MDCT performed with a dual energy setting may allow enhanced differentiation of polyps from fecal matter in an unprepped colon, meaning patients may be able to skip the uncomfortable colonic preparation. MDCT performed with a dual energy setting may allow enhanced differentiation of polyps from fecal matter in an unprepped colon, meaning patients may be able to skip the uncomfortable colonic preparation before CT colonography, according to a new study by researchers from Emory University School of Medicine in Atlanta, GA.

For the study, the researchers designed a human colon model with 17 lesions to simulate polyps and six lesions to simulate fecal matter. Two abdominal radiologists independently reviewed the MDCT scans of the model. The researchers found that accuracy for detection of the polyps was 73 and 69 per cent at the routinely used settings of 120 and 140 kVp, and 87 and 82 per cent at the lower 80 kVp.

"CT colonography can be a valuable non-invasive tool for screening for polyps and pre-cancerous lesions; however, every patient has to undergo a tedious and uncomfortable colonic preparation prior to the procedure. The recent introduction of dual-energy CT scanners provides a window of opportunity to explore the role of dual-energy CT to differentiate between polyps and fecal matter in an unprepped colon. Our study is the first step in this direction," said Sunit Sebastian, MD, of Emory University School of Medicine and lead author of the study.

The next step for the researchers is to test whether lower CT settings would work with actual patients. "We have since obtained an IRB approval to perform a dual-energy CT colonography in patients. If favorable results are obtained in the patient population, it would mean that we could avoid or totally bypass the uncomfortable colonic preparation, thereby making CT colonography more patient-friendly. This would further enhance patient compliance for screening for colon cancer," said Dr. Sebastian.

The full results of the study were presented on Monday, May 7, 2007 during the American Roentgen Ray Society Annual Meeting in Orlando, FL.