_________________________________________________________________________
-
What is MRI?
Magnetic Resonance Imaging is a
modern computerized method of scanning, creating images using a
strong magnetic field and radio waves. The hydrogen atoms in the
patient's body react to the magnetic field and emit signals which
are analyzed by a computer to produce images. The images obtained
help in detecting various abnormalities in the tissues scanned.
MRI is a non-invasive,
sophisticated diagnostic imaging technique that utilizes a strong
magnetic field in conjunction with low energy electromagnetic
waves to produce high-resolution images of internal body organs
and tissue from any angle and direction and without surgical
invasion. MRI has proven to be invaluable to the diagnosis of a
broad range of conditions, including
-
brain tumors;
- disorders of the eyes and inner
ear;
- cancer;
- stroke and heart disease; and
- Joint and musculoskeletal
disorders and diseases of the knee, shoulder, spine, hips,
wrists and hands, where it allows evaluation of parts of the
body not possible with other imaging techniques.
MRI can also create images of
vessels without depending on the significant volume of
contrast agent required by X-ray angiograph which patients may be sensitive
to.
MR Angiography (MRA) allows the physician to:
- evaluate aneurysms,
arteriovenous malformations (AVMs) and occlusions of the intra
cranial vessels; and
- screen for atherosclerotic
plaques and abnormalities in the carotid and iliofemoral
circulation, including in the extremities, abdomen and chest.
MRA is also well suited for
evaluation of the slow flow present within the dural venous
sinuses and to rule out superior sagittal sinus thrombosis, and
also clearly depicts arteries in the Circle of Willis as well as
the proximal portions of the anterior, middle and posterior
cerebral arteries.

- What type of equipment is use in
scanning
images?
-
There are
two types of MRI units;
high-field MRI and low-field, open MRI. In the former, the patient
lies still within a cylindrical magnet while radio waves are
directed at protons, the nuclei of hydrogen atoms, which are
alternately excited and relaxed, emitting radio signals which
are then processed by a computer to form an image.
High-field MRI produces superior
images in a shorter scan time and is preferred by most physicians.
Low field, open MRI is dictated for patients who are
claustrophobic or obese. Image quality is good but the scan time
is generally longer than the high-field unit.
Importance
of MRI
-
MRI is painless
and has no known side effects.
-
It usually reveals
more details than other imaging modalities. Usually there is a
clear distinction between healthy and diseased tissue on MRI.
- Harmful effects of
radiation are avoided.
MRI does not
use X-rays or radiation.
-
The MRI test does require
minimal
restrictions on diet or medication. Refrain from having a heavy
meal, as it is sometimes difficult to lie flat with a full
stomach.
-
If scheduled for a test of the
abdomen/pelvis, do not eat or drink anything for at least six
hours prior to the test.
-
If sedation has been scheduled, a full
set of instructions will be provided. Please inform us in
advance if claustrophobic. This will enable us to issue a set of
guidelines to you in advance.
-
Wear comfortable clothing without
zippers or snaps. You may be asked to change into a hospital
scrubs.
-
Please avoid jewelry and face or eye
makeup.
-
Your child may eat or drink prior to the
test. For small children, we have
found that they fall asleep more easily if they have been kept
up late the night prior and woken up early on the day of the
test.
-
Occasionally an intravenous
administration of contrast material (Gadolinium-chelate) may be
required.
-
Magnetic
resonance imaging (MRI) is a method of producing extremely detailed
pictures of body tissues and organs without the need for
radiation.
The electromagnetic energy that is released when exposing a patient to
radiofrequency waves in a strong magnetic field is measured and analyzed by a computer,
which forms two- or three-dimensional images that may be viewed on a monitor. MR angiography (MRA) is an MR study of the blood vessels. It
utilizes MR technology to detect, diagnose and aid the treatment of heart
disorders, stroke, and blood vessel diseases. MRA provides detailed images
of blood vessels without using any
contrast
material, although a special form of contrast material is often given
to make the MRI images even clearer. The procedure is painless, and the
magnetic field is not known to cause tissue damage of any kind.
-
What is MR
Arthrography?
The term "arthrogram" means "study of a joint." In an MR arthrogram, fluid is placed into the joint.
The addition of this contrast greatly enhances the quality of the examination. This examination gives your doctor important information about many problems with your joint. In most centers, X-rays are used to confirm placement of the
contrast into the joint.
If you have any questions during the examination, don’t
hesitate to ask your technologist or contact us at 601-485-2485 if there are other
questions we can answer for you.
|