An MRI of the heart, or cardiac MRI, is performed using a large magnet, radio waves, and a computer to create detailed images of the heart's structure and function. Here's a breakdown of the process:
Preparing for the MRI
- Medical History: You'll be asked about your medical history, including any allergies, especially to contrast dye, and whether you have any implanted medical devices like pacemakers or defibrillators. These devices may interfere with the MRI.
- Fasting: You might be asked to avoid eating or drinking for a few hours before the scan. Follow the specific instructions given by your doctor or the MRI center.
- Medications: Inform your doctor about all medications you are taking.
- Clothing and Jewelry: You will be asked to remove any jewelry, watches, and other metallic objects, as they can interfere with the magnetic field. You'll likely change into a hospital gown.
- Contrast Dye (Optional): In many cases, a contrast dye (gadolinium) is injected intravenously to enhance the images and provide better visualization of the heart's structures and blood flow.
During the MRI Scan
- Positioning: You will lie flat on a table that slides into the MRI machine, which is a large, tube-shaped device.
- Coils: A coil, which is a special device that helps improve image quality, is placed around your chest area.
- Communication: You will be able to communicate with the technologist performing the scan via a microphone and speaker system.
- Scanning: The MRI machine creates a strong magnetic field and emits radio waves. You'll hear loud thumping or clicking noises during the scan. Earplugs or headphones will be provided to reduce the noise.
- Breath-holding: You may be asked to hold your breath for short periods (usually 10-15 seconds) during specific scans to minimize motion artifacts and improve image clarity. The technologist will provide clear instructions.
- ECG Gating: Electrodes may be placed on your chest to monitor your heart's electrical activity (ECG). This technique, called ECG gating, helps synchronize the MRI images with your heartbeat, resulting in sharper images.
- Duration: The entire MRI procedure typically lasts between 30 and 90 minutes.
After the MRI
- Normal Activities: You can usually resume your normal activities immediately after the MRI, unless instructed otherwise by your doctor.
- Contrast Dye Effects: If contrast dye was used, drink plenty of fluids to help flush it out of your system.
- Results: The MRI images will be reviewed by a radiologist, who will then send a report to your doctor. Your doctor will discuss the results with you and determine the next steps, if any.
In summary:
Cardiac MRI is a non-invasive imaging technique that provides detailed information about the heart's structure and function. The procedure involves lying inside a large MRI machine while a strong magnetic field and radio waves are used to create images. Breath-holding and ECG gating may be used to improve image quality.
