Comparative dosimetry of radiography, tomosynthesis, and CT for chest imaging across 59 adult patients
There are three main x-ray based modalities for imaging the thorax: radiography, tomosynthesis, and CT. CT provides perhaps the highest level of feature resolution but at notably higher radiation dose. To implement the ALARA (as low as reasonable achievable) principle in making an appropriate choice between standard chest projection imaging, tomosynthesis, and CT to achieve the lowest possible dose to patients, the effective doses and risk indices for each modality should be accurately known. In this study, we employed 59 computational anthropomorphic male and female extended cardiac-torso (XCAT) adult phantoms and a Monte Carlo simulation program (PENELOPE, version 2006, Universitat de Barcelona, Spain). Effective dose and risk index was estimated for a clinical radiography system enabling to conduct chest radiography and tomosynthesis sweep (Definium 8000, Volume RAD, GE Healthcare) and a clinical CT system (LightSpeed VCT, GE Healthcare). It was found that the absolute effective dose and risk index increased greatly with increasing patient size for CT, while these two dose metrics only increased slightly for radiography and tomosynthesis. This suggests that it is important to specify patient size when comparing radiation dose across imaging modalities. © 2013 SPIE.
