is preferable that the image display means is a touch panel, and the reference area setting means is a position input device provided on a surface of the image display means.

According to the X-ray fluoroscopic apparatus according to the present invention, the image display means is a touch panel, and the reference area setting means is a position input device provided on the surface of the image display means. In this case, the operator sets a reference area of an arbitrary shape at an arbitrary position on the display image of the image display means by directly touching a position input device provided on the surface of the image display means with a finger or a touch pen. it can. Therefore, a reference region having a suitable shape can be newly set so as to exclude a region other than the region of interest as much as possible according to the position / shape of the region of interest.

Also, since the reference region is set by directly contacting the image display means for displaying the region of interest, the reference region can be quickly set so that the position and shape of the region of interest can be traced more accurately. As a result, the image luminance value calculated by the luminance value calculating means is closer to the appropriate luminance value of the region of interest, and thus an X-ray image with higher visibility of the region of interest can be generated.

1 is a functional block diagram illustrating a configuration of an X-ray fluoroscopic apparatus according to Embodiment 1. FIG. FIG. 6 is a diagram illustrating a configuration for setting a reference area in the first embodiment. (A) is a figure which shows the state from which the position of the reference | standard area | region has remove | deviated from the region of interest, (b) is a figure which shows the state which selects the area | region containing a region of interest and sets a reference area newly, (c) is a diagram showing a state in which two or more adjacent regions are newly set as reference regions, and (d) is a diagram showing a state in which two or more regions that are not adjacent are newly set as reference regions. . 3 is a flowchart for explaining an operation process of the X-ray fluoroscopic apparatus according to Embodiment 1; FIG. 10 is a diagram illustrating a configuration for setting a reference area in the second embodiment. (A) is a figure which shows the state from which the position of the reference | standard area | region has remove | deviated from the region of interest, (b) is a figure which shows the state which newly sets a reference | standard area | region using a mouse pointer, (c) is a touch pen It is a figure which shows the state which sets a reference area newly using. In a modification, it is a figure explaining the structure which aligns a reference | standard area | region and a region of interest before the start of X-ray fluoroscopy. (A) is a figure which shows the position of the region of interest in a subject, (b) is a figure which shows the range of the reference area in an initial setting state, (c) is a figure which shows the range of the reference area after a setting change. It is. It is a functional block diagram explaining the structure of the X-ray fluoroscopic apparatus which concerns on a prior art example. It is a figure explaining the structure which performs position alignment with a reference | standard area | region and a region of interest in a prior art example. (A) is a figure which shows the position of the region of interest in a subject, (b) is a figure which shows the state in which the region of interest is located in a reference | standard area | region, (c) is a figure which has removed the region of interest from the reference | standard area | region. It is a figure which shows a state.

Embodiment 1 of the present invention will be described below with reference to the drawings.

<Description of overall configuration>
As shown in FIG. 1, the X-ray fluoroscopic apparatus 1 according to the first embodiment includes a top plate 3 on which a subject M in a horizontal posture is placed, and an X-ray tube that irradiates the subject M with X-rays 5a. 5 and an X-ray detector 7 for detecting X-rays that have been irradiated and transmitted through the subject M. The X-ray tube 5 and the X-ray detector 7 constitute an imaging system, and are opposed to each other with the top plate 3 interposed therebetween. The X-ray tube 5 is provided with a collimator 9 that limits the X-rays 5a irradiated from the X-ray tube 5 to a cone shape. The configuration in which the collimator 9 restricts the X-ray 5a is not limited to a conical shape, and may be appropriately changed such as a pyramid shape.

The X-ray detector 7 detects the X-ray 5a irradiated from the X-ray tube 5 and transmitted through the subject M, converts it to an electrical signal, and outputs it as an X-ray detection signal. As an example of the X-ray detector 7, an image intensifier (II), a flat panel detector (FPD), or the like is used. The X-ray tube 5 corresponds to the X-ray source in the present invention, and the X-ray detector 7 corresponds to the X-ray detection means in the present invention.

The X-ray fluoroscopic apparatus 1 includes an input unit 11, an X-ray irradiation control unit 13, an image generation unit 15, a monitor 17, a reference area setting unit 19, a luminance value extraction unit 21, and an irradiation condition calculation unit. 23, a storage unit 25, and a main control unit 27. The input unit 11 is used to input an operator's instruction, and examples thereof include a mouse input type panel and a touch input type panel.

The X-ray irradiation control unit 13 is connected to the X-ray tube 5 and controls X-ray irradiation conditions. Examples of the X-ray irradiation conditions include tube voltage and tube current values, X-ray 5a irradiation time, and the like. That is, the X-ray irradiation control unit 13 controls the tube voltage and tube current of the X-ray tube 5, so that the dose of the X-ray 5 a irradiated from the X-ray tube 5 and the X-ray tube 5 irradiate the X-ray 5 a. Timing etc. are controlled. The X-ray irradiation control unit 13 corresponds to the irradiation control means in the present invention.

