What to Expect During an MRI: A Technologist Explains Step by Step
Quick answer: an MRI is painless and does not use radiation. Most exams take 30 to 60 minutes. You will lie still on a padded table inside a large tube while the scanner makes loud knocking and buzzing sounds; you will wear earplugs or headphones, and you can talk to the technologist at any time through an intercom or a squeeze ball. If your exam needs contrast, it is injected through an IV partway through the scan.
I have spent manyyears on the other side of the glass, running MRI scans and helping nervous patients through them. Most of the anxiety I see comes from not knowing what is about to happen. So here is the whole process, step by step, from the moment you check in to the moment you get your results.
Before your appointment
A few things are worth sorting out a day or two before your scan:
- Tell your doctor about any implants or devices. Pacemakers, defibrillators, cochlear implants, brain aneurysm clips, nerve or spinal stimulators and insulin pumps all need to be checked before you enter the scanner room. Most orthopedic implants, like hip replacements or screws, are not a problem. If your device came with an information card or leaflet, bring it.
- Mention any metal from an injury. Shrapnel, bullet fragments and, above all, metal near the eyes (common in welders and metalworkers) must be reported. Metal in the eye can move or heat up in the magnet.
- Say if you might be pregnant. MRI is often used safely in pregnancy, but the team needs to know, especially in the first trimester and if contrast is planned.
- If you are claustrophobic, plan ahead. Ask your doctor whether a mild sedative is appropriate. If you take one, arrange for someone to drive you home.
- Food, drink and medications: for most MRIs you can eat, drink and take your usual medications. Some exams, especially of the abdomen, have specific fasting instructions. Follow what your imaging center tells you.
For a full checklist, see our guide on [link: How to Prepare for an MRI].
Step 1: Check-in and the safety questionnaire
When you arrive, you will fill out a detailed safety form. It asks about surgeries, implants, devices, metal fragments, tattoos, allergies, kidney problems and pregnancy. It may feel repetitive, but it is the single most important safety step: the MRI magnet is always on, even when no one is being scanned.
A technologist will go over your answers with you. If there is any doubt about a piece of metal in your body, they may ask for an x-ray before the scan to check.
From the scanner room: [TU EXPERIENCIA: un ejemplo real (sin datos identificables) de algo que un paciente olvidó mencionar en el cuestionario y cómo se detectó, o qué preguntas suelen sorprender a los pacientes.]
Step 2: Changing and leaving metal behind
You will usually change into a hospital gown or scrubs. Some sportswear and «anti-odor» fabrics contain metallic fibers that can heat up, so even leggings with no zippers may have to come off.
Everything metal or electronic stays in a locker, including:
- jewelry, watches and smartwatches
- phones, credit cards and key fobs
- hearing aids and removable dental work
- hairpins, glasses and belts
- body piercings
- makeup with metallic particles and medication patches (ask the technologist before removing any patch)
Credit cards are a classic casualty: the magnet can wipe them in seconds.
Step 3: The IV line (only if your exam uses contrast)
Some MRI exams need a contrast agent called gadolinium to make certain tissues and blood vessels stand out. If yours does, a technologist or nurse will place a small IV line in your hand or arm before you go into the scanner. You might be asked about kidney disease beforehand, and some centers check a recent blood test.
Gadolinium is a different substance from the iodine-based contrast used in CT scans, and it can generally be used in people who are allergic to iodine contrast. Learn more in [link: MRI With vs Without Contrast].
Step 4: Getting positioned on the table
This is where the technologist does most of the hands-on work:
- You lie on a padded table, usually on your back. The position depends on the body part: head first for a brain scan, feet first for a knee or ankle.
- A coil is placed over or around the area being scanned. It looks like a plastic frame, cage or flexible pad. Coils act like antennas and are essential for sharp images.
- Foam pads and straps help you stay still comfortably. The technologist will also make sure your skin is not touching the inside of the scanner or other parts of your body (for example, hands touching thighs), because skin-to-skin contact can create a hot spot during the scan.
- You will get earplugs, headphones or both. Many centers can play music through the headphones.
- You will be given a squeeze ball or call button. Pressing it alerts the technologist immediately.
Then the table slides into the scanner. For a knee or foot MRI, your head may stay outside the tube; for a brain or spine scan, you will be fully inside.
From the scanner room: [TU EXPERIENCIA: tus trucos reales para pacientes nerviosos durante la colocación: qué les dices, si recomiendas cerrar los ojos antes de entrar, cómo usas la música o la comunicación.]
