Because MRI can give such clear pictures of soft-tissue structures near and
around bones, it is the most sensitive exam for spinal and joint problems. MRI
is widely used to diagnose sports-related injuries, especially
those affecting the knee, shoulder, hip, elbow, and wrist. The images allow
the physician to see even very small tears and injuries to ligaments and
muscles.
In addition, MRI of the heart, aorta, coronary arteries, and blood vessels
is a fast, noninvasive tool for diagnosing coronary artery disease and heart
problems. Physicians can examine the size and thickness of the chambers of the
heart, and determine the extent of damage caused by a heart attack or
progressive heart disease.
Organs of the chest and abdomen—including the lungs, liver, kidney, spleen,
pancreas, and abdominal vessels—can also be examined in high detail with
MRI,
enabling the diagnosis and evaluation of tumors and functional disorders. MRI
is growing in popularity as an alternative to traditional x-ray
mammography in the early diagnosis of breast cancer. Because no radiation
exposure is involved, MRI is often the preferred diagnostic tool for
examination of the male and female reproductive systems, pelvis and hips, and
the bladder.
How is the procedure performed?
The patient is placed on a sliding table and positioned comfortably for the
MRI examination. Then the radiologist and technologist leave the room and the
individual MRI sequences are performed. The patient is able to communicate
with the radiologist or technologist at any time using an intercom. Also, many
MRI centers allow a friend or, if a child is being examined, a parent to stay
in the room. Depending on how many images are needed, the exam will generally
take 15 to 45 minutes, although a very detailed study may take longer. You
will be asked not to move during the actual imaging process, but between
sequences some movement is allowed. Patients are generally required to remain
still for only a few seconds to a few minutes at a time.
Depending on the part of the body being examined, a contrast material may
be used to enhance the visibility of certain tissues or blood vessels. A small
needle connected to an intravenous line is placed in an arm or hand vein. A
saline solution will drip through the intravenous line to prevent clotting
until the contrast material is injected, about two-thirds of the
way through the exam.
When the exam is over the patient is asked to wait until the images are
examined to determine if more images are needed. A radiologist experienced in
MRI will analyze the images and send a report with his or her interpretation
to the patient's personal physician. This should take only a few days or less.