The image generation unit 15 is provided at the subsequent stage of the X-ray detector 7 and generates an X-ray image based on the X-ray detection signal output from the X-ray detector 7. The monitor 17 displays a reference area together with the X-ray image generated by the image generation unit 15, and is configured by a liquid crystal display as an example. The image field area of the X-ray image displayed on the monitor 17 is divided into a plurality of areas. Each of the number and shape of regions that divide the image field region of the X-ray image can be changed by an instruction input to the input unit 11. The input unit 11 corresponds to a divided area changing unit in the present invention. The image generation unit 15 corresponds to the image generation means in the present invention. The monitor 17 corresponds to the image display means in the present invention.

The reference area setting unit 19 sets a reference area on the X-ray image generated by the image generation unit 15. Examples of the configuration of the reference area setting unit 19 include a mouse, a joystick, and a touch pad. The reference area setting unit 19 is configured so that a reference area can be set for the X-ray image displayed on the monitor 17. It is more preferable that the reference area setting unit 19 is provided at or near the monitor 17 so that the reference area setting unit 19 can be operated while viewing the monitor 17. The reference area setting unit 19 corresponds to the reference area setting means in the present invention.

The luminance value extraction unit 21 is provided in the subsequent stage of the image generation unit 15 and extracts the luminance value of each pixel located in the reference area from the X-ray image generated by the image generation unit 15. Then, the luminance value extracting unit 21 calculates an image luminance value corresponding to the X-ray image based on the extracted luminance value in the reference area. As a method for calculating the image luminance value, there is a method for obtaining the average of the luminance values of the respective pixels located in the reference region, but is not limited thereto. In the reference area, such as taking the intermediate value of the luminance values of each pixel located in the reference area, or calculating the average value after multiplying the luminance value of each pixel located in the reference area by an appropriate weighting factor An arbitrary method for calculating the luminance value of may be used.

The irradiation condition calculation unit 23 calculates the correction irradiation condition based on the image luminance value calculated by the luminance value extraction unit 21, and outputs the calculated correction irradiation condition to the X-ray irradiation control unit 13. The irradiation condition calculation unit 23 compares the ideal luminance value determined in advance with the image luminance value to calculate a difference. Then, based on the X-ray irradiation condition relating to the X-ray image used for calculating the image luminance value and the difference calculated by the irradiation condition calculation unit 23, the X-ray whose image luminance value is the ideal luminance value An irradiation condition, that is, a corrected irradiation condition is calculated. The luminance value extraction unit 21 corresponds to the luminance value calculation unit in the present invention, and the irradiation condition calculation unit 23 corresponds to the irradiation condition calculation unit in the present invention.

The storage unit 25 includes an X-ray image generated by the image generation unit 15, a reference region set by the reference region setting unit 19, an ideal luminance value used by the irradiation condition calculation unit 23, and a corrected irradiation condition calculated by the irradiation condition calculation unit 23. Various information such as is stored. In addition, the storage unit 25 stores information such as the shape and number of regions for dividing the image field region of the X-ray image. The main control unit 27 controls the X-ray irradiation control unit 13, the image generation unit 15, the monitor 17, the reference region setting unit 19, the luminance value extraction unit 21, the irradiation condition calculation unit 23, and the storage unit 25. Control. The storage unit 25 corresponds to the divided area storage means in the present invention.

<Description of Configuration for Setting Reference Area in Embodiment 1>
Here, a configuration in which the reference area setting unit 19 sets the reference area on the display screen for the X-ray image will be described. The X-ray image generated by the image generation unit 15 is displayed on the monitor 17. As shown in each of FIGS. 2A and 2B, the image field area V of the X-ray image projected on the monitor 17 is configured to be divided into a plurality of rectangular areas E by a boundary line indicated by a two-dot chain line. A boundary line indicated by a two-dot chain line is displayed so as to be visible.

The reference area is an area indicating a range of pixels used for calculation of an image luminance value, which will be described later, and the reference area is set for one or more areas E in the first embodiment. In the default state, the reference region R is set to a region E located near the center of the image visual field region V as an example (FIG. 2A). The shape of the region E that divides the image visual field region V is not limited to a rectangle, and may be an arbitrary shape. Further, instead of the image viewing area V, the entire screen of the monitor 17 may be divided into a plurality of areas.

As shown in FIG. 2A, in the X-ray image generated by the image generation unit 15 by X-ray fluoroscopy, the preset range of the reference region R deviates from the position of the region of interest W of the subject M. There may be. In this case, the operator operates the reference area setting unit 19, that is, the mouse constituting the input unit 11, and selects the area E including the region of interest W by clicking the cursor F. The area E selected by the reference area setting unit 19 is set as a new reference area R as shown in FIG. Thus, by selecting the target area E using the reference area setting unit 19, the position and range of the reference area R are changed.

