MRI

Magnetic resonance imaging (MRI) uses radio waves and powerful magnets to create three-dimensional (3D) images of the inside of your body. Unlike x-rays and CT scans, MRIs do not use ionizing radiation. This makes them a safer option for people who need frequent imaging scans.

At Penn Medicine, we use MRIs to diagnose and monitor many conditions that affect the brain, spinal cord, nerves, lymph nodes, soft tissues, and other non-bony parts of your body. Our MRI services are accredited and led by an experienced multispecialty team, using state-of-the-art imaging technology to produce the best scans possible. For many conditions, MRI scans can give you an accurate diagnosis and help determine the most effective treatment.

An MRI works by creating a strong magnetic field around your body. The magnet forces hydrogen atoms (present in every cell) to align with its magnetic field.

Next, a scanner sends radio waves through your body to knock the atoms out of alignment. When the radio waves are turned off, the atoms realign with the magnetic field and release energy in the process.

Atoms in different types of tissue release different levels of energy. A sensor detects the energy and sends the data to a computer that creates 3D pictures.

Any MRI has many uses. We may use it to look for causes of unexplained symptoms such as headaches or back pain. It’s beneficial for monitoring conditions like brain tumors and cancer. Surgeons and interventional radiologists also use MRI guidance to perform certain treatments and procedures such as biopsies.

You may have an MRI with or without contrast. A contrast agent is a material that makes certain tissues or structures appear in more detail on imaging scans. MRI contrast is a safe and useful tool in many cases, open communication with your healthcare provider about your health history is essential to ensure your safety and well-being during the procedure. If you need an MRI with contrast, we inject the material into a vein in your arm.

Common types of MRI include:

• Abdominal and pelvic MRI: creates pictures of the bladder, liver, kidneys, spleen, and reproductive organs
• Brain MRI: evaluates the structure of the brain, brain tumors, and changes to brain tissue
• Breast MRI: provides more detailed images in people who are high risk for breast cancer, have received a recent breast cancer diagnosis, or had an abnormal mammogram
• Cardiac MRI: evaluates the size and function of the heart, as well as the tissue and blood vessels around it
• Functional MRI (fMRI): measures brain activity and blood flow when you speak, think, and move, and detects brain damage or degeneration
• MR angiography (MRA): evaluates (usually with contrast) narrowed or blocked blood vessels throughout your body
• MR enterography: evaluates the small intestine to detect problems in the digestive tract
• Musculoskeletal MRI: evaluates the joints, spine, and soft tissues around bones

We may recommend an MRI to diagnose:

• Abnormal blood vessels or aneurysms
• Cancer that has spread to lymph nodes or other areas of the body
• Damage or scarring from a stroke or heart attack
• Inflammatory diseases and infections
• Injuries to tendons, cartilage, ligaments, and muscles
• Neurological disorders such as epilepsy, multiple sclerosis, and Alzheimer’s disease
• Spinal cord injuries or degenerative diseases
• Stroke and bleeding in the brain
• Tumors anywhere in the body

An MRI typically takes 20 minutes to an hour, depending on the type of scan you need. Radiation technologists and radiologists work together to perform and review MRI scans. The scans are done at a hospital or outpatient imaging facility, and you may be given instructions on how to prepare for the scan. Tell your care team before your appointment if you’re pregnant or if you have an implanted medical device or other metal in your body.

An MRI is painless and noninvasive. Most MRI machines are enclosed, tube-shaped structures with a bed that slowly slides into the machine. If you have a fear of enclosed spaces, talk to your care team. Medication may help you relax, or an open MRI machine may be an option.

Once you arrive for your appointment, you’ll change into a hospital gown and remove all jewelry and other metal. If your scan includes the use of a contrast agent, you’ll be given it through an IV in your arm. After lying down on the scanning bed, a coil may be placed on part of your body to help take accurate images. After the bed moves into the scanner, you’ll hear loud knocking noises during the scan. The bed moves out of the scanner when the test is over.

There’s no downtime after an MRI. It doesn’t require anesthesia, so you can resume normal activities after the scan. You may need someone to drive you home if you have a sedative. If you have an MRI with contrast, we may ask you to remain at the hospital or imaging facility a bit longer so we can make sure you’re not experiencing any side effects from the contrast agent.

An MRI is a safe exam for most people. But some implanted devices that contain metal shouldn’t be scanned because the magnet can interfere with how they work. Tell the radiology technologist if you have any of the following medical implants:

• Artificial joint (prosthesis)
• Cochlear implant
• Pacemaker or defibrillator
• Clips or coils for aneurysms or other vascular conditions
• Neurostimulator

At Penn Medicine, we stay current on the latest advances in radiation technology to deliver accurate results and the answers you need. Our imaging program is home to renowned radiologists who are leaders in neurodiagnostics, breast imaging, cardiothoracic imaging, and other specialties. When you turn to us for your MRI scan, you’ll find:

• Recognized expertise: We are fully accredited in magnetic resonance imaging by the American College of Radiology. This accreditation demonstrates our commitment to exceptional care, from the training of our staff to the quality and safety of our equipment.
• Advanced technology: Our leading-edge MRI systems use some of the strongest magnets clinically available to produce high-resolution images with incredible speed. We also offer 3T MRIs with twice the magnetic field strength of traditional MRIs. They produce clearer, more detailed images. Our MRI systems allow you to spend less time in the scanner and are more likely to get an accurate scan the first time, reducing the need for a repeat MRI.
• Customized care: Your comfort and peace of mind are our top priorities. We offer special MRI systems that can accommodate larger people or those with claustrophobia at many of our imaging locations throughout Pennsylvania and New Jersey. Our 3T MRI machines have larger openings and are designed for you to enter feet first, making the test more comfortable. You may have the option of an ambient experience, which includes your choice of lighting, animation, and sounds—including themes designed for children—for a soothing environment.