JP5238175B2 - X-ray diagnostic imaging equipment - Google Patents

Description

  The present invention relates to an X-ray diagnostic imaging apparatus that detects transmitted X-rays of a subject with an X-ray flat panel detector (hereinafter sometimes referred to as FPD) in which semiconductor X-ray detection elements are two-dimensionally arranged. In particular, the present invention relates to an X-ray diagnostic imaging apparatus that reduces moire generated by using a grid for removing scattered X-rays.

  In recent years, X-ray diagnostic imaging apparatuses have been digitized. The reason is that the medium for detecting X-ray images is changing from image intensifiers, which are X-ray films and analog optical images, to FPDs that use semiconductors that can convert X-rays directly into digital electrical signals. Because there is.

  There are various types of FPDs. For example, a scintillator that converts X-rays transmitted through a subject into light, and a photodiode (for example, amorphous silicon) that converts light output from the scintillator into electric charge. And an X-ray image is obtained by reading the charge of the photodiode via a switching element {eg TFT (Thin Film Transistor)}, and the X-ray dose transmitted through the subject is obtained. A large number of detectors for converting into corresponding electrical signals are arranged in a planar matrix, and the X-ray dose is converted into an electrical signal by each of the detectors to become an electrical image signal. This electrical image signal is further converted into a digital image signal by an analog / digital converter and output from the FPD. After being input to the image processing apparatus, various image processing is performed and displayed as an X-ray image on a monitor or the like for diagnosis. Provided.

  In addition to the feature of obtaining X-ray images in real time, the FPD with this configuration is thinner and lighter than conventional screen / film detection systems, stimulable phosphor detectors, and detectors using image intensifiers. Because it is also advantageous for downsizing the system, it is possible to manufacture a wide-field FPD so that a wide range of parts such as the abdomen and thighs including the chest of the subject can be obtained at one time. Also, since it has a very wide dynamic range, it has an advantage that an X-ray image that is not affected by fluctuations in the exposure amount of X-rays can be obtained.

In the FPD having the above-described characteristics, the charge accumulated in the photodiode, that is, the dark current exists as an offset value even when X-rays are not irradiated due to the structure of the FPD. It is necessary to correct the image data by subtracting the dark current value from the output image data (hereinafter referred to as offset correction).
In addition, the FPD detection unit is composed of multiple pixels arranged in a planar matrix, and each pixel has a different gain. Therefore, in order to obtain a uniform output image for the input image, the gain for each pixel is obtained. Correction is required, and correction of defective pixels that output abnormal values is also required.

  On the other hand, in order to prevent scattered X-rays generated in the subject from entering the FPD, a grid may be provided at the front of the FPD to prevent the scattered X-ray component from being imaged by the grid. is there.

  However, with the X-ray detection mechanism configured as described above, in order to obtain an image signal by two-dimensionally sampling the output of the FPD, the pixel pitch and grid density of a plurality of pixels arranged in a matrix interfere with each other, and aliasing is performed. (Hereinafter referred to as moire) may occur.

  In order to reduce this moire, a filtering process is generally used. However, in a reduced image in which an X-ray image obtained by imaging a subject is confirmed in a preview display, depending on the size of the reduced image, a low frequency region is used. In some cases, grid components may appear, and filtering processing may be difficult.

Therefore, Patent Document 1 discloses a technique for performing a filtering process on a reduced image obtained by thinning out some pixels of an image output from an FPD.
This is a filtering process in which the weight of the defective pixel in the thinned image is set to 0, and the original weight of the defective pixel is distributed to other pixels and added.
JP 2005-211488

  However, in the technique disclosed in Patent Document 1, when a defective pixel is included in a pixel used for moire reduction, a filter coefficient (weight coefficient) for the defective pixel is uniformly set to 0. Since the amplitude of the filter changes depending on the included position, the frequency characteristic of the filter changes, and moiré cannot be reduced with high accuracy.

  In addition, in the auto-trimming process that automatically cuts out and processes a part of the entire image, the image size (filter mask size) of the cut-out image changes, so the weight of the defective pixel is set to 0, and the defect The technique of Patent Document 1 that distributes and adds the original weight of a pixel to other pixels still has a moire problem.

  An object of the present invention is to obtain a high-quality X-ray image by reducing the moire generated by interference between the pixel pitch of the pixel of the X-ray flat panel detector (FPD) and the grid density, and to reduce the moire. An object of the present invention is to provide an X-ray diagnostic imaging apparatus for forming a high-quality preview image and / or an auto-trimmed image.

