Estimation of the effective dose applied by routine investigation of the chest, heart and abdomen with conventional CT, electron beam tomography and coronary angiography.

Purpose: To compare the effective dose applied by sequential CT (SEQ), spir al CT (SCT), electron beam CT (EBT) and coronary angiography for investigat ions of the chest, abdomen and the heart. Methods: The Alderson Phantom was used to compare the effective dose for all modalities. In addition, the ef fective dose for conventional CT (SEQ and SCT) was estimated with a mathema tical phantom. Results: For CT investigation of the chest and abdomen the d ose 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 r equired the least dose (5,3 mSv and 8,8 mSv, respectively). For coronary ca lcium screening (0.8 mSv) and EBT coronary angiography (1.7 mSv) the dose w as lower than for coronary catheter angiography (3.3 mSv). For conventional CT the difference between the effective dose derived by the mathematical p hantom and by the Alderson phantom was 2% to 20%. Conclusions: For investig ations of the chest and abdomen the effective dose applied by SCT is signif icantly 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.