Low-dose cardiac imaging: reducing exposure but not accuracy

Abstract

Cardiac imaging techniques that use ionizing radiation have become an integral part of current cardiology practice. However, concern has arisen that ionizing radiation exposure, even at the low levels used for medical imaging, is associated with the risk of cancer. From a single diagnostic cardiac imaging procedure, such risks are low. On a population basis, however, malignancies become more likely on account of stochastic effects being more probable as the number of procedures performed increases. In light of this, and owing to professional and industrial commitment to the as low as reasonably achievable (ALARA) principle, over the last decade major strides have been made to reduce radiation dose in cardiac imaging. Dose-reduction strategies have been most pronounced in cardiac computed tomography. This was important since computed tomography has rapidly become a widely used diagnostic alternative to invasive coronary angiography, and initial protocols were associated with relatively high radiation exposures. Advances have also been made in nuclear cardiology and in invasive coronary angiography, and these reductions in patient exposure have all been achieved with maintenance of image quality and accuracy. Improvements in imaging camera technology, image acquisition protocols and image processing have lead to reductions in patient radiation exposure without compromising imaging diagnostic accuracy.

Keywords::

• cardiac catheterization
• cardiac computed tomography
• ionizing radiation
• positron emission tomography
• single-photon emission computed tomography

Acknowledgements

The authors are grateful to FJ Rybicki for his useful comments to explain asymmetrical cone beam processing.

Financial & competing interests disclosure

GR Small is supported by the University of Ottawa Cardiology Research Endowment Fund. BJW Chow is supported by CIHR New Investigator Award #MSH-83718. TD Ruddy is supported by the Vered Chair in Cardiology. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.