“What does a nuclear medicine exam entail?”
I was referred to a nuclear medicine exam after a routine checkup that showed issues within my cardiovascular system. He didn't give me much information on what this really means or what it involves. My main question is, what do these tests typically involve? Does it mean that I have a serious illness?
1 Answer
There are two main types of nuclear imaging studies done to evaluate the heart. One is a study that evaluates the motion of the left ventricle (the chamber that pumps blood to the rest of your body), looking at the various areas of the ventricle as your heart beats; it’s called a MUGA. For this test, a small amount of a radioactive substance is objected into your vein and images are acquired to check the motion of the left ventricle as its beating. It takes about 30 minutes.
The other type of study is called a nuclear stress test. This test is typically ordered when there is a concern about impaired blood flow to the cardiac muscle, which could reflect a blockage in one of the coronary arteries that supply blood to the left ventricle. It’s done in two parts: after a small amount of a radioactive substance is injected, the first dose used to evaluate blood flow to the left ventricle while you are resting and relaxed (rest) and another dose used to evaluate blood flow to the left ventricle under conditions that simulate exercise (stress). If you can’t walk on a treadmill that increases in speed until you reach your specific maximum heart rate (based on your age), you will be injected with a medication that causes the coronary arteries to dilate which in turn increases blood flow. For both the rest and stress portions of the study, the heart is imaged; the injected radioactive substance demonstrating blood flow uptake to the various areas to the left ventricle. If there are "defects" (areas with decreased uptake) on the stress study not seen on the rest study, then there is concern for ischemia (diminished blood flow) to that territory. This is consistent with a significant blockage of a particular coronary artery god which you may need a stent. If you’ve had a heart attack in the past, the interpreting physician will see a defect on both the stress and rest images, indicating heart muscle that is no longer alive, but scarred (hence no blood flow).
I hope this answers your question!!
The other type of study is called a nuclear stress test. This test is typically ordered when there is a concern about impaired blood flow to the cardiac muscle, which could reflect a blockage in one of the coronary arteries that supply blood to the left ventricle. It’s done in two parts: after a small amount of a radioactive substance is injected, the first dose used to evaluate blood flow to the left ventricle while you are resting and relaxed (rest) and another dose used to evaluate blood flow to the left ventricle under conditions that simulate exercise (stress). If you can’t walk on a treadmill that increases in speed until you reach your specific maximum heart rate (based on your age), you will be injected with a medication that causes the coronary arteries to dilate which in turn increases blood flow. For both the rest and stress portions of the study, the heart is imaged; the injected radioactive substance demonstrating blood flow uptake to the various areas to the left ventricle. If there are "defects" (areas with decreased uptake) on the stress study not seen on the rest study, then there is concern for ischemia (diminished blood flow) to that territory. This is consistent with a significant blockage of a particular coronary artery god which you may need a stent. If you’ve had a heart attack in the past, the interpreting physician will see a defect on both the stress and rest images, indicating heart muscle that is no longer alive, but scarred (hence no blood flow).
I hope this answers your question!!
