Dr Iannaccone and colleagues from Rome, Italy undertook a study to prospectively compare the performance of low-dose multidetector computed tomographic colonography (CTC) without cathartic preparation with that of colonoscopy for the detection of colorectal polyps.
The researchers included a total of 203 patients in the study, who underwent low-dose CTC without cathartic preparation followed by colonoscopy.
Before CTC, the investigators achieved fecal tagging by adding diatrizoate meglumine and diatrizoate sodium to regular meals.
No subtraction of tagged feces was performed.
The investigators performed colonoscopy 3–7 days after CTC.
3 readers interpreted the CTC examinations separately and independently using a primary 2-dimensional approach using multiplanar reconstructions and 3-dimensional images for further characterization.
|CTC had an average sensitivity of 95.5% for the identification of colorectal polyps ≥8 mm|
Colonoscopy with segmental unblinding was used as reference standard.
The investigators calculated the sensitivity of CTC both on a per-polyp and a per-patient basis. For the latter, the group also calculated specificity, positive predictive values, and negative predictive values.
The researchers found that CTC had an average sensitivity of 95.5% for the identification of colorectal polyps ≥8 mm.
With regard to per-patient analysis, the researchers calculated that CTC yielded an average sensitivity of 89.9%, an average specificity of 92.2%, an average positive predictive value of 88% and an average negative predictive value of 93.5% .
Dr Riccardo Iannacone concluded, "Interobserver agreement was high on a per-polyp basis and high to excellent on a per-patient basis."
He added, "Low-dose multidetector CTC without cathartic preparation compares favorably with colonoscopy for the detection of colorectal polyps."