Editorial Reviews. Review. Master virtual colonoscopy. About the Author. University of Wisconsin School of Medicine and Public Health Madison, WI USA. Request PDF on ResearchGate | On May 1, , Ged R. Avery and others published CT Colonography: Principles and Practice of Virtual Colonoscopy. In CT Colonography, Perry Pickhardt and David Kim present techniques for quicker evaluation and diagnosis of colon cancer through the.
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Prevalence of nonpolypoid flat and depressed colorectal neoplasms in asymptomatic and symptomatic adults. In many ways, the anorectal region represents the most important source of pitfalls at CTC, since common incidental findings may distract the reader from important underlying pathology, which may be relatively subtle due its specific location. At 3D Dthe preservation of the overlying colonic fold is a sign that the lesion is caused by extrinsic impression.
Careful attention to this area should be considered a routine part of CTC interpretation.
Degree of coverage and implications for polyp detection. An equilibrium pressure of 20 mm Hg was utilized for the automated CO 2. CT colonography virtual colonoscopy: Brain Imaging ov Behavioral Neuroscience.
A number of important artifacts result from post-processing of the MDCT source data. Additional reasons include that glucagon is generally not effective, Buscopan is not available in the U. The smooth thickening appears to be related to a point of slight twisting or torsion.
In contrast to hemorrhoids, rectal varices have a tubular, serpiginous appearance. However, there are additional pitfalls related to diverticular disease beyond fold thickening and inadequate luminal distention.
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For cases in which complete focal collapse persists at the same point on both supine and prone displays, a decubitus view will usually allow practicr diagnostic assessment. This carpet lesion was confirmed at same-day optical colonoscopy D and proved to be a tubulovillous adenoma. Potential pitfalls related to anatomy Thickened colonic folds Diverticular disease Flat lesions Submucosal and extrinsic lesions Anorectal Pitfalls Ileocecal valve pitfalls Appendiceal pitfalls.
How to write a great review. On the prone 2D CTC images C and Dthe polyp arrow colinography submerged under densely opacified fluid, which further decreases the apparent polyp size. Principles and Practice of Virtual Colonoscopy. Right lateral decubitus position for salvaging adequate luminal distention Supine 2D CTC image A shows long-segment collapse of the sigmoid colon, related to diverticular disease.
Artifacts related to respiratory and colonosfopy patient motion are much less common with multi-detector CT MDCT scanners having 16 or more channels, due to shorter acquisition times.
The search pattern for detecting polyps on 2D, especially small 6—9 mm lesions, is simply too onerous to maintain acceptable performance. Principles of Flexible Endoscopy for Surgeons.
These non-neoplastic lesions can be difficult to differentiate from neoplastic disease.
CT Colonography: Pitfalls in Interpretation
Compared with excellent luminal distention, such cases generally require more scrutiny, as the luminal narrowing is compounded by dynamic thickening of the colonic folds, which makes interpretation more challenging. A clear distinction must be made between relatively colonogrsphy lesions, and completely flat or depressed lesionswhich are quite rare. However, because relevant colorectal lesions require detection on just one view, confirmation on the lesser quality view is generally achievable even in cases of inadequate distention Fig.
A more extensive review with hundreds of illustrations can be found in our dedicated referenced textbook. A focal soft tissue protuberance on or pracgice to a fatty valve is suspicious for a true polyp Fig.
The 3D colon map shows three bookmarks red dots denoting focal colonohraphy in the regions of the anorectum, ileocecal valve, and the appendiceal orifice.
Prevalence, histology, and sensitivity for detection in an asymptomatic screening population. Although CAD has been advanced as a way to colonohraphy for inadequate training, this notion ignores the fact that poor specificity would lead to an unacceptable false-positive rate.
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Interventional Cardiology, Second Edition. Tube current modulation can avoid this discordance by boosting the mA only as needed to maintain a static noise level. Although CTC is the most accurate method available for polyp measurement, 30 inaccurate size assessment remains an important potential pitfall because it could lead to inappropriate patient management. Nonetheless, the sensitivity of combined 3D-2D polyp detection with contrast tagging appears to be satisfactory.
With proper attention to technique, including patient preparation, colonic distention, and scanning protocol, in addition to a combined 2D-3D interpretive strategy, the vast majority of these potential pitfalls can be handled appropriately. The review must be at least 50 characters long.
Although we initially performed electronic cleansing on the tagged fluid prior to interpretation very early on in our CTC experience, we discontinued this practice in due to the troublesome artifacts that were introduced discussed later.