Last week, we did a story about Dr. Mehmet Oz’s cancer scare. On routine screening colonoscopy, doctors found and removed an benign tumor called an adenomatous polyp. Dr. Oz underwent the traditional method of colonoscopy with a flexible colonoscope. However in February of this year, President Obama underwent a virtual colonoscopy during his annual physical exam. So, what are the pros and cons of tradition vs. virtual colonoscopy?
Virtual colonoscopy uses either a CT or MRI scanner to develop a 3-D image of the colon. Like traditional colonoscopy, a thorough bowel clean-out is necessary. Before the exam, a CT-scan patient drinks a liquid contrast media. To start the exam, a thin tube is inserted through the anus and into the rectum. For CT, carbon dioxide gas is pumped through the tube expanding the large intestine for better viewing. For MRI, contrast media will be given rectally to expand the large intestine.
What are the advantages of virtual colonoscopy? Source: NIDDK
Virtual colonoscopy has several advantages over other procedures:
What are the disadvantages of virtual colonoscopy?
Virtual colonoscopy has several disadvantages:
According to a May MedPage Today article, even when insurance companies cover virtual colonoscopy many people will decide to undergo the traditional colonoscopy. Reseacher Patrick Pfau, MD postulated that :” When doctors tell patients about the undiminished need for bowel preparation with CT colonography, as well as its lower sensitivity for certain lesions and the requirement that patients undergo a regular colonoscopy to confirm and treat positive findings, their enthusiasm for initial CT colonoscopy often wanes.
This video shows a virtual colonoscopy of the rectosigmoid colon performed in a retrograde fashion. There is a 10-mm colonoscopically-proven polyp in the sigmoid colon seen at the top of the frame at the midpoint of the movie. The movie concludes at the tip of the rectal tube which was used to insufflate the colon. CT dataset courtesy of C. Daniel Johnson, MD, Department of Radiology, Mayo Clinic, Rochester, MN, and was found on the National Institute of Health Clinical Center website.
Virtual colonoscopy images of a colon: left, with the patient scanned supine (face up) ; right, with the patient scanned prone(face down). The red colored area indicates a polyp detected by computer-aided detection (CAD). Images courtesy of Dr. Ronald M. Summers, Diagnostic Radiology Department, Clinical Center, National Institutes of Health.