AJR F and L Medical Products: Radiation Protection & More
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sosna, J.
Right arrow Articles by Libson, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sosna, J.
Right arrow Articles by Libson, E.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Hotlight (NEW!)
Right arrow
What's Hotlight?
DOI:10.2214/AJR.07.2099
AJR 2008; 190:374-385
© American Roentgen Ray Society

Original Research

Critical Analysis of the Performance of Double-Contrast Barium Enema for Detecting Colorectal Polyps ≥ 6 mm in the Era of CT Colonography

Jacob Sosna1,2, Tamar Sella1, Oumar Sy3, Philip T. Lavin3, Ruth Eliahou1, Shifra Fraifeld1 and Eugene Libson1

1 Department of Radiology, Hadassah Hebrew University Medical Center, POB 12000, Jerusalem, Israel.
2 Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA.
3 Boston Biostatistics Research Foundation, Framingham, MA.

Received February 21, 2007; accepted after revision September 9, 2007.

 
Address correspondence to J. Sosna (jacobs{at}hadassah.org.il).


Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
OBJECTIVE. The purpose of our study was to perform a meta-analysis comparing the performance of double-contrast barium enema (DCBE) with CT colonography (CTC) for the detection of colorectal polyps ≥ 6 mm using endoscopy as the gold standard.

MATERIALS AND METHODS. Prospective DCBE and CTC studies were identified. Percentages of polyps and of patients with polyps ≥ 10 mm and 6–9 mm were abstracted. The performance of DCBE versus CTC was determined by separately evaluating each technique's performance versus that of endoscopy, and contrasting the techniques. The I-squared statistic and Fisher's exact test were used for heterogeneity, the Cochran-Mantel-Haenszel and the Kruskal-Wallis tests for correlation, and the Az test for comparing pooled weighted estimates of performance.

RESULTS. Eleven studies of DCBE (5,995 patients, 1,548 polyps) and 30 studies of CTC (6,573 patients, 2,348 polyps) fulfilled inclusion criteria. For polyps ≥ 10 mm, a 0.121-perpatient sensitivity difference favored CTC (p < 0.0001; DCBE, 0.702 [95% CI, 0.687–0.715]; CTC, 0.823 [0.809–0.836]). For polyps ≥ 10 mm, a 0.031-per-polyp sensitivity difference favored CTC (p < 0.0001; DCBE, 0.715 [0.703–0.726]; CTC, 0.746 [0.735–0.757]). For polyps ≥ 10 mm, a specificity difference of 0.104 favored CTC (p = 0.001; DCBE, 0.850 [0.847–0.855]; CTC, 0.954 [0.952–0.955]). DCBE was also significantly less sensitive for 6- to 9-mm polyps (p < 0.001).

CONCLUSION. DCBE has statistically lower sensitivity and specificity than CTC for detecting colorectal polyps ≥ 6 mm.

Keywords: barium enema • colonoscopy • CT colonography • double-contrast barium enema • meta-analysis • virtual colonoscopy


Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Colorectal cancer is the second leading cause of death from cancer in the United States, with a 6% lifetime risk of disease [1]. Routine screening for malignancies and adenomatous polyps is recommended to begin at the age of 50 years, or at a younger age for those at higher risk [2–5]. Effective screening can greatly reduce colorectal cancer morbidity and mortality [6–8]; however, only 30–45% of those for whom screening is recommended comply with guidelines [9].

Potential screening options for colorectal cancer include fecal occult blood testing, flexible sigmoidoscopy, conventional colonoscopy, and double-contrast barium enema (DCBE). Although DCBE is an accepted and reimbursed screening method for colorectal cancer, published evidence from controlled studies examining the accuracy of this method is limited.

CT colonography (CTC), or virtual colonoscopy, was introduced in 1994 [10]. CTC has the potential to increase compliance because it is perceived to be more tolerable for patients and may have fewer associated complications than conventional colonoscopy [11–13]. However, the U.S. Preventive Services Task Force found insufficient evidence to conclude that CTC improves health outcomes and determined that rigorous studies must precede the acceptance of CTC as a routine screening tool [5]. The recent American Gastroenterological Association position paper stated that CTC is indicated only for incomplete colonoscopy but in the future may become an accepted screening technique [14]. Thus, CTC is considered an evolving technique pending results from multicenter trials.

DCBE needs to be reevaluated with comparable rigor because previous studies have questioned its performance [15]. Although several CTC meta-analyses have been published, to our knowledge no meta-analysis addresses DCBE performance. The purpose of this study was to perform a meta-analysis of the sensitivity and specificity of DCBE for the detection of colorectal polyps ≥ 6 mm in comparison with CTC, using endoscopy as the gold standard.


Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
This study did not involve human subjects directly and was exempt from institutional review board approval.

Data Sources and Literature Search
A comprehensive literature search of English-language studies was performed using the PubMed, MEDLINE, and EMBRACE databases, and the Cochrane Controlled Trials registry. DCBE keywords were double-contrast barium enema, barium enema, and pneumocolon. CTC articles were identified using the keywords CT colonography, CT colonoscopy, virtual colonoscopy, and CT pneumocolon. Searches included peer-reviewed DCBE studies published from January 1960 through December 2006, and CTC studies published from January 1994 through December 2006. Review articles, letters, comments, articles without original data, conference abstracts, and secondary presentations were excluded.

Study Eligibility
All DCBE and CTC studies included in the analysis were prospective. Additional DCBE study inclusion criteria were full colorectal preparation when air and barium were used to reveal colon segments, both spot and overhead films, evaluation of the entire colon, full conventional colonoscopy or sigmoidoscopy as the reference standard, DCBE reader blinding to the results of conventional colonoscopy or sigmoidoscopy, and reports of performance in absolute numbers and in percentages for polyps or masses of different sizes. Comparisons between flexible sigmoidoscopy and DCBE were made only in the rectum and sigmoid colon.

CTC study inclusion criteria were based on the CTC consensus document [16]. Additional CTC inclusion criteria were full colorectal preparation when the entire colon was evaluated, full conventional colonoscopy as the reference standard (with or without segmental unblinding), CTC reader blinding to the results of conventional colonoscopy, CTC performed with the patient in both the prone and supine positions after the insufflation of air or CO2, at least a single-detector CT scanner, slice thickness ≤ 5 mm, both 2D and 3D (full or partial) readings, and reports of performance in absolute numbers and in percentages for polyps or masses of different sizes. In some studies, these criteria were fulfilled with only a subgroup of patients, and findings for other groups were excluded from the analysis.

