What to Expect During an MRI: Complete Patient Guide

• MRI (Magnetic Resonance Imaging) uses strong magnets and radio waves, not radiation, to create detailed images of your body
• Most MRI scans take between 30 and 60 minutes, depending on the area being imaged and the type of study
• You will need to remove all metal objects before the scan; certain metal implants may make MRI unsafe for you
• The machine makes loud knocking and thumping sounds, but earplugs or headphones are always provided
• The scan is painless, and you can communicate with the technologist at all times through an intercom system

Magnetic Resonance Imaging (MRI) is a medical imaging technique that uses a powerful magnetic field, radio waves, and a computer to create detailed pictures of the inside of your body. Unlike X-rays and CT scans, MRI does not use ionizing radiation, making it one of the safest imaging methods available.

The MRI machine contains a large, powerful magnet. When you are inside the machine, the magnetic field temporarily aligns the hydrogen atoms in your body. Radio waves are then pulsed through the area being imaged, causing the atoms to emit signals. A computer processes these signals to create highly detailed cross-sectional images of your organs, bones, joints, and soft tissues.

Key facts about MRI:

• Invented in the 1970s; the first clinical MRI scan was performed in 1977
• MRI machines are rated by magnetic field strength in Tesla (T); most clinical scanners are 1.5T or 3T
• MRI can create images in any plane (axial, coronal, sagittal) without repositioning the patient
• It provides exceptional soft tissue contrast, making it ideal for brain, spine, joint, and organ imaging
• The procedure is painless and does not require needles (unless contrast is used)

Your doctor may order an MRI for many different reasons. Common indications include:

Neurological Conditions

• Brain tumors and other brain abnormalities
• Stroke evaluation and monitoring
• Multiple sclerosis diagnosis and tracking
• Seizure evaluation
• Headache workup when other causes are suspected
• Pituitary gland disorders

Spine Problems

• Herniated discs and nerve compression
• Spinal cord tumors or infections
• Degenerative disc disease
• Spinal stenosis
• Spinal cord injuries

Joint and Musculoskeletal Issues

• Knee injuries (meniscus tears, ligament tears)
• Shoulder problems (rotator cuff tears, labral tears)
• Hip conditions
• Ankle and foot injuries
• Wrist and hand problems
• Bone marrow abnormalities

Abdominal and Pelvic Conditions

• Liver lesions and liver disease
• Prostate cancer evaluation
• Uterine and ovarian abnormalities
• Kidney and adrenal gland evaluation
• Pancreatic conditions

Cardiac MRI

• Heart muscle function and structure
• Coronary artery disease evaluation
• Cardiac tumor assessment
• Heart valve evaluation

Breast MRI

• High-risk breast cancer screening
• Evaluating extent of known breast cancer
• Monitoring breast implant integrity

When You Schedule the Appointment

• Inform the scheduling staff about any metal implants, pacemakers, or implanted devices in your body
• Tell them about claustrophobia so they can plan accordingly (wide-bore machine, sedation options)
• Ask about insurance pre-authorization to avoid unexpected costs
• Confirm the location and arrival time (usually 15 to 30 minutes before the scan)

Metal Screening

This is the most critical safety step before an MRI. The magnetic field in an MRI machine is extremely strong and can be dangerous around certain metals.

You MUST inform the facility about any of the following:

• Cardiac pacemaker or defibrillator
• Aneurysm clips
• Cochlear implants
• Metal fragments or shrapnel in your body
• Artificial heart valves
• Implanted drug infusion pumps
• Neurostimulators
• Metal plates, screws, or rods from surgery
• Joint replacements (usually safe but must be verified)
• Dental braces or permanent retainers
• Bullet fragments
• Metalworking history (grinding, welding) that could have left metal particles in your eyes

The facility will provide a detailed safety questionnaire to complete before your scan. Be thorough and honest. Most orthopedic implants (joint replacements, plates, screws) are MRI-safe, but they must be verified.

