Magnetic Resonance Imaging (MRI) is a non-invasive medical technology that produces highly detailed, three-dimensional images of structures inside the body. This diagnostic tool uses a powerful magnetic field and radio waves to excite and detect the change in the alignment of protons found in the body’s water molecules. Unlike X-rays or Computed Tomography (CT) scans, the MRI procedure does not use ionizing radiation. This makes it particularly useful for imaging soft tissues such as the brain, spinal cord, muscles, ligaments, and tendons. The resulting images help physicians diagnose disease, monitor treatment effectiveness, and plan future medical procedures.
Securing the Medical Order
The process of obtaining an MRI begins with a formal assessment by a healthcare provider, such as a primary care physician or a specialist. The doctor evaluates your symptoms, medical history, and previous tests to determine if an MRI is the most appropriate diagnostic step. If the scan is deemed medically necessary, they will issue a formal medical order, which acts as a prescription for the imaging test.
This medical order initiates an administrative process concerning health insurance coverage. Because MRIs are expensive procedures, most insurance providers require prior authorization before agreeing to cover the cost. The doctor’s office must submit detailed clinical documentation to the insurance company to justify the medical necessity of the scan.
The prior authorization process can take a few business days while the insurer reviews the request. An approved authorization is often tied to a specific type of scan and a limited network of approved imaging facilities. Patients cannot typically schedule the test until this approval is secured, and the authorization confirms the service qualifies for coverage.
Essential Preparation Before the Scan
Once the appointment is scheduled, several preparation steps are required to ensure both your safety and image quality. Because the MRI machine generates an extremely strong magnetic field, all metallic objects must be removed from your person. This includes jewelry, watches, hairpins, hearing aids, and any clothing containing metal zippers, snaps, or underwire.
Patients must also inform the imaging staff about any internal metallic implants, as many older or specific devices are considered unsafe in the magnetic field. Examples of implants include:
- Pacemakers
- Aneurysm clips
- Cochlear implants
- Certain types of stents
For certain scans, particularly those involving the abdomen or pelvis, you may be asked to fast (not eat or drink) for four to six hours prior to the appointment. Fasting is often required if the physician anticipates administering a contrast agent, as this reduces the risk of nausea or vomiting while lying flat.
The most common contrast agent is a gadolinium-based solution, administered intravenously to enhance the visibility of specific tissues or blood vessels. If a contrast injection is planned, you must disclose any history of kidney problems, as poor kidney function can impair the body’s ability to safely clear the gadolinium from the system.
Navigating the MRI Procedure
Upon arrival at the imaging center, you will be asked to change into a gown and complete a final safety screening questionnaire regarding metal within or on your body. An MRI technologist will then guide you into the scanning room, where you will lie down on a narrow table that slides into the large, tube-shaped magnet. A specialized device called a coil may be placed over the body part being scanned, which helps to send and receive the radio signals for image acquisition.
The MRI machine is known for generating very loud, repetitive noises, often described as banging or knocking, which can reach sound levels well over 100 decibels. For this reason, the technologist will provide you with earplugs or headphones to protect your hearing. You will be able to communicate with the technologist via an intercom system throughout the entire procedure, and you may be given a call button to hold in your hand.
Remaining completely still is crucial, as even minor movement can blur the images and require the sequence to be repeated. The total scan duration typically lasts between 15 and 90 minutes. If contrast is required, the technologist will insert an intravenous line into your arm or hand, and you may experience a temporary sensation of warmth or a metallic taste in your mouth upon injection. The technologist operates the machine from an adjacent control room, monitoring you closely throughout the entire time the images are being acquired.
Understanding Costs and Receiving Results
The cost of an MRI can vary significantly based on the facility, with hospital-based imaging centers often charging more than independent outpatient clinics. Patients must contact their insurance provider before the appointment to understand their specific financial responsibilities, including any remaining deductible, copayment, or coinsurance amounts. Even with prior authorization, the final bill will still reflect these out-of-pocket expenses.
Once the scan is complete, the images are digitally sent to a radiologist, a physician specializing in interpreting medical images. The radiologist analyzes the cross-sectional images, prepares a detailed report that includes an “impression” of the findings, and electronically transmits this report to the doctor who ordered the test. Patients rarely receive their results immediately after the scan, as the interpretation process requires focused professional time. Your ordering physician will then contact you to discuss the radiologist’s findings and outline the next steps for your care.