Objective To assess the clinical values of computed tomographic colonography （CTC） in diagnosis of colonic polyps. Methods Forty-two patients who were clinically suspicious of colonic polyps or underwent colonic polyps screening received examinations with both CTC and conventional colonoscopy. Sixteen- or 64-slice spiral computed tomography and professional imaging processing techniques were used for evaluation. Per-polyp and per-patient results were analyzed. Those by per-polyp were subsequently divided into ≥10mm group

5-10 mm group

and ≤5mm group. Sensitivity

positive predictive value （PPV）

specificity

negative predictive value （NPV）

and accuracy were calculated using statistical method for diagnostic studies

with conventional colonoscopy as a gold standard. Results Ninety and 61 polyps were found by CTC and conventional colonoscopy

respectively. The per-polyp sensitivity/PPV were 80.3%/55.6% in total

and 100%/92.9%

93.8%/65.2%

and 68.8%/41.5% in the ≥10 mm group

5-10 mm group

and ≤5mm group

respectively. The per-patient sensitivity

PPV

specificity

NPV

and accuracy were 97.1%

89.5%

42.9%

75.0%

and 88.1%

respectively. Conclusion CTC can clearly reveal the morphology of colonic polyps and be used as a routine monitoring method for the clinical diagnosis of polyps.