What to Wear

• Wear comfortable, loose-fitting clothing without metal zippers, buttons, snaps, or underwire
• Avoid clothing with metallic decorations, sequins, or threads
• A hospital gown will be provided if needed
• Remove all jewelry, watches, body piercings, hairpins, and eyeglasses
• Do not wear makeup that contains metallic particles (some mineral-based products)
• Remove hearing aids, dentures with metal components, and removable dental work

Eating and Drinking

• For most MRI scans, there are no food or drink restrictions
• If you are having an MRI of the abdomen or pelvis with contrast, you may be asked to fast for 4 to 6 hours
• Take your regular medications unless told otherwise
• If you are receiving sedation, you will need to fast and arrange a driver

Other Preparation

• If you are having a brain MRI, wash and dry your hair without using hair products
• If you are having contrast, a kidney function blood test may be required beforehand
• Use the restroom before the scan begins, as you will need to lie still for 30 to 60 minutes

Step 1: Check-In and Safety Screening (15 to 20 minutes)

When you arrive, you will check in and complete a detailed safety questionnaire about metal implants and medical history. The technologist will review your forms, verify your identity, explain the procedure, and answer any questions.

Step 2: Changing and Preparation (5 to 10 minutes)

You may be asked to change into a hospital gown. You will be given a locker for your belongings. Remove all metal objects including jewelry, watches, hairpins, and eyeglasses.

Step 3: IV Placement (If Contrast Is Needed) (5 minutes)

If your MRI requires contrast (gadolinium), a nurse or technologist will place an IV line in your arm. The contrast is injected partway through the scan, not at the beginning. The IV is a small needle stick that feels like any other blood draw.

Step 4: Positioning on the MRI Table (5 minutes)

The technologist will help you lie on the MRI table. Depending on the type of scan, a special coil (a device that improves image quality) may be placed over or around the body part being scanned. For example:

• Brain MRI: A helmet-like coil goes over your head
• Knee MRI: A cylindrical coil wraps around your knee
• Abdominal MRI: A large coil rests on your abdomen

You will be given:

• Earplugs or headphones (the machine is very loud)
• A squeeze ball or call button to communicate with the technologist
• A blanket if you are cold

Step 5: Entering the MRI Machine

The table will slide into the MRI machine. For most scans, you will go in head-first. For lower body scans (knee, hip, foot), you may go in feet-first, with your head remaining near or outside the opening.

The machine makes loud noises during the scan. You will hear rhythmic knocking, thumping, buzzing, and beeping sounds. These sounds change throughout the scan as different image sequences are acquired. This is completely normal. The noise can reach 80 to 120 decibels (comparable to a lawnmower or concert), so hearing protection is essential.

Step 6: The Scan (30 to 60 minutes)

The actual scanning consists of multiple sequences, each lasting 2 to 10 minutes. Between sequences, the machine may be quiet for a few seconds.

During each sequence, you must remain completely still. Movement can blur the images and may require repeating the sequence. The technologist will tell you how long each sequence lasts.

If contrast is used, the technologist will pause halfway through the scan to inject the gadolinium contrast through your IV line. You may feel a cool sensation at the IV site. Additional images will be taken after the contrast injection.

Step 7: Completion (5 minutes)

Once all images are acquired, the table slides out of the machine. The IV is removed (if one was placed), and the technologist will check that the images are of good quality. You can then change back into your clothes and go home.

Total time at the facility: Plan for 1.5 to 2 hours from arrival to departure.

Immediate After-Effects

• You can resume normal activities immediately after a non-sedated MRI
• There are no lingering effects from the magnetic field
• If you received contrast, drink plenty of water to help flush it from your system
• If you received sedation, have someone drive you home and rest for the remainder of the day

Getting Your Results

• A radiologist will review the images and send a report to your doctor
• Results are typically available within 24 to 48 hours
• Your doctor will contact you to discuss the findings
• Some facilities provide results through a patient portal

By Field Strength

Specialized MRI Types

• MRI with contrast (Gadolinium): Enhances visibility of certain abnormalities
• MR Angiography (MRA): Evaluates blood vessels without radiation
• Functional MRI (fMRI): Maps brain activity
• Diffusion-weighted MRI (DWI): Detects early stroke, tumors, and infections
• MR Spectroscopy: Provides chemical analysis of tissues
• Cardiac MRI: Detailed heart imaging with ECG gating
• MRCP (Magnetic Resonance Cholangiopancreatography): Evaluates bile ducts and pancreas

What Is Gadolinium?