Studies in which IV iodinated contrast material was routinely administered to all patients were excluded because contrast material is not used consistently in colorectal cancer screening programs. We also excluded studies of which the primary aim was evaluating ultralow radiation dose, those with no or minimal colonic preparation, and studies evaluating computer-aided detection because these techniques are still experimental. When adenomas or the total amount of polyps were presented, the larger number was used. When two or more readers assessed the same study population, the average of their findings was used (Table 1).


View this table:
[in this window]
[in a new window]

  		TABLE 1: Studies Comparing Performance of Double-Contrast Barium Enema with Colonoscopy or Sigmoidoscopy and CT Colonography (CTC) with Colonoscopy, for Diagnosis of Polyps ≥ 6 mm

 

Data Extraction
The meta-analysis was performed in compliance with QUORUM (Quality of Reporting of Meta-Analyses) guidelines [17]. Two investigators extracted the data from each article separately, with disagreements resolved by consensus. Included studies were randomly sorted for data extraction, and only the first author, year of publication, sample size, and patient risk were recorded in the data sheet. Patients with symptoms or a history of colorectal neoplasia, those under surveillance, and those with positive findings on a previous screening test were considered high risk. DCBE and CTC technique, the experience of radiologists and the protocol for interpreting imaging studies, the number of patients per study, number of lesions detected by diameter (≥ 10 mm, 6–9 mm), number of patients in whom lesions of these size categories were detected, and specificity for detection of polyps ≥ 10 mm were recorded for each study. End points were per-polyp and per-patient sensitivity for DCBE or CTC, and specificity for polyps ≥ 10 mm.

Statistical Analysis
The relative performance of DCBE and CTC was determined by separately evaluating each technique's sensitivity and specificity in comparison with endoscopy on the basis of the pooled weighted results of the relevant series of studies, and then contrasting DCBE and CTC outcomes.

To determine whether data could be pooled across studies, the I-squared statistic and Fisher's exact test were used to assess heterogeneity within the DCBE and CTC series at each study end point. I-squared statistic values range from 0% to 100%, with smaller values indicating higher homogeneity and larger values indicating greater heterogeneity.

For each diagnostic technique, pooled specificity and sensitivity were estimated, weighted and unweighted by study size, and 95% CIs were computed. The relationship between polyp size and sensitivity was assessed for each technique using the Cochran-Mantel-Haenszel and the Kruskal-Wallis tests.

Analyses comparing pooled weighted estimates of DCBE and CTC outcomes were generated. The Az test comparing two independent population proportions was used because the specificity and sensitivity end points were both proportions, and the DCBE and CTC samples of articles were independent. A p value of < 0.05 was considered significant.


Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Literature Search
We retrieved 662 original articles addressing all aspects of DCBE from the databases; 11 fulfilled inclusion criteria [15, 18–27] (Table 1). Thirty studies were excluded because they were retrospective (n = 23) [28–50], compared techniques for a portion of patients rather than providing separate results for all parts (n = 5) [26, 51–54], did not mention absolute numbers (n = 1) [55], or involved children (n = 1) [56].

We retrieved 636 original articles addressing all aspects of CTC; 30 fulfilled inclusion criteria [11, 20, 57–82] (Table 1). Thirty-three studies were excluded because of overlap of published results (n = 3) [83–85], frequent IV contrast use (n = 6) [71, 86–90], single scanning position (n = 7) [91–97], minimal or no preparation (n = 6) [98–103], computer-aided detection (n = 4) [96, 104–106], ultralow radiation dose (n = 5) [107–111], or a small patient series (n = 2) [112, 113].

Two articles comparing DCBE and CTC in the same population of patients were included [20, 77]. In these studies, findings for each imaging method were analyzed separately and thus could be added to the cumulative experience for each technique.

No DCBE study involved 50 or fewer subjects, six (55%) had 51–500 patients, and five (45%) had more than 500. Six studies (55%) involved only high-risk patients, one study (9%) included a mixture of average- and high-risk patients, one study (9%) included average-risk patients, and three (27%) studies provided no information regarding patient selection. Conventional colonoscopy was the reference standard in five studies (46%), sigmoidoscopy in four (36%), and both conventional colonoscopy and sigmoidoscopy in two studies (18%).

Six of 30 CTC studies (20%) had 50 subjects or fewer, 19 (63.3%) had 51–500 patients, and five (17%) had more than 500. Six studies (20%) included only average-risk patients or a combination of high- and average-risk, and 24 (80%) included only high-risk patients. In 14 studies (53.3%), some or all patients were evaluated with MDCT scanners.

Data Synthesis
DCBE—A total of 5,995 patients were included in the 11 articles analyzed. In this population, 970 polyps were detected by conventional colonoscopy, including 549 polyps ≥ 10 mm in diameter and 421 polyps of 6–9 mm. Specific data for each article are given in Table 2.


View this table:
[in this window]
[in a new window]

  		TABLE 2: Summary of Statistics for Double-Contrast Barium Enema and CT Colonography

 

Pooling appropriateness tests for sensitivity and specificity analysis of DCBE studies yielded p < 0.001 for the Fisher's exact test on all end points except per-patient sensitivity for polyps 6–9 mm, for which the p value was 0.268. I-squared values ranged from 81.46% for per-patient sensitivity for polyps 6–9 mm to 96.01% for specificity. I-squared values could not be calculated for per-patient sensitivity for polyps ≤ 5 mm. Pooled study results, both unweighted and weighted by study size, are provided in Table 3.


View this table:
[in this window]
[in a new window]

  		TABLE 3: Pooling of Double-Contrast Barium Enema and CT Colonography Studies

 

Data analysis of trend using the Cochran-Mantel-Haenszel test showed increasing per-patient (p < 0.0001) and per-polyp (p = 0.0048) sensitivity for polyp detection with increasing polyp size. The Kruskal-Wallis tests for per-patient and per-polyp sensitivity trends as polyp size increased were not significant, with p values of 0.2765 and 0.2291, respectively.

CTC—A total of 6,673 patients were included in the 30 CTC articles analyzed. At conventional colonoscopy, 2,348 polyps were detected, including 925 polyps with diameters ≥ 10 mm and 1,423 polyps of 6–9 mm. Specific data for each article are given in Table 2. Tests for pooling appropriateness yielded p < 0.001 using the Fisher's exact test. I-squared values varied from 47.6% for per-polyp specificity for polyps ≥ 10 mm to 81.13% per-polyp sensitivity for polyps ≥ 10 mm, and 74.91% per-patient sensitivity for polyps ≥ 10 mm. Pooled CTC study results, both unweighted and weighted by study size, are provided in Table 3.

