Adaptive dose modulation during CT scanning

摘要

In a method for reducing a radiation dose in an x-ray CT (computed tomography) system, a maximum x-ray attenuation per projection is computed for every projection or for every nth projection and the measured angular attenuation profile for a last half rotation of the x-ray beam around a subject is stored, an extrapolation method is conducted for computing an extrapolated attenuation profile for a next half rotation based on the measured angular attenuation profile for the last half rotation, and a process is conducted for setting a dose level for the x-ray beam for a next projection, based on the extrapolated attenuation profile. The x-ray beam can be modulated, with characteristics of the beam modulation being set or controlled dependent on the extrapolated attenuation profile.