Information on the reference region R newly set by the reference region setting unit 19 is displayed on the monitor 17 and transmitted to the luminance value extracting unit 21. The luminance value extraction unit 21 extracts the luminance value of each pixel located in the newly set reference region R. In this way, the operator refers to the X-ray image displayed on the screen of the monitor 17 and sets a new reference region R on the display screen of the monitor 17, so that the exact position of the region of interest W displayed on the display screen is determined. Easy to select. Therefore, the reference region R can be set quickly and accurately so that the region of interest W is within the range of the reference region R during the fluoroscopy.

The reference area R that can be set by the reference area setting unit 19 is not limited to one area E. As shown in FIG. 2C, when the region of interest W is projected over a plurality of regions E, for example, by clicking and selecting a predetermined region E, the adjacent region E is moved to the reference region R by dragging. Can be set as Further, two or more regions E that are not adjacent to each other can be set as the reference region R as shown in FIG. Therefore, even when the range of the region of interest W is wide or there are a plurality of regions of interest W, the region of interest W can be accurately and quickly included in the range of the reference region R.

The monitor 17 may be a touch panel. That is, the monitor 17 has a panel-like position input device on the surface for detecting the touched position and inputting information on the position. The operator sets the touched area E as a new reference area R by touching the position input device of a part that reflects the arbitrary area E with a finger or a touch pen. In this case, the reference area setting unit 19 corresponds to a position input device provided in the monitor 17. In such a configuration, the operator can view only the monitor 17 and accurately select the region E including the region of interest W as the new reference region R. Therefore, the reference region R can be set on the display screen more quickly and reliably. As the position input device, a known method such as a resistive film method or a capacitance method may be appropriately used.

It should be noted that the settings relating to the number and shape of the areas E can be changed as appropriate by operating the input unit 11. In that case, information on the number and shape of the regions E after the change is transmitted to the storage unit 25 and stored. Then, according to the content of the instruction input to the input unit 11, arbitrary information regarding the number and shape of the areas E is read by the main control unit 27. The read information is transmitted to the monitor 17 and displayed in the image visual field region V.

<Description of operation>
Next, an operation for performing automatic brightness adjustment using the X-ray fluoroscopic apparatus 1 according to the first embodiment will be described. FIG. 3 is a flowchart for explaining the operation of the X-ray fluoroscopic apparatus according to the first embodiment.

Step S1 (Generation of X-ray fluoroscopic image)
First, an X-ray fluoroscopic image that is an X-ray image by X-ray fluoroscopy is generated. That is, after the subject M is placed on the top 3, the collimator 9 is controlled to set the X-ray irradiation field. Then, the operator operates the input unit 11 to input an instruction to irradiate the subject M with the X-ray 5a from the X-ray tube 5 by X-ray fluoroscopy. The main control unit 27 outputs a control signal to the X-ray irradiation control unit 13 in accordance with the input instruction. The X-ray irradiation control unit 13 controls the X-ray irradiation condition to a predetermined value according to the control signal.

The X-ray tube 5 irradiates the subject M intermittently with conical X-rays 5a under controlled X-ray irradiation conditions. The X-ray detector 7 detects the X-ray 5a that passes through the subject M, and outputs an X-ray detection signal based on the detected X-ray. The image generation unit 15 intermittently generates an X-ray fluoroscopic image of the subject M based on the X-ray detection signal. The generated X-ray fluoroscopic image is displayed on the monitor 17. In addition, information on the luminance value at each pixel of the fluoroscopic image is transmitted from the image generation unit 15 to the luminance value calculation unit 21.

Here, the operator observes the image visual field region V of the X-ray fluoroscopic image displayed on the monitor 17 and determines whether or not the region of interest W of the subject M is located within the preset reference region R. To branch the process. If it is determined that the region of interest W is located within the range of the reference region R, the process related to step S2 is omitted, and the process proceeds to step S3. If it is determined that the region of interest W is not located within the reference region R, the process proceeds to step S2.

Step S2 (reference area setting)
When the region of interest W is not located within the range of the reference region R, the processes after step S3 are performed based on the luminance value of the region other than the region of interest W, and the X-ray irradiation conditions are changed. Therefore, the visibility of the X-ray fluoroscopic image at the site of interest W is reduced. Therefore, the operator confirms the position of the region of interest W displayed on the monitor 17 and sets the reference region on the display screen of the monitor 17. In the first embodiment, the positional relationship between the reference region R and the region of interest W in the X-ray fluoroscopic image is as shown in FIG.

In this case, the region E where the region of interest W is located is deviated to the upper left from the region E in which the reference region R is preset. The operator selects the region E including the region of interest W by operating the reference region setting unit 19 while referring to the position of the boundary line dividing the image visual field region V into each region E. In the first embodiment, the reference area setting unit 19 is configured with a mouse. The operator operates the mouse to move the cursor F to the region E including the region of interest W and click to select it. As shown in FIG. 2B, the reference region setting unit 19 sets the selected region, that is, the region E including the region of interest W as a new reference region R. The set reference area R is displayed on the monitor 17. Further, the position information of the reference region R newly set in the X-ray fluoroscopic image is transmitted to the luminance value calculation unit 21.

