What is an MRI?
Magnetic Resonance Imaging, also known as MRI, is a common medical imaging exam used to view the interior of the human body. An MRI scan is like an X-ray or CT scan in that it provides physicians with a way to view an injury or condition that cannot be assessed from a physical examination alone. However, unlike an X-ray or CT scan, MRI generates these images using a powerful magnet, and can obtain extremely detailed, high resolution pictures of soft tissue within the body. Furthermore, an MRI scan is harmless, noninvasive, and does not expose patients to potentially harmful ionizing radiation.
In most cases, MRI is the standard for imaging joints, cartilage, ligaments, and muscles, as well as providing the clearest information regarding soft tissue abnormalities such as tumors and cysts. Because MRI is so valuable in providing diagnostic and prognostic information, over 30 million scans are performed each year in the U.S. In fact, countries all over the world are readily adopting this technology. 1
Why did my Doctor Order an MRI?
When a physician orders an MRI for a patient, it is because they need to gain more information about an injury or condition in order to establish a diagnosis and develop a treatment plan. An MRI gives doctors confidence in their diagnosis and can provide valuable information such as the precise location of a torn ligament or the stage of cancer.
Depending on the symptoms a patient is presenting, an MRI will scan a specific part of your body to diagnose:
- Heart damage
- Lung damage
- Sports injuries
- Herniated discs or spinal tumors
- Conditions with veins or arteries
- Brain abnormalities such as tumors and dementia
- Abnormal digestive tract problems
- Bone disease
- Pelvic issues
- Prostate issues 2
How to Prepare for an MRI
Once a patient decides to undergo an MRI, their physician will typically recommend a medical imaging center and schedule an appointment for them. This could be at a hospital or a radiology center. The patient’s doctor may also request that the MRI be performed with contrast. This means that a gadolinium-based contrast agent will be injected via an IV into the patient’s arm before the scan. This contrast “dye” helps improve the quality of the MRI images, provides more detail and clarity, and makes detecting and assessing tissue abnormalities easier for the radiologist.
On the day of the scheduled MRI, the patient will meet with the MRI technician who will help prepare them for the exam. There is little that the patient needs to do before arriving to the exam. Most patients can take their daily medications as they normally would and eat normal meals, unless advised otherwise by their physician. The only precaution the radiologist will give the patient is to not wear any metal. The magnet within the scanner is so strong that it will attract anything metal, potentially damaging the machine and causing harm to the patient.
When the patient is ready to be scanned, the MRI technician will ask them questions regarding their current condition and medical history. Then, the patient will change from their own clothes and into a hospital gown. This helps eliminate the risk of any metal being present in their personal garments. In fact, many MRI bays have the patient walk through a metal detector before beginning the procedure. This is to ensure that there is not metal on or within the patient’s body. Some medical devices that might have metal include:
- Cochlear implants
- Metal plates, screws or rods
- Artificial heart valves
- An intrauterine device
- A drug pump implant
- Artificial joints
- Dental fillings 2
What to Expect During the MRI Scan
An MRI machine looks like a large doughnut with a table attached to it where the patient can lay down. The scan itself can last anywhere from a few minutes to an hour depending on the part of the body being imaged and the complexity of the scan. When preparing for the scan, the technician will situate the patient as comfortably as possible. This is critical, because any movement of the body during the scan can cause blurry artifacts to appear in the final images. Motion blur could render the entire scan futile and call for a re-scan or prompt a misdiagnosis.
It is also important that the patient is prepared for the sound that the MRI machine makes while the scan is in progress. The machine will make a variety of loud clicking and humming noises that vary in pitch and volume. To help patients relax and ignore the sound, the MRI technician can provide them with headphones so they can listen to their favorite music.
In addition, some patients experience anxiety due to the tunnel-like opening of the MRI bore. Ranging anywhere from mild discomfort to serious claustrophobia, any form of anxiety can make an MRI scan challenging for patients. If necessary, a sedative can be administered to patients to help them stay calm and still during the exam.
Furthermore, every MRI machine is equipped with a two-way intercom system. This means that the MRI technician can hear everything a patient says, and they can communicate back and forth. The technician will remain with the patient throughout the entirety of the scan, ensuring that they are comfortable and relaxed.
What Happens When the MRI Scan is Complete?
Once the scan has been completed, the patient can typically leave the imaging center immediately and resume their daily activities. If a contrast dye was used, then the IV must be removed from the patient’s arm. Also, if the patient needed to be sedated during the scan then they will be required to stay at the clinic until they are alert and awake.
A radiologist who specializes in interpreting MRIs will then analyze the images and report the findings to the patient’s physician. The physician will then discuss any significant findings and next steps with the patient directly.
- "No Need to be Nervous! Here's What to Expect During an MRI Scan." Radiology Affiliates Imaging. 12 January 2016. Web. 21 August 2018. <https://4rai.com/blog/no-need-to-be-nervous-here-s-what-to-expect-during-an-mri-scan>.
- "Magnetic Resonance Imaging (MRI)." familydoctor.org. 18 January 2017. Web. 21 August 2018. <https://familydoctor.org/magnetic-resonance-imaging-mri/>.