Reduced blood flow to the heart muscle is the leading cause of death in the Western world, and now researchers are first to develop a reliable MRI with the ability of diagnosing heart disease.
An international team led by scientists from Lawson Health Research Institute and Cedars-Sinai Medical Center are the first to show that non-invasive cardiac functional Magnetic Resonance Imaging (MRI) can be used when it comes to diagnosing heart disease, measuring how the heart uses oxygen for both healthy patients and those with heart disease.
Measuring blood flow to the heart
Currently, the diagnostic tests available to measure blood flow to the heart require injection of radioactive chemicals or contrast agents that change the MRI signal and detect the presence of disease. There are small but finite associated risks and it is not recommended for a variety of patients including those with poor kidney function. More than 500,000 tests are performed each year in Canada.
Dr Frank Prato, Lawson Assistant Director for Imaging, explains: “This new method, cardiac functional MRI (cfMRI), does not require needles or chemicals being injected into the body.”
“It eliminates the existing risks and can be used on all patients.”
Using MRI to help when diagnosing heart disease
The team included researchers from Lawson, Cedars-Sinai Medical Center and University of California, USA, University Health Network and the University of Toronto, Canada, University of Edinburgh and King’s College, UK, and Siemens Healthineers.
“Our discovery shows that we can use MRI to study heart muscle activity,” explains Prato. “We’ve been successful in using a pre-clinical model and now we are preparing to show this can be used to accurately detect heart disease in patients.”
Repeat exposure to carbon dioxide is used to test how well the heart’s blood vessels are working to deliver oxygen to the muscle. A breathing machine changes the concentration of carbon dioxide in the blood. This change should result in a change in blood flow to the heart but does not happen when disease is present. The cfMRI method reliably detects whether these changes are present.
“Using MRI will not only be safer than present methods, but also provide more detailed information and much earlier on in the disease process,” adds Prato. Following initial testing through clinical trials, he sees this being used with patients clinically within a few years.
A lot to explore in the world of oxygen in health and disease
In addition to studying coronary artery disease, the method could be used in other cases where heart blood flow is affected such as the effects of a heart attack or damages to the heart during cancer treatment.
Due to its minimal risk, this new tool could be safely used with the same patient multiple times to better select the right treatment and find out early on if it is working.
Prato notes that “with this new window into how the heart works, we have a lot to explore when it comes to the role of oxygen in health and disease.”