Step S3 (calculation of image luminance value)
By setting the reference region R, the image luminance value is calculated. The luminance value calculation unit 21 calculates the luminance value of each pixel located within the range of the reference region R in the X-ray fluoroscopic image based on the luminance information of each pixel in the X-ray fluoroscopic image and the position information of the reference region R, respectively. Extract. Then, the luminance value extraction unit 21 calculates an image luminance value corresponding to the X-ray fluoroscopic image based on the extracted luminance value in the reference region. The calculation method of the image luminance value may be changed as appropriate, but in the first embodiment, an average value of luminance values extracted from each pixel located in the reference region is set as the image luminance value.

In step S2, the reference region R is set according to the position of the region of interest W. Therefore, the image luminance value calculated by the luminance value extraction unit 21 is close to the luminance value of the region of interest W. Information on the image luminance value calculated by the luminance value extraction unit 21 is transmitted from the luminance value extraction unit 21 to the irradiation condition calculation unit 23.

Step S4 (calculation of corrected irradiation conditions)
The irradiation condition calculation unit 23 calculates a correction irradiation condition based on the information on the image luminance value. Information on the ideal luminance value is stored in advance in the storage unit 25, and the information on the ideal luminance value is transmitted from the storage unit 25 to the irradiation condition calculation unit 23. As the ideal luminance value, a luminance value of an X-ray fluoroscopic image that can be suitably viewed by the operator is used. The irradiation condition calculation unit 23 compares the ideal luminance value determined in advance with the image luminance value to calculate a difference.

Then, the irradiation condition calculation unit 23 corrects based on the X-ray irradiation condition at the time of generating the X-ray fluoroscopic image for which the image luminance value is calculated and the difference between the ideal luminance value calculated by the irradiation condition calculation unit 23 and the image luminance value. Irradiation conditions are calculated. The corrected irradiation condition is an X-ray irradiation condition in which the image luminance value of the X-ray image becomes an ideal luminance value. Information on the corrected irradiation condition is transmitted from the irradiation condition calculation unit 23 to the X-ray irradiation control unit 13. Note that the correction irradiation condition calculation method described here is an example, and a known method may be used as appropriate.

Step S5 (Generation of X-ray image under corrected irradiation conditions)
The X-ray irradiation control unit 13 controls the X-ray irradiation conditions again according to the information on the correction irradiation conditions. That is, the X-ray irradiation control unit 13 controls the tube voltage and tube current of the X-ray tube 5 and various conditions such as X-ray irradiation to values according to the correction irradiation conditions. The X-ray irradiation control unit 13 controls the X-ray irradiation conditions again, so that the dose of the X-rays 5a irradiated from the X-ray tube 5, the timing at which the X-ray tube 5 irradiates the X-rays 5a, etc. are corrected irradiation conditions. Will be changed according to the information.

The X-ray tube 5 irradiates the subject M with a dose of X-rays based on the corrected irradiation conditions in accordance with a control signal from the X-ray irradiation control unit 13. By irradiating X-rays under X-ray irradiation conditions based on the corrected irradiation conditions, the image luminance value of the region of interest W of the X-ray fluoroscopic image generated again by the image generation unit 15 becomes an ideal luminance value. That is, in the X-ray fluoroscopic image, the luminance value of the reference region including the region of interest W is adjusted to an ideal luminance value that can be suitably viewed. As a result, the X-ray fluoroscopic image displayed again on the monitor 17 is an image with high visibility of the region of interest W. By generating an X-ray fluoroscopic image based on the corrected irradiation condition, the operation of the X-ray fluoroscopic apparatus according to the first embodiment is completed. That is, the operator proceeds with the surgical procedure or diagnoses the subject M based on an X-ray fluoroscopic image in which the region of interest W can be suitably viewed.

<Effects of Configuration of Example 1>
Thus, by having the structure which concerns on Example 1, the X-ray image with high visibility of a region of interest can be acquired more rapidly. Here, effects obtained based on the configuration of the first embodiment will be described.

In the automatic brightness adjustment using the X-ray fluoroscopic apparatus according to the conventional example, when the range of the reference region is out of the region of interest in the X-ray fluoroscopic image displayed on the monitor, the imaging system and the top plate are moved. Then, the X-ray irradiation condition is corrected according to the luminance of the region of interest by moving the region of interest of the subject shown in the X-ray fluoroscopic image into the range of the reference region previously set in the X-ray fluoroscopic image. . By performing X-ray fluoroscopy again under the corrected X-ray irradiation conditions, the brightness of the X-ray fluoroscopic image is adjusted so that the visibility of the region of interest is high.

