What is a gastric emptying scan?
A gastric emptying scan is also known as a gastric emptying study or test. This procedure uses nuclear medicine to determine how quickly food leaves the stomach. It differs from a standard X-ray test in that it uses a small amount of radioactive material to emit photon energy. This energy is detected by a gamma camera, which creates a computerized image.
Gastric emptying scans are often used to diagnose gastroparesis, a condition in which the stomach muscles do not work properly. This delays sending food to the small intestine. Your doctor may order a scan if you vomit frequently, feel bloated after eating, or complain of abdominal pain. Other common symptoms of gastroparesis include:
Many of these symptoms can affect your quality of life. A gastric emptying scan can help your doctor diagnose gastroparesis or other motility disorders causing these symptoms.
Gastric emptying scans are performed in hospitals by specialists trained in nuclear medicine or radiology. Before the scan, you will eat something solid (usually scrambled eggs), something liquid, and a small amount of tasteless radioactive material. The radioactive substance allows the camera to track your food through the digestive process. You then lie down on a table while the camera takes pictures. Over the course of three to five hours, the camera will take four to six scans, each lasting about a minute. Some hospitals use a gamma camera that takes pictures while you are standing. In either case, it is important to remain still during the scan.
Symptoms of gastroparesis in children are similar to those seen in adults. Ask your doctor to perform this test on your child if he or she is experiencing any of the symptoms listed above.
The test for older children is identical to the test for adults. If your child is an infant, your doctor will give your child radioactive food in milk or formula as part of a test called a milk test or fluid test. In this case, you may be instructed to bring your own formula or milk from home to make sure your baby does not have an allergic reaction. The radioactive substance is as safe for a child as it is for an adult. The test usually takes about three hours for children. If your child receives a liquid study instead, the camera takes continuous pictures for about an hour. It is important that your child stays for the entire study. Make sure you find ways to keep him or her calm or occupied before and during the test so that the results can be delivered smoothly. The following items can help your child stay calm:
Before the scan, you will experience a small exposure to radiation from material in the food you eat. This is not considered dangerous unless you are breastfeeding, pregnant or planning to become pregnant. Anyone in these circumstances should tell their doctor before having a gastric emptying test.
How to prepare
Other than a radioactive meal before the test, you should not eat or drink anything for four to six hours before the test. If you have diabetes, bring your medication or insulin if your doctor requests that you take it with the test. It is a good idea to bring books or music with you to pass the time. A parent may want to bring their child's favorite toy or pacifier.
Let the technician know if you are taking any medications. The following medications may affect how fast your stomach empties:
Health complications, such as diabetes or hypoglycemia, may affect the usefulness of the test. Hormones can also affect the test results, so let your doctor know if you are in the second half of your menstrual cycle.
Your doctor may also use other tests to diagnose gastroparesis, including:
Talk to your doctor about these alternatives if you have concerns about the gastric emptying test.
The doctor who ordered the test usually calls within a few days with the results. Your doctor may prescribe medications such as metoclopramide (Reglan), erythromycin, or antiemetics to treat gastroparesis and its symptoms. They may also suggest electrical stimulation of the stomach. In this procedure, a small device called a gastric neurostimulator is surgically inserted into your abdomen to stimulate your abdominal muscles. This is usually only recommended if you are not responding to medication. In rare, serious cases, you may need a jejunostomy. In this procedure, your doctor inserts a feeding tube through your abdomen into your jejunum, part of your small intestine. This procedure is only done if gastroparesis is severe and has a huge impact on your quality of life. In most cases, recognizing and treating gastroparesis before any serious symptoms develop leads to a positive outcome.