What is an MRI?

An MRI is a painless, noninvasive imaging test, or scan, that uses large magnets, radio waves, and a computer to produce detailed images of organs and body structures. This includes ligaments, cartilage, tendons, blood vessels, bones, spinal discs, and organs such as the pancreas or brain. 

An MRI, also called magnetic resonance imaging, provides information not available with X-rays, CT scans, or ultrasounds. Sometimes, patients receive a contrast agent or dye to further improve the clarity of MRI images.

A radiologist will review your MRI images and discuss them with your doctor, who will discuss the results with you. Together, you will decide what next steps, if any, you need to take based on the MRI results.

An MRI is only one method used to diagnose diseases, disorders and conditions. Discuss all of your testing options with your doctor to understand which options are right for you.

Types of MRIs

Doctors order MRIs to make detailed images of the organs and structures of the head, chest, abdomen, pelvis, spine, bones and joints. An MRI may be combined with other imaging techniques, such as ultrasound or CT scan. There are also a variety of specialized types of MRIs including:

  • Functional MRI (FMRI) uses MRI to identify areas of active brain function during specific tasks. FMRI can help plan certain types of brain surgery. 
  • Interventional MRI uses MRI images to guide minimally invasive procedures.
  • Magnetic resonance angiography (MRA) makes images of blood vessels.
  • Positron emission tomography/MRI (PET/MRI) is a type of nuclear imaging test that creates detailed images using a radioactive substance and a special camera combined with an MRI.
  • Real-time MRI captures real-time, continuous pictures of the body’s organs or structures in action, such as a beating heart or a moving joint.

Why is an MRI performed? 

Your doctor may recommend to diagnose, screen or monitor the following:

  • Abdominal organ diseases including liver cirrhosis, cholecystitis (gallbladder inflammation), choledocholithiasis (gallstones in the bile duct) and pancreatitis
  • Eye and inner ear disorders including eye tumors, thyroid ophthalmopathy, and Meniere's disease
  • Female pelvic conditions including fibroids, endometriosis, and uterine abnormalities that cause infertility
  • Heart and blood vessel problems including aneurysms, coronary heart disease, peripheral artery disease, renal artery stenosis (narrowing), pulmonary embolism, and birth defects 
  • Joint and bone problems including spinal cord injuries, spinal disc problems, and bone infections
  • Nervous system problems including seizures, stroke, multiple sclerosis, and birth defects of the brain and spinal cord
  • Tumors and cysts including benign masses and cancer in many parts of the body such as the breast, pancreas and kidney 

MRIs are also used to:

  • Confirm a diagnosis of symptoms including joint pain, changes in vision, leg pain with exercise, dizziness, and abdominal and pelvic pain 
  • Evaluate a fetus during pregnancy
  • Guide procedures including stent placements
  • Plan surgery and other treatments including coronary artery bypass grafting (CABG) and organ transplant surgeries

Who performs an MRI?

A radiologic technologist, under the supervision of a doctor, performs an MRI. A radiologic technologist is a healthcare provider who performs imaging procedures and takes care of patients during the procedures. 

The following types of doctors may supervise the radiologic technologist performing your MRI, and interpret the results of the MRI:

  • Radiologists specialize in using radiation and other imaging techniques to diagnose and treat a wide variety of conditions from broken bones and birth defects to cancer. 
  • Diagnostic radiologists focus on performing and interpreting imaging tests, such as ultrasounds, X-rays, angiograms, CTs, and MRIs. 
  • Pediatric radiologists specialize in diagnosing and treating diseases and conditions of children using imaging technologies.
  • Radiation oncologists focus on treating cancer and related diseases with radiation.