Radiation image detecting device, radiation imaging system and operation method thereof

A radiation imaging system comprising:

• (A) a radiation source for applying radiation to an object;
• (B) a source control device for controlling the operation of said radiation source;
• and
• (C) a radiation image detecting device having an image detector formed with an imaging area, and said radiation image detecting device being used together with a grid capable of being disposed in front of said image detector, said radiation image detecting device including:
• said grid having strip-shaped radiation transparent layers and radiation absorbing layers extending in a first direction to remove scattered rays produced upon radiation passing through an object, a plurality of said radiation transparent layers and said radiation absorbing layers being formed at a grid pitch G alternately in a second direction orthogonal to said first direction;
• said imaging area being provided with a plurality of pixels arrayed in said second direction at a pixel pitch Δ and a plurality of dose measurement sensors, said plurality of pixels accumulating electric charge in accordance with a received radiation dose in a readable manner to detect a radiographic image of said object, said plurality of dose measurement sensors measuring said received radiation dose;
• and
• in at least a group of dose measurement sensors out of said plurality of dose measurement sensors, a [C/D] number of dose measurement sensors being disposed or chosen in the following cycle Z:
• condition:
• Z=(R×C)±D
• wherein,
• C represents a cycle of a repetition pattern appearing in said second direction in a radiographic image of said grid, and is represented in units of the number of said pixels,
• R represents a natural number of 0 or more,
• D represents an integer less than said cycle C, and
• [C/D] represents a maximum integer equal to or less than C/D.

An operation method of a radiation imaging system including:

• (A) a radiation source for applying radiation to an object;
• (B) a source control device for controlling the operation of said radiation source;
• and
• (C) a radiation image detecting device having an image detector formed with an imaging area, and said radiation image detecting device being used together with a grid capable of being disposed in front of said image detector, said radiation image detecting device including:
• said grid having strip-shaped radiation transparent layers and radiation absorbing layers extending in a first direction to remove scattered rays produced upon radiation passing through an object, a plurality of said radiation transparent layers and said radiation absorbing layers being formed at a grid pitch G alternately in a second direction orthogonal to said first direction;
• said imaging area being provided with a plurality of pixels arrayed in said second direction at a pixel pitch Δ and a plurality of dose measurement sensors, said plurality of pixels accumulating electric charge in accordance with a received radiation dose in a readable manner to detect a radiographic image of said object, said plurality of dose measurement sensors measuring said received radiation dose;
• and
• in at least a group of dose measurement sensors out of said plurality of dose measurement sensors, a [C/D] number of dose measurement sensors being disposed or chosen in the following cycle Z:
• condition:
• Z=(R×C)±D
• wherein,
• C represents a cycle of a repetition pattern appearing in said second direction in a radiographic image of said grid, and is represented in units of the number of said pixels,
• R represents a natural number of 0 or more,
• D represents an integer less than said cycle C, and
• [C/D] represents a maximum integer equal to or less than C/D;
• said operation method comprising the steps of:
• (i) measuring a radiation dose by at least said group of dose measurement sensors out of said plurality of dose measurement sensors;
• (ii) judging whether or not a total radiation dose being an integrated value of each of said radiation doses measured by said group of dose measurement sensors or an average value of said total radiation doses has reached a target dose;
• and
• (iii) stopping the operation of said radiation source to stop emission of said radiation, at the instant when said total radiation dose or said average value reaches said target dose.