  The X-ray diagnostic imaging apparatus according to the present invention weights a non-zero positive value to a defective pixel of the X-ray flat panel detector by causing moire generated by interference between the pixel pitch of the X-ray flat panel detector pixel and the grid density. This is reduced by applying the filtering process according to (1), and is specifically achieved by the following means.

  That is, an X-ray plane detection comprising an X-ray source for irradiating the subject with X-rays and a plurality of two-dimensionally arranged X-ray detection elements arranged opposite to the X-ray source to detect the transmitted X-rays of the subject An X-ray irradiation area setting means for setting an X-ray irradiation area for the subject, an X-ray diaphragm means for focusing X-rays on the X-ray irradiation area set by the X-ray irradiation area setting means, and the subject A grid provided in front of the X-ray flat panel detector that prevents scattered X-rays generated in the specimen from entering the X-ray flat panel detector, and an offset (dark current) of each pixel of the X-ray flat panel detector An X-ray flat panel detector correcting unit that corrects a pixel value of a gain and a defective pixel, and a moire reducing unit that reduces a moire generated by interference between the pixel pitch of the pixel of the X-ray flat panel detector and the density of the grid. In the X-ray diagnostic imaging apparatus, the moire reduction means is the X-ray flat panel detector A filter processing means for weighting a defective pixel corrected by the correction means with a predetermined value is provided.

  The correction area of the pixel to be corrected by the X-ray plane detector correction means is an X-ray irradiation field area formed by the X-ray diaphragm means, and the X-ray plane detector correction means is the X-ray irradiation field area. Defective pixel detecting means for detecting a defective pixel by scanning in the X direction of the correction region in two dimensions in the X direction and Y direction is provided.

  The image forming apparatus further includes a reduced image forming unit that forms an image to be reduced by thinning out pixels of the entire image detected by the X-ray flat panel detector, and the reduced image forming unit includes the image data from the entire image data of the X-ray irradiation field region. Decimation number determining means for determining a thinning number for forming an image area to be reduced corresponding to the long axis of the X-ray irradiation field, and detecting the X-ray plane by shifting pixels thinned based on the thinning number Correction area setting means for setting the correction area of the detector, means for correcting the pixels in the correction area set by the correction area setting means by the X-ray flat panel detector correction means, and pixel values corrected by the correction means And the moire reduction means for reducing moire by the filter processing means.

  The correction of the defective pixel is performed by correcting pixels in a line separated by one line in the X direction which is one time the thinned number, and the moire reduction is performed by weighting pixels in a line separated by two lines of the thinned number. The reduced image is an image to be previewed by reducing the entire image detected by the X-ray flat panel detector.

  Even in the formation of an auto-trimmed image in which a part of the entire image is automatically cut out and processed, the moire of the auto-trimmed image is reduced by providing the trimmed image with the moire reducing means.

  According to the present invention, it is possible to obtain a high-quality X-ray image by reducing moire generated by interference between the pixel pitch of an X-ray flat panel detector (FPD) and the grid density, and to reduce the moire. An X-ray diagnostic imaging apparatus that forms a high-quality preview image and / or an auto-trimmed image can be provided.

  Hereinafter, preferred embodiments of an X-ray diagnostic imaging apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing a configuration of an X-ray image diagnostic apparatus of the present invention.
The X-ray diagnostic imaging apparatus of FIG. 1 includes an X-ray tube 2 (X-ray source) that generates X-rays irradiated to the subject 1, and an X-ray that limits the irradiation range of the X-rays irradiated to the subject 1 X-ray that detects the transmitted X-ray of the subject 1 and is converted to digital image data that is disposed opposite to the movable diaphragm device 3 (X-ray diaphragm means), the X-ray tube 2 and the X-ray movable diaphragm device 3 A flat detector (FPD) 4 and a grid provided at the front of the FPD 4 for preventing scattered X-ray components generated by the subject 1 from entering the FPD 4 and imaging the scattered X-ray component 5, the X-ray aperture operation device 6 for setting the X-ray irradiation range, and the X-ray irradiation range set by the X-ray aperture operation device 6 are input, and the X-ray irradiation range is set by the X-ray movable aperture device 3. A signal for controlling the X-rays emitted from the X-ray tube 2 based on the X-ray condition set by the X-ray diaphragm control device 7 (X-ray irradiation region setting means) to be controlled and set and an operation console 10 described later Generation An X-ray controller that generates a DC high voltage (hereinafter referred to as a tube voltage) applied between the anode and cathode of the X-ray tube 2 corresponding to a control signal from the X-ray controller, and the X-ray tube The X-ray high-voltage device 8 having a function of flowing a current flowing between the anode and the cathode (hereinafter referred to as tube current) for a predetermined time (imaging time) and an operation signal input from the operation console 10 described later. The system control and image processing apparatus 9 (X) which controls and manages the entire imaging system based on the image data and reads out the image data as the output of the FPD 4 and performs image processing such as correction on the image data to generate an X-ray image. An X-ray image generated by the system control and image processing device 9 and the input device 10a for inputting the setting of the X-ray conditions, operation signals, and the like. And a display for displaying information related to the image And an operation console 10 provided with a device 10b.

