Cardiac magnetic resonance imaging (MRI) is a highly precise imaging test. It provides detailed pictures of the heart and allows evaluation of how it functions.
Beyond simply observing the heart’s shape and structure, this technique also analyzes the quality of the heart muscle itself. It can determine whether the tissue is normal, thickened, scarred, inflamed, or altered by disease.
These details are particularly helpful in certain conditions present from birth, in diseases where abnormal substances accumulate within the heart muscle, or in disorders affecting the lining surrounding the heart (the pericardiumThe pericardium is a sac surrounding the heart and containing a lubricating fluid that allows it to glide with each beat without friction.).
What a Resting Cardiac MRI Evaluates
A resting cardiac MRI allows assessment of:
- the size of the heart chambers
- the thickness and movement of the heart muscle
- the quality of contraction
- the possible presence of scarring or inflammation
This examination helps better understand various heart muscle diseases, including cardiomyopathies, prior heart attack damage, and certain inflammatory conditions.
The Nature of the Examination
This technique does not use ionizing radiation, unlike X-rays, CT scans (computed tomography), or certain nuclear medicine tests. Instead, it relies on a powerful magnetic field (1.5 or 3 Tesla), radiofrequency waves, and a sophisticated computer system to generate detailed images.
It is therefore recognized as a very safe examination when performed according to established protocols.
A Complement to Echocardiography
Cardiac MRI becomes particularly useful when echocardiography does not provide images that are detailed enough. In such cases, it can offer additional information that may be important for establishing a diagnosis or guiding treatment decisions.
Scheduling the Appointment
An appointment is required.
In many cases, the referring physician arranges the test. The medical office will then contact the individual to confirm the date and time of the examination.
Duration
The examination generally lasts between 20 and 30 minutes.
No Special Preparation Required
It is usually possible to eat normally on the day of the test and to take regular medications, unless otherwise instructed.
On the Day of the Appointment
A safety questionnaire must be completed before the examination. It is designed to verify:
- the presence of claustrophobia or significant discomfort in enclosed spaces
- the presence of a cardiac pacemaker
- any allergies, particularly to gadolinium
- pregnancy or breastfeeding
- kidney function (a bloodBlood is composed of red blood cells, white blood cells, platelets, and plasma. Red blood cells are responsible for transporting oxygen and carbon dioxide. White blood cells make up our immune defense system. Platelets contribute to blood test may be required if necessary)
- the presence of implants or metallic fragments, especially in the brain or eyes
Changing for the Examination
You will be asked to remove clothing from the upper body and wear a hospital gown.
Metal Objects
No metallic objects may be kept on the body (coins, jewelry, belt, etc.). The procedure is similar to airport security measures.
A catheter may then be placed in a vein in the forearm by the technologist if the injection of contrast material is required.
Final Safety Checks
Before entering the examination room, the technologist reviews the questionnaire and confirms all safety instructions.
Placement of an Intravenous Line
An intravenous catheter is inserted into the forearm. It allows administration of the contrast agent needed to obtain the images.
You are then accompanied to the imaging room.
Positioning
The room is well lit and often kept slightly cool.
Three electrodes are placed on the chest to monitor heart activity during the examination. You then lie comfortably on your back on the movable table.
Headphones, a pillow, and a blanket are provided to ensure optimal comfort.
The Procedure
As the examination continues, the head and upper chest gently move into the scanner. The machine is shaped like a large ring (often compared to a donut). The table moves automatically, so no effort is required.
The tunnel is wide and open at both ends, which significantly reduces any feeling of confinement.
Continuous Monitoring
It is possible to communicate how you are feeling at any time.
Once positioning is complete, the technologist moves to the adjacent control room. A glass partition separates the two rooms, allowing continuous visual monitoring throughout the examination.
Communication remains constant: the technologist’s voice is heard through the provided headphones, and built-in microphones allow easy two-way communication.
A Noisy Machine
The MRI produces intermittent, sometimes loud sounds while images are being acquired. The headphones help reduce the noise and allow instructions to be heard clearly.
Between image sequences, it is possible to listen to music or the radio, depending on the preference expressed before the examination begins.
The Importance of Breathing Instructions
At certain moments, specific breathing instructions are given.
Carefully following these directions is essential to optimize image quality.
Image Acquisition
As with an MRI of the brain, liver, or spine, the examination begins with still images used to evaluate the anatomy of the heart and the major bloodBlood is composed of red blood cells, white blood cells, platelets, and plasma. Red blood cells are responsible for transporting oxygen and carbon dioxide. White blood cells make up our immune defense system. Platelets contribute to blood vessels.
Dynamic sequences are then recorded. These moving images (often referred to as “cine” mode), comparable to a short video, allow evaluation of heart function from different angles and provide a three-dimensional assessment of its ability to contract effectively.
Contrast Injection
The initial images already provide valuable information.
During the examination, a contrast agent (gadolinium) may be administered through the catheter placed in the forearm vein. This substance improves the precision of the analysis, particularly in assessing heart muscle tissue and detecting possible scarring or areas of inflammation.
The technologist then returns to the control room to complete the image acquisition.
After the Examination
The catheter is removed at the end of the procedure.
You may then get dressed and leave immediately, unless otherwise instructed.
The results are sent to the physician who ordered the examination. The findings will be interpreted and discussed during the follow-up appointment, along with any recommended next steps.
Results
The results of the examination are sent to the physician who ordered the test.
The findings will be explained and any next steps, if necessary, will be discussed during the follow-up appointment.
Copy for Another Physician
It is also possible to request that a copy of the report be sent to another healthcare professional.
Simply provide the name and contact information of the physician, either before or after the examination.
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