Radiation image processing device, radiation image processing method, and radiation image processing program
A processor acquires a first radiation image and a second radiation image, which are acquired by imaging a subject with radiation having different energy distributions, derives a body thickness of the subject based on at least one of the first radiation image or the second radiation image, specifies a soft region of the subject in the first radiation image and the second radiation image, derives a first attenuation coefficient and a second attenuation coefficient, which correspond to the body thickness in the soft region, for each of the first radiation image and the second radiation image, and derives an attenuation ratio, which is a ratio according to the body thickness between the first attenuation coefficient and the second attenuation coefficient, as an indicator representing a quality of the radiation.
1 . A radiography system comprising:
an imaging apparatus including:
a radiation source that emits radiation;
a first radiation detector that generates a first radiation image; and
a second radiation detector that generates a second radiation image, the first radiation image and the second radiation image being acquired by imaging a subject with radiation having different energy distributions; and
a radiation image processing device including at least one processor,
wherein the processor
acquires the first radiation image and the second radiation image,
derives a body thickness of the subject based on at least one of the first radiation image or the second radiation image,
specifies a soft region of the subject in the first radiation image and the second radiation image,
derives a first attenuation coefficient and a second attenuation coefficient, which correspond to the body thickness in the soft region, for each of the first radiation image and the second radiation image,
derives an indicator representing a quality of the radiation, the indicator being an attenuation ratio of the first attenuation coefficient to the second attenuation coefficient according to the body thickness,
determines whether or not a difference between the indicator and a standard indicator exceeds a predetermined threshold value, and
displays a warning on a display in a case in which a negative determination is made in the determination.
2 . The radiography system according to claim 1 ,
wherein the processor
derives a first primary ray image and a second primary ray image by removing scattered ray components of the first radiation image and the second radiation image, and
derives the first attenuation coefficient and the second attenuation coefficient based on the first primary ray image and the second primary ray image.
3 . The radiography system according to claim 1 ,
wherein the indicator represents a relationship between the body thickness and the attenuation ratio.
4 . The radiography system according to claim 1 ,
wherein the processor derives the first attenuation coefficient and the second attenuation coefficient based on pixel values of the soft region in a first primary ray image and a second primary ray image, the first primary ray image being obtained by removing a scattered ray component from the first radiation image, and the second primary ray image being obtained by removing the scattered ray component from the second radiation image.
5 . The radiography system according to claim 2 ,
wherein the indicator represents a relationship between the body thickness and the attenuation ratio.
6 . A radiation image processing method for a radiography system comprising:
an imaging apparatus including:
a radiation source that emits radiation;
a first radiation detector that generates a first radiation image; and
a second radiation detector that generates a second radiation image, the first radiation image and the second radiation image being acquired by imaging a subject with radiation having different energy distributions; and
a radiation image processing device,
the method comprising:
acquiring the first radiation image and the second radiation image;
deriving a body thickness of the subject based on at least one of the first radiation image or the second radiation image;
specifying a soft region of the subject in the first radiation image and the second radiation image;
deriving a first attenuation coefficient and a second attenuation coefficient, which correspond to the body thickness in the soft region, for each of the first radiation image and the second radiation image;
deriving an indicator representing a quality of the radiation, the indicator being an attenuation ratio of the first attenuation coefficient to the second attenuation coefficient according to the body thickness;
determining whether or not a difference between the indicator and a standard indicator exceeds a predetermined threshold value; and
displaying a warning on a display in a case in which a negative determination is made in the determination.
7 . A non-transitory computer-readable storage medium that stores a radiation image processing program for a radiography system comprising:
an imaging apparatus including:
a radiation source that emits radiation;
a first radiation detector that generates a first radiation image; and
a second radiation detector that generates a second radiation image, the first radiation image and the second radiation image being acquired by imaging a subject with radiation having different energy distributions; and
a radiation image processing device,
the radiation image processing program causing a computer to execute:
a procedure of acquiring the first radiation image and the second radiation image;
a procedure of deriving a body thickness of the subject based on at least one of the first radiation image or the second radiation image;
a procedure of specifying a soft region of the subject in the first radiation image and the second radiation image;
a procedure of deriving a first attenuation coefficient and a second attenuation coefficient, which correspond to the body thickness in the soft region, for each of the first radiation image and the second radiation image;
a procedure of deriving an indicator representing a quality of the radiation, the indicator being an attenuation ratio of the first attenuation coefficient to the second attenuation coefficient according to the body thickness;
a procedure of determining whether or not a difference between the indicator and a standard indicator exceeds a predetermined threshold value; and
a procedure of displaying a warning on a display in a case in which a negative determination is made in the determination.