Data analysis of trend using the Cochran-Mantel-Haenszel test showed increasing perpatient and per-polyp sensitivity with increasing polyp size (p < 0.0001). The Kruskal-Wallis test confirmed these findings.

Comparison of CTC and DCBE—Estimates comparing pooled DCBE performance with pooled CTC performance showed significant differences in favor of CTC for specificity and per-polyp sensitivity in polyps ≥ 6 mm (Table 4).


View this table:
[in this window]
[in a new window]

  		TABLE 4: Comparison of Performance of Double-Contrast Barium Enema (DCBE) and CT Colonography (CTC)

 


Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
Although DCBE is an accepted and widely used technique, we could retrieve only 11 prospective studies comparing DCBE with conventional colonoscopy or sigmoidoscopy, even when the search was extended back to 1960. Of interest is the relatively small number of prospective studies addressing DCBE performance. In fact, studies that used sigmoidoscopy as the reference standard were included to increase the number of studies analyzed. We attributed the relatively small number of prospective DCBE studies in comparison with CTC to rising methodologic standards in recent years. The routine use of less demanding methods in previous years resulted in 24 retrospective DCBE studies. No DCBE study published before 1982 was prospective. We decided not to use retrospective studies even though their use would have increased considerably the number of studies analyzed. Data gathering and analysis vary greatly in retrospective and prospective studies, and including retrospective studies could increase heterogeneity of the pooled data. Indeed, tighter acceptance criteria for CTC studies in our analysis led to greater homogeneity in our data compared with other meta-analyses, as pointed out later. DCBE was assessed rather than single-contrast barium enema because DCBE is the more widely accepted technique for radiologic imaging of the large bowel.

The 30 CTC articles analyzed in this study emanate from a variety of groups that have used CTC over the past 13 years. Acceptance criteria for CTC studies included dual positioning, ≤ 5-mm slice thickness, 2D and 3D reading, and use of a single-detector or preferably MDCT scanner. Techniques in the studies differ for technical factors such as section width and reconstruction interval. We decided to include only studies with section width ≤ 5 mm, which provides acceptable thickness [114], although thinner collimation is optimal and has been shown to improve performance. Tube current was also variable. Although ultralow tube currents have been shown to have good diagnostic yield, they were excluded from the analysis because they are not yet used routinely for CTC studies [107–110]. Although IV contrast material may increase CTC sensitivity for medium-sized polyps [115], we also excluded articles in which contrast material was administered because it would not be routinely used for screening.

This analysis showed more heterogeneity in sensitivity and specificity measures among DCBE studies and more homogeneity among CTC studies. Whereas DCBE heterogeneity was greater than 80% for all end points, heterogeneity was 47% for CTC specificity and 74% for CTC per-patient sensitivity to polyps ≥ 10 mm in diameter. Although heterogeneity is higher for DCBE, we did not specifically aim to determine the sources of heterogeneity in the relatively small number of DCBE studies. For CTC, the most important parameters for population-based decisions—for example, test specificity and perpatient sensitivity of the clinically important finding (polyps ≥ 10 mm)—are at lower but potentially acceptable levels compared with conventional colonoscopy.

DCBE had lower performance levels, with specificity of 0.850 and per-patient sensitivity for larger polyps of 0.702. On the other hand, the meta-analysis showed that CTC has a very good specificity for polyps ≥ 10 mm (0.954) and good per-patient sensitivity (0.823). The difference was statistically significant.

On the basis of our results, CTC has a very good record for specificity. Extrapolation of our findings to a population of 1,000 patients, including 50 patients with polyps ≥ 10 mm (5% prevalence), would result in six more underdiagnosed cases on DCBE (35 true-positive polyps of 50 patients with polyps) than on CTC (41 true-positive polyps). Although some of these polyps could be diagnosed in subsequent screening studies, it seems likely that some of these missed polyps might be diagnosed as malignancies at a later stage when interventions are less effective. We believe that the primary end point in screening is indeed detection of patients with polyps and that sensitivity should be as high as possible. According to our findings, DCBE would also result in 90 more overdiagnosed cases (138 false-positive cases on DCBE compared with 48 at CTC), leading to unnecessary biopsies, higher costs, and greater uncertainty for patients and their families.

The true goal in screening is to reduce the morbidity and mortality rates of colorectal cancer. As always, this goal is balanced against financial requirements and potential harm to the patient. Nevertheless, high-risk adenomas, and even some early cancers, are surrogate end points that may have no influence on true patient outcome. Most high-risk adenomas will never progress to cancer. Thus, the statistical differences found in our study need ultimate verification in long-term studies addressing the end point of mortality associated with colorectal cancer.

Pooled CTC sensitivity and specificity in this analysis are comparable to those in previously published CTC meta-analyses [114, 116, 117], with less heterogeneity. This may be partially explained by stricter inclusion criteria in this study, which resulted in a smaller number of included articles (e.g., 30 studies in this analysis vs 33 in the metaanalysis by Mulhall et al. [114]).

The reports we analyzed included mostly high-risk patients. There were more polyps per patient in the CTC than the DCBE studies, which may partly explain improved CTC performance because higher prevalence affects and increases positive predictive value. However, this is unlikely to be the sole explanation for the better performance of CTC because high-risk patients represented the majority in both groups.

Although DCBE is widely considered an acceptable screening method for colorectal cancer, our findings indicate that it may be less specific and less sensitive than CTC for detection of polyps ≥ 6 mm. Although meta-analysis does not replace large prospective clinical trials, reports have shown that findings based on analysis of pooled data of a series of smaller studies do not differ significantly from outcomes of large trials [118, 119]. And although CTC is not recommended for screening, the results of this analysis suggest that CTC may be considered at least as effective as DCBE. Although short-term results of CTC used in a screening population with third-party coverage were recently published [120], further studies should be performed to address the economic aspects and radiation considerations of the widespread use of CTC as a reimbursable screening tool. CTC has the added benefit of evaluating extracolonic organs [121, 122].

