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What is MRI?
Magnetic resonance imaging, or MRI, is one of the safest, most comfortable
imaging techniques available today. It combines a powerful magnet
with an advanced computer system and radio waves. Together, they
produce accurate, detailed pictures of organs and tissues for the
diagnosis of a variety of medical conditions.
Common uses of this procedure
Since MRI can provide 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
.   
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 in MRI images, enabling the diagnosis
and evaluation of tumors and functional disorders.
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 does it work?
MRI is a unique imaging method because, unlike the usual radiographs
(x-rays), radioisotope studies, and even CT scanning, it does not
rely on ionizing radiation. Instead, radio waves are directed at
protons, the nuclei of hydrogen atoms, in a strong magnetic field.
The protons are first "excited" and then "relaxed," emitting
radio signals, which can be computer-processed to form an image.
In the body, protons are most abundant in the hydrogen atoms of
water -- the "H" of H2O -- so that an MRI image shows
differences in the water content and distribution in various body
tissues. Even different types of tissue within the same organ,
such as the gray and white matter of the brain, can easily be distinguished.
Typically an MRI exam consists of two to six imaging sequences,
each lasting two to 15 minutes. Each sequence has its own degree
of contrast and shows a cross section of the body in one of several
planes (right to left, front to back, upper to lower).
Benefits vs. risks of a MRI?
Benefits
- Images of the soft-tissue structures of the body - such as the
heart, lungs, liver, and other organs - are clearer and more detailed
than with other imaging methods.
- MRI images can help physicians evaluate the function as well
as the structure of many organs.
- The detail of MRI images makes MRI an invaluable tool in early
diagnosis and evaluation of tumors.
- MRI contrast material is less likely to produce an allergic reaction
than the iodine-based materials used for conventional x-rays
and CT scanning.
- MRI enables the detection of abnormalities that might be obscured
by bone with other imaging methods
- MRI provides a fast, noninvasive alternative to x-ray angiography
for diagnosing problems of the heart and cardiovascular system.
- Exposure to radiation is avoided.
Risks
- An undetected metal implant may be affected by the strong magnetic
field.
- MRI is generally avoided in the first 12 weeks of pregnancy. Doctors
usually use other methods of imaging, such as ultrasound, on
pregnant women, unless there is a strong medical reason.
Patient Comfort
Image North’s MRI system was designed with patient comfort
in mind.
During the exam, the patient may be injected with an image enhancement
agent, which in some conditions, helps to provide additional information.
Music is provided through headphones during the exam. Patients may
choose a favorite radio station or CD.
The exam takes 15 to 60 minutes, depending upon the type of information
needed.
Preparation Required
There is no special preparation for an MRI exam. The patient should
wear comfortable clothing, like a sweat suit without metal snaps
or zippers. Gowns are also available. Hairpins should not be worn.
No jewelry or watches should be worn into the scan room, and it
is best to leave jewelry at home.
An MRI exam is safe, simple, and painless. However, because some
metal interferes with the MRI machine, a patient cannot be examined
if they have:
- Brain aneurysm clips
- A pacemaker or pacing wires
- Metal fragments in one or
both eyes
- Inner ear implants
- An implanted spinal cord stimulator
or brain stimulator
After the test
The patient may leave immediately following the exam because the
MRI has no side effects.
Getting Your Results
Image North has radiologists on site to promptly provide analysis
and reporting. In most cases, the results of the test will be available
to the referring doctor before the patient leaves the facility.
The radiologist at Image North may discuss the results with the
patient, or privately and securely send the results to the referring
physician.
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