Cl. Kay et al., Virtual endoscopy - Comparison with colonoscopy in the detection of space-occupying lesions of the colon, ENDOSCOPY, 32(3), 2000, pp. 226-232
Background and Study Aims: A new technique has been described which combine
s abdominal helical computed tomography (CT) scanning and virtual reality c
omputer technology, known as virtual colonoscopy (VC); the reconstructed im
ages provide a simulation of the interior of the colon as viewed by endosco
py, We compared VC with conventional colonoscopy in patients with suspected
or known colonic neoplasia.
Patients and Methods: A total of 38 patients, in whom there was a high like
lihood of colonic polyps or cancer, underwent a noncontrast helical CT scan
of the abdomen and pelvis after regular colonoscopy bowel preparation,The
images were reconstructed into a VC presentation and compared with the subs
equent conventional colonoscopy in a blinded manner.
Results: Conventional colonoscopy identified a total of 24 polyps 5 mm or g
reater. VC correctly identified five of 13 polyps 5-9 mm in size, and ten o
f II lesions greater than or equal to 10 mm in diameter. The reasons for fo
ur missed lesions were identified as being secondary to a collapsed rectum
in two patients and stool in the right colon in two patients, The sensitivi
ty and specificity per patient of VC for lesions greater than or equal to 5
mm were 66.7% and 75.0% respectively, and for lesions greater than 1 cm we
re 90.0% and 82.1%, respectively.
Conclusions: Virtual colonoscopy is feasible, well tolerated, and capable o
f detecting most lesions seater than 10 mm in diameter, This technique is c
ontinuing to be developed and warrants further evaluation as a diagnostic a
nd screening tool in colorectal neoplasia.