Conventional colonoscopy performed with video endoscopy, as in recent years, may be more sensitive than it was in the 1980s, when fiberoptic viewing was standard. Thus, the relative performance of DCBE compared with conventional colonoscopy in earlier studies may not accurately represent the relative performance today, given the recent improvement in conventional colonoscopy sensitivity. More than half of the DCBE studies focused on the rectum and sigmoid because flexible sigmoidoscopy was the standard of reference. DCBE is known to be least accurate in these colon segments, possibly skewing data downward. However, prevalence of polyps in these regions is also higher, which may limit a possible reduction in patient sensitivity and specificity.

Limitations of our study may include an inherent publication bias, because studies that show positive effect tend to be published more often than those that do not [123]. There is also a possible tendency to publish studies with positive results of newer technologies (e.g., CTC) compared with older techniques (DCBE), which are considered less attractive for research. In addition, several weakly positive studies may add to a strong positive result when pooled. A rich delineation of possible sources of heterogeneity requires a more sensitive technique than meta-analysis. We included information on study characteristics, but our ability to discriminate sources of heterogeneity was limited. We also could not evaluate other factors, such as the impact of varying expertise among radiologists reading CTC studies and the notion that younger radiologists are less trained in the performance and interpretation of DCBE. We think that the main reason for the slow demise of DCBE is low reimbursement and the lack of radiologists who are adequately trained in this technique. When properly performed, DCBE remains a cost-effective clinical tool. Even though DCBE is performed with deceasing frequency, it is still a reimbursable technique that is used in common practice by radiologists worldwide and by technologists in some countries such as the United Kingdom.

In conclusion, despite its widespread use, scientific data on the overall performance of DCBE compared with CTC are limited. Our study suggests that DCBE has lower sensitivity and specificity than CTC for detecting polyps ≥ 6 mm, with the difference being statistically significant.


