Outpatient Abdoment CT Scans That Were "Combination" (Double) Scans

What is a "combination" CT scan?

• For some CT scans, a substance called "contrast" is put into the patient's body before the scan begins, to help make parts of the body stand out more clearly on the x-rays. Contrast can be either swallowed or injected into a vein.
• "Combination" CT scan means that the patient gets two CT scans - one scan without contrast followed by a second scan with contrast.

What does this measure tell you about the hospital imaging facility's use of CT scans of the abdomen?
Combination scans involve additional radiation exposure and risks associated with use of contrast.

For this measure, if a number is very close to 1, it may mean that the facility is routinely giving patients combination CT scans of the abdomen when a single scan is all they need.

• Giving patients two scans when they only need one needlessly doubles their exposure to radiation:
  • Radiation exposure from a single CT scan of the abdomen is about 11 times higher than for an ordinary X-ray of the abdomen.
  • For a combination CT scan, radiation exposure is 22 times higher than for an X-ray of the abdomen because the patient is given two scans.
• Risks of injected contrast include possible harm to the kidneys or allergic reactions. Contrast shouldn't be used if it isn't needed.

CT scans of the abdomen are one of the most commonly requested imaging procedures. If you need to have a CT scan of the abdomen, talk to your doctor about what's best for your medical condition:

• Do you need a single scan - either with or without contrast - or is a combination scan necessary?
• Is using contrast appropriate for your medical condition?

The information that follows shows hospital imaging facilities' use of CT scans of the abdomen. Talk with your doctor about the results you see here and what a facility's results mean for you and your care.

What is a "CT scan"?
A CT scan (also called a CAT scan) uses multiple x-rays to produce detailed pictures of the inside of the body (bones, organs, and other body parts).