What to Expect During an MRI: A Patient's Complete Guide

If your doctor has ordered an MRI, you probably have questions. MRI (magnetic resonance imaging) is one of the most detailed diagnostic tools in medicine, producing high-resolution images of soft tissues, organs, and joints without using radiation. But the experience of lying inside a narrow, noisy tube can be intimidating for first-timers. Knowing what to expect at each stage can help reduce anxiety and make the process smoother.

Before the Scan

Screening Questionnaire

Before you enter the MRI suite, you will complete a detailed safety screening form. Because MRI uses a powerful magnetic field, any metallic implants or devices in your body could pose a safety risk. The questionnaire will ask about cardiac pacemakers, cochlear implants, aneurysm clips, joint replacements, shrapnel or metal fragments, and any history of metal work (grinding, welding). Some implants are MRI-compatible and some are not; the technologist and radiologist will review your answers before proceeding.

You will be asked to remove all metal objects: jewelry, watches, hairpins, belt buckles, and clothing with metal components (zippers, underwire bras). Most facilities provide a gown and a secure locker for your belongings. Credit cards and electronic devices must also be left outside the scan room, as the magnetic field can erase magnetic strips and damage electronics.

Contrast Agents

Some MRI exams require an intravenous contrast agent, most commonly a gadolinium-based compound. Contrast helps certain tissues and abnormalities stand out more clearly on the images. If contrast is needed, a nurse or technologist will place an IV line in your arm before the scan. Let the team know if you have kidney disease or have ever had an allergic reaction to MRI contrast, as these may affect whether contrast can be safely administered.

What to Wear

Wear comfortable clothing without metal fasteners. Athletic wear (sweatpants and a cotton T-shirt without metallic logos) often works well and may allow you to keep your own clothes on during the scan. Some facilities require everyone to change into a gown regardless of clothing.

During the Scan

You will lie on a padded table that slides into the MRI machine, a large tube-shaped magnet. Depending on the body part being imaged, you may enter the tube head-first or feet-first. For brain and upper body scans, your head will be inside the tube. For knee or ankle scans, only the lower portion of your body will be inside.

The technologist will position you and may place a coil, a device that looks like a cage or frame, over the body part being scanned. The coil acts as an antenna to capture the MRI signal and produce better image quality. You will be given earplugs or headphones because the machine is loud.

The Noise

MRI machines produce a series of loud knocking, thumping, and buzzing sounds during scanning. These sounds are caused by the rapid switching of gradient coils inside the magnet and are a normal part of the process. The noise level can reach 100 decibels or more, which is comparable to a jackhammer. Ear protection is essential and is always provided.

Many facilities offer music through MRI-compatible headphones to help mask the noise and keep you relaxed. You can usually bring your own music on a non-metallic device or request a specific genre.

Staying Still

The most important thing you can do during an MRI is hold still. Even small movements can blur the images and require sequences to be repeated, which extends the scan time. The technologist will tell you when each sequence begins and how long it will last. Some sequences run for two to three minutes, while others may last five to seven minutes. Between sequences, you may have brief pauses.

You will have a squeeze ball or call button in your hand at all times. If you feel uncomfortable, anxious, or need to stop for any reason, squeeze it, and the technologist will communicate with you through a speaker in the machine. You can always stop the scan.

How Long It Takes

Most MRI scans take 30 to 60 minutes, depending on the body part and the number of sequences needed. Brain MRIs typically take 30 to 45 minutes. Spinal MRI scans may take 45 to 60 minutes. Cardiac MRI and abdominal MRI scans can take up to 90 minutes in some cases. If contrast is administered, additional sequences will be run after the injection, which adds time.

After the Scan

Once the scan is complete, the table slides out of the machine, and you can get up immediately. If an IV was placed for contrast, it will be removed. There is no recovery period; you can eat, drink, and drive normally right away.

Some people experience mild dizziness or a metallic taste during or after the scan, particularly if contrast was used. These effects are temporary and typically resolve within an hour.

Getting Your Results

A radiologist, a physician who specializes in interpreting medical images, will review your MRI and generate a report. This process typically takes 24 to 48 hours for non-urgent scans. In hospital or emergency settings, preliminary results may be available within hours. Your ordering physician will contact you with the results, or you may be able to access the report through a patient portal.

If you are anxious about waiting for results, ask the facility what their typical turnaround time is and whether results will be posted to a portal.