However, in such a conventional example, the reference region and the region of interest cannot be aligned unless hardware such as an imaging system or a top plate is moved. When the position is adjusted by controlling hardware parts, it is difficult to quickly align the reference region and the region of interest even if the reference region and the region of interest displayed on the monitor are visually recognized. That is, it is difficult for the operator to accurately recognize the distance to move the imaging system or the like for alignment based on the distance between the reference region displayed on the monitor and the region of interest.

Therefore, the operator repeats fine adjustment of the position of the imaging system and the like in order to align the reference region and the region of interest. As a result, there have been concerns about the problem that the exposure dose received by the subject increases and the time required to acquire an X-ray image that allows the region of interest to be viewed appropriately. Further, during fine adjustment, the operator needs to constantly check the input unit for performing operations such as the imaging system and the monitor on which the region of interest and the reference region are displayed. As a result, the line of sight is repeatedly moved with respect to the input unit and the monitor, which increases the burden on the operator.

In order to solve such a problem, the fluoroscopic imaging apparatus 1 according to the first embodiment includes a reference area setting unit 19 that sets a reference area on the display screen of the monitor 17 that displays an X-ray image. The image viewing area V of the X-ray fluoroscopic image is divided into a plurality of areas E in advance, and an area E selected by the mouse or touch pen as the reference area setting unit 19 is newly set as the reference area R.

In such a configuration, the operator visually recognizes the monitor 17 and confirms the positional relationship between the region of interest W and the reference region R. A new reference region R is set on the display screen by manually selecting a region E that includes the region of interest W using the reference region setting unit 19. Since the boundary line of the region E is visible on the display screen, the operator can easily and reliably confirm the region E including the region of interest W. Therefore, it is possible to quickly and reliably execute the setting of the reference region R that includes the region of interest W inside. Further, when the reference region R is newly set, the operator does not need to move his / her line of sight other than the monitor 17, so that the burden on the operator such as fatigue is further reduced.

The luminance value calculation unit 21 extracts the luminance value of each pixel located within the range of the reference region R, and calculates the image luminance value based on the luminance value in the reference region. The irradiation condition calculation unit 23 calculates the corrected irradiation condition based on the information on the image luminance value. The X-ray irradiation control unit 13 controls the X-ray irradiation conditions again according to the information on the correction irradiation conditions. The corrected irradiation condition is an X-ray irradiation condition in which the image luminance value of the X-ray image is an ideal luminance value, that is, a luminance value that can be suitably viewed by the operator. The reference region R is set so as to surely include the region of interest W.

Therefore, the image luminance value calculated by the luminance value extraction unit 21 is closer to the luminance value of the region of interest W. Since the correction irradiation condition is calculated based on the image luminance value close to the luminance value of the region of interest W, the fluoroscopic image generated based on the correction irradiation condition is an image that allows the operator to visually recognize the region of interest W suitably. It becomes. Therefore, it is possible to accurately advance the surgical procedure while referring to an X-ray fluoroscopic image that allows the region of interest W to be suitably viewed.

Further, the setting change of the reference region R by the reference region setting unit 19 can be performed during the execution of X-ray fluoroscopy. That is, even if it is found that the range of the reference region R is out of the position of the region of interest W after the start of fluoroscopy, the position of the reference region R can be quickly changed on the display screen of the monitor 17. Therefore, it is possible to change the setting of the reference region quickly so as to flexibly cope with a change in the status of the surgical procedure during the fluoroscopy, and to advance the surgical procedure more suitably.

Next, an X-ray fluoroscopic apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings. The overall configuration of the X-ray fluoroscopic apparatus according to the second embodiment is the same as that of the X-ray fluoroscopic apparatus according to the first embodiment. Further, the operation process of the X-ray fluoroscopic apparatus according to the second embodiment is the same as the operation process of the X-ray fluoroscopic apparatus according to the first embodiment.

However, in the first embodiment, the image field area V of the X-ray image displayed on the monitor 17 is configured to be divided into a plurality of areas in advance. On the other hand, the X-ray fluoroscopic apparatus according to the second embodiment has a configuration in which the reference region can be set without dividing the image visual field region V in advance. Hereinafter, the configuration for setting the reference region, which is characteristic of the second embodiment, will be described with reference to FIG.

<Description of Configuration for Setting Reference Area in Embodiment 2>
In the second embodiment, as shown in FIG. 4B or 4C, the reference area setting unit 19 selects an arbitrary position on the display screen of the monitor 17, and sets the reference area R at the selected position. It has a configuration to do. 4A is the same as FIG. 2A in the first embodiment, in the X-ray fluoroscopic image displayed on the monitor 17, the range of the reference region R set in advance of the subject M from the position of the region of interest W. It shows a state of being detached.

In the X-ray fluoroscopic apparatus according to the second embodiment as illustrated in FIG. 4B, the reference region setting unit 19 sets a new reference region R around the selected position on the display screen of the monitor 17. have. Examples of the configuration of the reference area setting unit 19 that selects the reference area on the display screen include a mouse pointer and a keyboard. It is more preferable that the reference area setting unit 19 is provided at or near the monitor 17 so that the reference area setting unit 19 can be operated while viewing the monitor 17.

