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DOI: 10.1055/s-2000-100
Virtual Endoscopy - Comparison with Colonoscopy in the Detection of Space-Occupying Lesions of the Colon
Publication History
Publication Date:
31 December 2000 (online)
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Background and Study Aims: A new technique has been described which combines abdominal helical computed tomography (CT) scanning and virtual reality computer technology, known as virtual colonoscopy (VC); the reconstructed images provide a simulation of the interior of the colon as viewed by endoscopy. 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 likelihood 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 subsequent conventional colonoscopy in a blinded manner.
Results: Conventional colonoscopy identified a total of 24 polyps 5 mm or greater. VC correctly identified five of 13 polyps 5 - 9 mm in size, and ten of 11 lesions greater than or equal to 10 mm in diameter. The reasons for four missed lesions were identified as being secondary to a collapsed rectum in two patients and stool in the right colon in two patients. The sensitivity 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 were 90.0 % and 82.1 %, respectively.
Conclusions: Virtual colonoscopy is feasible, well tolerated, and capable of detecting most lesions greater than 10 mm in diameter. This technique is continuing to be developed and warrants further evaluation as a diagnostic and screening tool in colorectal neoplasia.
References
- 1 Wingo P A, Tong T, Bolden B. Cancer Statistics, 1995. Cancer Journal Clinics. 1995; 45 8-13
- 2 Stryker S J, Wolff B G, Culp C E, et al. Natural history of untreated colonic polyps. Gastroenterology. 1987; 93 1009-1013
- 3 Hardcastle J D, Thomas W M, Chamberlain J, et al. Randomized controlled trial of fecal occult blood screening for colorectal cancer: results for first 107 349 subjects. Lancet. 1989; 111 60-64
- 4 Kewenter R J, Bjork S, Haglind E, et al. Screening and rescreening for colorectal cancer: a controlled trial of fecal occult blood testing in 27 700 subjects. Cancer. 1988; 62 645-651
- 5 Day J J, Freeman A H, Coni N K, Dixon A K. Barium enema or computed tomography for the frail elderly patient?. Clin Radiol. 1993; 48 48-51
- 6 Amin Z, Boulos P B, Lees W R. Technical report: spiral CT pneumocolon for suspected colonic neoplasms. Clin Radiol. 1996; 51 56-61
- 7 Hara A K, Johnson C D, Reed J E, et al. Detection of colorectal polyps by computed tomographic colography: feasibility of a novel technique. Gastroenterology. 1996; 110 284-290
- 8 Vining D J, Gelfand D W. Non-invasive colonoscopy using helical CT scanning, 3D reconstruction, and virtual reality. Presented at the Society of Gastrointestinal Radiologists' Annual Meeting. Maui, HI; February 1994
- 9 Vining D J, Teigen L, Stelt S D. Virtual colonoscopy: a 60-second colon examination (abstract). Radiology. 1995; 197 281
- 10 Fenlon H M, Ferruci J T. Virtual colonoscopy: what will the issues be?. Am J Roentgenol. 1997; 169 453-458
- 11 Teigen E, Vining D J, McCorquodale D. Improving virtual colonoscopy with a fecal contrast agent. Presented at the Society of Gastrointestinal Radiologists' Annual Meeting. Cancun, Mexico; March 1997
- 12 Royster A P, Fenlon H M, Clarke P D, et al. CT colonoscopy of colorectal neoplasms: two-dimensional and three-dimensional virtual-reality techniques with colonoscopic correlation. Am J Roentgenol. 1997; 169 1237-1242
- 13 Ferruci J T. Screening for colon cancer: programs of the American College of Radiology. Am J Roentgenol. 1993; 160 999-1003
- 14 Rex D K, Cutler C S, Lemmel G T, et al. Colonoscopic miss rates of adenomas determined by back-to-back colonoscopies. Gastroenterology. 1997; 112 24-28
- 15 Morales T G, Sampliner R E, Garewal H S, et al. The difference in colon polyp size before and after removal. Gastrointest Endosc. 1996; 43 (1) 25-28
- 16 Gopalswamy N, Shenoy V N, Choudrhry U, et al. Is in vivo measurement of polyps during colonoscopy accurate?. Gastrointest Endosc. 1997; 46 (6) 497-502
- 17 Hara A K, Johnson C D, Reed J E, et al. Reducing data size and radiation dose for CT colonography. Am J Roentgenol. 1997; 168 1181-1184
- 18 Vining D J. Virtual endoscopy: is it reality?. Radiology. 1996; 200 30-31
- 19 Kay C L, Evangelou H A. A review of the technical and clinical aspects of virtual endoscopy. Endoscopy. 1996; 28 768-775
- 20 American Cancer Society guidelines for screening and surveillance for early detection of colorectal cancer and polyps. Update 1997. Cancer. 1997; 47 154-160
- 21 Hermanek P. Dysplasia-carcinoma sequence, types of adenomas and early colorectal carcinoma. Eur J Surg Oncol. 1987; 13 141-143
- 22 Shinya H, Wolff W I. Morphology, anatomic distribution and cancer potential of colonic polyps. Ann Surg. 1979; 190 679-683
- 23 Hofstad B, Vatn M H, Andersen I, et al. Growth of colorectal polyps: redetection and evaluation of unresected polyps for a period of three years. Gut. 1996; 39 449-456
- 24 Kay C L, Aabakken L, Evangelou H, et al. Virtual colonoscopy - a pig model for optimization of study parameters (abstract). Am J Gastroenterol. 1996; 91 349
- 25 Dachman A H, Lieberman J, Osnis R B, et al. Small simulated polyps in pig colon: sensitivity of CT virtual colography. Radiology. 1997; 203 427-430
- 26 Luboldt W, Bauerfeind D P, Steiner P, Fried M, et al. Preliminary assessment of three dimensional magnetic resonance imaging for various colonic disorders. Lancet. 1997; 349 1288-1291
- 27 Schoenenberger A W, Bauerfeind D P, Krestin G, Debatin G F. Virtual colonoscopy with magnetic resonance imaging: in vitro evaluation of a new concept. Gastroenterology. 1997; 112 1863-1870
- 28 Springer P, Dessl A, Giacomuzzi S M, et al. Viral computed tomographic gastroscopy: a new technique. Endoscopy. 1997; 29 632-634
- 29 Morrin M M, Kruskal J B, Farrell R J, et al. Endoluminal CT colonography after an incomplete endoscopic colonoscopy. Am J Roentgenol. 1999; 172 913-918
- 30 Macari M, Berman P, Dicker M, et al. Usefulness of CT colonography in patients with incomplete colonoscopy. Am J Roentgenol. 1999; 173 561-564
F.R.C.R. M.R.C.P. C. L. Kay
Dept. of Radiology Bradford Royal Infirmary
Duckworth Lane
Bradford BD9 6RJ
United Kingdom
Phone: +44-113-230/722
Email: kaycl44@hotmail.com