Step 5: The scan itself
Once you are in position, the technologist leaves the room and runs the scan from a computer behind a window. They can see and hear you the whole time, and they will talk to you through the intercom between sequences.
An MRI is not one long picture but a series of separate scans called sequences. Each one lasts from under a minute to several minutes. Here is what that feels like:
- The noise. Each sequence has its own sound: loud knocking, tapping, buzzing or a machine-gun rattle. It is the normal sound of the coils working, not a sign that anything is wrong.
- Staying still. This is the hardest part. Any movement during a sequence blurs the images. Between sequences, the noise stops and you can relax a little, but try to keep the same position.
- Breath-holds. For chest and abdominal scans, the technologist may ask you to hold your breath for several seconds at a time.
- Warmth. It is normal for the area being scanned to feel slightly warm. If any spot feels hot, especially near a tattoo, tell the technologist right away.
The scanner room is air-conditioned and well lit. If you feel cold, ask for a blanket.
Step 6: The contrast injection (if needed)
If your exam uses contrast, it is usually given partway through, after a first set of images. The technologist injects it through your IV, often while you stay inside the scanner, and then repeats some sequences.
You may notice a cool or warm feeling at the injection site, or a brief metallic taste in your mouth. Both are normal. Reactions to gadolinium are uncommon and usually mild, such as nausea or a headache. Itching, hives or other allergic symptoms are very rare; tell the technologist at once if you notice anything unusual. A doctor is always available in the department.
Step 7: Finishing up
When the last sequence ends, the table slides out. The technologist may ask you to wait a few minutes while a radiologist checks that the images are complete, in case extra views are needed. If you had an IV, it is removed and a small bandage is applied.
After your MRI
- You can go back to normal life right away. Eat, drink, drive and work as usual, unless you received a sedative. In that case, someone needs to drive you home.
- Mild side effects from contrast, like a headache or some soreness where the IV was, usually pass quickly. Contact your doctor if anything worries you.
- Results: a radiologist (a doctor who specializes in reading medical images) reviews your scan and sends a report to the doctor who ordered it. Many centers also release the report to your online patient portal, sometimes before your doctor has seen it. Reports are written for doctors and can sound alarming out of context, so always go over the results with your own doctor.
How long does an MRI take?
Most MRI exams take 30 to 60 minutes, depending on the body part, the scanner and whether contrast is needed. Add time for check-in, screening and changing. For more detail by body part, see [link: How Long Does an MRI Take?].
Tips from the technologist
[TU EXPERIENCIA: 4-6 consejos propios, en primera persona. Ideas para inspirarte: ir al baño antes de entrar, ropa sin metal para no tener que cambiarse, llegar con tiempo para el cuestionario, cerrar los ojos al entrar, respirar despacio durante el ruido, avisar enseguida si algo duele o calienta.]
Frequently asked questions
Does an MRI hurt?
No. The scan itself is painless. Some people find it uncomfortable to lie still for a long time, and the IV for contrast feels like a regular blood draw.
Does an MRI use radiation?
No. MRI uses a strong magnetic field and radio waves, not x-rays. Learn more in [link: Do MRI and Ultrasound Use Radiation?].
Can I listen to music during an MRI?
Often, yes. Many centers play music through MRI-safe headphones. Ask when you book.
Can someone stay in the room with me?
Many facilities allow a family member or friend to stay in the room, as long as they also pass the safety screening and leave all metal outside.
What if I panic inside the scanner?
Squeeze the ball or call out. The technologist will stop the scan and talk to you, or bring you out. If you know you are claustrophobic, see [link: Claustrophobic in an MRI? 12 Tips That Actually Help] and ask about wide-bore or open MRI scanners, which feel less enclosed.
Is an MRI safe if I have a metal implant?
Most implants are safe, including most joint replacements, plates and screws. Some pacemakers, defibrillators, cochlear implants, aneurysm clips and nerve stimulators need special checks or may rule out an MRI. Your imaging team must confirm the exact model first. See [link: Can You Have an MRI With Metal Implants, Tattoos or a Pacemaker?].
How much does an MRI cost?
It varies widely depending on the body part, your insurance and where you have it done. Independent imaging centers are often much cheaper than hospitals for the same scan. See [link: How Much Does an MRI Cost Without Insurance?].
This article is for general information and does not replace advice from your doctor or imaging team. Always follow the specific instructions of the facility where you are scanned.
Sources
RadiologyInfo.org (ACR and RSNA): Body MRI
RadiologyInfo.org (ACR and RSNA): How to Prepare for Your MRI Exam