Limited-preparation CT colonography in frail elderly patients: a feasibility study. AJR Am J Roentgenol. 2010;194:1279-1287. [PMID: 20410415 DOI: 10.2214/ajr.09.2896]

Computed Tomography Colonography: 2025 Update

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the United States. Most cases arise from polyps, which can be detected and removed before becoming cancerous. Computed tomography colonography (CTC), also known as virtual colonoscopy, was first introduced in 1994 as a minimally invasive method for CRC screening and diagnosis. This 2025 update on CTC will focus on (1) techniques and dose reduction strategies, (2) image display methods, (3) reporting and classification systems, (4) tumor staging capabilities, (5) integration of advanced imaging techniques, and (6) cost-effectiveness and reimbursement.

Computed Tomography Colonography (CTC): Is It Really the Non-Invasive Option We Think It Is? A Patient Experience Study

Aims: Computed tomography colonography (CTC) is seen as a more tolerable alternative to colonoscopy, but patients struggle with the steps required for optimal diagnostic imaging. This prospective study aims to understand the experience of patients undergoing CTC. Methods: A survey was completed by a convenience sample of patients before and after CTC over 7 months. The 13-item questionnaire covered pre-test information, overall and specific experience of the test. The responses were tabulated and analyzed using descriptive statistics. Qualitative free-text responses were coded for content and thematic analysis. Results: At a response rate of 51%, surveys were received from 41 patients. Overall, most patients (54%) found the investigation better than expected. However, 18% stated they were not informed of potential side effects. Side effects were experienced by 49% of patients, including diarrhea (34%) and abdominal pain (24%). About 59% experienced discomfort with gas insufflation, and 86% found turning during the investigation difficult. Conclusion: A significant proportion of patients undergoing CTC experience side effects and difficulties completing the investigation. Patient information is important to improve patient experience of CTC.

CTC technique: methods to ensure an optimal exam

CT colonography (CTC) has demonstrated equivalent accuracy to optical colonoscopy in the detection of clinically relevant polyps and tumors but this is only possible when technique is optimized. The two most important features of a high-quality CTC are a well-prepared colon and a distended colon. This article will discuss the dietary, bowel preparation, and fecal/fluid tagging options to best prepare the colon. Strategies to optimally distend the colon will also be discussed. CT scan techniques including patient positioning and radiation dose optimization will be reviewed. With proper technique which includes sufficient bowel preparation, fecal/fluid tagging, bowel distension, and optimized scan technique, high-quality CTC examinations should become more feasible, easier to interpret, and more consistently reproducible leading to increased utilization and increased referrals.

CT Colonography: an update on current and future indications

Computed tomographic colonography (CTC) is a minimally invasive, patient-friendly, safe and robust colonic imaging modality. The technique is standardized and consolidated evidence from the literature shows that the diagnostic performances for the detection of colorectal cancer and large polyps are similar to colonoscopy (CS) and largely superior to alternative radiological exams, like barium enema. A clear understanding of the exact role of CTC will be beneficial to maximize the benefits and minimize the potential sources of frustration or disappointment for both referring clinicians and patients. Incomplete, failed, or unfeasible CS; investigation of elderly, and frail patients and assessment of diverticular disease are major indications supported by evidence-based data and agreed by the endoscopists. The use of CTC for symptomatic patients, colorectal cancer screening and colonic surveillance is still under debate and, thus, recommended only if CS is unfeasible or refused by patients.

Low-residue versus clear liquid diet before colonoscopy: a meta-analysis of randomized, controlled trials

BACKGROUND AND AIMS

Colonoscopy is extremely important for the identification and removal of precancerous polyps. Bowel preparation before colonoscopy is essential for adequate visualization. Traditionally, patients have been instructed to consume only clear liquids the day before a colonoscopy. However, recent studies have suggested using a low-residue diet, with varying results. We evaluated the outcomes of patients undergoing colonoscopy who consumed a clear liquid diet (CLD) versus low-residue diet (LRD) on the day before colonoscopy by a meta-analysis.

METHODS

Scopus, PubMed/MEDLINE, Cochrane databases, and CINAHL were searched (February 2015). Studies involving adult patients undergoing colonoscopy examination and comparing LRD with CLD on the day before colonoscopy were included. The analysis was conducted by using the Mantel-Haenszel or DerSimonian and Laird models with the odds ratio (OR) to assess adequate bowel preparations, tolerability, willingness to repeat diet and preparation, and adverse effects.

RESULTS

Nine studies (1686 patients) were included. Patients consuming an LRD compared with a CLD demonstrated significantly higher odds of tolerability (OR 1.92; 95% CI, 1.36-2.70; P < .01) and willingness to repeat preparation (OR 1.86; 95% CI, 1.34-2.59; P < .01) with no differences in adequate bowel preparations (OR 1.21; 95% CI, 0.64-2.28; P = .58) or adverse effects (OR 0.88; 95% CI, 0.58-1.35; P = .57).

