Toronto Western Hospital this week became the first hospital in the Greater Toronto Area to perform PET-CT rubidium scans on cardiac patients – a type of stress test which measures blood flow to the heart and can quickly and accurately diagnose heart disease.
A new leading-edge PET/CT scanner – the Siemens Biograph Vision – was delivered to Toronto Western Hospital last month and the first patient scan was performed on Wednesday, April 12. The goal is to perform more than 1,800 PET stress tests on high-risk cardiac patients per year.
"Getting a PET stress test means a shorter exam and less overall radiation exposure for our patients," says Dr. Robert Mark Iwanochko, a cardiologist at UHN. "It's more comfortable for the patient and provides a more accurate diagnosis."
The entire exam takes about 45 minutes compared to some cardiac studies that can take up to five hours.
During the process, a radioactive tracer called Rubidium-82 is administered into the body intravenously and quickly taken up by the heart muscle. The positron emission tomography (PET) scan uses the radioactive tracer to highlight areas of abnormal blood flow to the heart muscle.
The computed tomography (CT) scan uses X-rays to create 3D pictures of tissue and organs. This combined imaging technique enables UHN's cardiologists and radiologists to see how the heart is functioning and whether there's a blood supply shortage or any blockages.
"This new service will allow us to assess blood flow to the heart more accurately than conventional methods," says Dr. Ur Metser, Division Head, Molecular Imaging at the Joint Department of Medical Imaging, which includes UHN, Sinai Health and Women's College Hospital.
Images are taken at rest and during stress by giving patients a special medication that creates stress blood flow in the heart muscle, like what happens during exercise.
Zeinul Somani has worked in Nuclear Cardiology as a medical radiation technologist for more than 30 years. He says there's no doubt that the new rubidium program will improve patient care.
"Cardiac rubidium provides enhanced accuracy, less radiation and increased efficiency in the detection of coronary artery disease compared to current modes of nuclear stress testing," he says. "It's also more convenient. Previously, some patients had to come to the hospital for two separate appointments."
The new scanner will be used on eight to 10 patients a day. Some high-risk cases include patients preparing for transplants, patients with known significant heart disease and patients with higher body mass index (BMI).
Patients with ischemic heart disease – narrowed heart arteries – and those at high risk of having a heart attack, could also benefit significantly from this test.
"This program became a reality because of the remarkable teamwork and coordination by teams from JDMI, Nuclear Cardiology, the Peter Munk Cardiac Centre, Biomedical Engineering, Radiation Safety and Facilities Management – Planning, Redevelopment & Operations (FM-PRO)," says Hayley Panet, Senior Manager, Medical Imaging.
"Now our Nuclear Cardiology team will be able to provide even better patient experiences and outcomes."
In addition to supporting cardiac patients, the new scanner creates up to 25 per cent additional capacity for UHN's oncology PET program. PET scans can help diagnose, and determine treatment impact, or disease spread for certain cancers such as lung, lymphoma or breast cancer.