  The system control and image processing device 9 includes a CPU (central processing unit) 9a that executes control of the entire system and a program that reads out image data from the FPD 4 and generates a captured image, and the processing described in this embodiment is the CPU 9a. A hard disk 9b for storing a control program and X-ray conditions necessary for imaging, correction data for correcting image data read from the FPD 4, a control program read from the hard disk 9b, an X-ray A RAM (temporary storage memory) 9c for storing conditions, correction data, image data read from the FPD 4, etc., an input / output interface 9d with each element, and a common bus 9e for connecting the elements to each other Configured.

  The CPU 9a executes various control programs in the system control and image processing apparatus 9. A control program for executing processing according to this embodiment described later is loaded from the hard disk 9b to the RAM 9c by the CPU 9a via the OS and executed by the CPU 9a.

In the RAM 9c, an area for storing image data read from the FPD 4 is secured, and photographed image data is temporarily stored therein.
Further, a correction data area for correcting the image data is secured on the RAM 9c, and correction data for use in correcting the image data is stored in this area.

The input / output interface 9d is connected to the input device 10a and the display device 10b such as a keyboard 10a1 and a mouse 10a2 that serve as an interface with the operator of the X-ray image diagnostic apparatus.
Of course, it is obvious that the input device 10a and the display device 10b may be configured by a display device or the like having a touch panel type input unit.

  The system control and image processing device 9 is further provided with a ROM (read only memory), and the control program, X-ray conditions, correction data, etc. are stored in the ROM, and the control program, X Line conditions, correction data, and the like may be loaded into the RAM 9c to generate imaging control and an X-ray image.

  Next, a process for generating a preview image (reduced image) and a process for generating the entire image, which are performed with the X-ray image diagnostic apparatus having the above-described configuration and prior to the entire image processing, will be described with reference to the flowchart of FIG. To do.

(1) Shooting process (S200)
An operator operates the keyboard 10a1 and the mouse 10a2 of the input device 10a of the operation console 10 to input imaging parts, X-ray imaging conditions, operation commands, etc., and set various conditions necessary for imaging.
Corresponding to these set conditions, X-ray conditions such as tube voltage, tube current and imaging time are set in the X-ray high-voltage apparatus 8, and the operator operates the X-ray aperture operation device 6 to operate the desired X-ray. An X-ray irradiation field is set by controlling the X-ray movable diaphragm device 3 with the X-ray diaphragm controller 7 so as to be an irradiation field.
When the preparation for imaging such as setting of the X-ray imaging conditions and the X-ray irradiation field is completed, the operator presses the first switch of the X-ray irradiation switch (not shown) to set the X-ray conditions from the X-ray high voltage apparatus 8 Is applied to the filament of the X-ray tube 2 to heat the filament between the anode and the cathode of the X-ray tube 2 and the filament is heated, and then the second stage of the X-ray exposure switch The tube voltage corresponding to the X-ray condition is applied from the X-ray high voltage device 8 to the anode and cathode tube of the X-ray tube 2 to emit X-rays, and imaging is started.
When the set shooting time is reached, shooting ends, and the shot image data is stored in the FPD 4.

(2) Reading and storing all image data from FPD (S201)
When shooting is completed, an image data read command is input from the CPU 9a to the FPD 4 via the input / output interface 9d, and all image data shot from the FPD 4 is read and stored in the RAM 9c.

(3) Formation of preview image and all images and image display (S202)
Processing for forming and displaying a preview image prior to all images is performed in steps S203 to S208, and processing for forming, storing, and displaying all images in parallel with these processing is performed in steps S209 to S212.

