What Happens During an MRI: The Process Step by Step

An MRI follows a predictable path: your doctor orders the scan, the center schedules it and checks coverage, you complete a safety screening, a technologist positions you, you hold still for 15 to 60 minutes or more while the machine makes loud noises, and a radiologist later sends a report to your doctor. It is painless, uses no ionizing radiation and usually takes less than an hour on the table. Knowing each step in advance reduces anxiety and helps you avoid the mistakes that cause repeats or surprise bills.

Step 1: The order

A licensed clinician writes an order that names the body part, whether contrast is requested and the reason for the scan. That reason matters, because it guides the radiologist's protocol and the insurer's decision about medical necessity. Ask for a copy and the CPT code. If you are paying cash, the center may still require an order.

Step 2: Scheduling, price and authorization

When you call to book, the center asks for the order, your coverage and your date of birth. This is the moment to:

• Get a written price or Good Faith Estimate (see Good Faith Estimate for MRI).
• Confirm network status of the facility and the radiologist.
• Confirm that prior authorization is on file, if required.
• Ask about fasting, arrival time and what to bring.

Appointments for routine scans are often available within days at freestanding centers. Hospital scheduling may take longer for routine studies.

Step 3: Preparation at home

Instructions depend on the study. Typical examples:

• Joint or spine scans: usually no fasting; wear comfortable clothing without metal.
• Abdominal or pelvic scans: the center may ask you not to eat for several hours beforehand, and sometimes to drink or avoid certain liquids.
• Contrast scans: you may need a recent kidney function result, and you should tell the center about allergies, kidney disease and pregnancy.
• Anxiety: if a sedative is prescribed, arrange a driver.

Follow the center's written instructions over any general advice. See preparation and results timeline for details.

Step 4: Check-in and screening

At the center you present your ID, order and insurance card, and sign consent and financial forms. Read the financial form before you sign, and compare it with your estimate. You then complete an MRI safety questionnaire, which asks about:

• Pacemakers, defibrillators, cochlear implants, neurostimulators and insulin or pain pumps.
• Aneurysm clips, stents, joint replacements, plates, screws and surgical hardware.
• Metal fragments in the eyes or body, which matter for people who have worked with metal.
• Tattoos or permanent makeup, which may contain metallic pigments and can occasionally warm.
• Pregnancy, kidney disease, allergies and previous contrast reactions.
• Past MRIs and any problems.

Be thorough. The magnet is always on, and metal objects can be pulled toward it. A device marked "MR conditional" can be scanned under specific conditions; staff need its manufacturer and model.

Step 5: Changing and removing metal

You may change into a gown or remain in metal-free clothing. Remove jewelry, watches, hearing aids, hair pins, eyeglasses, dentures, credit cards, phones and anything magnetic. Leave them in a locker. The technologist may check you with a handheld detector.

Step 6: Positioning

The technologist helps you lie on the scanner table. Depending on the scan, they place a coil, a device that detects the signal, over or around the body part. They use pillows, straps or padding to keep you still and comfortable. You are given earplugs or headphones because the scanner is loud, and often a call button or squeeze ball. For some scans, your head stays outside the tube.

Step 7: Contrast injection, if ordered

If your scan uses gadolinium-based contrast, a nurse or technologist places a small IV in your arm or hand. Some scans pause midway for the injection; you may feel a cool sensation or a brief taste of metal. Most people feel nothing unusual. Report itching, hives, nausea, a rash or swelling at the injection site.

Step 8: The scan

The table slides into position. The technologist leaves the room but sees and hears you through a window and an intercom. The machine runs a series of sequences, each lasting from seconds to several minutes, and each makes its own noises: thumping, knocking, buzzing and high-pitched beeping. The sound can reach levels that require hearing protection, which is why earplugs are standard.

What you need to do:

• Stay still. Movement blurs images and may force a repeat sequence.
• Breathe normally, except for some chest or abdominal sequences where you may be asked to hold your breath for 10 to 20 seconds.
• Use the call button if you feel unwell or too anxious. The technologist can stop the scan.

Typical times: joint scans 20 to 45 minutes; spine 30 to 60; brain 30 to 45; abdominal or multi-region and contrast studies up to 60 to 90 minutes. Your center will tell you its estimate.

Step 9: After the scan

You get up, change and, in most cases, drive home and resume normal activity. If you had a sedative, you need a ride and shouldn't drive or make important decisions until it has worn off. If you got contrast, some centers recommend drinking fluids; follow their instructions. Ask when your report will reach your doctor.

Step 10: Reading and results

A radiologist reviews hundreds of images, writes a report and sends it to the ordering doctor, often within one to three business days, sooner for urgent cases. Your doctor then explains the findings and next steps. Many portals now release reports to patients directly, sometimes before the doctor has spoken to you. Don't interpret terms alone. Words such as "degenerative changes" are common and often not the cause of pain.

Step 11: Billing

The bill may arrive in pieces: one from the center and one from the radiologist, plus an Explanation of Benefits from your insurer. Compare each with your estimate. If they don't match, see what to do if an MRI bill is too high.

Timeline at a glance

Worked example (illustrative)

A lumbar spine MRI without contrast: you arrive 20 minutes early, spend 15 minutes on forms and screening, 5 minutes positioning, and 35 minutes in the scanner. You are out the door in about 80 minutes. The report reaches your doctor the next business day; the doctor's office calls two days later. The all-in bill matches the $620 estimate you saved. These times are illustrations, not guarantees.

When to consult a professional

Tell the technologist right away if you have a device, are pregnant or feel unwell. After the scan, contact your doctor, not the center, for the meaning of results. If you have chest pain, trouble breathing or a severe reaction, call 911.

Frequently asked questions

Does an MRI hurt?

No. Lying still can be uncomfortable, and the noise is loud, but the scan itself is painless.

Can I eat before an MRI?

For many scans yes; for abdominal and some others you may need to fast. Follow the center's instructions.

Can I listen to music?

Most centers offer headphones or music; ask when booking.

How soon will I get results?

The report usually goes to your doctor within a few days, and your doctor reviews it with you.

Sources

• RadiologyInfo.org — what to expect in an MRI exam
• U.S. Food and Drug Administration — MRI safety and implanted devices
• American College of Radiology — MRI safety and contrast guidance
• Centers for Medicare & Medicaid Services — estimates and billing rights