KR20250046994A - X-ray detection apparatus with scintillator sensitivity correction function and schintillator sensitivity correction method thereof - Google Patents

Abstract

An X-ray detection device having a scintillator sensitivity correction function according to a preferred embodiment of the present invention includes an image acquisition unit which irradiates an X-ray to a predetermined target object to obtain an X-ray image, an offset correction unit which receives the X-ray image from the image acquisition unit and removes an offset component of the X-ray image using offset correction data prepared in advance, a first sensitivity correction unit which performs sensitivity correction of the X-ray image from which the offset component has been removed using a gain map prepared in advance, and a second sensitivity correction unit which corrects sensitivity values for each pixel of the sensitivity-corrected X-ray image received from the first sensitivity correction unit.

Description

X-ray detection apparatus having scintillator sensitivity correction function and scintillator sensitivity correction method thereof {X-RAY DETECTION APPARATUS WITH SCINTILLATOR SENSITIVITY CORRECTION FUNCTION AND SCHINTILLATOR SENSITIVITY CORRECTION METHOD THEREOF}

The present invention relates to an X-ray detection device having a scintillator sensitivity correction function and a scintillator sensitivity correction method thereof.

Medical imaging technology using X-rays is a technique that creates images of the inside of the human body by utilizing the fact that the degree of attenuation varies depending on the attenuation coefficient of the material forming the object when X-rays pass through the object. Since X-rays can visualize the anatomical structure of the human body, they are used to identify pathological phenomena, diseases, or abnormal anatomical structures inside the human body.

The most commonly used X-ray detectors are the intensifier-type XRII (X-Ray Image Intensifier) and the flat panel X-ray detector (FPXD).

The flat panel detector has a structure in which a scintillator is applied to the input surface of a semiconductor element, so there is almost no image distortion and no optical system or separate camera is required.

Flat panel detectors use fluorescent materials such as CsI or Gadox to convert X-rays into visible light. Medical flat panel detectors mainly use CsI, which has a high conversion rate, to reduce patient exposure.

However, the flat panel detector using CsI has a problem in that the visible light conversion rate decreases due to the decrease in scintillator sensitivity as the radiation dose from X-ray detection accumulates. In particular, when a collimator is used to irradiate X-rays only to a specific area, the scintillator sensitivity level of the specific area decreases, resulting in ring artifacts in imaging such as CBCT (ConBeam Computed Tomography).

These ring artifacts can be resolved through sensitivity calibration, but there is a problem that it is difficult to continuously perform sensitivity calibration.

Republic of Korea Patent No. 10-2447358

Accordingly, the present invention has been made in consideration of the above circumstances, and aims to provide an X-ray detection device having a scintillator sensitivity correction function that performs offset correction and sensitivity correction of an X-ray image, and also corrects the sensitivity value of each pixel that has decreased according to the accumulated radiation dose using a sensitivity correction map, and a scintillator sensitivity correction method thereof.

According to a preferred embodiment of the present invention for achieving the above object, an X-ray detection device having a scintillator sensitivity correction function includes: an image acquisition unit which irradiates an X-ray to a predetermined target object to obtain an X-ray image; an offset correction unit which receives the X-ray image from the image acquisition unit and removes an offset component of the X-ray image using offset correction data prepared in advance; a first sensitivity correction unit which performs sensitivity correction of the X-ray image from which the offset component has been removed using a gain map prepared in advance; and a second sensitivity correction unit which corrects a sensitivity value for each pixel of the sensitivity-corrected X-ray image received from the first sensitivity correction unit.

When an X-ray activation signal is transmitted from the outside, the device may further include a radiation dose accumulator that receives an offset-corrected X-ray image from the offset correction unit.

The above radiation dose accumulation unit accumulates and stores pixel-by-pixel sensitivity values of the received X-ray image, and can convert the accumulated pixel-by-pixel sensitivity values into pixel-by-pixel accumulated radiation doses using a pre-prepared sensitivity reduction graph.

The method may further include a sensitivity reduction ratio calculation unit that calculates a sensitivity reduction ratio per pixel using the accumulated radiation dose per pixel.

The method may further include a compensation map generation unit that generates a sensitivity compensation map using the pixel-by-pixel sensitivity reduction ratio.

The second sensitivity correction unit can correct a pixel-by-pixel sensitivity value reduced according to an accumulated radiation dose by using the sensitivity-corrected X-ray image received from the first sensitivity correction unit and the sensitivity correction map received from the correction map generation unit.

