Cardiac Nuclear Imaging
Cardiac nuclear imaging measures the flow of blood in your heart at rest
and then during exercise. The images are compared to determine whether
there are any blockages in the arteries or if there has been a prior heart
attack. The test will also measure how efficient the heart pumps. This
test is sometimes called a "perfusion scan" or a "SPECT
MPI" (single photon emission computed tomography myocardial perfusion
imaging). For the scan, a safe amount of radioactive matter called "tracer"
is delivered into the bloodstream. A special camera then scans the tracer
in the blood as it flows through the heart muscle. Areas of the heart
that have good blood flow absorb the tracer. Areas that are not getting
enough blood will not absorb the tracer. This can be a sign of a blocked
artery or damage from a heart attack.
Before your test
- The total test time is approximately 3-4 hours.
- When you schedule the test, be sure to tell your doctor about any medications
you take. Ask if you should stop taking any of them the day of the test.
- Before your test, stop smoking and avoid caffeine for as long as directed.
This includes avoiding medications that have caffeine as an ingredient
and all caffienated beverages and foods such as coffee, tea and chocolate.
- Do not eat or drink for 4-6 hours before the test. Sips of water are okay.
- On the day of the test, dress for comfort. Wear a two-piece outfit, top
and bottoms. Be sure to wear walking shoes.
During your test
- You may be asked to change into a hospital gown.
- You will be attached to EKG and blood pressure monitors. An IV line will
be started in your arm.
- At some point, scanning pictures will be taken while you rest. This may
be done before you exercise or you may be asked to return for resting
scans later that day or the next day.
- You will exercise on a treadmill for a few minutes.
- Speak up when you feel that you cannot exercise for even one more minute.
At this point, the tracer is given to you through the IV.
- After you have received the tracer, you will be positioned on the scanning bed.
- You must lie very still for up to 30 minutes. During this time, a scanning
camera will be taking pictures. The images will show where blood flows
through your heart muscle.
After your test
Your test results will be sent to your primary care physician.