References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Cancer facts and figures 2006. American Cancer Society Website. Available at www.cancer.org. Updated 2007. Accessed July 2, 2007
  2. Rex DK, Johnson DA, Lieberman DA, Burt RW, Sonnenberg A. Colorectal cancer prevention 2000: screening recommendations of the American College of Gastroenterology. American College of Gastroenterology. Am J Gastroenterol 2000; 95:868 –877[Medline]
  3. Smith RA, Cokkinides V, Eyre HJ. American Cancer Society guidelines for the early detection of cancer, 2004. CA Cancer J Clin 2004; 54:41 –52[Abstract/Free Full Text]
  4. Winawer SJ, Fletcher RH, Miller L, et al. Colorectal cancer screening: clinical guidelines and rationale. Gastroenterology 1997;112 : 594–642[CrossRef][Medline]
  5. Pignone M, Rich M, Teutsch SM, Berg AO, Lohr KN. Screening for colorectal cancer in adults at average risk: a summary of the evidence for the U.S. Preventive Services Task Force. Ann Intern Med2002; 137:132 –141[Abstract/Free Full Text]
  6. Wagner J, Tunis S, Brown M, Ching A, Almeda R. The cost-effectiveness of colorectal cancer screening in average risk adults. In: Young G, Levin B, eds. Prevention and early detection of colorectal cancer. Philadelphia, PA: Saunders, 1996:321 –356
  7. Winawer SJ, Flehinger BJ, Schottenfeld D, Miller DG. Screening for colorectal cancer with fecal occult blood testing and sigmoidoscopy. J Natl Cancer Inst 1993;85 :1311 –1318[Abstract/Free Full Text]
  8. Winawer SJ, Zauber AG, Ho MN, et al. Prevention of colorectal cancer by colonoscopic polypectomy. The National Polyp Study Workgroup. N Engl J Med 1993;329 :1977 –1981[Abstract/Free Full Text]
  9. Ioannou GN, Chapko MK, Dominitz JA. Predictors of colorectal cancer screening participation in the United States. Am J Gastroenterol 2003; 98:2082 –2091[CrossRef][Medline]
  10. Vining DJ, Gelfand DW, Bechtold RE, Scharling ES, Grishaw EK, Shifrin RY. Technical feasibility of colon imaging with helical CT and virtual reality. (abstr) AJR 1994;162 [American Roentgen Ray Society 94th Annual Meeting Program Book suppl]: 104
  11. Van Gelder RE, Nio CY, Florie J, et al. Computed tomographic colonography compared with colonoscopy in patients at increased risk for colorectal cancer. Gastroenterology 2004;127 : 41–48[CrossRef][Medline]
  12. Burling D, Halligan S, Slater A, Noakes MJ, Taylor SA. Potentially serious adverse events at CT colonography in symptomatic patients: national survey of the United Kingdom. Radiology2006; 239:464 –471[Abstract/Free Full Text]
  13. Sosna J, Sella T, Bar-Ziv J, Libson E. Perforation of the colon and rectum: a newly recognized complication of CT colonography. Semin Ultrasound CT MR 2006; 27:161 –165[CrossRef][Medline]
  14. AGA Clinical Pratice and Economics Committee. Position of the American Gastroenterological Association (AGA) Institute on computed tomographic colonography. Gastroenterology2006; 131:1627 –1628[CrossRef][Medline]
  15. Winawer SJ, Stewart ET, Zauber AG, et al. A comparison of colonoscopy and double-contrast barium enema for surveillance after polypectomy. National Polyp Study Work Group. N Engl J Med 2000; 342:1766 –1772[Abstract/Free Full Text]
  16. Zalis ME, Barish MA, Choi JR, et al. CT colonography reporting and data system: a consensus proposal. Radiology2005; 236:3 –9[Free Full Text]
  17. Moher D, Cook DJ, Eastwood S, Olkin I, Rennie D, Stroup DF. Improving the quality of reports of meta-analyses of randomised controlled trials: the QUOROM statement. Quality of Reporting of Meta-analyses. Lancet 1999; 354:1896 –1900[CrossRef][Medline]
  18. Farrands PA, Vellacott KD, Amar SS, Balfour TW, Hardcastle JD. Flexible fiberoptic sigmoidoscopy and double-contrast barium-enema examination in the identification of adenomas and carcinoma of the colon. Dis Colon Rectum 1983; 26:725 –727[CrossRef][Medline]
  19. Jensen J, Kewenter J, Haglind E, Lycke G, Svensson C, Ahren C. Diagnostic accuracy of double-contrast enema and rectosigmoidoscopy in connection with faecal occult blood testing for the detection of rectosigmoid neoplasms. Br J Surg 1986;73 : 961–964[Medline]
  20. Johnson CD, MacCarty RL, Welch TJ, et al. Comparison of the relative sensitivity of CT colonography and double-contrast barium enema for screen detection of colorectal polyps. Clin Gastroenterol Hepatol 2004; 2:314 –321[CrossRef][Medline]
  21. Kewenter J, Brevinge H, Engaras B, Haglind E. The yield of flexible sigmoidoscopy and double-contrast barium enema in the diagnosis of neoplasms in the large bowel in patients with a positive Hemoccult test. Endoscopy 1995;27 : 159–163[Medline]
  22. Rex DK, Lehman GA, Lappas JC, Miller RE. Sensitivity of double-contrast barium study for left-colon polyps. Radiology 1986;158 : 69–72[Abstract/Free Full Text]
  23. Rockey DC, Koch J, Yee J, McQuaid KR, Halvorsen RA. Prospective comparison of air-contrast barium enema and colonoscopy in patients with fecal occult blood: a pilot study. Gastrointest Endosc2004; 60:953 –958[CrossRef][Medline]
  24. Saito Y, Slezak P, Rubio C. The diagnostic value of combining flexible sigmoidoscopy and double-contrast barium enema as a one-stage procedure. Gastrointest Radiol 1989;14 : 357–359[CrossRef][Medline]
  25. Steine S, Stordahl A, Lunde OC, Loken K, Laerum E. Double-contrast barium enema versus colonoscopy in the diagnosis of neoplastic disorders: aspects of decision-making in general practice. Fam Pract 1993; 10:288 –291[Abstract/Free Full Text]
  26. Thoeni RF, Petras A. Double-contrast bariumenema examination and endoscopy in the detection of polypoid lesions in the cecum and ascending colon. Radiology 1982;144 : 257–260[Abstract/Free Full Text]
  27. Williams CB, Macrae FA, Bartram CI. A prospective study of diagnostic methods in adenoma follow-up. Endoscopy1982; 14:74 –78[Medline]
  28. Anderson N, Cook HB, Coates R. Colonoscopically detected colorectal cancer missed on barium enema. Gastrointest Radiol1991; 16:123 –127[CrossRef][Medline]
  29. Bloomfield JA. Reliability of barium enema in detecting colonic neoplasia. Med J Aust 1981;1 : 631–633[Medline]
  30. Brewster NT, Grieve DC, Saunders JH. Double-contrast barium enema and flexible sigmoidoscopy for routine colonic investigation. Br J Surg 1994; 81:445 –447[Medline]
  31. Connolly DJ, Traill ZC, Reid HS, Copley SJ, Nolan DJ. The double contrast barium enema: a retrospective single centre audit of the detection of colorectal carcinomas. Clin Radiol 2002;57 : 29–32[CrossRef][Medline]
  32. Culpan DG, Mitchell AJ, Hughes S, Nutman M, Chapman AH. Double contrast barium enema sensitivity: a comparison of studies by radiographers and radiologists. Clin Radiol 2002;57 : 604–607[CrossRef][Medline]