In order to achieve the above object, a method for correcting the sensitivity of a scintillator of an X-ray detection device according to a preferred embodiment of the present invention comprises: an image obtaining step in which an image obtaining unit irradiates an X-ray to a predetermined target object to obtain an X-ray image; an offset correction step in which an offset correction unit receives the X-ray image from the image obtaining unit and removes an offset component of the X-ray image using data for offset correction prepared in advance; a first sensitivity correction step in which a first sensitivity correction unit performs sensitivity correction of the X-ray image from which the offset component has been removed using a gain map prepared in advance; and a second sensitivity correction step in which a second sensitivity correction unit corrects a sensitivity value for each pixel of the sensitivity-corrected X-ray image received from the first sensitivity correction unit.

The method may further include an accumulated radiation dose calculation step of accumulating and storing pixel-wise sensitivity values of the X-ray image received by the radiation dose accumulation unit, and converting the accumulated pixel-wise sensitivity values into pixel-wise accumulated radiation dose using a pre-prepared sensitivity reduction graph.

The sensitivity reduction ratio calculation unit may further include a sensitivity reduction ratio calculation step in which the sensitivity reduction ratio calculation unit calculates the sensitivity reduction ratio for each pixel using the accumulated radiation dose for each pixel.

The second sensitivity correction step can correct the pixel-by-pixel sensitivity value reduced according to the accumulated radiation dose by using a sensitivity correction map prepared based on the sensitivity-corrected X-ray image and the pixel-by-pixel sensitivity reduction ratio.

According to an X-ray detection device having a scintillator sensitivity correction function and a scintillator sensitivity correction method thereof according to a preferred embodiment of the present invention, the lifespan of the X-ray detection performance is increased by performing offset correction and sensitivity correction of an X-ray image and correcting the sensitivity value of each pixel that has deteriorated according to the accumulated radiation dose using a sensitivity correction map.

Additionally, it has the effect of increasing the gain compensation cycle.

FIG. 1 is a block diagram of an X-ray detection device having a scintillator sensitivity correction function according to a preferred embodiment of the present invention.
FIG. 2 is a drawing showing an example of a sensitivity reduction graph according to the relationship between radiation dose and sensitivity according to a preferred embodiment of the present invention.
FIG. 3 is a flowchart of a method for correcting the scintillator sensitivity of an X-ray detection device according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. First, when adding reference symbols to components of each drawing, it should be noted that the same components are given the same symbols as much as possible even if they are shown in different drawings. In addition, although preferred embodiments of the present invention will be described below, it should be understood that the technical idea of the present invention is not limited or restricted thereto and can be modified and implemented in various ways by those skilled in the art.

FIG. 1 is a block diagram of an X-ray detection device having a scintillator sensitivity correction function according to a preferred embodiment of the present invention.

Referring to FIG. 1, an X-ray detection device (100) equipped with a scintillator sensitivity correction function according to a preferred embodiment of the present invention is characterized by performing offset correction and sensitivity correction of an X-ray image, and correcting a sensitivity value per pixel that has decreased according to an accumulated radiation dose using a sensitivity correction map.

An X-ray detection device (100) equipped with a scintillator sensitivity correction function according to a preferred embodiment of the present invention is a flat panel detector, and has a structure in which a scintillator is applied to a semiconductor element input surface, so that there is almost no image distortion. In this case, the scintillator may be any one of CsI or Gadox.

An X-ray detection device (100) equipped with a scintillator sensitivity correction function according to a preferred embodiment of the present invention includes an image acquisition unit (110), an offset correction unit (120), a first sensitivity correction unit (130), a radiation dose accumulation unit (140), a sensitivity reduction ratio calculation unit (150), a correction map generation unit (160), and a second sensitivity correction unit (170).

The image acquisition unit (110) can acquire an X-ray image by irradiating an X-ray to a predetermined target object. Here, the X-ray can be irradiated to the target object by a separate X-ray generating device (not shown). The target object can include a human body requiring medical examination. The captured image can be transmitted to the image acquisition unit (110).

The offset correction unit (120) can perform offset correction to remove offset components from an X-ray image using data for offset correction prepared in advance. The data for offset correction can be updated to the latest value before X-ray photography.

The first sensitivity correction unit (130) can perform sensitivity correction of an offset-corrected X-ray image using a pre-prepared gain map.

The radiation dose accumulation unit (140) can receive a separate X-ray activation signal from the outside to determine whether or not to perform X-ray irradiation. When the radiation dose accumulation unit (140) receives the X-ray activation signal, it can receive an offset-corrected X-ray image from the offset correction unit (120).

The radiation dose accumulation unit (140) can accumulate and store the sensitivity values for each pixel of the received X-ray image. The radiation dose accumulation unit (140) can convert the accumulated sensitivity values for each pixel into accumulated radiation dose for each pixel using a pre-prepared sensitivity reduction graph. When using an AOI (Area Of Interest), the radiation dose accumulation unit (140) can accumulate the radiation dose only for pixels at a corresponding location based on the overall size of the X-ray image.