(4) Preview image formation and image display (S203 to S208)
1) X-ray field detection (S203)
The X-ray irradiation field area set by the X-ray diaphragm operator 6 is read from the X-ray diaphragm controller 7 and stored in the RAM 9c. The X-ray irradiation field may be obtained from image data read from the FPD 4.

2) Determination of thinning number (S204)
A thinning number of pixels in the detected X-ray irradiation field region for forming a reduced image to be previewed on the display device 9b is determined (thinning number determination means).
For example, if the number of pixels in the reduced image is 666 × 666 pixels, the thinning-out number is set so that the long axis of the X-ray irradiation field set in the X-ray movable diaphragm device 3 shown in FIG. 3 and the reduced image become 666 × 666 pixels. It is obtained from the relationship with the thinning number. That is, when the number of long-axis pixels of the X-ray field narrowed by the X-ray movable diaphragm device 3 is 666, the thinning number is 1, and when the number of long-axis pixels of the X-ray field is 1333, the thinning number is 2, X When the number of long-axis pixels of the X-ray field is 2000, the thinning number is 3, and when the number of long-axis pixels of the X-ray field is 2666, the thinning number is 4 and the number of long-axis pixels of the X-ray field is 3000. The time decimation is 4.5.
The relationship between the thinning number determined in this way and the long axis of the X-ray field is stored in the hard disk 9b, which is read out to the RAM 9c and the length of the long axis of the X-ray field detected by the CPU 9a. Decide accordingly.

  Fig. 4 shows an example where the long axis of the X-ray field is 2666 pixels shown in Fig. 4 (a). Up to 2666 pixels for all FPD pixels 3000 when the X-ray diaphragm of the X-ray movable diaphragm device 3 is fully opened. This is a case where the X-ray irradiation field is narrowed down and the number of thinnings of 2666 pixels in the X-ray irradiation field region is set to 4, and previewing is performed by reducing the number to 666 × 666 pixels as shown in FIG.

3) Calculation of correction target area (S205)
According to the determined thinning number, the correction target position of the FPD4 offset correction, gain correction and defective pixel correction (X-ray plane detector correction means) is shifted to set the correction target area (correction area setting means). The correction target area is stored in the RAM 9c.

4) Image data correction in the correction target area (S206, S207)
FPD4 offset correction, gain correction, and defective pixel correction are performed on the target pixel in the calculated correction target area, and the corrected image data of the correction target area is stored in the RAM 9c.

  Here, before describing the correction of image data according to the present invention, a conventional technique for reducing moire when defective pixels are included will be described with reference to FIG.

If the pixel used for moiré reduction includes a defective pixel {pixel c, pixel h} in FIG. 5 (a), the filter coefficient for the defective pixel (which represents the amplitude of the filter and is the same as the weighting coefficient in Patent Document 1) Set to 0.
For this reason, the frequency characteristics of the filter change as indicated by the solid line in FIG. 5 (b), which may cause distortion in the displayed image and prevent the moire from being accurately reduced.
As described above, this occurs because the weight of the defective pixel in the thinned image is set to 0, and the original weight of the defective pixel is distributed and added to other pixels.

  Therefore, in the present invention, the defective pixels in the correction target area obtained in step S205 are detected by one loop process, that is, one scan to reduce moire. This moire reduction will be described with reference to FIG. 6 as an example where the X-ray irradiation field is reduced to 666 pixels when the long axis is 2666 pixels.

  In FIG. 6, when the long axis of the X-ray field is 2666 pixels, the thinning number to be reduced to 666 pixels is 4 pixels from FIG. 3, so the pixels thinned out in the X direction are a, b, c,. ..., the pixels to be thinned out in the Y direction are d, g, e, h, f, i, .... If the pixel of interest is i, the line in the X direction of this pixel is N Line, the line in the X direction 4 lines above the N line is the N-1 line, and the line in the X direction 4 lines above the N-1 line is the N-2 line.

  As described above, when the major axis of the X-ray irradiation field is 2666 pixels, the thinning number to be reduced to 666 pixels is 4, but the moire appears as a vertical stripe pattern in the image, as shown in FIG. The pixels in the X direction are scanned in the X direction of the X-ray irradiation field without thinning out, and defective pixels are detected (defective pixel detecting means), and the pixel value of the defective pixels is corrected to reduce moire.

  Then, offset correction and gain correction of each pixel in the thinned line are performed in advance, and defective pixels are separated by one line (1 times the thinning number, N-1 line in FIG. 6). In order to reduce moire, pixels that are separated by two lines (twice the number of thinning out and N-2 line in FIG. 6) are used.

