Computed Tomography Radiation Safety

Completed August 2006


Computed tomography (CT) is a powerful tool for the accurate and effective diagnosis and treatment of a variety of conditions because it allows high-resolution three-dimensional images to be acquired very quickly. Therefore, the use of CT has increased substantially over the past decade, resulting in growing concern over the radiation dose from CT. CT technological advances, such as the 64-slice CT scanner released in 2005, have led to new clinical CT applications that could result in further increases in patient radiation dose.

This report discusses the CT radiation dose issues found through a literature review, a CT survey conducted at 20 Ontario healthcare institutions (18 respondents) with 64-slice CT scanners, and interviews with CT experts. The topics that are appraised in this report include methods to reduce radiation dose, testing and inspection of CT scanners, coronary CT angiography radiation issues, and dental CT radiation issues.

Findings show significant variations between Ontario healthcare institutions in several areas of CT radiation protection practices, including the use of CT scanning protocols, the use of CT patient shielding, and CT scanner testing. The findings from this appraisal have provided insights on areas of CT radiation protection that require improvements.

*Update* In 2011, amendments were made to the Healing Arts Radiation Protection Act (HARP Act) to include CT Scanners, thereby improving the controlled and safe regulation of CT scanners in Ontario.

Funding Agency

Ontario Ministry of Health and Long Term Care

Project Sponsor

Dr. Tony Easty

Refereed Proceedings:

Seto, E., Easty, A. (2007, Jun). Current Ontario CT radiation protection issues. Proceedings of the 30th Conference of the Canadian Medical and Biological Engineering Society.

Research Reports:

Seto, E., Easty A. (2006). Computed tomography radiation safety issues in Ontario. Retrieved from: CT_radiation_safety


University Health Network

Medical Advisory Secretariat, Ministry of Health and Long-term Care

Ontario Health Technology Advisory Committee (OHTAC)

Ontario Hospital Association (OHA)

Project Team

Emily Seto

Tony Easty

For information about this project, contact:

Tony Easty