Comparison of 64-Detector CT Colonography and Conventional Colonoscopy in the Detection of Colorectal Lesions.
BACKGROUND
Colon cancer is a leading cause of morbidity and mortality in developed countries. The early detection of colorectal cancer using screening programs is important for managing early-stage colorectal cancers and polyps. Modalities that allow examination of the entire colon are conventional colonoscopy, double contrast barium enema examination and multi-detector computed tomography (MDCT) colonography.


OBJECTIVE
To compare CT colonography and conventional colonoscopy results and to evaluate the accuracy of CT colonography for detecting colorectal lesions.


METHODS
In a prospective study performed at Gastroenterology and Radiology Departments of Medical Faculty of Eskisehir Osmangazi University, CT colonography and colonoscopy results of 31 patients with family history of colorectal carcinoma, personal or family history of colorectal polyps, lower gastrointestinal tract bleeding, change in bowel habits, iron deficiency anemia and abdominal pain were compared. Regardless of the size, CT colonography and conventional colonoscopy findings for all the lesions were cross - tabulated and the sensitivity, specificity, and positive and negative predictive values were calculated. To assess the agreement between CT colonography and conventional colonoscopy examinations, the Kappa coefficient of agreementt was used. Statistical analysis was performed by SPSS ver 15.0.


RESULTS
Regardless of the size, MDCT colonography showed 83% sensitivity and 95% specificity, with a positive predictive value of 95% and a negative predictive value of 83% for the detection of colorectal polyps and masses. MDCT colonography displayed 92% sensitivity and 95% specificity, with a positive predictive value of 92% and a negative predictive value of 95% for polyps ≥ 10 mm. For polyps between 6mm and 9 mm, MDCT colonography displayed 75% sensitivity and 100% specificity, with a positive predictive value of 100% and a negative predictive value of 90%. For polyps ≤ 5 mm MDCT colonography displayed 88% sensitivity and 100% specificity with a positive predictive value of 100% and a negative predictive value of 95%.


CONCLUSIONS
CT colonography is a safe and minimally invasive technique, a valuable diagnostic tool for examining the entire colon and a good alternative compared to other colorectal cancer screening tests because of its high sensitivity values in colorectal lesions over 1 cm.
Department of Radiology, Research and Training Hospital, Kutahya Dumlupinar University, Kutahya, Turkey.
Cigdem
C
Devir
Department of Radiology, Medical Faculty, Eskisehir Osmangazi University, Eskisehir, Turkey.
Mahmut
M
Kebapci
Department of Gastroenterology, Medical Faculty, Eskisehir Osmangazi University, Eskisehir, Turkey.
Tuncer
T
Temel
Department of Gastroenterology, Medical Faculty, Eskisehir Osmangazi University, Eskisehir, Turkey.
Aysegul
A
Ozakyol
Colonic Polyps; Colonography, Computed Tomographic; Colonoscopy; Colorectal Neoplasms