The University of Ottawa Heart Institute (UOHI) is setting the stage in what could become a revolution in medical imaging in Canada as it announces striking results in radiation reduction for the diagnosis of cardiovascular disease.
As a result of an initiative that combines optimizing test protocols, state-of-the art equipment, and high-tech software, over 90 per cent of the Ottawa Heart Institute’s Nuclear Cardiology patients are currently receiving half the radiation dosage that they would normally get at most Canadian centres. Radiation reduction techniques have been achieved across all types of radiation-based cardiac imaging—nuclear, CT and PET. The Heart Institute is one of only a few centres in Canada with the in-house expertise to evaluate and clinically apply such advances across these technologies.
The American Society for Nuclear Cardiology has challenged the nuclear cardiology community to reduce radiation exposure below nine millisieverts (mSv) by 2014. The techniques being employed at the Heart Institute regularly reduce exposure to below five mSv, and often much less, putting the heart health centre well ahead of the game.
UOHI clinicians are taking a much more critical look at who they are testing with methods using radiation and making decisions based upon risk and benefit which will only expose patients to radiation who need the test. These responsible practices, along with appropriate use of technology, can reduce radiation exposure by 50 per cent for patients undergoing cardiac imaging in Canada.
The Ottawa Heart Institute uses a combination of powerful and effective tools that enable better diagnosis of cardiovascular disease. The cadmium zinc telluride camera system used for nuclear imaging is a significant innovation and was implemented by Dr. Glenn Wells, Medical Physicist, and Dr Terrence Ruddy in Nuclear Cardiology. The Heart Institute was one of the first centres in the world with this technology in 2009, and it had a major impact on reducing radiation in SPECT perfusion scans, by far the most common cardiac imaging test.
Software is another critical part of imaging, turning the scanner data into three-dimensional pictures of what is found in a patient’s body. The Heart Institute has worked with commercial developers to evaluate and improve new advanced software packages scanners that maintain image quality while using smaller doses of radioactive isotopes.
Over the years, radiation with medical testing has become a concern for our society. Yet often we do not appreciate the significant benefits of highly accurate diagnostic information from techniques which may require very low amounts of medical radiation. Careful and appropriate selection of the right test for the right patient while balancing benefit and risk enables optimal patient care.