Getting an MRI scan starts with a referral from a healthcare provider who determines the scan is medically necessary. You can’t simply walk into an imaging center and request one. A doctor, nurse practitioner, or other licensed provider must order the scan to diagnose or rule out a specific condition. From there, the process involves insurance approval, preparation, and the scan itself. Here’s what each step looks like.
Getting a Referral
Your primary care doctor, an urgent care provider, or a specialist can all order an MRI. The key requirement is medical necessity: your provider needs to document a reason the scan is needed, whether that’s persistent joint pain, a neurological symptom, a suspected tumor, or follow-up after an injury. In most cases, your provider will have tried other approaches first, like a physical exam, X-rays, or a course of physical therapy, before moving to an MRI.
If you believe you need an MRI but your doctor hasn’t suggested one, ask directly. Explain your symptoms and why you think imaging would help. Some providers are cautious about ordering advanced imaging too early, but a clear conversation about your symptoms and their duration can move things forward.
Insurance and Prior Authorization
Many insurance plans require prior authorization before they’ll cover an MRI. This means your provider’s office submits documentation to the insurer explaining why the scan is necessary, and the insurer reviews it against their clinical criteria before approving. This process can take anywhere from a few hours to several business days. Your provider’s office typically handles the paperwork, but it’s worth calling your insurance company to confirm whether authorization is needed and whether the imaging center you’re going to is in-network.
Medicare covers MRIs under Part B when ordered by a licensed provider, but the imaging facility must be accredited. If you’re getting your scan at a freestanding radiology center rather than a hospital, confirm accreditation before your appointment.
What It Costs
MRI pricing varies dramatically depending on where you go. Hospital outpatient departments frequently charge four to ten times more than independent imaging centers or private orthopedic practices for the exact same scan. If you’re paying out of pocket or have a high deductible, call several facilities and ask for their cash price. Freestanding imaging centers are almost always cheaper, and the image quality from a high-field scanner is identical regardless of the setting.
Choosing the Right Scanner
MRI machines come in two main types: closed bore and open. Closed-bore scanners use magnets ranging from 1.0 to 3.0 Tesla in strength, producing high-resolution images that allow radiologists to see fine anatomical detail. These are the standard for most diagnostic scans. The trade-off is that you lie inside a narrow tube, which can be difficult if you’re claustrophobic or larger-bodied.
Open MRI scanners have magnets on the top and bottom with open sides, making them more comfortable. However, their magnetic field strength is typically only 0.2 to 0.3 Tesla, which produces lower-quality images. In some cases, a scan done on an open machine may need to be repeated on a closed scanner to get a clear enough picture for diagnosis. If claustrophobia is your main concern, ask your provider about sedation options (more on that below) rather than defaulting to an open scanner, since image quality matters for an accurate reading.
Weight and Size Limits
Standard MRI scanners have weight limits that typically range from 450 to 550 pounds, depending on the machine. But the bore diameter is often the bigger limiting factor. Most scanners have a 70 cm (about 27.5 inch) opening, and once protective padding and imaging coils are placed inside, the usable space shrinks by roughly 5 cm. If you’re concerned about fit, call the imaging center ahead of time. Some facilities have wider-bore machines (up to 80 cm), though availability is limited.
Preparing for Your Scan
Preparation depends on the type of MRI you’re getting. For a standard scan without contrast, you usually don’t need to change your diet or stop medications. If your scan involves contrast dye injected through an IV, you may be asked to avoid solid food for four to eight hours beforehand. Certain cardiac MRI exams require no food for two hours before the scan and no caffeine, coffee, tea, or chocolate for a full 24 hours prior.
Leave all metal and electronics at home or in a locker. Jewelry, watches, hairpins, eyeglasses, credit cards, pens, and clothing with metal zippers, hooks, or buttons all need to come off before you enter the scan room. Most facilities provide a gown. If you want to wear your own clothes, choose something with no metal at all, including bra clasps and drawstring tips.
Safety Screening
Before every MRI, you’ll fill out a safety questionnaire about implants, devices, and any metal that might be in your body. This isn’t a formality. The MRI’s magnetic field is powerful enough to move ferromagnetic metal and heat conductive materials, which can cause serious injury.
Devices and implants that may prevent you from having an MRI include:
- Certain pacemakers and heart leads: Temporary pacing leads and abandoned heart leads are not safe in an MRI. Some newer pacemakers are MRI-conditional, meaning they can be scanned under specific settings, but this requires coordination with your cardiologist.
- Insulin pumps: Both external and implanted pumps are affected by the magnetic field. External pumps must be removed and kept outside the scan room. Implanted pumps may need to be removed entirely before imaging.
- Metal fragments in the eye: If you’ve ever had metal shavings or fragments enter your eye (common in welding or metalworking), you may need a screening CT of your eye sockets before the MRI is approved.
- Certain gastric devices: Some reflux management systems use magnetic beads and are completely incompatible with MRI at any field strength.
If your scan requires contrast dye, your kidney function matters. The contrast agent used in MRI is gadolinium-based, and in people with reduced kidney function, it carries a small risk of a serious condition. If you have a history of kidney disease, diabetes treated with medication, high blood pressure requiring medication, or a prior organ transplant, you’ll need a blood test measuring your kidney filtration rate within six weeks of the scan.
Managing Claustrophobia
Feeling anxious about being inside a narrow tube for 20 to 60 minutes is common, and imaging centers deal with it routinely. If you know you’re claustrophobic, tell your ordering provider before the appointment. They can prescribe a mild oral anti-anxiety medication to take shortly before the scan. These medications make you drowsy and relaxed enough to lie still through the procedure.
If you take a sedative, you won’t be able to drive yourself home, so plan to bring someone with you. Some people manage without medication by using strategies like keeping their eyes closed the entire time, listening to music through the MRI-compatible headphones most centers provide, or asking for a washcloth over their eyes. The technologist can also talk to you through a speaker during the scan and will give you a squeeze ball to signal if you need a break.
What Happens During the Scan
You’ll lie on a padded table that slides into the scanner. Depending on the body part being imaged, the technologist may place a coil (a specialized antenna) over or around the area. You’ll need to stay very still, since even small movements blur the images. The machine makes loud knocking, buzzing, and thumping sounds throughout the scan, which is normal. You’ll be given earplugs or headphones.
A standard MRI takes 20 to 45 minutes. Scans with contrast take longer because images are captured both before and after the injection. Some complex studies, like cardiac or abdominal MRIs, can run up to 60 minutes or more. The scan is painless. The only sensation you might notice is mild warmth in the area being scanned, which is harmless.
Getting Your Results
After your scan, a radiologist reviews the images and writes a report for your ordering provider. Turnaround time varies by facility, urgency, and staffing. Emergency scans are read within minutes to hours. For routine outpatient MRIs, you can generally expect results within 24 hours to a few business days. Some facilities have patient portals where results post automatically once the report is finalized, sometimes before your doctor has had a chance to review them.
Your ordering provider will contact you to discuss the findings and next steps. If you see results on a portal and find the language confusing, wait for your provider’s interpretation rather than trying to decode radiology terminology on your own. Terms like “mild degenerative changes” or “small focus of signal abnormality” sound alarming but are often incidental findings that don’t require treatment.