摘要 |
A moiré fringe difference detector detects a change in moiré fringes occurring in first and second differential phase images between actual radiography and preliminary radiography, and calculates a characteristic amount corresponding to the change. This characteristic amount is a period of an artifact occurring in a corrected differential phase image, which is obtained by subtracting the second differential phase image captured in the preliminary radiography from the first differential phase image captured in the actual radiography. A system controller compares this period with a view size of an X-ray image detector. When the period is smaller than the view size, a message to suggest re-execution of the preliminary radiography is displayed on a monitor. When the preliminary radiography is re-executed, a new second differential phase image obtained by the re-execution of the preliminary radiography is subtracted from the first differential phase image, to produce a new corrected differential phase image. |