Danielle Hock, Presenter: Nothing to Disclose

Roxanne Ouhadi, Abstract Co-Author: Nothing to Disclose

Roland Materne MD, Abstract Co-Author: Nothing to Disclose

Isabelle Mancini, Abstract Co-Author: Nothing to Disclose

Alain Nchimi MD, Abstract Co-Author: Nothing to Disclose

To evaluate and compare the prevalence of colonic findings at Virtual Colonoscopy (VC) among subjects within a large cohort.

This retrospective study includes 9624 consecutive subjects who underwent VC between June 2003 and December 2010. High-risk subjects for colorectal cancer (n=1662), subjects of less than 50 years of age (n=1481) and subjects with unknown clinical status at the time of VC (n=179) were excluded. The remaining 6302 subjects (3615 F, mean age 64.9±10.5; range 50–95 years) were divided into 3 groups (A, B, and C) according to their gastrointestinal symptoms. Group A (n=2197; 1086 F; mean age 63,8±9,1 years; range 50-91 years) represents an average-risk group for colorectal cancer screening and includes all asymptomatic subjects. Group B (n=3277; 2076 F; mean age 65,7±9,9 years; range 50–95 years) includes subjects with one or more minor gastrointestinal symptoms (abdominal discomfort, irregular bowel movement, abdominal bloating) and group C (n=828; 453 F; mean age 64,1±15,0 years; range 50–95 years) includes subjects with one or more major gastrointestinal symptoms (rectorrhage, anemia, unexplained loss of weight). Significant VC findings were defined as polyps ≥ 6mm or colonic masses. VC findings were compared to optical colonoscopy in a subset of 532 subjects.

VC comparison to OC yields respective sensitivity and false positive fraction of 98.9% and 84.9% in detecting significant colonic findings. These findings were present respectively in group A, B and C in 228/2197 patients (10.4%), 360/3277 (11.0%) and 188/828 (22.7%) subjects. Prevalence of findings was not significantly different in groups A versus B (p=0.504), but significantly higher in group C versus A (p<0.0001) and B (p<0.0001).

Prevalence of significant colonic findings at VC is comparable between subjects with minor gastrointestinal symptoms and asymptomatic subjects but significantly higher in subjects with major gastrointestinal symptoms.

Due to a comparable prevalence of colonic findings in subjects with average-risk for colorectal cancer, indications for VC screening can be extended to subjects with minor gastrointestinal symptoms.

Hock, D, Ouhadi, R, Materne, R, Mancini, I, Nchimi, A, Distribution of Colonic Findings at Virtual Colonoscopy According to Gastrointestinal Symptoms in Almost 10,000 Patients.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11014800.html