Demonstration of Patient in Position in CT Scanner Used for Virtual Colonoscopy

CT Scan of Colon Filled With Air

Virtual Colonoscopy is now available at Lexington Diagnostic Center

Using our high speed, Multislice CT, this procedure has been developed and proven effective and safe and is used routinely in several prominent hospitals and medical centers.  Dr. Perry J. Pickhardt and others reported in the New England Journal of Medicine on December 4, 2003, a study o 1233 patients undergoing both virtual colonoscopy and optical (conventional) colonoscopy.  This study found that virtual colonoscopy is as good as optical colonoscopy for the detection of clinically relevant lesions.

Cross Sectional Images and 3d Reconstruction Showing Colon Polyp

How does Virtual CT Colonoscopy work?

Virtual (CT) Colonoscopy is the latest technological advance in CT scanning and allows excellent images of the colon without the risks and inconvenience of anesthesia.  After a one-day bowel cleansing prep using a light low fiber diet and an oral laxative (Fleet Phospha-soda) the evening before, the colon is slowly and gently filled with carbon dioxide (one of the components of air) by way of an enema tip.  About 70 images are obtained in one or two breath holds while the patient is supine, and the scan is repeated with the patient turned over to the prone position.  The total procedure time is less than 30 minutes and the patient can return to usual activity. 

A special colonoscopy computer program produces 2D and 3D pictures of the inside of the colon, which our Board Certified Radiologist reviews and the findings are relayed to the patient and doctor within 24 hours.  This test has been shown to be almost as accurate and sensitive as conventional flexible colonoscopy and is becoming very popular.  In some cases the Virtual Colonoscopy will demonstrate parts of the colon that the conventional colonoscopy cannot reach.  The possible findings on colonoscopy are polyps, diverticula and tumors. 

The advantages of virtual CT colonoscopy over conventional colonoscopy are as follows:

• No anesthesia, sedation or pain medication is required.
• There is high patient acceptance and compliance for the procedure.
• Patient can return to normal activities immediately afterward.
• There are virtually no complications.
• The test is almost as sensitive as conventional colonoscopy, and it allows visualization of the junction between the small intestine and the large intestine (right colon), an area that is not completely visualized 10 to 15% of cases with conventional colonoscopy.
• A CT scan of all the other organs of the abdomen and pelvis is included.
• The total cash price is $650 and is much less than the charges for conventional colonoscopy (about $2,000). Some insurance companies may reimburse for the Virtual Colonoscopy.
• There are many patients who refuse conventional colonoscopy who will have a virtual CT colonoscopy.
• Virtual colonoscopy is an excellent option for patients who cannot be taken off anticoagulants for conventional colonoscopy.

The disadvantages of virtual CT colonoscopy over conventional colonoscopy are as follows:

• The ability to differentiate stool from artifact and polyp may not be as good.
• If a biopsy is needed, conventional colonoscopy will still be required.
• There is exposure to significant radiation.
• CT of the abdominal and pelvic organs may reveal benign findings that require additional testing and costs.

 Virtual CT colonoscopy is performed at Lexington Diagnostic Center in the following manner:

• The patient is asked to be on a clear liquid diet for 24 hours.
• A colon bowel cleansing prep is used the evening before, the Fleet Phospo-soda prep #1 with the recommended oral fluids.
• The patient is placed on their back on the CT table, a small rectal tube is inserted and the colon is filled with CO2 gas.  This causes a feeling of fullness and usually only mild discomfort, although occasionally there is moderate cramping. 
• During one breath hold, totaling 15 to 20 seconds, a fast CT scan is obtained through the abdomen and pelvis, covering the entire colon.  The patient is then asked to turn to the prone position (on the stomach) and the procedure is repeated.
• The patient is then discharged to return to normal activities.   The gas is expelled and/or absorbed.  The total time in our office should be 1 hour or less.
• The CT scan images are then processed by a special computer viewer and the axial images and 3d surface (Virtual) rendering is prepared for the radiologist to interpret.  A report is ready in about 24 hours. 

 Contraindications to virtual CT colonoscopy includes a history of the following: 

• Total hip replacement (metal in hips causes CT scan artifact).
• Active Crohn’s disease, ulcerative colitis, inflammatory bowel disease or diverticulitis (increased risk of perforation).
• History of previous bowel perforation.
• Severe pain or cramps on day of examination.

What are the indications for virtual CT colonoscopy? 

The indications are the same as for conventional screening colonoscopy, i.e. Special dietary considerations may be needed for diabetics. Alternate low sodium bowel prep is recommended for cardiac and renal patients

• Patients over 50 years of age
• Patient over 40 with history of colon cancer
• Repeat scan every 5 years, or more frequently at doctors discretion.

If your doctor has recommended a colonoscopy and you feel you would be an appropriate candidate for Virtual Colonoscopy, or if you have additional questions, please call us in Lexington at 859-278-7226 or toll free at 800-755-7441. 

© Neurodiagnostics P.S.C., 2001-07
1725 Harrodsburg Road, Suite 100
Lexington, KY 40504
Phone 859-278-7226 or Toll Free 800-755-7441