Radiation exposure associated with imaging of the chest - Comparison of different radiographic and computed tomography techniques

Exposure to ionizing radiation due to radiologic examinations is associated with the risk of induction of malignancy. This has to be balanced against the potential benefits of detection of a malignant tumor with radiologic ex aminations. For comparison of radiation exposure levels from different sources, the con cept of effective dose equivalent was developed, which is used to assess an individual's risk of developing malignancy. Effective dose equivalent rang es from 0.06 to 0.25 millisieverts (mSv) with chest radiography in 2 views, 3-27 mSv with computed tomography (CT) using conventional examination para meters, and 0.3-0.55 mSv using low dose CT settings. These Values can be co mpared with radiation exposure levels from natural sources (on average 2.4 mSv per year in Germany). Based on considerations by the International Commission on Radiological Pro tection, it can be expected that radiation exposure with an effective dose equivalent of 1 mSv would lead to 5 additional malignancies in 100,000 indi viduals exposed. Cancer 2000;89:2457-60. (C) 2000 American Cancer Society.