Colonoscopy, virtual

Cotton PB, Durkalski VL, Pineau BC, Palesch YY, Mauldin PD, Hoffman B et al. (2004) Computed tomographic colonoscopy (virtual colonoscopy) a multi-center comparison with standard colonoscopy for detection of colorectal neoplasia. JAMA 291 1713-1719... 

Virtual Reality Diagnosis Systems. The third type of information-enhancing system is virtual reality diagnosis systems. These systems, typically used in diagnostic endoscopy and colonoscopy, replace an actual exploration on the patient with a virtual exploration on MRI images. A three-... 

Virtual endoscopy of the colon is a typical and probably the most important example of a dedicated study in the field of virtual endoscopy. The so-called virtual colonoscopy allows the evaluation of the internal surface of the colon in a minimally invasive manner, providing promising results for the diagnosis of cancer and clinically significant polyps (Fig. 7.1). 

Fig. 9.3. Virtual colonoscopy with unfolding enables inspection of folds from all sides. From Vilanova et al. (2003)...

Fig.9.5a-c. Virtual colonoscopy with surface smoothing, a Original dose (64mAs) b6.25mAs c 1.6 mAs. From Peters (200)... 

In any case, virtual gastroscopy should be considered a natural complement to a CT or MR study of the upper abdomen when a gastric disease is suspected or when a known neoplastic lesion must be staged. At the moment, mainly due to the fact that conventional gastroscopy is not invasive as colonoscopy, there is no indication to use this imaging technique as a primary method for evaluation of the gastric lumen. 

Polyps between 6 and 9 mm are defined as intermediate lesions. Most of them are eventually found to be low-grade dysplasia adenomas, less than 1% are found to be harbour invasive carcinomas and 30% are found to be hyperplastic lesions. Thus, surveillance either with conventional or virtual colonoscopy may be a reasonable option in these cases... 

Akerkar GA, Yee J, Hung R et al (2001) Patient experience and preferences toward colon cancer screening a comparison of virtual colonoscopy and conventional colonoscopy. Gastrointest Endosc 54 310-315... 

Pass R, Do S, Hixson LI (1993) Fatal hyperphosphatemia following Fleet Phospo-Soda in a patient with colonic ileus. Am 1 Gastroenterol 88 929-932 Fenlon HM, Nunes DP, Schroy PC S " et al (1999) A comparison of virtual and conventional colonoscopy for the detection of colorectal polyps. N Engl J Med 341 1496-1503... 

Fletcher )G, lohnson CD, Welch T1 et al (2000) Optimization of CT colonography technique prospective trial in 180 patients. Radiology 216 704-711 Forbes GM, Mendelson RM (2000) Patient acceptance of virtual colonoscopy. Endoscopy 32 274-275... 

Kamar M, Portnoy O, Bar-Dayan A et al (2004) Actual colonic perforation in virtual colonoscopy report of a case. Dis Colon Rectum 47 1490-1491... 

Pickhardt PJ, Taylor AJ (2006) Extracolonic findings identified in asymptomatic adults at screening CT colonography. AJR Am J Roentgenol 186 718-728 Pineau BC, Paskett ED, Chen GJ et al (2003) Virtual colonoscopy using oral contrast compared with colonoscopy for the detection of patients with colorectal polyps. Gastroenterology 125 304-310... 

Schoenenberger AW, Bauerfeind P, Krestin GP et al (1997) Virtual colonoscopy with magnetic resonance imaging in vitro evaluation of a new concept. Gastroenterology 112 1863-1870... 

Summers RM, Yao J, Pickhardt PJ et al (2005) Computed tomographic virtual colonoscopy computer-aided polyp detection in a screening population. Gatroenterology 129 1832-1844... 

In both fiber-optic colonoscopy and CT colonog-raphy, polyps behind colonic folds may be not seen at standard oral views due to the structure of the colon. Further endoscopic views visualize only a small part of the inner colonic surface. The technique of virtual dissection avoids these problems and presents the colonic surface in the same manner as on the pathologist s table. Theoretically, due to the view from above , all polyps should be displayed - and not hidden by the colonic folds. 

Pickhardt PJ (2003) Three-dimensional endoluminal CT colonography (virtual colonoscopy) comparison of three commercially available systems. AJR Am J Roentgenol 181 1599-1606... 

Hoppe H, Quattropani C, Spreng A, Mattich J, Netzer P, Dinkel HP (2004) Virtual colon dissection with CT colonography compared with axial interpretation and conventional colonoscopy preliminary results. AJR Am J Roentgenol 182 1151-1158... 

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