The defective pixel is corrected by detecting a defective pixel from the thinned pixels and performing interpolation using the thinned peripheral pixels of the detected defective pixels.
For example, in FIG. 6, the defective pixel among the thinned out pixels a, b, c, d, e, f, g, h, i in the N to N-2 lines after offset correction and gain correction is e. Then, it is obtained by interpolation such as an average value of pixels a, b, c, d, f, g, h, i in eight directions around e.
As described above, the defective pixels are corrected by shifting the pixels to be thinned out in the X direction in order to secure sufficient pixels for correction by interpolation.
This is because defective pixels are corrected with high accuracy using pixels in the Y direction.

The moire reduction is performed by filtering a pixel in the X direction on a line that is two lines away from the line of the target pixel (for example, i) that has undergone the offset correction, gain correction, and defective pixel correction (defective pixel). Is weighted with a non-zero positive value).
For example, the moiré is reduced by weighting the pixels using several pixels centered on c on which the offset correction, the gain correction, and the defective pixel correction in the X direction are performed.
As described above, since the moire is reduced by assigning a positive appropriate weight to the defective pixel without setting the weight of the defective pixel to 0, the conventional image distortion does not occur.

  The reduced image data in which correction and moire are reduced as described above are stored in the RAM 9c.

5) Preview image display (S208)
The reduced image data to be previewed stored in the RAM 9c is subjected to image display control processing to generate a preview image, and the generated preview image is displayed on the display device 10b.

(5) Formation, storage and display of all images (S209 to S212)
Read all image data stored in the RAM 9c in the step S201, perform FPD4 offset correction, gain correction (S209), defective pixel correction and moire reduction processing (S210) on the entire image data, and correct the FPD4 Then, image processing is performed on the image data that has been subjected to moire reduction processing (S211).
The defective pixel correction is obtained by interpolation using peripheral pixels of the defective pixel, and the moire reduction process is performed by the same method as in S207.
The image data processed in this way is stored in the hard disk 9b, or an image display control process is performed on the image data to generate all images, and the generated all images are displayed on the display device 10b for diagnosis. Provide (S212).

  As described above, the FPD4 offset correction and gain correction are performed as described above, and defective pixel correction is performed on the pixels on which these corrections have been performed, and the defective pixel is weighted with a positive non-zero value. Since the processing has been performed, it is possible to obtain a high-quality X-ray image by reducing the moire of the vertical stripe pattern generated by the interference of the pixel pitch and the grid density of a plurality of pixels arranged in a matrix of FPD4.

  Also, the pixel thinning number of the image data detected by the FPD4 is determined according to the long axis of the X-ray irradiation field, a reduced image to be previewed is formed based on the determined thinning number, and the offset of the FPD4 is formed on the formed reduced image. Correction and gain correction are performed, and the defective pixel correction is performed on the pixels subjected to these corrections to reduce moire, so a high-quality preview image with reduced moire can be displayed. This makes it possible to accurately determine the quality of shooting.

Note that the moire reduction according to the present invention of the above embodiment can also be applied to an auto-trimming process in which a part of the entire image is automatically cut out and processed.
In other words, even if the image size (filter mask size) of the image cut out by the auto-trimming process changes, the offset correction, gain correction, and defective pixel correction of the correction target line are performed in the X direction of the trimmed image. In addition, by performing the moire reduction process in the same manner as in the above embodiment, it is possible to reduce the moire satisfactorily.

  Fig. 7 shows an example in which the long axis of the X-ray irradiation field in auto-trimming is 2500 pixels as shown in Fig. 7 (a). The X-ray movable aperture device 3 expands the X-ray aperture area to 2666 pixels. A part of 2666 pixels is cut out and reduced to 666 × 666 pixels and trimmed as shown in FIG.

While the X-ray diagnostic imaging apparatus according to the present invention has been described above, various modifications can be made without departing from the spirit of the present invention.
For example, the thinning number for forming the reduced image may be obtained by calculation in proportion to the long axis of the X-ray irradiation field, and the correction of the defective pixel is not limited to the embodiment, and the weight of the defective pixel As long as is not set to 0, any method may be used for correction.

In the above embodiment, all image data from the FPD 4 is read after shooting, and then a preview image (reduced image) and all images are formed, but the present invention is not limited to this. Instead, the X-ray irradiation field may be detected after imaging to determine the thinning number, and the reduced image data may be read prior to all image data based on the determined thinning number to form a preview image. .
As described above, the reduced image data is read out in advance of all the images, and the preview image is formed and displayed on the display device 10b, thereby reducing the time until the preview image is displayed and contributing to the improvement of the shooting throughput. To be.

