At Verrazano Radiology, we have been performing CT colonoscopy since 2007.

CT colonography uses CT scanning to obtain an interior view of the colon (the large intestine) that is otherwise only seen with a more invasive procedure where an endoscope is inserted into the rectum.

The purpose of CT colonography is to detect polyps or cancers in the large intestine.

CT colonography is often ordered after an incomplete endoscopic colonoscopy (when the GI doctor is unable to see all of colon) or the patient is considered high risk for endoscopic colonoscopy (bleeding problems, anesthesia risk).

No anesthesia is required for CT colonography.

Preparation for the examination:

Similar to conventional colonoscopy (bowel prep begins day before procedure). You will be asked to drink extra glasses of water throughout the day before your exam, followed by multiple tablets beginning at dinner time. A rectal suppository is used 2 hours before you arrive on the day of your exam. (All these instructions are explained in detail in the packet) You will be instructed to come to Verrazano Radiology at least two days prior to the exam to pick up a bowel prep kit. Please follow the instructions in the kit.

How is the procedure performed?

The technologist begins by positioning you on the CT examination table, usually lying flat on your back or possibly on your side or stomach. Straps and pillows may be used to help you maintain the correct position and to hold still during the exam.

A very small, flexible tube will be passed two inches into your rectum to allow carbon dioxide gas to be gently pumped into the colon using a pressure controlled device.

The purpose of the gas is to distend the colon as much as possible to eliminate any folds or wrinkles that might obscure polyps from the physician's view.

Next, the table will move through the scanner. Patients are asked to hold their breath for about 15 seconds before turning over and lying on their back or side for a second pass through the scanner.

The procedure is usually completed within 15- 20 minutes.

What can I expect to feel?

The patient usually has a feeling of fullness when the colon is inflated during the exam, as if they need to pass gas.

After the tube is inserted, your privacy will be respected. The scanning procedure itself causes no pain or other symptoms. You will be alone in the exam room during the CT scan. However, the technologist will be able to see, hear and speak with you at all times.

After the exam, you can return to your normal activities. Carbon dioxide gas causes fewer symptoms (flatulence) after the procedure than room air.

Who will interpret the examination?

Your examination will be interpreted by a Radiologist, who is a Physician (M.D.) specifically trained to supervise and interpret radiology examinations. He/she will analyze the images and send a signed report to your primary care or referring physician, who will discuss the results with you. Upon request, you can arrange a consultation with the Radiologist who interpreted your examination.