Radiation image capturing apparatus and method of controlling radiation image capturing apparatus

A method of controlling a radiation image capturing apparatus for capturing a radiation image of a subject, comprising the steps of:

• applying a radiation from a radiation source to a region to be imaged of the subject;
• detecting a dose of the radiation which has passed through said region to be imaged at a plurality of radiation dose measuring positions;
• multiplying respective pieces of radiation dose information measured at said radiation dose measuring positions by respective weighting coefficients depending on said radiation dose measuring positions for selecting one or more of said radiation dose measuring positions based on the radiation dose information multiplied by said weighting coefficients;
• and
• determining an exposure control condition for the radiation from said radiation source based on said radiation dose information measured at the selected one or more radiation dose measuring positions, wherein said step of multiplying respective pieces of the radiation dose information comprises:
• a first step of multiplying respective pieces of radiation dose information measured at said radiation dose measuring positions by respective weighting coefficients depending on said radiation dose measuring positions for selecting one or more of predetermined radiation dose measuring positions;
• and
• a second step of comparing the multiplied radiation dose information with radiation dose information before being multiplied in said first step, for selecting one or more of radiation dose measuring positions having radiation dose information within a predetermined range, and
• wherein said step of determining the exposure control condition for the radiation comprises the step of determining the exposure control condition for the radiation from said radiation source based on respective pieces of radiation dose information at respective radiation dose measuring positions that have been selected in said first step and said second step.

An apparatus for capturing a radiation image, for use as a mammographic system for imaging a breast of the subject as said region to be imaged, comprising:

• a radiation source for applying a radiation to a region to be imaged of a subject;
• a radiation dose information detector for detecting a dose of the radiation which has passed through said region to be imaged at a plurality of radiation dose measuring positions, and acquiring respective pieces of radiation dose information for exposure control at said radiation dose measuring positions;
• weighting coefficient allocating means for multiplying the respective pieces of the radiation dose information measured at said radiation dose measuring positions by respective weighting coefficients depending on said radiation dose measuring positions;
• measuring position selecting means for selecting one or more of said radiation dose measuring positions;
• and
• radiation source control means for controlling the dose of the radiation emitted from said radiation source based on the pieces of the radiation dose information measured at the one or more radiation dose measuring positions which are selected by said measuring position selecting means;
• and
• an image capturing base housing said radiation dose information detector therein;
• and
• holding position identifying means for identifying a holding position of the breast on said image capturing base;
• wherein said weighting coefficient allocating means comprises weighting coefficient shifting means for shifting the weighting coefficients by which the pieces of the radiation dose information are to be multiplied along the chest wall of the subject depending on the holding position of the breast which is identified by said holding position identifying means.