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Radiology Research and Practice
Volume 2013, Article ID 482403, 5 pages
Research Article

Four-Year Cumulative Radiation Exposure in Patients Undergoing Computed Tomography Angiography for Suspected Pulmonary Embolism

1John A. Burns School of Medicine at the University of Hawaii, 651 Ilalo Street Honolulu, HI 96813, USA
2Kaiser Foundation Hospital, Diagnostic Imaging, 3288 Moanalua Road, Honolulu, HI 96819, USA

Received 22 April 2013; Revised 5 July 2013; Accepted 7 July 2013

Academic Editor: Andreas H. Mahnken

Copyright © 2013 Edwin A. Takahashi and Hyo-Chun Yoon. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Purpose. The objective of this study was to determine the estimated effective radiation dose of pulmonary CT angiography (CTA) for suspected pulmonary embolism (PE) contributing to total medical radiation exposure over a 4-year period. Materials and Methods. This investigation retrospectively reviewed 300 patients who presented to the emergency department and received a pulmonary CTA scan for suspected PE. We evaluated these patients' electronic medical record to determine their estimated radiation exposure to CT scans during the following four years. Using DLP to E conversion coefficients, we calculated the cumulative effective radiation dose each subject received. Results. A total of 900 CT scans were reviewed in this study. Pulmonary CTA delivered an average effective radiation dose of 10.7 ± 2.5 mSv and accounted for approximately 65% of subjects' 4-year cumulative medical radiation dose. Only 6.3% of subjects had a positive acute PE according to their radiology report. Conclusion. Pulmonary CTA accounted for the majority of subjects’ medically related effective radiation dose over a 4-year period. With only a minority of subjects having positive findings for acute PE, increased efforts should be made to clinically assess pretest probability before the consideration of imaging.