A mammography imaging arrangement for tomosynthesis, which arrangement includes a mammography imaging apparatus which includes - a substantially vertically standing frame part or a frame part which can be fixed to a wall or a ceiling, - an arm structure in connection with said frame part and turnable relative to a horizontal rotation axis, - wherein out of first and second opposite ends of said arm structure, substantially at the first end is placed an X-radiation source comprising a focus point and substantially at the second end is placed an image data receiving means, and - wherein in connection with said second end of the arm structure is additionally arranged a lower tray structure which positions substantially on top of the image data receiving means and wherein to the arm structure is also arranged above said lower tray structure an upper compression plate which is arranged movable along the arm structure, and - control means for moving at least one component of the arm structure and for controlling operation of the image data receiving means, and processing means which include an information recording means and a means for processing information, characterized in that one or more calibration structure component including balls or other small objects which absorb X-radiation is attached - in connection with said second end of the arm structure whereto said lower tray structure is arranged or - to said lower tray structure, a mutual geometry of said balls or other small objects being implemented as a three-dimensional structure, and wherein the one or more calibration structure component and attachment thereof to the apparatus are implemented such that, in tomosynthesis imaging projections of the apparatus, said balls or other small objects or at least a portion of them position in the apparatus into a volume which a radiation beam extending from the focus of the radiation source to the image data receiving means covers, and that information on the mutual geometry of said balls or other small objects is recorded in said processing means. a mammography imaging apparatus which includes - a substantially vertically standing frame part or a frame part which can be fixed to a wall or a ceiling, - an arm structure in connection with said frame part and turnable relative to a horizontal rotation axis, - wherein out of first and second opposite ends of said arm structure, substantially at the first end is placed an X-radiation source comprising a focus point and substantially at the second end is placed an image data receiving means, and - wherein in connection with said second end of the arm structure is additionally arranged a lower tray structure which positions substantially on top of the image data receiving means and wherein to the arm structure is also arranged above said lower tray structure an upper compression plate which is arranged movable along the arm structure, and - control means for moving at least one component of the arm structure and for controlling operation of the image data receiving means, - a substantially vertically standing frame part or a frame part which can be fixed to a wall or a ceiling, - an arm structure in connection with said frame part and turnable relative to a horizontal rotation axis, - wherein out of first and second opposite ends of said arm structure, substantially at the first end is placed an X-radiation source comprising a focus point and substantially at the second end is placed an image data receiving means, and - wherein in connection with said second end of the arm structure is additionally arranged a lower tray structure which positions substantially on top of the image data receiving means and wherein to the arm structure is also arranged above said lower tray structure an upper compression plate which is arranged movable along the arm structure, and - control means for moving at least one component of the arm structure and for controlling operation of the image data receiving means, and processing means which include an information recording means and a means for processing information, characterized in that one or more calibration structure component including balls or other small objects which absorb X-radiation is attached - in connection with said second end of the arm structure whereto said lower tray structure is arranged or - to said lower tray structure, - in connection with said second end of the arm structure whereto said lower tray structure is arranged or - to said lower tray structure, a mutual geometry of said balls or other small objects being implemented as a three-dimensional structure, and wherein the one or more calibration structure component and attachment thereof to the apparatus are implemented such that, in tomosynthesis imaging projections of the apparatus, said balls or other small objects or at least a portion of them position in the apparatus into a volume which a radiation beam extending from the focus of the radiation source to the image data receiving means covers, and that information on the mutual geometry of said balls or other small objects is recorded in said processing means.