  33. Gillespie JS, Kelly BE. Double contrast barium enema and colorectal carcinoma: sensitivity and potential role in screening. Ulster Med J 2001; 70:15 –18[Medline]
  34. Johnson CD, Carlson HC, Taylor WF, Weiland LP. Barium enemas of carcinoma of the colon: sensitivity of double- and single-contrast studies. AJR 1983; 140:1143 –1149[Abstract/Free Full Text]
  35. Law RL, Longstaff AJ, Slack N. A retrospective 5-year study on the accuracy of the barium enema examination performed by radiographers. Clin Radiol 1999;54 : 80–83; discussion 83–84[CrossRef][Medline]
  36. Morosi C, Ballardini G, Pisani P, et al. Diagnostic accuracy of the double-contrast enema for colonic polyps in patients with or without diverticular disease. Gastrointest Radiol1991; 16:345 –347[CrossRef][Medline]
  37. Myllylä V, Päivänsalo M, Laitinen S. Sensitivity of single and double contrast barium enema in the detection of colorectal carcinoma. Rofo 1984;140 : 393–397[Medline]
  38. Ott DJ, Gelfand DW, Wu WC, Kerr RM. Sensitivity of double-contrast barium enema: emphasis on polyp detection. AJR1980; 135:327 –330[Abstract]
  39. Ott DJ, Gelfand DW, Wu WC, Munitz HA, Chen YM. How important is radiographic detection of diminutive polyps of the colon? AJR 1986; 146:875 –878[Free Full Text]
  40. Ott DJ, Scharling ES, Chen YM, Gelfand DW, Wu WC. Positive predictive value and posttest probability of diagnosis of colonic polyp on single- and double-contrast barium enema. AJR1989; 153:735 –739[Abstract/Free Full Text]
  41. Ott DJ, Scharling ES, Chen YM, Wu WC, Gelfand DW. Barium enema examination: sensitivity in detecting colonic polyps and carcinomas. South Med J 1989;82 : 197–200[Medline]
  42. Ferrucci JT. Double-contrast barium enema: use in practice and implications for CT colonography. AJR 2006;187 : 170–173[Abstract/Free Full Text]
  43. Kung JW, Levine MS, Glick SN, Lakhani P, Rubesin SE, Laufer I. Colorectal cancer: screening double-contrast barium enema examination in average-risk adults older than 50 years. Radiology2006; 240:725 –735[Abstract/Free Full Text]
  44. Rex DK, Cutler CS, Lemmel GT, et al. Colonoscopic miss rates of adenomas determined by back-to-back colonoscopies. Gastroenterology 1997;112 : 24–28[CrossRef][Medline]
  45. Smith GA, O'Dwyer PJ. Sensitivity of double contrast barium enema and colonoscopy for the detection of colorectal neoplasms. Surg Endosc 2001; 15:649 –652[CrossRef][Medline]
  46. Stefansson T, Bergman A, Ekbom A, Nyman R, Pahlman L. Accuracy of double contrast barium enema and sigmoidoscopy in the detection of polyps in patients with diverticulosis. Acta Radiol1994; 35:442 –446[Medline]
  47. Tawn DJ, Squire CJ, Mohammed MA, Adam EJ. National audit of the sensitivity of double-contrast barium enema for colorectal carcinoma, using control charts. For the Royal College of Radiologists Clinical Radiology Audit Sub-Committee. Clin Radiol 2005;60 : 558–564[CrossRef][Medline]
  48. Wafula JM. Diagnostic yield from barium enemas: a study among patients referred by general practitioners and hospital outpatient departments. Br J Gen Pract 1992;42 : 330–332[Medline]
  49. Warden MJ, Petrelli NJ, Herrera L, Mittelman A. Endoscopy versus double-contrast barium enema in the evaluation of patients with symptoms suggestive of colorectal carcinoma. Am J Surg1988; 155:224 –226[CrossRef][Medline]
  50. Cheong Y, Farrow R, Frank CS, Stevenson GW. Utility of flexible sigmoidoscopy as an adjunct to double-contrast barium enema examination. Abdom Imaging 1998;23 : 138–140[CrossRef][Medline]
  51. Irvine EJ, O'Connor J, Frost RA, et al. Prospective comparison of double contrast barium enema plus flexible sigmoidoscopy v colonoscopy in rectal bleeding: barium enema v colonoscopy in rectal bleeding. Gut 1988; 29:1188 –1193[Abstract/Free Full Text]
  52. Jensen J, Kewenter J, Asztely M, Lycke G, Wojciechowski J. Double contrast barium enema and flexible rectosigmoidoscopy: a reliable diagnostic combination for detection of colorectal neoplasm. Br J Surg 1990; 77:270 –272[Medline]
  53. Norfleet RG, Ryan ME, Wyman JB, et al. Barium enema versus colonoscopy for patients with polyps found during flexible sigmoidoscopy. Gastrointest Endosc 1991;37 : 531–534[Medline]
  54. Thoeni RF, Menuck L. Comparison of barium enema and colonoscopy in the detection of small colonic polyps. Radiology1977; 124:631 –635[Abstract]
  55. Durdey P, Weston PM, Williams NS. Colonoscopy or barium enema as initial investigation of colonic disease. Lancet1987; 2:549 –551[CrossRef][Medline]
  56. Aggarwal V, Mittal SK, Kumar N, Chowdhury V. A comparative study of double contrast barium enema and colonoscopy for evaluation of rectal bleeding in children. Trop Gastroenterol 1995;16 : 132–137[Medline]
  57. Cotton PB, Durkalski VL, Pineau BC, et al. Computed tomographic colonography (virtual colonoscopy): a multicenter comparison with standard colonoscopy for detection of colorectal neoplasia. JAMA 2004; 291:1713 –1719[Abstract/Free Full Text]
  58. Dachman AH, Kuniyoshi JK, Boyle CM, et al. CT colonography with three-dimensional problem solving for detection of colonic polyps. AJR 1998; 171:989 –995[Abstract/Free Full Text]
  59. Fenlon HM, Nunes DP, Schroy PC 3rd, Barish MA, Clarke PD, Ferrucci JT. A comparison of virtual and conventional colonoscopy for the detection of colorectal polyps. N Engl J Med 1999;341 :1496 –1503[Abstract/Free Full Text]
  60. Fletcher JG, Johnson CD, Welch TJ, et al. Optimization of CT colonography technique: prospective trial in 180 patients. Radiology 2000;216 : 704–711[Abstract/Free Full Text]
  61. Gluecker T, Dorta G, Keller W, Jornod P, Meuli R, Schnyder P. Performance of multidetector computed tomography colonography compared with conventional colonoscopy. Gut 2002;51 : 207–211[Abstract/Free Full Text]
  62. Hara AK, Johnson CD, MacCarty RL, Welch TJ, McCollough CH, Harmsen WS. CT colonography: single-versus multi-detector row imaging. Radiology 2001;219 : 461–465[Abstract/Free Full Text]
  63. Johnson CD, Harmsen WS, Wilson LA, et al. Prospective blinded evaluation of computed tomographic colonography for screen detection of colorectal polyps. Gastroenterology 2003;125 : 311–319[CrossRef][Medline]
  64. Lefere PA, Gryspeerdt SS, Dewyspelaere J, Baekelandt M, Van Holsbeeck BG. Dietary fecal tagging as a cleansing method before CT colonography: initial results polyp detection and patient acceptance. Radiology 2002;224 : 393–403[Abstract/Free Full Text]
  65. Macari M, Bini EJ, Jacobs SL, et al. Significance of missed polyps at CT colonography. AJR 2004;183 : 127–134[Abstract/Free Full Text]
