How is the test performed ?

Myocardial perfusion imaging (MPI) with gated imaging is performed in two parts: (1) Rest study, (2) Stress study

Part I: Rest study: In the rest study, the patient is injected with a radioactive tracer in an arm vein. Depending on the type of radioactive tracer used for the rest study, the patient then waits approximately 30 to 45 minutes. Pictures (or scan) of the heart are then taken using a special type of camera, called SPECT.

Part II: In the stress study, the patient undergoes a stress test on a treadmill or, if the patient cannot exercise on the treadmill, is given a drug in a vein that simulates stress. A cardiologist monitors the patient's blood pressure, heart rate, and EKG throughout the stress study. At a specified time during the stress test, the patient is injected with the radioactive tracer and, shortly thereafter, the stress test is terminated. Depending on the type of stress test done, and radioactive tracer injected during the stress study, the patient waits approximately 15 to 30 minutes before scans of the heart are taken with the SPECT camera.

There are two types of SPECT cameras used at the Washington Hospital Center. These are the conventional or regular SPECT camera and the new, advanced D-SPECT® camera. Only one type of camera is used for each patient's rest and stress studies.

Conventional SPECT camera

With the conventional SPECT camera, the patient lies flat on an imaging table and the camera rotates around the patient's chest to scan the heart for approximately 20 to 30 minutes.

New D-SPECT® camera

With the new D-SPECT® camera, the patient sits in a specially designed reclining chair with a smaller sized camera that is fixed in place over the patient's chest. Unlike the conventional SPECT camera, the D-SPECT® does not rotate around the patient. The D-SPECT® takes scans of the heart for as short as 2 to 4 minutes.

The images are computer-processed and both stress and rest images are reviewed, compared, and analyzed by a Nuclear Medicine physician.

Evaluating Test Results

A Nuclear Medicine physician will read the images once they are computer-processed. The physician will compare the stress images with the rest images to determine if there is abnormal blood flow to the heart muscle during stress, which indicates significant blockage of a coronary artery.

Gated perfusion imaging is done as part of myocardial perfusion imaging. Scans of the heart are obtained and synchronized (or timed) with the patient's heart rhythm, making it possible to display scans of a beating heart for evaluation of heart muscle motion and pumping function.

Preparing for an MPI Test

You will receive detailed instructions regarding the test when you schedule. Please follow the detailed instructions provided by our staff scheduling the appointment.

Myocardial perfusion imaging (MPI) with gated imaging:

  • Do not eat or drink after midnight, except for water or clear liquids for taking your medicines.
  • If you have diabetes and take insulin or other medication for your diabetes, do not take your morning dose; however, bring your insulin or diabetes pills with you. After your stress test, you will be allowed to have something to eat, and you can take your diabetes medicine at that time.
  • Do not drink coffee or other drinks or food that contain caffeine (including decaffeinated drinks), at least 12 hours before your study.
  • Do not smoke at least 24 hours before the study.
  • Wear comfortable clothing. If you are scheduled to exercise on a treadmill exercise, wear comfortable, rubber-soled shoes.
  • Bring your doctor's referral form for your study along with your medical insurance card.

Medications

  • If you are on any prescription drugs for your heart and/or high blood pressure, ask your doctor if he wants you to continue taking, or stop taking, these medicines before your study.
  • Bring a list of all your medications.

Precautions

  • If there is a possibility that you are pregnant, or if you are breast feeding, notify your doctor immediately, and also notify the staff in Nuclear Medicine.

MUGA (Multiple gated acquisition) also evaluates motion of the heart muscle and pumping function of the heart, but is done differently than the gated perfusion imaging. It is ordered primarily in patients undergoing chemotherapy to determine the presence and extent of side effect of chemotherapy on heart function. Patients with heart failure or heart valve disease can also be evaluated with this study to determine the severity of the disease based on its effect on the pumping function of the heart.

MUGA is done by using radioactive tracer that attaches (or tags) to the red blood cells circulating through the heart. Scans of the heart are also synchronized with the patient's heart rhythm for evaluation of heart muscle motion and pumping function of the heart. 

Precautions

  • If there is a possibility that you are pregnant, or if you are breast feeding, notify your doctor immediately, and also notify the staff in Nuclear Medicine.
  • Othewise, no other special preparation for a MUGA imaging.

How does a patient make an appointment for Nuclear Cardiology Imaging

  • To make an appointment, please call the Division of Nuclear Medicine at (202) 877-6066 between the hours of 8:00 AM to 5:00 PM, Monday - Friday.
  • You will receive additional instructions over the phone from the office staff scheduling your appointment.

What can a patient expect on arrival in Nuclear Medicine

  • You will be met by one of the receptionist who will escort you to the registration desk with your document file (most of your documents would have already been completed ahead of time by the registration staff prior to your arrival).
  • Once you have completed registration, you will be asked to fill out a history questionnaire.
  • You will then be escorted to the changing room where you will be asked to change into a hospital gown (you will only need to change the top part of your clothing).
  • The technologist or technologist assistant will then review with you the procedure involve with your study, and will also answer questions that you might have about the study.