Nuclear Medicine: Bone Scans, Myocardial Perfusion Imaging, Stress Testing, Preparation, and Travel

Overview

Nuclear medicine exams use a small amount of radioactive tracer to help create images of how parts of the body are functioning. The tracer is usually injected into a vein, and images are taken with a special camera.

The preparation and timing depend on the exam. Some nuclear medicine tests are done in one visit. Others, such as bone scans and myocardial perfusion imaging, may involve more than one part. Patient Prep (Nuclear Medicine)

What You Need to Know

• A nuclear medicine test may involve a small tracer injection.
• The tracer helps the camera show how a body system or organ is working.
• The tracer naturally decays and leaves the body over time.
• Drinking fluids may help clear unused tracer from the body, unless you have been told to restrict fluids.
• Preparation depends on the test being performed.
• Bone scans are commonly done in two parts.
• Myocardial perfusion imaging is commonly done as a rest portion and a stress portion.
• Myocardial perfusion stress testing may involve treadmill exercise or a medication called Persantine.
• Bring a complete and current medication list to your appointment.
• If you are diabetic, ask for specific fasting instructions before your test.

Bone Scan Preparation and Timing

A bone scan looks at bone activity or metabolism. This is different from an X-ray, which mainly shows bone structure.

Bone scans are usually done in two parts:

1. Part 1: Injection visit
   You receive the tracer injection. This part is usually short and may take about 15 minutes.
2. Part 2: Imaging visit
   You return later for pictures. Imaging may take about 30–60 minutes, depending on the area being examined and your medical history.

The return time for Part 2 is usually about 2–5 hours after the injection. The exact timing depends on the body area being scanned, the reason for the exam, and camera availability.

There is usually no special preparation for a bone scan unless you are told otherwise.

Why You May Be Asked to Drink Fluids

You may be asked to drink extra fluids between the injection and imaging portions of a bone scan. This helps clear unused tracer from your body and can improve image quality.

Unless you have a fluid restriction, aim to follow the fluid instructions given by the clinic.

Myocardial Perfusion Imaging

Myocardial perfusion imaging looks at blood flow to the heart muscle. It is often used to compare the heart at rest and under stress.

This test is usually done in two parts:

Part 1: Rest Imaging

For the rest portion, you usually receive a small tracer injection, wait about 30–45 minutes, and then have imaging under a special camera for about 20 minutes.

There is usually no special preparation for the rest day unless you are told otherwise. Eat and take your medications as usual, and bring a full medication list.

Part 2: Stress Imaging

For the stress portion, your heart is assessed under stress. This may be done by walking on a treadmill or by receiving a medication that mimics the effect of exercise on blood flow.

You usually receive a tracer injection, wait about 30–45 minutes, and then have imaging for about 20 minutes.

The rest and stress portions are usually not done on the same day so the first tracer has time to clear and the second set of images can be clearer.

Stress Testing Options

Treadmill Stress Test

During a treadmill stress test, you walk on a treadmill while your heart rhythm, heart rate, and blood pressure are monitored. The treadmill gradually becomes more challenging.

The exercise portion usually lasts about 5–10 minutes, depending on how long you are able to safely continue.

Persantine Stress Test

Persantine is an IV medication used when a patient cannot exercise adequately on a treadmill. It widens blood vessels to mimic some effects of exercise.

Temporary side effects may include:

• Headache
• Flushing
• Shortness of breath
• Nausea
• Chest discomfort

These effects usually last a short time. Medication can be given to reverse the effects if needed.

The referring physician may recommend treadmill or medication stress testing, and the cardiologist confirms the safest approach before the test.

How to Prepare for Myocardial Perfusion Stress Testing

For the stress portion of myocardial perfusion imaging, you may be asked to:

• Fast for at least 4 hours
• Avoid caffeine for 12 hours, including decaf products
• Avoid smoking for 2 hours
• Avoid chewing gum for 2 hours
• Bring a full and current medication list
• Follow any medication instructions provided after Part 1

Do not stop medications unless you have been instructed to do so.

Diabetes and Fasting

If you are diabetic, tell the clinic before your test.

You may need adjusted fasting instructions. Diabetic patients are often given specific timing instructions for food and insulin before the stress portion of the exam.

Do not guess or skip diabetes medication without medical guidance. Confirm your instructions before the appointment.

Medications

Bring a complete and updated medication list to your nuclear medicine appointment, especially for myocardial perfusion imaging.

After Part 1, staff may advise which medications to pause before Part 2. Only pause medications if you have been instructed to do so.

Do You Need a Driver?

Most patients do not need a driver after a nuclear medicine test and can usually drive themselves unless they are told otherwise.

If you are unsure, or if you feel unwell after the test, ask staff before leaving.

Travel After a Nuclear Medicine Injection

If you are travelling soon after a nuclear medicine injection, especially across a border or through security, ask for a medical note.

Sensitive detectors may detect the tracer for up to about a week after injection.

Safety Notes

Nuclear medicine tests use a small amount of radioactive tracer. The tracer naturally decays over time and leaves your body.

Drink fluids as instructed unless you have been told to restrict fluids.

For myocardial perfusion stress testing, there is a very small risk of a serious heart event. You are monitored during the test, and trained staff and emergency equipment are available.

When to Contact GNMI

Contact GNMI before your appointment if:

• You are diabetic
• You are unsure whether to fast
• You are unsure whether caffeine includes decaf products
• You cannot avoid caffeine before the test
• You take heart medications or other medications you are unsure about
• You do not have a current medication list
• You are travelling soon after the test
• You are unable to walk on a treadmill
• You have questions about Persantine
• You are pregnant, might be pregnant, or are breastfeeding
• You need accessibility support