Patent ID: 7317781

Claim:
An image processing device comprising: an extraction unit configured to determine and extract an area necessary for reconstruction based on a geometric condition of a tomographic image slice position to be reconstructed, in plural projection images; and a reconstruction processing unit configured to execute a reconstruction process by using the area extracted by said extraction unit, wherein, in a case where it is assumed that a difference in height between the center of an area being the target of the reconstruction and an X-ray source is Z i , a distance in a horizontal direction between the center of the area being the target of the reconstruction and the X-ray source is D, a distance in a horizontal direction between the center of the area being the target of the reconstruction and a sensor is S, and a radius of the area being the target of the reconstruction is R, said extraction unit extracts, as the area necessary for reconstruction, the area from Z i ×(D+S)/(D+R) to Z i +(D+S)/(D−R) in height, based on the location of the X-ray source and the sensor.