Magnetic Resonance Imaging is truly one of the medical wonders of the modern world, giving physicians the ability to see internal tissues and even brain function in three-dimensional detail.
Hoag stands ready, with a convenient MRI imaging center near you. From joint issues to next-generation techniques like functional magnetic resonance imaging (fMRI) and Magnetic Resonance Venography (MRV), Hoag has the tools and technology to get to the root of the problem and find the treatment you need to heal.
Magnetic resonance imaging (MRI) is a noninvasive diagnostic imaging technology that can produce detailed images of almost every internal structure in the body, including organs, ligaments, muscles, brain tissue, the spine and spinal cord, blood vessels and more.
In addition to being three-dimensional, these images allow tissues and organs to be viewed in cross-section as if divided into very thin slices, giving a radiologist or treatment team very precise control of angles and views.
A traditional MRI scan creates high-quality images of the body by sliding the patient into a large tube, around which are arranged powerful magnets. During scans, radio waves interact with the magnetic field created by these magnets to produce MRI images. These images provide physicians with data that can be helpful when diagnosing conditions and in the research and planning phase prior to medical procedures and treatments.
There are a number of different types of specialized MRI scan, including functional magnetic resonance imaging (fMRI), which can be used to visualize which areas of the brain are activated during different body movements or thinking exercises, and Magnetic Resonance Venography (MRV), which utilizes a special dye to create high-detail images of veins and arteries.
An MRI machine is a large, often cylindrical device with an opening in the center through which the patient’s body is passed on a sliding table. Once a patient is moved inside the machine, it creates a strong magnetic field around the patient.
This causes the atoms inside the patient’s body to align in a specific direction. Pulses of radio waves are then delivered through the magnetic field by the MRI machine, causing these atoms to move out of their original position. When the radio waves are turned off, this causes the atoms to return to their original position and send back radio signals.
These signals are then converted into high resolution imaging by a computer, with the image displayed on a video monitor. This video can then be viewed and interpreted by a healthcare specialist.
As a diagnostic procedure, MRI is a very versatile technology, and can be used to safely diagnose or monitor a wide range of conditions throughout the body. Nearly any part of the body that can remain motionless during imaging can be visualized through MRI.
MRI is especially useful for visualizing soft tissue, including the brain, spinal cord, muscles and joints. These structures can be seen much more clearly in MRI images than in images created through X-rays or CT scan, making it the preferred choice for diagnosing a range of medical issues, including brain injuries, seizures, knee and shoulder injuries, joint problems and much more.
The technology can also help diagnose or monitor cancerous tumors, aneurysms, cognitive diseases like Alzheimer’s, spinal cord injuries and other serious medical issues.
While both MRI and CT scan are types of medical imaging techniques, they use different technologies. CT scans utilize X-ray radiation to create an image, while MRI uses strong magnetic fields and radio waves.
MRI is better at differentiating between soft tissues, creates higher-quality images, can be used to visualize brain function and doesn’t use ionizing radiation. These qualities make MRI more versatile and potentially safer for patients than medical imaging through technologies like CT scan or ultrasound.
Some MRI exams require a special liquid called a contrast agent to be injected into the patient’s bloodstream before the exam to help differentiate certain internal tissues from others. This contrast agent helps enhance the clarity and precision of the image produced, especially when looking at blood vessels or detecting tumors.
Preparation for MRI tests and what you can expect as a patient can vary depending on the type of MRI. Always be sure to follow the instructions of your physician and imaging center staff, but in general:
Ask your doctor if you should bring ear plugs, as the equipment can create loud noise as it operates.
Patients who experience claustrophobia should be sure to tell their doctor when they schedule the test, as MRI exams usually include being in a tight space inside the machine for an extended period of time. Your health care provider can potentially prescribe anti-anxiety medication to help you have a positive experience, or you may be referred to an imaging center with a special type of machine — called an Open MRI — that’s much less restrictive for the patient during tests.
Patients can usually eat, drink and take medications as usual before an MRI scan. If the MRI requires contrast, however, you should expect to fast or follow specific dietary instructions before the procedure, so be sure to check with your doctor
Because of the strong magnetic field used to produce an MRI scan, there is a risk of serious injury to people or damage to the equipment if anything metal is brought near the MRI machine while the test is being performed.
To reduce these risks, it’s essential that nothing that can be attracted by a magnet be brought into the environment near the equipment while it is operating.
In particular:
Make sure the clothing you wear to your MRI appointment has no metal buttons, zippers, hooks, grommets or other metal closures. Some shoes have metal parts hidden inside the soles, so patients should wear soft footwear if possible. Purses or wallets with metal rings or clasps should also be left at home.
Remove all metal jewelry, piercings, belt buckles, change, pocket knives, rings, earrings, keys and other metal objects before the MRI appointment. If in doubt, leave it at home.
Make sure to tell your doctor or the staff at the imaging facility before the test if you have any metal in your body, including devices like pacemakers, metal screws or pins used to repair broken bones, metal plates, metal hip, shoulder or knee implants, cochlear implants, etc.
Don’t bring any debit, credit or swipe cards with a magnetic strip or any electronic devices like cell phones near MRI equipment, as the magnetic field could attract the metal inside or damage the information contained on these cards and devices.
If there’s a risk you have a piece of metal anywhere in your body, like a fragment of shrapnel or a sliver of steel in your finger, hand or eye due to metalworking, be sure to tell your doctor or imaging center staff so it can be investigated before the procedure.
Unlike imaging options that utilize X-ray energy, no ionizing radiation is produced or utilized during an MRI exam. Because X-rays and other forms of radiation aren’t used to produce images, the procedure is potentially safer for patients than many other types of medical imaging.
The time required to complete the imaging can vary from patient to patient, but most scans take between 30 minutes to an hour.
It’s important to remain still during the procedure to ensure clear images, so let your doctor know before the scan if you have a condition that makes being still or control of your movements for long periods hard or impossible.
After the test, the information collected is analyzed by a radiologist. Usually, results are available within a few days, but this can vary depending on the type of procedure performed and other factors