This page explains what will happen at your gastric emptying scan at Royal Brompton Hospital and how to prepare for it. It does not replace the need for personal advice from a healthcare professional. Please ask us if you have any questions.

What is a nuclear medicine scan?

A nuclear medicine scan is a way of taking images of the body. You are given a tracer, which is a substance with a small amount of radioactivity. The tracer highlights the part of the body we need to see in more detail.

About your gastric emptying scan

A gastric emptying scan is a type of nuclear medicine scan. It measures how quickly your stomach empties food into your intestines. This helps your specialist understand if your stomach is working more slowly or more quickly than expected.

What the scan involves

For this scan, we mix a very small amount of radioactive tracer with a meal, usually porridge. If you cannot eat porridge, we will offer a different meal.

The tracer is not absorbed by your stomach. It moves through your digestive system with the food. A technologist will then use a gamma camera to take images. These show how quickly the meal leaves your stomach and travels through your intestines.

What will happen on the day

When you arrive

• A technologist will prepare the meal and mix in the tracer.
• You will be asked to eat the meal slowly over up to 10 minutes.
• We will give you gloves and a disposable apron in case the meal spills.
• If your clothing has metal fastenings that cannot be removed, we may ask you to change into a gown.

During the scan

• As soon as you finish the meal, we will take the first scan.
• You will lie on the scanning couch. You need to stay as still as possible.
• We will take 1 minute scans every 30 minutes for the first 2 hours.
• We will then take 2 more scans. 1 at 3 hours and 1 at 4 hours after you started the meal.
• Between the 3 hour and 4 hour scans, you may leave the department if you wish.
• You must not eat, drink or smoke during this time.

How to prepare for the scan

We will call you before your appointment. We will check your medicines and any food allergies.

• You will be asked to stop any medicines that affect stomach emptying for 24 hours before the scan.
• Please make sure you have a list of the medicines and doses you are taking.
• Have a pen and paper ready to write down any instructions we give you.
• You must not eat or drink anything for 8 hours before the scan.

Risks of radiation during a gastric emptying scan

The amount of radiation used during a gastric emptying scan is small and kept to a minimum. We believe that the benefits of having the scan far outweigh any risks.

The risk of a person getting cancer because of this radiation is low, 1 in 100,000 to 1 in 10,000 people. This level of risk is very small compared with the overall lifetime chance of getting cancer. The overall lifetime chance of getting cancer is around 1 in 2 people.

After the scan

• A doctor will check the images while you wait.
• Once the images are confirmed, you can go home.
• The radiation dose from this scan is very small, so you can be around other people as normal afterwards.
• The tracer will not make you sleepy.
• You can drive and return to normal activities.

Your results

A nuclear medicine consultant will review your scan and send the report to your referring specialist. Your specialist doctor will discuss the results with you and explain any next steps.

Contact us

If you have any questions about your appointment, procedure or treatment please call us between 9am and 5pm. We will answer any messages left on our answerphone within 24 hours.

Phone 020 7351 8666 or 020 7351 8669

Address Nuclear medicine department, Level 3, Chelsea Wing, Sydney Street, Royal Brompton Hospital, SW3 6NP