Radiographic imaging apparatus, radiographic imaging system, and radiographic imaging method

A radiographic imaging method comprising:

• a signal electric charge accumulation step of accumulating signal electric charges corresponding to amounts of radiation, which is emitted onto a subject and is incident into a plurality of pixels, through a radiographic image detection section having the plurality of pixels, which receives the radiation and detects a radiographic image, and being capable of nondestructively reading data, which indicate the radiographic image, from the pixels;
• a radiographic image reading step of reading the radiographic image by amplifying signals corresponding to the signal electric charges through an amplification section which is capable of amplifying the signals and is capable of varying gain used for reading the radiographic image when the radiographic image is read from the radiographic image detection section;
• a rereading necessity determination step of obtaining an evaluation value for evaluating the radiographic image based on pixel values in a predetermined region of the radiographic image which is read by setting the gain of the amplification section to an initial value, and binning and reading several pixels or performing thinning-out reading, and determining whether or not performing a rereading of the radiographic image is necessary based on the evaluation value;
• a gain calculation step of calculating a new gain of the amplification section used at the time of the rereading based on the evaluation value when the rereading is determined to be necessary from a result of the determination as to whether or not performing the rereading is necessary;
• and
• a rereading step of changing the gain of the amplification section to the calculated gain and rereading the radiographic image using the calculated gain.

A radiographic imaging apparatus comprising:

• a radiographic image detection section that receives radiation, which is emitted from a radiation source and transmitted through a subject, and detects a radiographic image of the subject, the radiographic image detection section having a plurality of pixels, in which signal electric charges corresponding to amounts of the radiation incident are accumulated, and being capable of nondestructively reading data, which indicates the radiographic image based on the amounts of the accumulated signal electric charges, from the pixels;
• an amplification section capable of amplifying signals corresponding to the signal electric charges and capable of varying gain used for reading the radiographic image when the radiographic image is read from the radiographic image detection section;
• an image synthesizing section that outputs the radiographic image, which is read first by the radiographic image detection section, as a synthesized radiographic image when the radiographic image is read first by setting the gain of the amplification section to an initial value, and binning and reading several pixels or performing thinning-out reading, and synthesizes a plurality of the radiographic images, which are read from the radiographic image detection section through the rereading by binning and reading several pixels or performing thinning-out reading, so as to generate a synthesized radiographic image when the plurality of the radiographic images is read;
• a determination section that obtains an evaluation value for evaluating the radiographic image based on pixel values in a predetermined region of the synthesized radiographic image, and determines whether or not performing a rereading of the radiographic image is necessary based on the evaluation value;
• and
• a gain calculation section that calculates a new gain of the amplification section used at the time of the rereading based on the evaluation value when the rereading is determined to be necessary from a result of the determination performed by the determination section,
• wherein the gain of the amplification section is changed to a value of the new gain which is calculated by the gain calculation section, the radiographic image is reread using the changed gain, and a new synthesized radiographic image including the new radiographic image, which is obtained through the rereading, is generated.

A radiographic imaging method comprising:

• a signal electric charge accumulation step of accumulating signal electric charges corresponding to amounts of radiation, which is emitted onto a subject and is incident into a plurality of pixels, through a radiographic image detection section having the plurality of pixels, which receives the radiation and detects a radiographic image, and being capable of nondestructively reading data, which indicates the radiographic image, from the pixels;
• a radiographic image reading step of reading the radiographic image by amplifying signals corresponding to the signal electric charges through an amplification section which is capable of amplifying the signals and is capable of varying gain used for reading the radiographic image when the radiographic image is read from the radiographic image detection section;
• an image synthesis step of outputting the radiographic image, which is read first by the radiographic image detection section, as a synthesized radiographic image when the radiographic image is read first by setting the gain of the amplification section to an initial value, and binning and reading several pixels or performing thinning-out reading, and synthesizing a plurality of the radiographic images, which are read from the radiographic image detection section through the rereading by binning and reading several pixels or performing thinning-out reading, so as to generate a synthesized radiographic image when the plurality of the radiographic images is read;
• a rereading necessity determination step of obtaining an evaluation value for evaluating the radiographic image based on pixel values in a predetermined region of the radiographic image, and determining whether or not performing a rereading of the radiographic image is necessary based on the evaluation value;
• a gain calculation step of calculating a new gain of the amplification section used at the time of the rereading based on the evaluation value when it is determined that the rereading is necessary from a result of the determination as to whether or not it is necessary to perform the rereading;
• a rereading step of changing the gain of the amplification section to the calculated gain and rereading the radiographic image using the changed gain;
• and
• a second image synthesis step of generating a new synthesized radiographic image including the new radiographic image which is obtained through the rereading.