| 摘要 |
A diagnostic imaging system includes an x-ray source ( 16 ), which is rotated around an examination region ( 20 ). A subject, disposed on a couch ( 30 ), is translated longitudinally through the examination region ( 20 ). The x-ray source ( 16 ) is pulsed at selected angular location(s), e.g. one or both of 6 and 12 o'clock, to transmit x rays through the subject as it is being translated through the examination region ( 20 ). The transmitted radiation is being detected by a radiation detector ( 22 ) and is reconstructed by an image processor ( 52 ) into a two-dimensional projection pilot scan image. A subject contour is calculated and is used along with the radiation attenuation data by a dose calculator ( 60 ) to determine the minimum radiation dose required to produce a constant quality image. |