In the configuration shown in FIG. 4B, the operator refers to the monitor 17 and clicks the cursor F at the position of the region of interest W shown in the X-ray image. By the selection operation, a reference region R having a predetermined shape is set around the position selected by clicking. The shape of the reference region R can be changed as appropriate by an icon 17a on the screen of the monitor 17. In other words, the shape of the reference region R to be set can be changed from a rectangular shape to a circular shape by selecting the circular icon 17a from the state in which the rectangular icon 17a is initially selected (FIG. 4A) ( FIG. 4 (b)). Further, the size of the reference region R can be appropriately changed by an operation of selecting and dragging the boundary line of the reference region R.

In the configuration shown in FIG. 4B, the reference region R can be set without dividing the image field region V in advance. Further, since the position serving as the center of the reference region R can be arbitrarily selected, the reference region R can be set at a more appropriate position according to the position of the region of interest W displayed on the monitor 17. Further, the configuration illustrated in FIG. 4B is not limited to the configuration in which the shape of the reference region R is changed with the icon 17a. That is, a configuration in which a pointer such as the cursor F is operated using a pointing device such as a mouse to draw the outline of the reference region R on the display screen of the monitor 17 may be adopted. In this case, since the position and shape of the reference region R can be arbitrarily set, the reference region R having a more preferable shape can be newly set.

FIG. 4C shows a modification of the X-ray fluoroscopic apparatus according to the second embodiment. In the X-ray fluoroscopic apparatus according to the second embodiment as illustrated in FIG. 4C, the monitor 17 is configured by a touch panel. That is, the monitor 17 has a panel-like position input device on the surface for detecting the touched position. The operator touches the position input device using a finger or a touch pen T and directly draws an area to be a reference area, thereby setting the range of the reference area R on the display screen of the monitor 17. In such a configuration, the position input device constituting the monitor 17 corresponds to the reference region setting unit 19 which is a reference region setting means.

In the case of a configuration in which the reference area R is directly drawn on the monitor 17, the operator can set the reference area R having an arbitrary shape at an arbitrary position. Therefore, a reference region R having a suitable shape can be newly set so as to exclude a region other than the region of interest W as much as possible according to the position / shape of the region of interest W. As a result, the image luminance value calculated by the luminance value calculation unit 21 is closer to the luminance value of the region of interest W, and thus it is possible to generate an X-ray fluoroscopic image with higher visibility of the region of interest W.

As described above, in the X-ray fluoroscopic apparatus according to the second embodiment, the reference region setting unit 19 sets a new reference region R on the display screen as in the first embodiment. That is, in the second embodiment, as in the first embodiment, the operator can quickly set the reference region R manually without moving the line of sight other than the monitor 17. As a result, it is possible to more quickly obtain an X-ray fluoroscopic image that allows the operator to visually recognize the site of interest W while reducing the burden on the operator.

In the second embodiment, the reference field R is set on the display screen without dividing the image viewing field V and the screen of the monitor 17 into a plurality of areas E in advance. Therefore, the technique according to the present invention can be applied to the monitor 17 having a configuration that is not divided into a plurality of regions E, and thus the versatility of the X-ray fluoroscopic apparatus can be enhanced. In addition, since the step of dividing the image visual field region V or the like into a plurality of regions in advance can be omitted, it is possible to avoid spending time for setting work.

Furthermore, in the second embodiment, the position and shape of the reference region R can be changed more flexibly according to the region of interest W shown on the monitor 17 without being affected by the shape of the region E that divides the image viewing region V or the like. That is, a more preferable range of the reference region R can be newly set so that the region other than the region of interest W is out of the range as much as possible according to the shape of the region of interest W or the like. As a result, the image luminance value calculated by the luminance value calculation unit 21 is closer to the luminance value of the region of interest W. Therefore, the visibility of the region of interest W can be further improved in the fluoroscopic image generated based on the corrected irradiation condition.

The present invention is not limited to the above embodiment, and can be modified as follows.

(1) In each of the above-described embodiments, the irradiation condition fixing unit 29 (not shown) may be further provided. The irradiation condition fixing unit is, for example, a button or a switch provided in the input unit 11. In such a modification, at least the calculation of the image luminance value performed by the luminance value calculation unit 21 and the calculation of the correction irradiation condition performed by the irradiation condition calculation unit 23 are performed by turning on the irradiation condition fixing unit. One is configured to stop. As a result, since the automatic brightness adjustment function is turned off, the corrected irradiation condition is fixed under the most recently calculated condition and is no longer updated. The irradiation condition fixing unit corresponds to the luminance adjustment switching means in the present invention.

