A gastric emptying scan, also known as a gastric emptying study or test, is an exam that uses nuclear medicine to determine how fast food leaves the stomach.
It differs from a standard X-ray in that it uses a small amount of radioactive material to emit photon energy. The energy is detected by a gamma camera, which creates a computerized image.
What Is a Gastric Emptying Scan Used For?
Gastric emptying scans are often used to diagnose gastroparesis, a condition in which the stomach’s muscles don’t work properly. This results in a delay in sending food to the small intestine.
Doctors order the scans for adults and children who frequently vomit, feel bloated after eating, or complain of abdominal pain. Weight loss or changes in sugar levels are also symptoms of gastroparesis.
Where and How Will the Test Be Administered?
Gastric emptying scans take place at hospitals. They are performed by professionals trained in nuclear medicine or radiology.
Before the scan, the patient will eat a meal. This is usually scrambled eggs treated with a small amount of tasteless radioactive material.
For children who refuse to eat, the radioactive substance can be administered through a nasal feeding tube or gastrostomy tube.
Infants and toddlers are usually given formula, milk, or juice. The radioactive substance allows the camera to follow the food through the digestive process.
The patient will lie on a table while the camera takes pictures. Over the course of three to five hours, four to six scans lasting about a minute each will be taken.
In the case of infants and toddlers, the camera takes continuous images for about an hour. Some hospitals use a gamma camera that takes pictures while the patient is standing.
It is important to remain still during the scan.
What Are the Risks of a Gastric Emptying Scan?
A person will experience a small amount of radiation exposure from the material put in the food eaten before the scan.
This is not considered dangerous, unless a woman is breast-feeding, pregnant, or planning to become pregnant. Anyone in these circumstances should tell her doctor before having a gastric emptying scan.
How Does a Patient Prepare for Gastric Emptying Scan?
Other than the radioactive meal before the scan, patients should not eat or drink anything for four to six hours before the test.
It’s a good idea to bring books to read or a personal listening device to pass the time. A parent might want to bring their child’s favorite toy or pacifier.
Be sure to let the technician know if you are taking any medications or have any health complications, such as diabetes.
What Is the Outlook After Gastric Emptying Scan?
The doctor who ordered the test usually calls with results within a few days.
How is the scan done?
You will be given 2 small sandwiches, one filled with jam and one filled with 4 cooked egg whites that have been injected with a small dose of radioactive material.
You will be asked to eat the sandwiches and drink water within 10 minutes. The egg will taste just like a regular egg.
If you are allergic to eggs or wheat, please tell the person you schedule your appointment with. A different meal will be used.
After eating, you will be asked to lie flat on your back while the gamma camera take a picture of your stomach. You must lie still when the camera is taking pictures.
If you move, the pictures will be blurry and may have to be taken again.
What will I feel during the scan?
Lying still on the exam table may be hard for some patients. The technologist will help make you comfortable.
How long will the scan take?
From start to finish, your gastric emptying scan will take about 4 hours. There are 4 parts to the test:
First half hour: Eat meal, then take pictures with gamma camera (pictures take 5 minutes)
1 hour after meal: Take pictures (5 minutes)
2 hours after meal: Take pictures (5 minutes)
4 hours after meal: Take pictures (5 minutes)
After eating the meal:
You may leave the Nuclear Medicine department between the times you have the pictures taken.
Do not eat or exercise until after the last set of pictures has been taken.
Who interprets the results and how do I get them?
When the test is over, the nuclear medicine doctor will review your images, write up a report, and talk with your doctor about the results. Your doctor will talk with you about the results and your treatment options.