  66. Macari M, Bini EJ, Jacobs SL, et al. Colorectal polyps and cancers in asymptomatic average-risk patients: evaluation with CT colonography. Radiology 2004;230 : 629–636[Abstract/Free Full Text]
  67. Macari M, Bini EJ, Xue X, et al. Colorectal neoplasms: prospective comparison of thin-section low-dose multi-detector row CT colonography and conventional colonoscopy for detection. Radiology2002; 224:383 –392[Abstract/Free Full Text]
  68. Macari M, Milano A, Lavelle M, Berman P, Megibow AJ. Comparison of time-efficient CT colonography with two- and three-dimensional colonic evaluation for detecting colorectal polyps. AJR2000; 174:1543 –1549[Abstract/Free Full Text]
  69. McFarland EG, Pilgram TK, Brink JA, et al. CT colonography: multiobserver diagnostic performance. Radiology2002; 225:380 –390[Abstract/Free Full Text]
  70. Mendelson RM, Foster NM, Edwards JT, Wood CJ, Rosenberg MS, Forbes GM. Virtual colonoscopy compared with conventional colonoscopy: a developing technology. Med J Aust 2000;173 : 472–475[Medline]
  71. Morrin MM, Farrell RJ, Raptopoulos V, McGee JB, Bleday R, Kruskal JB. Role of virtual computed tomographic colonography in patients with colorectal cancers and obstructing colorectal lesions. Dis Colon Rectum 2000; 43:303 –311[CrossRef][Medline]
  72. Ginnerup Pedersen GB, Christiansen TE, Bjerregaard NC, Ljungmann K, Laurberg S. Colonoscopy and multidetector-array computed-tomographic colonography: detection rates and feasibility. Endoscopy 2003;35 : 736–742[CrossRef][Medline]
  73. Pescatore P, Glucker T, Delarive J, et al. Diagnostic accuracy and interobserver agreement of CT colonography (virtual colonoscopy).Gut 2000; 47:126 –130[Abstract/Free Full Text]
  74. Pickhardt PJ, Choi JR, Hwang I, et al. Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults. N Engl J Med 2003;349 :2191 –2200[Abstract/Free Full Text]
  75. Pineau BC, Paskett ED, Chen GJ, et al. Virtual colonoscopy using oral contrast compared with colonoscopy for the detection of patients with colorectal polyps. Gastroenterology 2003;125 : 304–310[CrossRef][Medline]
  76. Rex DK, Vining D, Kopecky KK. An initial experience with screening for colon polyps using spiral CT with and without CT colography (virtual colonoscopy). Gastrointest Endosc 1999;50 : 309–313[CrossRef][Medline]
  77. Rockey DC, Paulson E, Niedzwiecki D, et al. Analysis of air contrast barium enema, computed tomographic colonography, and colonoscopy: prospective comparison. Lancet 2005;365 : 305–311[Medline]
  78. Royster AP, Fenlon HM, Clarke PD, Nunes DP, Ferrucci JT. CT colonoscopy of colorectal neoplasms: two-dimensional and three-dimensional virtual-reality techniques with colonoscopic correlation. AJR 1997; 169:1237 –1242[Abstract/Free Full Text]
  79. Spinzi G, Belloni G, Martegani A, Sangiovanni A, Del Favero C, Minoli G. Computed tomographic colonography and conventional colonoscopy for colon diseases: a prospective, blinded study. Am J Gastroenterol 2001; 96:394 –400[CrossRef][Medline]
  80. Taylor SA, Halligan S, Saunders BP, et al. Use of multidetector-row CT colonography for detection of colorectal neoplasia in patients referred via the Department of Health "2-week-wait" initiative. Clin Radiol 2003; 58:855 –861[CrossRef][Medline]
  81. Yee J, Akerkar GA, Hung RK, Steinauer-Gebauer AM, Wall SD, McQuaid KR. Colorectal neoplasia: performance characteristics of CT colonography for detection in 300 patients. Radiology2001; 219:685 –692[Abstract/Free Full Text]
  82. Yee J, Kumar NN, Hung RK, Akerkar GA, Kumar PR, Wall SD. Comparison of supine and prone scanning separately and in combination at CT colonography. Radiology 2003;226 : 653–661[Abstract/Free Full Text]
  83. Fenlon HM, Nunes DP, Clarke PD, Ferrucci JT. Colorectal neoplasm detection using virtual colonoscopy: a feasibility study. Gut1998; 43:806 –811[Abstract/Free Full Text]
  84. Laghi A, Iannaccone R, Carbone I, et al. Computed tomographic colonography (virtual colonoscopy): blinded prospective comparison with conventional colonoscopy for the detection of colorectal neoplasia. Endoscopy 2002;34 : 441–446[CrossRef][Medline]
  85. Vos FM, van Gelder RE, Serlie IW, et al. Three-dimensional display modes for CT colonography: conventional 3D virtual colonoscopy versus unfolded cube projection. Radiology 2003;228 : 878–885[Abstract/Free Full Text]
  86. Harvey CJ, Amin Z, Hare CM, et al. Helical CT pneumocolon to assess colonic tumors: radiologic–pathologic correlation. AJR 1998; 170:1439 –1443[Abstract/Free Full Text]
  87. Laghi A, Iannaccone R, Bria E, et al. Contrast-enhanced computed tomographic colonography in the follow-up of colorectal cancer patients: a feasibility study. Eur Radiol 2003;13 : 883–889[Medline]
  88. Miao YM, Amin Z, Healy J, et al. A prospective single centre study comparing computed tomography pneumocolon against colonoscopy in the detection of colorectal neoplasms. Gut 2000;47 : 832–837[Abstract/Free Full Text]
  89. Munikrishnan V, Gillams AR, Lees WR, Vaizey CJ, Boulos PB. Prospective study comparing multislice CT colonography with colonoscopy in the detection of colorectal cancer and polyps. Dis Colon Rectum 2003; 46:1384 –1390[CrossRef][Medline]
  90. Neri E, Giusti P, Battolla L, et al. Colorectal cancer: role of CT colonography in preoperative evaluation after incomplete colonoscopy. Radiology 2002;223 : 615–619[Abstract/Free Full Text]
  91. Cohnen M, Vogt C, Aurich V, Beck A, Haussinger D, Modder U. Multi-slice CT-colonography in low-dose technique: preliminary results. Rofo 2002; 174:835 –838[Medline]
  92. Gluecker T, Meuwly JY, Pescatore P, et al. Effect of investigator experience in CT colonography. Eur Radiol2002; 12:1405 –1409[CrossRef][Medline]
  93. Hara AK, Johnson CD, Reed JE, et al. Detection of colorectal polyps with CT colography: initial assessment of sensitivity and specificity. Radiology 1997;205 : 59–65[Abstract/Free Full Text]
  94. Kay CL, Kulling D, Hawes RH, Young JW, Cotton PB. Virtual endoscopy: comparison with colonoscopy in the detection of space-occupying lesions of the colon. Endoscopy 2000;32 : 226–232[CrossRef][Medline]
  95. Luo M, Shan H, Zhou K. CT virtual colonoscopy in patients with incomplete conventional colonoscopy. Chin Med J (Engl)2002; 115:1023 –1026[Medline]
  96. Summers RM, Jerebko AK, Franaszek M, Malley JD, Johnson CD. Colonic polyps: complementary role of computer-aided detection in CT colonography. Radiology 2002;225 : 391–399[Abstract/Free Full Text]
  97. Wong BC, Wong WM, Chan JK, et al. Virtual colonoscopy for the detection of colorectal polyps and cancers in a Chinese population. J Gastroenterol Hepatol 2002;17 :1323 –1327[CrossRef][Medline]