  According to the present embodiment, offset correction (dark current correction) and gain correction of the X-ray flat panel detector are performed, and defective pixels are corrected for the pixels subjected to these corrections, and a positive non-zero value is applied to the defective pixels. X-ray image with high-quality X-ray image obtained by reducing the moire of vertical stripes generated by interference of the pixel pitch and grid density of the pixels of the X-ray flat panel detector because of the filtering process by weighting the values A diagnostic device can be provided.

  Further, the thinning number of pixels of the image data detected by the X-ray flat panel detector is determined according to the long axis of the X-ray irradiation field, and a reduced image to be previewed is formed by the determined thinning number, and the formed reduced image In addition, offset correction and gain correction of the X-ray flat panel detector are performed, and the defective pixel correction is performed on the pixels subjected to these corrections to reduce moire, so that high image quality with reduced moire is achieved. The preview image can be displayed, whereby the quality of shooting can be accurately determined. Furthermore, even in the formation of an auto-trimmed image in which a part of the entire image is automatically cut out and processed, a high-quality auto-trimmed image with reduced moire can be obtained by providing the formed trimmed image with the moire reducing means. Can be acquired.

The figure which shows the structure of the X-ray image diagnostic apparatus of this invention. The flowchart of the process which produces | generates a preview image, and the process which produces | generates all the images. The figure which shows the relationship between a thinning number and the pixel count of the long axis of an X-ray irradiation field. The figure which shows the example which reduces and previews to 2666x2666 X-ray irradiation fields and a thinning number to 4 to 666x666 pixels. The figure which shows the conventional example which reduces a moire when a defective pixel is contained. Explanatory drawing of the reduction | restoration of the moire by this invention when the long axis of an X-ray irradiation field reduces to 666 pixels by 2666 pixels. The figure which shows the example which cuts out a part of image of 2500x2500 pixels, and performs automatic trimming to 666x666 pixels.

Explanation of symbols

  1 subject, 2 X-ray tube (X-ray source), 3 X-ray movable aperture device, 4 X-ray flat panel detector (FPD), 5 grid, 6 X-ray aperture controller, 7 X-ray aperture controller, 8 X Line high voltage device, 9 system control and image processing device, 9a CPU (central processing unit), 9b hard disk, 9c RAM (temporary storage memory), 9d input / output interface, 10 operation console, 10a input device, 10b display device

Claims (3)

An X-ray source for irradiating the subject with X-rays, and an X-ray flat panel detector comprising a plurality of two-dimensionally arranged X-ray detection elements arranged opposite to the X-ray source and detecting transmitted X-rays of the subject An X-ray irradiation area setting means for setting an X-ray irradiation area on the subject, an X-ray diaphragm means for focusing X-rays on the X-ray irradiation area set by the X-ray irradiation area setting means, and the subject The generated scattered X-rays are reduced by thinning out a grid provided in front of the X-ray flat panel detector that prevents the incident X-ray flat panel detector from entering, and pixels of all images detected by the X-ray flat panel detector. Reduced image forming means for forming an image, X-ray plane detector correcting means for correcting the offset, gain, and pixel value of a defective pixel of each pixel of the X-ray plane detector, and pixels of the X-ray plane detector Moire caused by pixel pitch and grid density interference In X-ray image diagnostic apparatus having display means for displaying the moire reduction means and the reduced image reduced, and
The grid includes a plurality of openings opened in one direction in parallel, and the reduced image forming means includes pixels in the same direction as the one direction with respect to pixels of all images detected by the X-ray flat panel detector. The X-ray plane detector correction unit corrects the defective pixel detected in the reduced image, and the moire reduction unit has a predetermined frequency with respect to the reduced image in which the defective pixel is corrected. The reduced image forming means forms a reduced image to be displayed on the display means based on the reduced image that has been subjected to correction of the defective pixels and reduced moire. X-ray image diagnostic apparatus. 2. The X-ray flat panel detector correcting unit corrects the detected defective pixel using a pixel in a reduced image formed by thinning out pixels in the same direction as the one direction. The X-ray diagnostic imaging apparatus described. 3. The filtering process according to claim 1 or 2, wherein moire reduction is performed by performing predetermined weighting on a pixel obtained by correcting the defective pixel, and the weighting weight is a positive value other than 0. An X-ray diagnostic imaging apparatus according to 1.

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