Colonoscopy Diagnostic

In selected patients, sigmoidoscopy, colonoscopy, or abdominal computed tomographic (CT) scan can provide useful diagnostic information. 

The administration of prophylactic antibiotics solely to prevent endocarditis is not recommended for patients who undergo GI tract procedures, including diagnostic esophagogastroduodenoscopy or colonoscopy, as recommended by American Heart Association 2007 guidelines. 

Additional diagnostic steps that can be taken include sigmoidoscopy or colonoscopy examination of the stool for occult blood and ova and parasites complete blood cell count erythrocyte sedimentation rate and serum electrolytes. In some cases, radiographic imaging studies, such as computed tomography scans or barium swallows or enemas, may also be necessary if the findings of the above assessment are not typical for IBS. ... 

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-... 

Dafnis G, Ekbom A, Pahlman Let al (2001) Complications of diagnostic and therapeutic colonoscopy within a defined population in Sweden. Gastrointest Endosc 2001 54 302-309... 

Prentice RL, Thomson CA, Caan B et al. (2007) Low-fat dietary pattern and cancer incidence in the Women s Health Initiative Dietary Modification Randomized Controlled Trial. J Natl Cancer Inst 99 1534 1543 Purkayastha S, Tekkis PP, Athanasiou T et al. (2005) Magnetic resonance colonography versus colonoscopy as a diagnostic investigation for colorectal cancer a meta-analysis. Clin Radiol 60 980 989... 

Conventional colonoscopy is also not without risk to the patient and significant morbidity and mortality has been reported (Garbay et al. 1996). The most common adverse outcome associated with conventional colonoscopy includes hemorrhage and perforation. The rate of perforation of the colon ranges from 0.2 to 0.4% after diagnostic colonoscopy, increases with polypectomy, and approximates 5% with hydrostatic balloon dilatation of colonic strictures (Zubarik et al. 1999). 

The indications for diagnostic CTC closely follow those for conventional colonoscopy (Rankin 1987). Rectal bleeding, heme positive stool, anemia and constipation are just a few examples. Indications for screening and diagnostic CTC are summarized in Table 2.1. 

Diagnostic CTC may be used to further evaluate findings on conventional colonoscopy. Not infrequently, diagnostic CTC is performed in patients with suspicious intramural or extra-mural masses detected on optical colonoscopy (Fig. 2.2). 

Virtual colonoscopy, now ten years old, has made substantial progress in the detection of adenomas and colorectal cancer. Recent studies report comparable sensitivities and specificities to conventional colonoscopy for polyps 10 mm or larger on a per polyp basis. CTC is currently approved by Medicare as a diagnostic study in patients with positive symptoms and after failed colonoscopy. Work continues to approve CTC as a colorectal cancer screening exam. Many experts believe CTC is also ready to be adopted into the colorectal screening algorithm. 

The sensitivity per polyp is used as a criterion for the functioning of the review methods different diagnostic modes, since it is a more precise way to measure the visibility of a polyp. However, in a screening setting the sensitivity per patient is a more important outcome parameter since the consequence of a positive colonography will be a referral for colonoscopy. 

PiNEAU et al. (2003) conducted a comparative study with optic colonoscopy assessing the diagnostic accuracy of virtual colonoscopy using oral contrast. The colonography examination was done with a primary 2D method with 3D problem solving. in a population of 205 patients the sensitivity for large (>10 mm) colorectal polyps was 78%. The reported specificity was higher (95%). This decreased for medium-sized (6-9 mm) polyps to 75 and 83% respectively. 

The matching of conventional colonoscopy (CC) and CTC for size and location is required in order to understand the diagnostic accuracy of the technique. Every effort should be made to measure accurately the size of each lesion detected. Ideally,... 

Bruzzi JF, Moss AC, Fenlon HM (2001) Clinical results of CT colonoscopy. Eur Radiol 11(11) 2188-2194 Dachman AH (2002) Diagnostic performance of virtual colonoscopy. Abdom Imaging 27 260-267 Dachman AH, Yoshida H (2003) Virtual colonography past, present, and future. Radiol Clin North Am 41 377-393 Dachman AH, Zalis ME (2004) Quality and consistency in CT colonography and research reporting. Radiology 230 319-323... 

The number of subjects of the study is very small, but, as its main aim was to see the viability of obtaining the readings, we think that it is enough for that purpose. Obtaining EIS readings from patients undergoing diagnostic total colonoscopy was carried out very easily, with practically very little additional discomfort for the subjects. In all cases, it took, in total, less than two minutes to have... 

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