CONCLUSION

An LRD before colonoscopy resulted in improved tolerability by patients and willingness to repeat preparation with no differences in preparation quality and adverse effects.

Computed tomographic colonography compared with colonoscopy or barium enema for diagnosis of colorectal cancer in older symptomatic patients: two multicentre randomised trials with economic evaluation (the SIGGAR trials)

BACKGROUND

Computed tomographic colonography (CTC) is a relatively new diagnostic test that may be superior to existing alternatives to investigate the large bowel.

OBJECTIVES

To compare the diagnostic efficacy, acceptability, safety and cost-effectiveness of CTC with barium enema (BE) or colonoscopy.

DESIGN

Parallel randomised trials: BE compared with CTC and colonoscopy compared with CTC (randomisation 2 : 1, respectively).

SETTING

A total of 21 NHS hospitals.

PARTICIPANTS

Patients aged ≥ 55 years with symptoms suggestive of colorectal cancer (CRC).

INTERVENTIONS

CTC, BE and colonoscopy.

MAIN OUTCOME MEASURES

For the trial of CTC compared with BE, the primary outcome was the detection rate of CRC and large polyps (≥ 10 mm), with the proportion of patients referred for additional colonic investigation as a secondary outcome. For the trial of CTC compared with colonoscopy, the primary outcome was the proportion of patients referred for additional colonic investigation, with the detection rate of CRC and large polyps as a secondary outcome. Secondary outcomes for both trials were miss rates for cancer (via registry data), all-cause mortality, serious adverse events, patient acceptability, extracolonic pathology and cost-effectiveness.

RESULTS

A total of 8484 patients were registered and 5384 were randomised and analysed (BE trial: 2527 BE, 1277 CTC; colonoscopy trial: 1047 colonoscopy, 533 CTC). Detection rates in the BE trial were 7.3% (93/1277) for CTC, compared with 5.6% (141/2527) for BE (p = 0.0390). The difference was due to better detection of large polyps by CTC (3.6% vs. 2.2%; p = 0.0098), with no significant difference for cancer (3.7% vs. 3.4%; p = 0.66). Significantly more patients having CTC underwent additional investigation (23.5% vs. 18.3%; p = 0.0003). At the 3-year follow-up, the miss rate for CRC was 6.7% for CTC (three missed cancers) and 14.1% for BE (12 missed cancers). Significantly more patients randomised to CTC than to colonoscopy underwent additional investigation (30% vs. 8.2%; p < 0.0001). There was no significant difference in detection rates for cancer or large polyps (10.7% for CTC vs. 11.4% for colonoscopy; p = 0.69), with no difference when cancers (p = 0.94) and large polyps (p = 0.53) were analysed separately. At the 3-year follow-up, the miss rate for cancer was nil for colonoscopy and 3.4% for CTC (one missed cancer). Adverse events were uncommon for all procedures. In 1042 of 1748 (59.6%) CTC examinations, at least one extracolonic finding was reported, and this proportion increased with age (p < 0.0001). A total of 149 patients (8.5%) were subsequently investigated, and extracolonic neoplasia was diagnosed in 79 patients (4.5%) and malignancy in 29 (1.7%). In the short term, CTC was significantly more acceptable to patients than BE or colonoscopy. Total costs for CTC and colonoscopy were finely balanced, but CTC was associated with higher health-care costs than BE. The cost per large polyp or cancer detected was £4235 (95% confidence interval £395 to £9656).

CONCLUSIONS

CTC is superior to BE for detection of cancers and large polyps in symptomatic patients. CTC and colonoscopy detect a similar proportion of large polyps and cancers and their costs are also similar. CTC precipitates significantly more additional investigations than either BE or colonoscopy, and evidence-based referral criteria are needed. Further work is recommended to clarify the extent to which patients initially referred for colonoscopy or BE undergo subsequent abdominopelvic imaging, for example by computed tomography, which will have a significant impact on health economic estimates.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN95152621.

Fecal tag CT colonography with a limited 2-day bowel preparation following incomplete colonoscopy

PURPOSE

This study aimed to assess the feasibility and patient tolerance of a 2-day limited fecal tag bowel preparation in computed tomographic colonography (CTC) performed for incomplete conventional colonoscopy (CC) patients.

MATERIALS AND METHODS

Seventy-five patients who underwent a CTC examination fbecause of incomplete CC were included. A low-residue diet was given for 2 days before CTC. Fecal tagging (FT) was done using a barium sulfate suspension. The quality of the preparation, success of tagging and patient experience with the bowel preparation were investigated.

