Laxative-Free CT Colonography

Lefere, Philippe; Gryspeerdt, Stefaan; Baekelandt, Marc; Holsbeeck, B Van

doi:10.2214/ajr.183.4.1830945

Cited by 67 publications

(37 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is unlikely, however, that non-laxative CTC will reliably match the diagnostic accuracy of full cathartic examinations. Notably, in our own clinical experience of nonlaxative CTC and also within the existing literature [13,14], tagging quality may be suboptimal in the left colon, presumably because of slow intestinal transit of tagging agents in some patients. The majority of colorectal cancers arise in the rectum and distal colon, with approximately 50% arising from the rectum and rectosigmoid area, with a further 25% arising from the sigmoid colon [15].…”

mentioning

confidence: 77%

“…Such reduced laxative regimes use oral contrast agents (such as barium and/or iodinated contrast) to label or ''tag'' the residual colonic contents to a higher attenuation, facilitating the detection of true neoplasia in the stool-laden colon [10,13,14]. It is unlikely, however, that non-laxative CTC will reliably match the diagnostic accuracy of full cathartic examinations.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated?

Davis

Nisbet²,

Hare³

et al. 2011

BJR

View full text Add to dashboard Cite

Objective: The purpose of this study was to investigate the efficacy and tolerance of an additional phosphate enema prior to non-laxative CT colonography (CTC). Methods: 71 patients (mean age 80 years, 28 male, 43 female) underwent non-laxative CTC following 4 oral doses of diluted 2% w/w barium sulphate. Patients were invited to self-administer a phosphate enema 2 h before CTC. An experienced observer graded the volume of retained stool (1 (nil) to 4 (.75% bowel circumference coated)), retained fluid ((1 (nil) to 4 (.50% circumference obscured)), retained stool tagging quality (1 (untagged) to 5 (>75% to 100%) tagged) and confidence a polyp >6 mm could be excluded (yes/no) for each of six colonic segments. Tolerance of the enema was assessed via questionnaire. Data were analysed between those using and not using the enema by Mann-Whitney and Fisher's exact test. 18/71 patients declined the enema. Results: There was no reduction in residual stool volume with enema use compared with non-use either overall (mean score 2.6 vs 2.7, p50.76) or in the left colon (mean 2.3 vs 2.4, p50.47). Overall tagging quality was no different (mean score 4.4 vs 4.3, p50.43). There was significantly more retained left colonic fluid post enema (mean score 1.9 vs 1.1, p,0.0001), and diagnostic confidence in excluding polyps was significantly reduced (exclusion not possible in 35% segments vs 21% without enema, p50.006). Of 53 patients, 30 (56%) found the enema straightforward to use, but 4 (8%) found it unpleasant. Conclusion: Phosphate enema use prior to non-laxative CTC leads to greater retained fluid, reducing diagnostic confidence, and is not recommended.

show abstract

mentioning

confidence: 77%

mentioning

confidence: 99%

Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated?

Davis

Nisbet²,

Hare³

et al. 2011

BJR

View full text Add to dashboard Cite

show abstract

“…Fecal tagging is a means of "marking" fecal residue (stool and fluid) in the colon with oral administration of a positive contrast agent (barium or iodine), thereby allowing differentiation of this residue from colonic soft-tissue structures at CT colonography (3)(4)(5)(6)(7). Large-scale and multicenter clinical trials have demonstrated that CT colonography has a sensitivity comparable to that of optical colonoscopy in the detection of clinically significant polyps in a screening population (8)(9)(10).…”

Section: Introductionmentioning

confidence: 99%

Informatics in Radiology: Dual-Energy Electronic Cleansing for Fecal-Tagging CT Colonography

Cai¹,

Kim²,

Lee³

et al. 2013

RadioGraphics

View full text Add to dashboard Cite

Electronic cleansing (EC) is an emerging technique for the removal of tagged fecal materials at fecal-tagging computed tomographic (CT) colonography. However, existing EC methods may generate various types of artifacts that severely impair the quality of the cleansed CT colonographic images. Dual-energy fecal-tagging CT colonography is regarded as a nextgeneration imaging modality. EC that makes use of dual-energy fecal-tagging CT colonographic images promises to be effective in reducing cleansing artifacts by means of applying the material decomposition capability of dual-energy CT. The dual-energy index (DEI), which is calculated from the relative change in the attenuation values of a material at two different photon energies, is a reliable and effective indicator for differentiating tagged fecal materials from various types of tissues on fecal-tagging CT colonographic images. A DEI-based dual-energy EC scheme uses the DEI to help differentiate the colonic lumen-including the luminal air, tagged fecal materials, and air-tagging mixture-from the colonic soft-tissue structures, and then segments the entire colonic lumen for cleansing of the tagged fecal materials. As a result, dual-energy EC can help identify partialvolume effects in the air-tagging mixture and inhomogeneous tagging in residual fecal materials, the major causes of EC artifacts. This technique has the potential to significantly improve the quality of EC and promises to provide images of a cleansed colon that are free of the artifacts commonly observed with conventional single-energy EC methods.

show abstract

“…3 Laxative cleansing interferes with patients' daily activities by causing diarrhea, and there are potential side effects such as nausea, abdominal discomfort, vomiting, and/or flatulence. 4 Studies have indicated that computed tomographic colonography ͑CTC͒ could be used to implement an effective laxative-free colorectal screening scheme. [4][5][6] Laxative bowel cleansing and diarrhea may be avoided in CTC if residual bowel contents are opacified by use of a tagging agent that does not induce cathartic effect.…”

Section: Introductionmentioning

confidence: 99%

Virtual tagging for laxative‐free CT colonography: Pilot evaluation

Näppi¹,

Yoshida²

2009

Medical Physics

View full text Add to dashboard Cite

Laxative-free computed tomographic colonography ͑lfCTC͒ could significantly improve patient adherence to colorectal screening. However, the interpretation of lfCTC data is complicated by the presence of poorly tagged feces and partial-volume artifacts that imitate colorectal lesions. The authors developed a method for virtual tagging of such artifacts. A probabilistic model of colonic wall was developed, and virtual tagging was performed on artifacts that were identified by the model. The method was evaluated with 46 clinical lfCTC cases that were prepared with dietary fecal tagging only. Visual examples show that the method can label partial-volume artifacts, poorly tagged feces, nonadhering completely untagged feces, and artifacts such as rectal tubes. The effect of virtual tagging was evaluated by comparing the detection accuracy of a fully automated polyp detection scheme without and with the method. With virtual tagging, the per-lesion detection sensitivity was 100% for lesions ജ10 mm ͑n =4͒ with 3.8 false positives per patient ͑per two CT scan volumes͒ and 90% for lesions ജ6 mm ͑n =10͒ with 5.4 false positives per patient on average. The improvement in detection performance by virtual tagging was statistically significant ͑p = 0.03; JAFROC and JAFROC-1͒.

show abstract

Laxative-Free CT Colonography

Cited by 67 publications

References 6 publications

Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated?

Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated?

Informatics in Radiology: Dual-Energy Electronic Cleansing for Fecal-Tagging CT Colonography

Virtual tagging for laxative‐free CT colonography: Pilot evaluation

Contact Info

Product

Resources

About