When using an X-ray fluoroscopic apparatus including an irradiation condition fixing unit, the operator uses the reference region setting unit 19 to set the range of the reference region R according to the position of the region of interest W. Then, after the X-ray fluoroscopic image displayed on the monitor 17 is adjusted to a luminance that allows the region of interest W to be suitably viewed, the irradiation condition fixing unit is operated to be turned on. In this case, since the correction irradiation condition is fixed, the luminance of the X-ray fluoroscopic image is always in a state where the region of interest W can be suitably viewed.

Since the metal has a very high X-ray absorption rate, the luminance value is generally excessively high in a pixel in which the metal is reflected. Therefore, in the configuration in which the correction irradiation condition is always calculated based on the luminance value in the reference region, when a metal piece is newly reflected in the reference region R, the luminance value calculation unit 21 is affected by the luminance of the metal piece, A higher value of the image luminance value is calculated. As a result, the brightness of the X-ray fluoroscopic image generated based on the corrected irradiation condition is drastically reduced, so that the visibility of the region of interest W is lowered.

On the other hand, in the configuration according to the modification, the irradiation condition fixing unit is turned on, so that the correction irradiation condition is not changed even when the luminance in the reference region changes. That is, even when a metal piece such as a scalpel or scissors is newly reflected within the range of the reference region R due to the progress of the surgical procedure, the luminance of the X-ray fluoroscopic image does not change, and the region of interest W can be suitably viewed. State is maintained. Therefore, a situation in which the brightness of the X-ray fluoroscopic image rapidly decreases as a result of the brightness value in the pixels that show the metal piece having an influence on the correction irradiation condition due to the metal piece appearing in the reference region R can be preferably avoided.

(2) In each of the above-described embodiments, the luminance value calculation unit 21 extracts all the luminance values of each pixel located in the reference region, and calculates the image luminance value based on the extracted luminance value in the reference region. However, it is not limited to this. That is, the upper limit luminance value and the lower limit luminance value are set in advance and stored in the storage unit 25, and the luminance value calculation unit 21 calculates the luminance value from the lower limit luminance value to the upper limit luminance value among the luminance values of each pixel located in the reference area. The configuration may be such that only the luminance value between the values is extracted to calculate the image luminance value.

In addition to the region of interest in the reference region, there may be an X-ray image showing an extreme luminance value such as a luminance value exceeding the upper limit luminance value or a luminance value falling below the lower limit luminance value. As an example of a case where the luminance value is higher than the upper limit luminance value, there is a case where a metal piece such as the above-described knife or fixing bolt is reflected in the reference region. Therefore, when an X-ray image of a metal piece or the like is reflected in the reference area, the high luminance value indicated by the metal piece affects the image luminance value and the correction irradiation condition, and the luminance of the X-ray fluoroscopic image sharply decreases. Is concerned.

On the other hand, an example of a case where the luminance value is lower than the lower limit luminance value is a case where X-rays are detected by the X-ray detector without passing through the subject M. That is, when the region of interest W has a complicated shape such as a finger of the subject M, X-rays directly enter the X-ray detector without passing through the subject M in a part of the reference region R. As a result, since the luminance value is extremely low in a pixel to which X-rays are directly incident, the extremely low luminance value affects the image luminance value and the correction irradiation condition, and the luminance of the X-ray fluoroscopic image becomes excessively high. Therefore, there is a concern that the visibility of the site of interest is reduced.

In such a modification, among the pixels located in the reference area, the luminance value calculation unit 21 determines the luminance value of the pixel that indicates a luminance value higher than the upper limit luminance value and the pixel that indicates a luminance value lower than the lower limit value. Excluded from extraction. In this case, the brightness value calculation unit 21 automatically excludes pixels that show extreme brightness values, such as pixels that directly receive X-rays or pixels that project metal pieces, and calculates image brightness values. Therefore, it is possible to suitably avoid a situation in which the visibility of the region of interest is lowered as a result of pixels that exhibit an extreme luminance value affecting the correction irradiation condition and the luminance of the fluoroscopic image changes excessively.

(3) In each of the above-described embodiments, the case where a reference area is newly set on the display screen during X-ray fluoroscopy has been described as an example, but the present invention is not limited thereto. As an example, the setting of the reference area performed on the display screen may be executed before the X-ray fluoroscopy is started. Examples of setting the reference area before fluoroscopy include the following cases. That is, when the positional relationship between the X-ray irradiation field B confirmed with visible light or the like and the region of interest W in the subject M placed on the top 3 is as shown in FIG. It is easily expected to appear below the image viewing area.

Therefore, the operator changes the setting of the reference region R initially set in the center of the screen (FIG. 5B) to the lower side of the screen of the monitor 17 and then starts X-ray irradiation by X-ray fluoroscopy ( FIG. 5 (c)). Since the reference region R is set according to the position of the region of interest W from the beginning of X-ray fluoroscopy, it is possible to shorten the time until the luminance of the X-ray fluoroscopic image is adjusted. As a result, the exposure dose received by the subject M in the brightness adjustment of the X-ray fluoroscopic image can be reduced.