The sensitivity reduction ratio calculation unit (150) receives the accumulated radiation dose per pixel from the radiation dose accumulation unit (140) and can calculate the sensitivity reduction ratio per pixel using the accumulated radiation dose per pixel.

Since the sensitivity of each pixel is different depending on the binning mode, the sensitivity reduction ratio of each pixel according to the accumulated radiation dose can be converted into a digital level value according to the basic mode (Non Binning mode).

The compensation map generation unit (160) can generate and store a sensitivity compensation map using the sensitivity reduction ratio per pixel calculated by the sensitivity reduction ratio calculation unit (150).

The second sensitivity correction unit (170) can correct the pixel sensitivity value of the X-ray image that has been reduced according to the accumulated radiation dose by using the sensitivity-corrected X-ray image received from the first sensitivity correction unit (130) and the sensitivity correction map received from the correction map generation unit (160).

FIG. 2 is a drawing showing an example of a sensitivity reduction graph according to the relationship between radiation dose and sensitivity according to a preferred embodiment of the present invention.

Referring to Fig. 2, a sensitivity reduction graph according to the relationship between the accumulated dose and sensitivity for each of the three scintillator types (Type 1, Type 2, Type 3) can be confirmed. Here, the three scintillator types (Type 1, Type 2, Type 3) can be appropriately selected according to the user's needs. This sensitivity reduction graph can be used to convert the accumulated pixel-by-pixel sensitivity value into the accumulated pixel-by-pixel radiation dose.

The compensation map generation unit (160) can generate and store a sensitivity compensation map using a pixel-by-pixel sensitivity reduction ratio prepared based on the converted pixel-by-pixel accumulated radiation dose.

FIG. 3 is a flowchart of a method for correcting the scintillator sensitivity of an X-ray detection device according to a preferred embodiment of the present invention.

Referring to FIG. 3, a method for correcting the scintillator sensitivity of an X-ray detection device according to a preferred embodiment of the present invention is characterized by performing offset correction and sensitivity correction of an X-ray image, and correcting a sensitivity value per pixel that has decreased according to an accumulated radiation dose using a sensitivity correction map.

Referring to FIG. 3, a method for calibrating the scintillator sensitivity of an X-ray detection device according to a preferred embodiment of the present invention may include an image acquisition step (S310), an offset correction step (S320), a first sensitivity correction step (S330), a cumulative radiation dose calculation step (S340), a sensitivity reduction ratio calculation step (S350), and a second sensitivity correction step (S360).

In the image acquisition step (S310), the image acquisition unit (110) can irradiate an X-ray to a predetermined target object to acquire an X-ray image. Here, the X-ray can be irradiated to the target object by a separate X-ray generating device (not shown). The target object can include a human body requiring a medical examination. The captured image can be transmitted to the image acquisition unit (110).

In the offset correction step (S320), the offset correction unit (120) can perform offset correction to remove an offset component from an X-ray image using data for offset correction prepared in advance. The data for offset correction can be updated to the latest value before X-ray photography.

In the first sensitivity correction step (S330), the first sensitivity correction unit (130) can perform sensitivity correction of an offset-corrected X-ray image using a pre-prepared gain map.

In the cumulative radiation dose calculation step (S340), the radiation dose accumulation unit (140) can receive a separate X-ray activation signal from the outside to determine whether or not to perform X-ray irradiation. When the radiation dose accumulation unit (140) receives the X-ray activation signal, it can receive an offset-corrected X-ray image from the offset correction unit (120).

The radiation dose accumulation unit (140) can accumulate and store the sensitivity values for each pixel of the received X-ray image. The radiation dose accumulation unit (140) can convert the accumulated sensitivity values for each pixel into accumulated radiation dose for each pixel using a pre-prepared sensitivity reduction graph. When using an AOI (Area Of Interest), the radiation dose accumulation unit (140) can accumulate the radiation dose only for pixels at a corresponding location based on the overall size of the X-ray image.

In the sensitivity reduction ratio calculation step (S350), the sensitivity reduction ratio calculation unit (150) can receive the accumulated radiation dose per pixel from the radiation dose accumulation unit (140) and calculate the sensitivity reduction ratio per pixel using the accumulated radiation dose per pixel. Since the sensitivity per pixel is different depending on the binning mode, the sensitivity reduction ratio per pixel according to the accumulated radiation dose can be converted into a digital level value according to the basic mode (Non Binning mode).

In the second sensitivity correction step (S360), the second sensitivity correction unit (170) can correct the pixel sensitivity value of the X-ray image reduced according to the accumulated radiation dose by using the sensitivity-corrected X-ray image received from the first sensitivity correction unit (130) and the sensitivity correction map received from the correction map generation unit (160).