RESULTS

Four hundred fifty bowel segments were evaluated. The number of solid stool balls of 6-9 mm size was 284; the corresponding figure was 93 for solid stool balls ≥ 10 mm. Residual fluid was present in about one-third of the segments. The fecal tagging efficacy for ≥ 6 mm residual stool balls was 92 %. Overall, 16 (21.3 %) patients presented with colonic lesions at CTC. Three out of four colonic mass lesions had not been diagnosed with CC. Most patients reported mild discomfort.

CONCLUSION

FT-CTC performed after a limited 2-day bowel preparation seems to be a technically feasible, safe and acceptable procedure that allows a complete a colonic study in incomplete CC patients.

Computed tomography colonography in 2014: an update on technique and indications

Twenty years after its introduction, computed tomographic colonography (CTC) has reached its maturity, and it can reasonably be considered the best radiological diagnostic test for imaging colorectal cancer (CRC) and polyps. This examination technique is less invasive than colonoscopy (CS), easy to perform, and standardized. Reduced bowel preparation and colonic distention using carbon dioxide favor patient compliance. Widespread implementation of a new image reconstruction algorithm has minimized radiation exposure, and the use of dedicated software with enhanced views has enabled easier image interpretation. Integration in the routine workflow of a computer-aided detection algorithm reduces perceptual errors, particularly for small polyps. Consolidated evidence from the literature shows that the diagnostic performances for the detection of CRC and large polyps in symptomatic and asymptomatic individuals are similar to CS and are largely superior to barium enema, the latter of which should be strongly discouraged. Favorable data regarding CTC performance open the possibility for many different indications, some of which are already supported by evidence-based data: incomplete, failed, or unfeasible CS; symptomatic, elderly, and frail patients; and investigation of diverticular disease. Other indications are still being debated and, thus, are recommended only if CS is unfeasible: the use of CTC in CRC screening and in surveillance after surgery for CRC or polypectomy. In order for CTC to be used appropriately, contraindications such as acute abdominal conditions (diverticulitis or the acute phase of inflammatory bowel diseases) and surveillance in patients with a long-standing history of ulcerative colitis or Crohn's disease and in those with hereditary colonic syndromes should not be overlooked. This will maximize the benefits of the technique and minimize potential sources of frustration or disappointment for both referring clinicians and patients.

Bowel cleansing before CT colonography: comparison between two minimal-preparation regimens

AIM

To compare two regimens of reduced bowel preparation and faecal tagging for CT colonography.

MATERIALS AND METHODS

Single centre, prospective, randomized, noninferiority study, in which 52 consecutive adults underwent routine CT colonography. Patients, following a three-day low-fibre diet, received one of the two reduced preparations: 1-L polyethylene glycol and four tablets of bisacodyl in association with 90 mL of Iopamidol for faecal tagging administered on the same day as CTC examination (group 1); or a standard "iodine-only" preparation, consisting in 180 ml of Iopamidol the day before the examination (group 2). Primary outcome was the overall quality of bowel preparation.

RESULTS

Twenty-six patients per group were included. Per segment analysis showed preparation of diagnostic quality in 97.4% of segments in group 1 and in 95.5% in group 2 (p = ns). Per-patient analysis showed optimal quality of preparation in 76.9% of patients in group 1 and in 84.6% in group 2 (p = ns). Patient tolerability to both preparations was not different.

CONCLUSION

A limited bowel preparation consisting of 1-L PEG and four tablets of bisacodyl in association with 90 mL of Iodine for faecal tagging administered on the same day as CTC examination is feasible and offers bowel cleansing comparable to "iodine-only" preparation.

KEY POINTS

• Low-dose PEG bisacodyl and Iopamidol preparation is feasible, providing adequate bowel cleansing. • Faecal tagging is not different from the two limited preparations. • Patient tolerability to the two colon cleansing regimens is similar.

[Optical colonoscopy and virtual colonoscopy: the current role of each technique]

The importance of optical or conventional colonoscopy in diagnosing colon disease is undisputed. In this context, optical colonoscopy is the gold standard against which other techniques must be validated. Apart from enabling direct inspection of the colonic mucosa, optical colonoscopy enables biopsies and techniques to treat and prevent colorectal cancer. Virtual colonoscopy or CT colonography has been validated in multicenter studies; virtual colonoscopy is as sensitive as optical colonoscopy for the detection of polyps and colon cancer. It is currently the only valid alternative to optical colonoscopy. Its role in patients with medium or high risk of colon cancer is in the process of being defined as multidisciplinary teams gain experience. This article aims to discuss the usefulness of virtual colonoscopy in different clinical situations, emphasizing the situations in which there is enough scientific evidence, and to discuss the controversies surrounding its possible use for population-based screening.

Factors associated with incomplete colonoscopy at a Japanese academic hospital

AIM: To evaluate significant risk factors for incomplete colonoscopy at a Japanese academic hospital.