(4) In each of the above-described embodiments, a reference region is set on the display screen for the X-ray fluoroscopic image, and the X-ray fluoroscopic image can be suitably visually recognized based on the set range of the reference region. Although it was set as the structure which calculates X-ray irradiation conditions as correction | amendment irradiation conditions, it is not restricted to this. The X-ray image for setting the reference area may be an X-ray image. Further, the X-ray irradiation condition of the X-ray image may be calculated as the correction irradiation condition based on the range of the reference region.

In such a modification, the irradiation condition calculation unit 23 corrects the irradiation condition in the X-ray imaging that captures a still image based on the luminance value of the pixel in the reference region that is preferably set according to the position of the region of interest W. Is calculated. The corrected irradiation condition calculated by the irradiation condition calculation unit 23 is an X-ray irradiation condition for generating an X-ray image having a luminance value that allows the region of interest to be suitably viewed. Therefore, the X-ray irradiation control unit 13 can acquire an X-ray image that can suitably visually recognize the region of interest by controlling the X-ray tube 5 based on the corrected irradiation condition.

(5) In each of the above-described embodiments, the X-ray image is generated for the subject M in the supine posture. However, the present invention is not limited to this, and the configuration of the X-ray fluoroscopic apparatus according to the embodiment is established. The present invention can also be applied to the subject M taking a posture. In this case, the x direction, that is, the body axis direction of the subject M is parallel to the vertical direction. Moreover, it is good also as a structure which can displace the top plate 3 from a horizontal state to a vertical state, or the structure which abbreviate | omits the top plate 3. FIG.

1 X-ray fluoroscopic apparatus
5 ... X-ray tube (X-ray source)
7 ... X-ray detector (X-ray detection means)
11: Input section (division area changing means)
13 ... X-ray irradiation control unit (irradiation control means)
15 Image generating unit (image generating means)
17 ... Monitor (image display means)
19: Reference area setting section (reference area setting means)
21 ... Luminance value calculation unit (luminance value calculation means)
23 ... Irradiation condition calculation unit (irradiation condition calculation means)
25 ... Storage unit (divided area storage means)
27 ... Main control section

Claims

An X-ray source for irradiating the subject with X-rays;
X-ray detection means for detecting X-rays irradiated from the X-ray source and transmitted through the subject;
Image generation means for generating an X-ray image using a detection signal output by the X-ray detection means;
Irradiation control means for controlling the X-ray irradiation conditions of the X-ray source;
Image display means for displaying an X-ray image generated by the image generation means;
Reference area setting means for arbitrarily setting one or more areas in the X-ray image as a reference area on the display screen of the image display means;
A luminance value calculating means for extracting a luminance value of each pixel in the reference region and calculating an image luminance value corresponding to the X-ray image based on the extracted luminance value;
Irradiation condition calculation means for calculating a correction irradiation condition, which is the X-ray irradiation condition so that a luminance value of a pixel in the reference region becomes a predetermined value, based on the image luminance value and the predetermined value; Prepared,
The X-ray fluoroscopic imaging apparatus, wherein the irradiation control unit controls an X-ray irradiation condition of the X-ray source based on the corrected irradiation condition calculated by the irradiation condition calculation unit.
The X-ray fluoroscopic apparatus according to claim 1,
The display screen of the image display means is divided into a plurality of areas,
The X-ray fluoroscopic imaging apparatus, wherein the reference area setting means sets the reference area by selecting one or more areas among the plurality of areas as the reference area.
The X-ray fluoroscopic apparatus according to claim 2,
Divided region changing means for changing at least one of the number and shape of the plurality of regions dividing the display screen of the image display means;
A divided area storage means for storing the number and shape of the plurality of areas changed by the divided area changing means;
The X-ray fluoroscopic apparatus, wherein the image display means reads out information on the number and shape of the plurality of areas stored by the divided area storage means and displays the information on a display screen.
The X-ray fluoroscopic apparatus according to claim 1,
The X-ray fluoroscopic imaging apparatus, wherein the reference area setting means sets the reference area by drawing an arbitrary area on the display screen of the image display means as the reference area.
The X-ray fluoroscopic apparatus according to claim 1,
The luminance value calculating means extracts the luminance value included between a predetermined upper limit value and a predetermined lower limit value among the luminance values of the pixels in the reference region, and based on the extracted luminance value An X-ray fluoroscopic apparatus that calculates an image luminance value corresponding to an X-ray image.
In the X-ray fluoroscopic apparatus according to any one of claims 1 to 5,
An X-ray fluoroscopic imaging apparatus comprising: a brightness adjustment switching unit that fixes the correction irradiation condition calculated by the irradiation condition calculation unit to the correction irradiation condition calculated most recently.
The X-ray fluoroscopic apparatus according to any one of claims 1 to 6,
The image display means is a touch panel,
The reference region setting means is an X-ray fluoroscopic apparatus that is a position input device provided on the surface of the image display means.