Assessment of the effective dose for routine protocols in conventional CT, electron beam CT and coronary angiography

Abstract

To compare the effective dose applied by sequential CT (SEQ), spiral CT (SCT), electron beam CT (EBT) and coronary angiography for investigations of the chest, abdomen and the heart. The Alderson Phantom was used to compare the effective dose for all modalities. In addition, the effective dose for conventional CT (SEQ and SCT) was estimated with a mathematical phantom. For CT investigation of the chest and abdomen the dose was highest for the EBT (11 mSv and 25 mSv, respectively) and slightly lower for the SEQ (7.8 mSv and 21.5 mSv, respectively), whereas spiral CT required the least dose (5.3 mSv and 8.8 mSv, respectively). For coronary calcium screening (0.8 mSv) and EBT coronary angiography (1.7 mSv) the dose was lower than for coronary catheter angiography (3.3 mSv). For conventional CT the difference between the effective dose derived by the mathematical phantom and by the Alderson phantom was 2% to 20%. For investigations of the chest and abdomen the effective dose applied by SCT is significantly lower than that with EBT and SEQ. For investigation of the coronary arteries the effective dose applied by EBT is lower than that for coronary catheter angiography.