  98. Gryspeerdt S, Lefere P, Herman M, et al. CT colonography with fecal tagging after incomplete colonoscopy. Eur Radiol2005; 15:1192 –1202[CrossRef][Medline]
  99. Iannaccone R, Laghi A, Catalano C, et al. Computed tomographic colonography without cathartic preparation for the detection of colorectal polyps. Gastroenterology 2004;127 :1300 –1311[CrossRef][Medline]
  100. Kealey SM, Dodd JD, MacEneaney PM, Gibney RG, Malone DE. Minimal preparation computed tomography instead of barium enema/colonoscopy for suspected colon cancer in frail elderly patients: an outcome analysis study. Clin Radiol 2004;59 : 44–52[CrossRef][Medline]
  101. Lefere P, Gryspeerdt S, Marrannes J, Baekelandt M, Van Holsbeeck B. CT colonography after fecal tagging with a reduced cathartic cleansing and a reduced volume of barium. AJR 2005;184 :1836 –1842[Abstract/Free Full Text]
  102. Lipscomb G, Loughrey G, Thakker M, Rees W, Nicholson D. A prospective study of abdominal computerized tomography and colonoscopy in the diagnosis of colonic disease in an elderly population. Eur J Gastroenterol Hepatol 1996;8 : 887–891[Medline]
  103. Thomeer M, Carbone I, Bosmans H, et al. Stool tagging applied in thin-slice multidetector computed tomography colonography. J Comput Assist Tomogr 2003; 27:132 –139[CrossRef][Medline]
  104. Luboldt W, Mann C, Tryon CL, et al. Computer-aided diagnosis in contrast-enhanced CT colonography: an approach based on contrast. Eur Radiol 2002;12 :2236 –2241[Medline]
  105. Yoshida H, Masutani Y, MacEneaney P, Rubin DT, Dachman AH. Computerized detection of colonic polyps at CT colonography on the basis of volumetric features: pilot study. Radiology 2002;222 : 327–336[Abstract/Free Full Text]
  106. Yoshida H, Nappi J, MacEneaney P, Rubin DT, Dachman AH. Computer-aided diagnosis scheme for detection of polyps at CT colonography. RadioGraphics 2002;22 : 963–979[Abstract/Free Full Text]
  107. Cohnen M, Vogt C, Beck A, et al. Feasibility of MDCT colonography in ultra-low-dose technique in the detection of colorectal lesions: comparison with high-resolution video colonoscopy. AJR2004; 183:1355 –1359[Abstract/Free Full Text]
  108. Iannaccone R, Laghi A, Catalano C, et al. Detection of colorectal lesions: lower-dose multi-detector row helical CT colonography compared with conventional colonoscopy. Radiology 2003;229 : 775–781[Abstract/Free Full Text]
  109. Iannaccone R, Laghi A, Catalano C, Mangiapane F, Piacentini F, Passariello R. Feasibility of ultra-low-dose multislice CT colonography for the detection of colorectal lesions: preliminary experience. Eur Radiol 2003; 13:1297 –1302[Medline]
  110. Vogt C, Cohnen M, Beck A, et al. Detection of colorectal polyps by multislice CT colonography with ultra-low-dose technique: comparison with high-resolution videocolonoscopy. Gastrointest Endosc2004; 60:201 –209[CrossRef][Medline]
  111. Iannaccone R, Catalano C, Mangiapane F, et al. Colorectal polyps: detection with low-dose multi-detector row helical CT colonography versus two sequential colonoscopies. Radiology 2005;237 : 927–937[Abstract/Free Full Text]
  112. Abdel Razek AA, Abu Zeid MM, Bilal M, Abdel Wahab NM. Virtual CT colonoscopy versus conventional colonoscopy: a prospective study. Hepatogastroenterology 2005;52 :1698 –1702[Medline]
  113. Kalra N, Suri S, Bhasin DK, et al. Comparison of multidetector computed tomographic colonography and conventional colonoscopy for detection of colorectal polyps and cancer. Indian J Gastroenterol 2006; 25:229 –232[Medline]
  114. Mulhall BP, Veerappan GR, Jackson JL. Metaanalysis: computed tomographic colonography. Ann Intern Med2005; 142:635 –650[Abstract/Free Full Text]
  115. Morrin MM, Farrell RJ, Kruskal JB, Reynolds K, McGee JB, Raptopoulos V. Utility of intravenously administered contrast material at CT colonography. Radiology 2000;217 : 765–771[Abstract/Free Full Text]
  116. Halligan S, Altman DG, Taylor SA, et al. CT colonography in the detection of colorectal polyps and cancer: systematic review, meta-analysis, and proposed minimum data set for study level reporting. Radiology 2005;237 : 893–904[Abstract/Free Full Text]
  117. Sosna J, Morrin MM, Kruskal JB, Lavin PT, Rosen MP, Raptopoulos V. CT colonography of colorectal polyps: a metaanalysis. AJR 2003; 181:1593 –1598[Abstract/Free Full Text]
  118. Cappelleri JC, Ioannidis JP, Schmid CH, et al. Large trials vs meta-analysis of smaller trials: how do their results compare? JAMA 1996; 276:1332 –1338[Abstract/Free Full Text]
  119. LeLorier J, Gregoire G, Benhaddad A, Lapierre J, Derderian F. Discrepancies between meta-analyses and subsequent large randomized, controlled trials. N Engl J Med 1997;337 : 536–542[Abstract/Free Full Text]
  120. Pickhardt PJ, Taylor AJ, Kim DH, Reichelderfer M, Gopal DV, Pfau PR. Screening for colorectal neoplasia with CT colonography: initial experience from the 1st year of coverage by third-party payers. Radiology 2006;241 : 417–425[Abstract/Free Full Text]
  121. Gluecker TM, Johnson CD, Wilson LA, et al. Extracolonic findings at CT colonography: evaluation of prevalence and cost in a screening population. Gastroenterology 2003;124 : 911–916[CrossRef][Medline]
  122. Sosna J, Kruskal JB, Bar-Ziv J, Copel L, Sella T. Extracolonic findings at CT colonography. Abdom Imaging2005; 30:709 –713[CrossRef][Medline]
  123. Irwig L, Macaskill P, Glasziou P, Fahey M. Metaanalytic methods for diagnostic test accuracy. J Clin Epidemiol1995; 48:119 –130; discussion 131–132[CrossRef][Medline]
  124. Thoeni RF, Petras A. Detection of rectal and rectosigmoid lesions by double-contrast barium enema examination and sigmoidoscopy: accuracy of technique and efficacy of standard overhead views.Radiology 1982;142 : 59–62[Abstract/Free Full Text]
  125. Arnesen RB, Adamsen S, Svendsen LB, Raaschou HO, von Benzon E, Hansen OH. Missed lesions and false-positive findings on computed-tomographic colonography: a controlled prospective analysis. Endoscopy 2005;37 : 937–944[Medline]
  126. Reuterskiold MH, Lasson A, Svensson E, Kilander A, Stotzer PO, Hellstrom M. Diagnostic performance of computed tomography colonography in symptomatic patients and in patients with increased risk for colorectal disease. Acta Radiol 2006;47 : 888–898[CrossRef][Medline]

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?



This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sosna, J.
Right arrow Articles by Libson, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sosna, J.
Right arrow Articles by Libson, E.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Hotlight (NEW!)
Right arrow
What's Hotlight?

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS