Abstract

Abstract- The purpose of the study is to estimate the risk of exposure-induced cancer death (REID) values for computed tomography pulmonary angiography (CTPA) examination. During the study period, 152 patients (77 women and 75 men) were referred for evaluation of suspected pulmonary embolism (PE) with CTPA examination. Organ doses and the effective dose were calculated by means of Monte Carlo simulations for each patient. The REID values were estimated for CTPA, using models developed in the Biological Effects of Ionizing Radiation VII (BEIR VII) – Phase 2 report. The REID values varied from 53 to 248 per million depending on the age and gender of patients. These values were considerably higher for females (173±61 per million) than males (82±26 per million) and higher for younger than older patients. The REID values changed with age at exposure by a about factor of 3–5 between the ages of 18 years and 89 years. Results of this study will help the referring physicians to weigh medical benefits of CTPA in clinical practice against possible risks to justify each CTPA decision in order to reduce unnecessary examinations or use alternative imaging modalities with low risk.