Application of computed tomographic colonography in diagnosis of colonic polyps

To assess the clinical values of computed tomographic colonography (CTC) in diagnosis of colonic polyps.

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 > or = 10 mm group, 5-10 mm group, and < or =5 mm 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.

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 > or = 10 mm group, 5-10 mm group, and < or =5 mm group, respectively. The per-patient sensitivity, PPV, specificity, NPV, and accuracy were 97.1%, 89.5%, 42.9%, 75.0%, and 88.1%, respectively.

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