CT VIRTUAL COLONOSCOPY IN COLORECTAL NEOPLASM

Abstract

CT colonography (virtual colonosc9py) is a new-generrtion ' . technique for detecting colorectal polyps and cancers, which much help

to reduce there high morbidity and mortality] This technique was ade possible by the recent advances in helidal technology as wdll as computer software's for image processing. The aim of this study was to provide a simplified approach to the sophisticated technology ofCT colonographand to evaluate its rolk as a

non m• vas1•ve

d!.agnost•ic moda11•ty compI ared

to other

dm.

gnI,ostl•c

modalities as barium enema and colonoscopy in colorectal neoplas s.

We retrospectively performed CT i colonography follo ing

. conventional colonoscopy in 40 patients {23 males and 17 females, ranging in age from 15 to 75 years). Twenty[two patients had maliknant colonic neoplasms, eight patients had solitary polyp, four patienthad multiple polyps, five patients had an inflammatory bowel diseasb and one patient had diverticulosis.

CT colonographic examinations were performed on a helical

scanner, at 120 KVP, 70-140 MAS, using a -mm collimation, a piJch of up to 2-3 mm image interval, 512 X 512 Jatrix, field of view io fit, standard reconstruction algorithm. CT scannings were performd in both supine and prone positions. Both the su'pine and prone axial 4ages . I 1 were reviewed at both lung window and sbft-tissue window settings.

Antegrade and retrograde navigations throuh the colon were revibwed for visualization, surface- shaded and tissue ansition projection i ages were reconstructed in 3 patients..