The Radiologist’s Role in Radiation Exposure during Chest Computed Tomography

Abstract

Stochastic somatic and genetic effects of ionising radiation exposure are recognised to be biologically significant. Effective dose is the single best parameter to estimate the biologic impact. Depending on the geographic location, natural population exposure in central Europe is estimated to be around 3 mSv/year and medical exposure 1–1.5 mSv/year (Table 1). More important, the relative contribution of 25–50% [1, 2, 3, 4] of CT to the medical exposure of the population is increasing due both to a still increasing number of studies and a decreasing contribution by non-computed tomography (CT) studies (caused by decreasing frequency and individual dose due to more and more pulsed fluoroscopy). Individual exposure through chest examinations has a wide range between around 0.05 mSv for a single posteroanterior chest radiograph and more than 20 mSv for cardiac intervention (Table 2). CT is characterised by an extraordinary medical usefulness but also a relatively high individual exposure. This fact makes it important both for the medical doctor requesting a study and the radiologist performing it to be aware of the exposure, to check for alternatives without ionising radiation and to reduce exposure during CT studies to the very minimum needed medically.