Attenuation‐based estimation of patient size for the purpose of size specific dose estimation in CT. Part I. Development and validation of methods using the CT image

Patient attenuation can be quantified in terms of the diameter of a water cylinder that absorbs same average dose as the irradiated cross section of the patient. The linear dependence of A(w) on object attenuation makes it straightforward to calculate A(w) from a CT image on most operator consoles or clinical workstations.