Nuclear imaging
A reference guide so you know what to expect
If you are having tests or procedures done at St. Luke's, please
read this before your visit.
All females between the ages of 10 and 50 years old will be asked if they are
pregnant or nursing. If you confirm that you are pregnant or nursing, the
radiologist will discuss available options with you and your doctor. Options
include adjusting the amount of radioactive material given, postponing or
canceling the test.
Nuclear imaging
Nuclear imaging
Sestamibi Exercise Stress test
Also known as myocardial perfusion imaging, this test determines how well
the heart is supplied with blood at rest and after exercise. It will show if
there is decreased blood flow to the heart muscle during exercise and if
blood flow then increases with rest. If there is no blood flow in part of
the heart, a previous heart attack may have occurred.
Patients should avoid eating or drinking anything for 4 hours prior to
the procedure. For 24 hours prior to the test avoid all caffeine, including
diet pills, chocolate, coffee (including decaf), all soda, energy drinks and
some brands of aspirin. Patients who take medications for diabetes, asthma
or other conditions should discuss with their physician what can be taken
before the test. Wear comfortable shoes and clothing for exercising.
Patients who are unable to exercise are injected with a drug that simulates
the heart's reaction to exercise.
For the procedure, an IV will be inserted into a vein in the hand or arm
and a small amount of radioactive material (sestamibi) is injected into the
body to produce images of the heart. After a minimum of 30 minutes, the
patient is taken to a scan room. The patient lies on a table with arms
raised overhead while a camera scans over the heart. The scan may last 20 -
30 minutes. These images show the blood flow to the heart at rest.
For the stress portion of the procedure, 10 sensors are attached to the
chest with adhesive. These connect to an electrocardiogram (ECG) machine
that charts electrical activity in the heart. A resting ECG is performed. In
addition, blood pressures are taken throughout the stress test. Then the
patient exercises (walking on a treadmill) until the patient needs to stop.
Patients who are unable to exercise are injected with a drug that simulates
the heart's reaction to exercise. Shortly before exercise is stopped,
sestamibi is again injected into the IV. Nuclear images are again taken
after an appropriate delay. These images reflect the blood flow to the heart
at stress.
The entire test length is approximately 4 hours. You may bring reading
material, puzzles, etc.
For more information,
click here.
[ Top of page ]
Thallium Exercise Stress test
This is similar to the sestamibi
exercise stress test in its purpose. Patient preparation is also the
same as the sestamibi exercise stress test.
For this procedure, an IV will be inserted into a vein in the hand or
arm. The patient is connected to an electrocardiogram (ECG) machine, and a
blood pressure cuff. A resting ECG and blood pressure will be taken.
The stress portion of the test involves walking on a treadmill until the
patient needs to stop. Patients who are unable to exercise are injected with
a drug that simulates the heart's reaction to exercise. Shortly before
exercise is stopped, thallium, a radioactive material, is injected into the
IV. After exercising is complete, the patient is taken to a scan room. The
patient lies on a table with arms raised overhead while a camera scans over
the heart. The scan may last 30 45 minutes. These images show the blood
flow to the heart at stress.
After the stress scan is completed, there is a delay of 2 4 hours while
the heart returns to a resting state. A 2nd dose of thallium is then
injected and a resting scan of the blood flow to the heart is taken.
[ Top of page ]
Multigated acquisition scan
(MUGA)
The MUGA evaluates the pumping function of the heart's lower chambers
(ventricles). For the test, 3 electrodes are attached to the chest with
adhesive patches. They connect to an ECG machine to record the heart's
electrical activity. An IV is inserted into a vein in the hand or arm. A
sample of the patient's blood is drawn, mixed with a radioactive material,
and re-injected into the IV. Using the radioactive blood cells, a nuclear
camera acquires images that are then analyzed to determine the amount of
blood pumped out of the heart with each contraction or heartbeat. The MUGA
scan may take up to 2 hours to perform.
[ Top of page ]
Positron Emission Tomography (PET)
A PET scan helps provide information about the heart's metabolism and blood
flow as well as function of the heart muscle. It is most commonly used to
detect heart muscle weakness, rather than permanent heart damage. A weakened
heart may still benefit from angioplasty or heart bypass surgery.
The nuclear medicine staff will discuss diet and medication restrictions
when you are called to arrange your appointment. In general, however, you
will be asked to refrain from strenuous exercise for 48 hours before your
test, and avoid eating or drinking anything from the night before the PET
scan until the procedure is completed. If you are diabetic, the staff will
discuss your medication schedule for the day of the test.
For the procedure, an IV will be inserted in a vein in the hand or arm.
Your blood sugar will be checked by drawing a small sample of blood from the
IV, and testing it in a glucometer. A radioactive material will be injected
through the IV. Depending on the test ordered, a medication may be injected
to make the heart work harder. Imaging may be immediately after injection,
or there may be a delay of up to an hour (again, depending upon the test
ordered). The PET camera is shaped like a donut. The patient lies on a table
connected to the machine that slides into the center hole of the donut
(similar to a CT scanner). The procedure may take 3 4 hours.
For more information,
click here.
[ Top of page ]
|
