What is a Cardiac MRI?
Cardiac MRI relies on a magnetic field and radiofrequency waves to develop detailed cardiovascular system images. This non-invasive test is increasingly used to examine heart and blood vessels and diagnose heart disease. Unlike a CT scan, the cardiac MRI does not use ionizing radiation. Therefore, it is a safer alternative for pregnant women.
What are some frequent uses of the procedure?
A cardiac MRI can diagnose a broad range of heart conditions such as coronary heart disease, congenital heart disease, heart valve disease, and cardiac tumors. It also detects inherited heart conditions like hypertrophic or dilated cardiomyopathy. A cardiac MRI is usually recommended for complex cases and identifies diseases where other scans have been ambiguous. It gives high-resolution images and very accurate measurements of the heart. It is safe, which is essential as some patients, like those with complex inherited heart disease, need numerous scans over time.
Cardiac MRI helps doctors see if the heart is damaged from a heart attack or inadequate blood flow to the cardiac muscle due to narrowed or blocked arteries. It also diagnoses stroke risk factors, aneurysm, and other brain abnormalities.
How should I prepare?
Before the MRI, tell your doctor if you have a pacemaker. Based on the kind of pacemaker, your doctor might propose another testing method, such as an abdominal CT scan. However, some pacemaker models can be differently programmed before an MRI, so they aren’t disturbed during the scan. Since the MRI uses magnets, it can attract metals. Hence inform your doctor of any kind of metal implant from your prior surgeries. These may involve:
- artificial heart valves
- clips and pins
- plates and screws
- stent objects
Sometimes, a special dye is used to highlight your heart, a gadolinium-based contrast agent administered through an IV. Allergic reactions to the dye are occasional. However, your doctor must always be informed about any concerns or a history of allergic reactions you have.
There is no need to fast for this exam, so you may eat and drink like normal. You can also take medications as usual.
How does the procedure work?
Cardiac MRI utilizes the power of magnetic fields, radiofrequency waves, and a computer to make detailed cross-sectional (2-dimensional) and 3-dimensional images of the heart without using ionizing radiation (like X-rays, computed tomography, or nuclear imaging). The test shows your heart’s structure (muscle, valves, and chambers), as well as the extent of blood flow through the heart and related vessels.
How is the procedure performed?
An MRI machine is made up of a bench that gradually glides into a big tube attached to a doughnut-shaped opening. Remove all your metal like body jewelry, watches, and earrings.
The technologist will request you to lie on your back on the table. The machine will make loud noises as it takes the required pictures of your body. The technologist will also ask you to hold your breath for a few seconds during the procedure. The entire process can take around 30 to 90 minutes.
What can I expect once the procedure is completed?
After the test, you can carry out your usual activities unless given anti-anxiety medicine or sedation. Initial results from your heart MRI can be available within a few days. However, complete results can take up to a week or more. When the reports are available, your doctor will review them with you and discuss any follow-up steps you should take.