The above description is merely an example of the technical idea of the present invention, and those skilled in the art will appreciate that various modifications, changes, and substitutions may be made without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention, but rather to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings.

The steps and/or operations according to the present invention may occur simultaneously in other embodiments, in a different order, in parallel, for different epochs, etc., as would be understood by one of ordinary skill in the art.

In some embodiments, some or all of the steps and/or operations may be implemented or performed at least in part using instructions, programs, interactive data structures, clients and/or servers stored on one or more non-transitory computer-readable media. The one or more non-transitory computer-readable media may be, for example, software, firmware, hardware, and/or any combination thereof. Furthermore, the functionality of a "module" discussed herein may be implemented in software, firmware, hardware, and/or any combination thereof.

100: X-ray detection device
110: Image acquisition section
120: Offset compensation section
130: 1st sensitivity compensation unit
140: Accumulated radiation dose
150: Sensitivity reduction ratio calculation section
160: Compensation map generation section
170: Second sensitivity compensation unit

Claims (10)

An image acquisition unit that acquires an X-ray image by irradiating an X-ray to a target object;
An offset correction unit that receives the X-ray image from the image acquisition unit and removes the offset component of the X-ray image using data for offset correction prepared in advance;
A first sensitivity correction unit that performs sensitivity correction of the X-ray image from which the offset component has been removed using a pre-prepared gain map; and
A second sensitivity correction unit for correcting the sensitivity value per pixel of the sensitivity-corrected X-ray image received from the first sensitivity correction unit;
An X-ray detection device having a scintillator sensitivity correction function including: In paragraph 1,
A radiation dose accumulator that receives an offset-corrected X-ray image from the offset correction unit when an X-ray activation signal is transmitted from the outside;
An X-ray detection device having a scintillator sensitivity correction function, characterized in that it further includes. In the second paragraph,
The above radiation dose accumulation part is,
An X-ray detection device having a scintillator sensitivity correction function, characterized in that the pixel-by-pixel sensitivity values of the received X-ray image are accumulated and stored, and the accumulated pixel-by-pixel sensitivity values are converted into pixel-by-pixel accumulated radiation dose using a pre-prepared sensitivity reduction graph. In the third paragraph,
A sensitivity reduction ratio calculation unit that calculates a sensitivity reduction ratio for each pixel using the accumulated radiation dose for each pixel;
An X-ray detection device having a scintillator sensitivity correction function, characterized in that it further includes. In paragraph 4,
A compensation map generation unit that generates a sensitivity compensation map using the sensitivity reduction ratio per pixel;
An X-ray detection device having a scintillator sensitivity correction function, characterized in that it further includes. In paragraph 5,
The above second sensitivity compensation unit,
An X-ray detection device having a scintillator sensitivity correction function, characterized in that the sensitivity-corrected X-ray image received from the first sensitivity correction unit and the sensitivity correction map received from the correction map generation unit are used to correct the pixel-by-pixel sensitivity value decreased according to the accumulated radiation dose. An image acquisition step in which an image acquisition unit acquires an X-ray image by irradiating an X-ray to a predetermined target object;
An offset correction step in which an offset correction unit receives the X-ray image from the image acquisition unit and removes an offset component of the X-ray image using data for offset correction prepared in advance;
A first sensitivity correction step in which a first sensitivity correction unit performs sensitivity correction of the X-ray image from which the offset component has been removed using a gain map prepared in advance; and
A second sensitivity correction step in which a second sensitivity correction unit corrects the sensitivity value per pixel of the sensitivity-corrected X-ray image received from the first sensitivity correction unit;
A method for calibrating the scintillator sensitivity of an X-ray detection device including a . In paragraph 7,
An accumulated radiation dose calculation step of accumulating and storing the pixel-by-pixel sensitivity values of the X-ray images received by the radiation dose accumulation unit, and converting the accumulated pixel-by-pixel sensitivity values into pixel-by-pixel accumulated radiation dose using a pre-prepared sensitivity reduction graph;
A method for correcting the scintillator sensitivity of an X-ray detection device, characterized in that it further includes a. In Article 8,
A sensitivity reduction ratio calculation step in which a sensitivity reduction ratio calculation unit calculates a sensitivity reduction ratio for each pixel using the accumulated radiation dose for each pixel;
A method for correcting the scintillator sensitivity of an X-ray detection device, characterized in that it further includes a. In Article 9,
The second sensitivity correction step is,
A method for correcting the sensitivity of a scintillator in an X-ray detection device, characterized in that the sensitivity value for each pixel, which has been reduced according to the accumulated radiation dose, is corrected using a sensitivity correction map prepared based on the sensitivity-corrected X-ray image and the sensitivity reduction ratio for each pixel.

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