Magnetic Resonance Imaging (or MRI) is a unique tool that constructs
cross-sectional pictures of internal organs and structures using radio
waves and magnets. MRI technology utilizes a powerful magnet to create a
magnetic field that attracts and aligns hydrogen atoms inside the body.
Radio wave pulses are then focused on the aligned atoms in a specific
organ or body part. These radio signals are returned to a computer which
translates them into three-dimensional images that radiologists can use
to depict small and hidden structures within organs, blood vessels or
joints or to contrast benign and cancerous tissue.
MRI imaging provides a unique view into the interior of the human body
and has become an essential tool of modern medical imaging and disease
diagnosis. In many cases, MRI provides important diagnostic information
that cannot be obtained with other imaging techniques.
MRI is particularly useful for:
Examining the brain, neck and spinal cord
Identifying bone and joint damage
Revealing brain abnormalities in people with Alzheimer's Disease
Helping with the diagnosis of central nervous system disorders,
like multiple sclerosis and strokes
Detecting breast cancer and damage to soft tissues
Evaluating blood vessels to detect areas of blockage
Main Line Health Imaging utilizes the latest MRI technologies, including
powerful 1.5-Tesla MRIs with 8-channel GE EXCITE coils. These machines
offer extremely precise and detailed views of the body, aiding in
complex diagnoses. And with their shorter tunnel length and less
confining space, the new high-field magnets provide a greater degree of
patient comfort than older MRI machines.
MRI has proven itself as an invaluable tool for the last 20 years, and
Main Line Health Imaging radiologists are confident that advancing
technology will find new applications for this important diagnostic
All MRI imaging requires a high-power magnet as part of the imaging
process. People with prostheses, artificial heart valves, implants, or
any metal device in their body must notify the MRI technologist before
entering the MRI. Under no circumstance should any patient with a
pacemaker enter the MRI room. Metalworkers who may have metal fragments
in the eyes have a risk of damage to the eyes if a small metal fragment
is present, and must have either a plain film or CT scan of the orbits
before entering the MRI. Hip prostheses and other imbedded prostheses
are usually safe for MRI imaging. As a precaution, every patient is
asked about any metal before entering the MRI. If you have any implant
or prosthesis, please have as much information about the implant on hand
for your MRI appointment.
State-of-the-art MRI scanners, such as those used at Main Line Health
Imaging, must place the magnetic field in very close proximity to the
body to create a good quality image. This requires the patient to lie
very still on a sliding table. The table is then slid into a narrow,
enclosed cylinder where each of the MRI sequences is performed. When the
MRI exam is completed, you are slid out of the machine. The entire
procedure is painless.
Some people can feel uncomfortable, even in modern short-bore MRI
magnets. "Open" MRIs have been developed for this reason. Main Line
Health Imaging does have open-bore MRIs at Bryn Mawr Hospital Outpatient
Imaging and Paoli MRI for those patients unable to tolerate conventional
MRI scanners. In addition, your doctor might prescribe a one-time dose
of oral sedation. This dose can do wonders for making you more
comfortable and can also reduce motion, which degrades the images.
Most MRI studies can be performed within 20-30 minutes. Some specialized
MRI studies or dual studies can take longer. If you think you may need
sedation, consult your primary doctor for a prescription for sedation
before the examination. It will make your MRI experience much more
For more information, call 1.866.CALL.MLH.