Magnetic Resonance Imaging
Jennifer and Janelle
MRI is based on a physics phenomenon
discovered in the 1930s, called nuclear magnetic
resonance or NMR, in which magnetic fields and
radio waves cause atoms to give off tiny radio
The 2003 Nobel Prize in Physiology or Medicine
was awarded to Paul C Lauterbur and Peter
Mansfield for their discoveries concerning
magnetic resonance imaging.
MRI is primarily a medical imaging technique
most commonly used in radiology to visualize the
structure and function of the body.
MRI provides much greater contrast between the
different soft tissues of the body than computed
tomography (CT) does, making it especially useful
in neurological (brain), musculoskeletal,
cardiovascular, and oncological (cancer) imaging.
• MRI has been in use for
little more than 30 years
(compared with over 110
years for X-ray
radiography). The first
MR Image was published
in 1973 and the first study
performed on a human
took place on July 3,
Organs of the chest,
abdomen and pelvis—
including the heart, liver,
biliary tract, kidney, spleen,
and pancreas and adrenal
Pelvic organs including the
reproductive organs in the
male (prostate and testicles)
and the female (uterus,
cervix and ovaries).
Pelvic and hip bones
Blood vessels (MR
conditions such as:
tumors, coronary artery
of the heart, diseases of
How It Works
• You will be positioned on the moveable
• Straps may be used to help you stay still and
• Small devices that contain coils capable of
sending and receiving radio waves may be
placed around the area of the body being
How It Works cont.
If a contrast material will be used in the MRI exam, a
nurse will insert and IV into a vein in your hand or
You will be moved into the magnet of the MRI and
the radiologist will leave the room while the
procedure is done.
When the examination is completed you may be
asked to wait until the technologist checks the
The IV will be removed.
Generally includes multiples runs, some of which
may last several minutes.
The entire exam is usually completed within 45
• Does not involve
exposure to radiation.
• More likely to identify
abnormalities than any
other imaging method.
• Proven valuable in
heart disease, and
• Less likely to produce
an allergic reaction.
• Provides a fast
to x-ray angiography
problems of the heart
and blood vessels.
• Allows doctors to
assess the biliary
and without contract
• Poses almost no risk to
the average patient.
• If sedation is used
there are risk of
• Medical devices that
contain metal may
malfunction or cause
For the Patients
May be asked to wear a
gown during exam.
Guidelines to eating may
Take normal medications
Some MRI’s may require
the patient to swallow
contrast material or
receive an injecgtion.
For the Patient cont.
• The radiologist should
know if you have any
health problems, or if
you may be pregnant.
• No jewlery, hair pins,
removable dental work,
pocket knifes, or body
• You may have metal
implants, a pacemaker,
ear implant, and/or
brain aneurysm clamps.
The magnetic field is
produced by passing an
electric current through
wire coils in most MRI
units. Other coils,
located in the machine
and in some cases,
placed around the part
of the body being
imaged, send and
receive radio waves,
producing signals that
are detected by the
• A computer then processes the signals and
generates a series of images each of which shows
a thin slice of the body. The images can then be
studied from different angles by the interpreting
• Overall, the differentiation of abnormal (diseased)
tissue from normal tissues is often easier with
MRI than with other imaging modalities such as x-
ray, CT and ultrasound.
• The body is mainly composed of water molecules which
each contain two hydrogen nuclei or protons. When a
person goes inside the powerful magnetic field of the
scanner these protons align with the direction of the field.
• A second radiofrequency electromagnetic field is then
briefly turned on causing the protons to absorb some of its
energy. When this field is turned off the protons release
this energy at a radiofrequency which can be detected by
the scanner. The position of protons in the body can be
determined by applying additional magnetic fields during
the scan which allows an image of the body to be built up.
These are created by turning gradients coils on and off
which creates the knocking sounds heard during an MR
• Diseased tissue, such as tumors, can be detected
because the protons in different tissues return to
their equilibrium state at different rates. By
changing the parameters on the scanner this
effect is used to create contrast between different
types of body tissue.
• MRI is used to image every part of the body, but
is particularly useful in neurological conditions,
disorders of the muscles and joints, for evaluating
tumors and showing abnormalities in the heart
and blood vessels.
What does MRI stand for?
• A) Magnets Rebel Inside
• B) Maggots really icky
• C) Magnetic Resonance Imaging
• D) My Resource imaging
Which of the following is not
what MRI is used to look at?
• A) Bones
• B) Hair
• C) Your friend
• D) Tissue
True or False: You are permitted to wear
jewelry and hair pins during the procedure?
• A) True
• B) False
Which of the following is a
Benefit of MRI’s?
• A) You will not be cured
• B) Your cat will die
• C) No exposure to radiation
• D) your hair will fall out
Which of the following can
determine abnormal from normal