Gadolinium is the contrast agent used in MRI. It is different from the iodine-based contrast used in CT scans. Gadolinium is injected through an IV and helps highlight areas of inflammation, tumors, blood vessel abnormalities, and other conditions.

When Is Contrast Used?

Your doctor may order MRI with contrast for:

• Brain and spine tumors
• Infections and inflammation
• Cancer staging and follow-up
• Blood vessel abnormalities
• Post-surgical evaluation
• Certain joint and musculoskeletal conditions

Contrast Safety

• Allergic reactions are rare (less than 0.1% for mild reactions)
• Serious allergic reactions are extremely rare
• Gadolinium is cleared by the kidneys, so kidney function should be adequate
• A condition called nephrogenic systemic fibrosis (NSF) is a rare but serious risk for patients with severe kidney disease
• Recent research suggests trace amounts of gadolinium may be retained in the brain, though no clinical effects have been definitively linked to this
• Newer gadolinium agents have a much better safety profile

Tips for Managing Costs

• Check that the facility is in your insurance network
• Ask about cash-pay or self-pay discounts
• Compare prices at different facilities (prices can vary dramatically)
• Ensure pre-authorization is obtained if required by your insurance
• Freestanding imaging centers are often less expensive than hospital-based facilities

Is an MRI painful? No. The MRI scan itself is completely painless. The only discomfort may be the IV placement if contrast is used, and the need to lie still for an extended period.

How loud is the MRI machine? Very loud. The knocking and thumping sounds can reach 80 to 120 decibels. You will be given earplugs and/or headphones with music to protect your hearing and reduce the noise.

Can I move during the scan? You must remain as still as possible during each imaging sequence (which lasts 2 to 10 minutes). Between sequences, you can shift slightly. If you move too much during a sequence, it may need to be repeated.

What if I feel claustrophobic? Tell the technologist before the scan begins. They can provide a cloth to cover your eyes, offer headphones with music, and keep you informed about progress. If claustrophobia is severe, your doctor can prescribe a mild sedative, or you can be scheduled at a facility with an open or wide-bore MRI machine.

Can I have an MRI if I have tattoos? Yes, most tattoos are safe during MRI. Rarely, some older tattoos with metallic-based inks may cause a mild burning or tingling sensation. Tell the technologist if you experience any discomfort in the area of a tattoo.

Can I listen to music during the scan? Most facilities provide MRI-safe headphones and allow you to listen to music. Some facilities even let you bring your own playlist. Music serves as both a distraction and a way to cope with the loud scanner noise.

Will the MRI affect my dental fillings? Modern dental fillings, crowns, and bridges are not affected by MRI. They may cause some local image distortion but are not a safety concern. Removable dental appliances with metal should be taken out before the scan.

How does MRI compare to CT in terms of radiation? MRI uses no ionizing radiation at all. This is one of its key advantages over CT, especially for children, pregnant women, and patients who need repeated imaging.

Can I have an MRI while pregnant? MRI is generally considered safe during pregnancy, especially after the first trimester, because it does not use radiation. However, gadolinium contrast is usually avoided during pregnancy unless absolutely necessary. Always inform your doctor if you are or might be pregnant.

What should I do with my medical device information? Bring any medical device identification cards you have to your appointment. This includes cards for joint replacements, pacemakers, implanted ports, stents, and any other devices. The MRI team needs to verify the MRI safety status of each device.

An MRI scan is a safe, painless, and extremely valuable diagnostic tool that provides detailed images of your body without using radiation. While the experience can feel intimidating, especially the enclosed space and loud noises, understanding what to expect can significantly reduce anxiety.

The key to a successful MRI experience is preparation: follow instructions about metal objects, wear appropriate clothing, communicate with the imaging team, and use the coping strategies that work best for you.

Use WellAlly to track all your imaging appointments, store your MRI reports, and maintain a complete record of your medical devices for easy reference at future appointments.