A CT scan is a series of X-rays that a computer puts together to make 3-D pictures of your insides. You may have CT scans of your chest, belly (abdomen), and pelvis. They're used to check for signs of cancer in other organs, such as your liver or lungs. The scans show nearby lymph nodes, too. Cancer often spreads to lymph nodes.
You may be asked to drink a contrast dye 4 to 6 hours before the scan. Or a dye might be put into your blood through an IV (intravenous) line in your hand or arm. The dye helps to clearly show tissues and organs on the images. The dye may cause a warm flush feeling from head to toe. Tell your healthcare provider if you’re allergic to dye, or if you have had a reaction to the dye in the past.
A CT scan doesn't hurt. During the test, you’ll lie still on an exam table. The table slides through the center of the ring-shaped CT scanner. The scanner doesn't touch you. It directs X-ray beams at your body. You may be asked to hold your breath a few times during the scan.
Endoscopic ultrasound (EUS)
An ultrasound uses sound waves and a computer to make images of the inside of your body. An EUS is done from inside your stomach using a tool called an endoscope. This test can show how far cancer has spread into your stomach wall and nearby tissues and lymph nodes. It gives very specific information about the stage of your stomach cancer. This information helps your healthcare providers plan your treatment.
An endoscope is a long, thin, flexible tube with a light and a tiny camera. It also has a special ultrasound tool at the tip. Before the test, you'll be given medicine to make you sleepy. A numbing medicine will be sprayed into your throat to help prevent gagging. Then the endoscope is put into your mouth or nose. It’s gently guided down into your throat, through your esophagus, and into your stomach. The ultrasound tip sends images to a computer.
An EUS can show how far the tumor has grown in or through your stomach wall. It can also be used to look at lymph nodes around your stomach. This is to see if cancer cells might have spread to them. Your healthcare provider may pass a thin needle through the endoscope, through your stomach wall, and into nearby lymph nodes. Then the needle can be used to take tiny pieces of tissue (called samples) from the lymph nodes. This is called a biopsy. The tissue samples are sent to a lab. A specialist (pathologist) checks them for cancer.
An MRI scanner uses large magnets and radio waves to make images of your insides. This creates very clear images. MRI is not used as often as CT scans to look for the spread of stomach cancer. But it can help show if the cancer has spread to your brain and spinal cord.
For this test, you’ll lie still on a table as it slides into a long, narrow, tube-like scanner. The scanner sends radio waves at the part of your body to be scanned. A computer puts together the data to make a 3-D image of the inside of your body.
The scanner is very loud. You may be given earplugs or headphones to wear. If you’re uncomfortable in small spaces, you may need a sedative before this test. A 2-way intercom will let you talk to and hear the technician during the test.
This test helps show if cancer has spread beyond the stomach. A mildly radioactive sugar (glucose) solution is put into your blood through a vein in your hand or arm. Cancer cells use the glucose faster than normal cells do. After about an hour, a scan is done to make images that show where the glucose has collected. These areas may be cancer, but they may be other things too. The scan looks at your whole body. So this test can help find stomach cancer that has spread.
For this test, you’ll lie still on a table that’s pushed into the PET scanner. It will rotate around you and take pictures. Other than the injection, a PET scan is painless. Some people are sensitive to the glucose. This may cause nausea, a headache, or vomiting. Some machines can do PET and CT scans at the same time. This way, areas that show up on the PET scan can be compared with the more detailed images of the CT scan.
This procedure is used to see if the cancer has spread to other organs and tissue, such as the liver and lymph nodes. It can find tiny growths that are not easily seen on CT scans.
This procedure is done in an operating room. First you’ll be given medicine that puts you into a deep sleep. Then your healthcare provider makes a small cut in the skin over your belly. A long, thin, flexible tube with a camera on the end is put into your belly through the cut. The camera is moved around inside your belly to get close-up images of the organs and lymph nodes near your stomach.
If suspicious areas are seen, your healthcare provider can remove them for testing. This is called a laparoscopic biopsy.