Purpose: to rule out the role of Multislice Helical CT (MSCT) in screening of colorectal cancer as it
allows high-speed acquisition of truly volumetric datasets, it also describes the combination of colonic
imaging with surface extraction and rendering of the gas-mucosal interface which simulates the view
obtained during conventional fibro-optic video-endoscopy.
Material and methods: (60) patients (51) men, (9) women; age range, (45-75) years were included in
this study. Patients eligible for inclusion were those who were seen in a gastroenterology clinic and were
scheduled for colonoscopic evaluation because of a positive fecal occult blood test, iron deficiency anemia,
hematochezia, or a family history of polyps. No patient was known to have polyps. CT colonography was
performed first, and colonoscopy was performed 3 hours later.
Results: In a comparison of MSCT-colonography with endoscopic colonoscopy in 60 patients referred
for exclusion or early diagnosis of colorectal cancer, MSCT-colonography detected a total of 32 of 38
polyps (84%) and 2 Of 2 carcinoma (100%). All polyps greater than 10 mm were detected ( 6 of 6 polyps),
8 of 8 polyps ranging from 6 to 9 mm and 18 of 24 polyps smaller than 6 mm were identified. 26 false
positive finding affected 16 patients. 6 false negative finding affect two patients, results are summarized in
table 1.
Conclusion: with thin-section low-dose multi—detector row CT colonography, there is excellent
sensitivity and depiction of large colorectal polyps. Ultimately, low-dose thin-section multi—detector
row CT colonography, by facilitating decreased radiation doses and decrease false-positive rates while
maintaining excellent sensitivity for detection of large polyps, may lead to increased patient and clinician
acceptance of the use of this examination. |
