A CT or CAT scan is a shortened name for computerized tomography. A CT scan takes pictures of the inside of the body. The pictures are more detailed than a typical x-ray. During a CT scan of the chest, pictures are taken of cross sections or slices of the thoracic structures in your body. The thoracic structures include your lungs, heart and the bones around these areas. When contrast is used during a CT scan of the chest thoracic structures are highlighted even more.
CT scans can help determine a diagnosis early. Your doctor will use this information to determine the best treatment for you.
Preparing for the Test
- For children under 18 years - Do not eat 4 hours before the test is scheduled. You/your child may drink clear fluids only. It is important that you drink enough clear liquids (like water) to be well hydrated prior to the test.
- For adults –There is no food restriction for this scan. It is important that you drink enough clear liquids (like water) to be well hydrated prior to the test.
- Wear clothing you can remove from the waist up. You will be given a gown to wear.
- Avoid having any barium studies done 2 to 3 days before the CT scan.
- Talk with your doctor before the test if you have a history of reactions to contrast in the past.
- If you take metformin or metformin-containing drugs for diabetes (Glucophage, Glucovance, Janumet, etc.), discuss this with your doctor prior to your CT appointment. There are specific requirements for you following your scan.
- If you have not had a recent blood test for creatinine, a finger-poke blood test will be done just prior to your scan.
- Please arrive 20 minutes before the test is scheduled. The radiology technologist will ask you questions and have you complete a questionnaire.
During the Test
The radiology technologist will explain the CT scan with contrast to you before you start. Ask questions if you don’t understand. Before the study you/your child will need to remove all clothing and jewelry from the waist up. You will be given a hospital gown to wear. The technologist will start an IV. The IV will be used to give you the contrast media. The contrast media will be injected into the IV.
The CT scan does not hurt. You will feel a prick when the IV is started. Many people feel a warm “flush” as the contrast media is injected. This is normal and passes quickly.
The CT scanner includes a table you will lie on and a doughnut-shaped ring. You will lie still on the table while it advances through the ring. The technologist will give you instructions during the test. You will be asked to raise your arms above your head at times. You will also be asked to hold your breath for 10 to 12 seconds. While you hold your breath the table will move through the ring while pictures are taken. The pictures will be taken before, during and after the contrast media is injected into the IV. It is important to lie still while the images are taken.
Young children may have trouble lying still during the CT scan. If this is the case, the child may be given medicine to make him or her sleepy first. This is done is the Pediatric Care Unit. If this is done first, a nurse will also be at the CT scan. If you are concerned your young child may not be able to hold still, talk with your doctor before the CT scan.
After the Test
Drink extra fluids for several hours after the test.
Length of the Test
A CT scan of the chest with contrast takes about 40 minutes. This includes 20 minutes for the test and 20 minutes for preparation.
Day of the Test
Your appointment is in radiology. Radiology is on the third floor of the Smith Building. On the day of your test, first report to the Admissions Desk just inside the Main Entrance. Admissions will direct you to the appropriate location for your test.
If you have questions, or will not be able to make your appointment, please call 303.398.1611.
This information has been approved by Will Cook, ARRT, MA and Eric Yager, ARRT, BS (July 2012).