METHODS: A total of 11812 consecutive Japanese people were identified who underwent a colonoscopy at an academic hospital. A multiple logistic regression model was used to evaluate retrospectively the significant risk factors for incomplete colonoscopy.

RESULTS: The cecal intubation rate was 95.0%. By univariate analysis, age, female sex, poor bowel cleansing, and a history of abdominal or pelvic surgery were significant risk factors for incomplete colonoscopy (P < 0.001). Moreover, age- and sex-adjusted analysis showed that significant risk factors for incomplete colonoscopy were female sex (OR = 1.38, 95%CI: 1.17-1.64, P = 0.0002), age ≥ 60 years old (OR = 1.44, 95%CI: 1.22-1.71, P < 0.0001), a history of prior abdominal or pelvic surgery (OR = 1.55, 95%CI: 1.28-1.86, P < 0.0001), poor bowel cleansing (OR = 4.64, 95%CI: 3.69-5.84, P < 0.0001), and inflammatory bowel disease (IBD) (OR = 1.48, 95%CI: 1.13-1.95, P = 0.0048). In Japanese men, by age-adjusted analysis, IBD (OR = 1.69, 95%CI: 1.18-2.43, P = 0.005) was an independent risk factor for incomplete colonoscopy.

CONCLUSION: Several characteristics in the Japanese population were identified that could predict technical difficulty with colonoscopy.

Noncathartic CT colonography: Image quality assessment and performance and in a screening cohort

OBJECTIVE

Cathartic bowel preparation is a major barrier for colorectal cancer screening. We examined noncathartic CT colonography (CTC) quality and performance using four similar bowel-tagging regimens in an asymptomatic screening cohort.

SUBJECTS AND METHODS

This prospective study included 564 asymptomatic subjects who underwent noncathartic CTC without dietary modification but with 21 g of barium with or without iodinated oral contrast material (four regimens). The quality of tagging with oral agents was evaluated. A gastrointestinal radiologist evaluated examinations using primary 2D search supplemented by electronic cleansing (EC) and 3D problem solving. Results were compared with complete colonoscopy findings after bowel purgation and with retrospective unblinded evaluation in 556 of the 564 (99%) subjects.

RESULTS

Of the 556 subjects, 7% (37/556) and 3% (16/556) of patients had 52 and 20 adenomatous polyps ≥ 6 and ≥ 10 mm, respectively. The addition of iodine significantly improved the percentage of labeled stool (p ≤ 0.0002) and specificity (80% vs 89-93%, respectively; p = 0.046). The overall sensitivity of noncathartic CTC for adenomatous polyps ≥ 6 mm was 76% (28/37; 95% CI, 59-88%), which is similar to the sensitivity of the iodinated regimens with most patients (sensitivity: 231 patients, 74% [14/19; 95% CI, 49-91%]; 229 patients, 80% [12/15; 95% CI, 52-96%]). The negative predictive value was 98% (481/490), and the lone cancer was detected (0.2%, 1/556). EC was thought to improve conspicuity of 10 of 21 visible polyps ≥ 10 mm.

CONCLUSION

In this prospective study of asymptomatic subjects, the per-patient sensitivity of noncathartic CTC for detecting adenomas ≥ 6 mm was approximately 76%. Inclusion of oral iodine contrast material improves examination specificity and the percentage of labeled stool. EC may improve polyp conspicuity.

Investigating the frail elderly patient with lower bowel symptoms: what do we do now and can we improve?

AIMS

To assess the utility of flexible sigmoidoscopy (FS) and minimal preparation CT (MPCT) in investigating lower gastrointestinal (LGI) symptoms in elderly patients who are too frail to undergo colonoscopy or spiral CT.

METHODS

All FS examinations performed in patients aged over 70 between 1 January and 31 December 2008 were analysed. Predictors of usefulness were determined using multivariable analysis. In patients who also underwent MPCT, we analyzed the correlation between FS and MPCT.

RESULTS

426 FS were performed. Bowel preparation was inadequate in 24% of procedures. Indications in which FS was useful were: radiological abnormality (odds ratio [OR] 9.32), history of polyps (OR 4.54) and rectal bleeding (OR 1.73). Indications for which FS was least useful were: change in bowel habit (OR 0.22), diarrhoea (OR 0.46) and constipation (OR 0.38).

CONCLUSIONS

LGI investigation in frail elderly patients can be rationalised according to indication. Performing FS and MPCT together is not always necessary.

Evolving role of computed tomographic colonography in colon cancer screening and diagnosis

Computed tomographic colonography (CTC) is a relatively new imaging modality for the examination of patients for colorectal polyps and cancer. It has been validated in its accuracy for the detection of colon cancer and larger polyps (more than likely premalignant). CTC, however, is not widely accepted as a primary screening modality in the United States at present by many third-party payers, including Medicare, and its exact role in screening is evolving. Moreover, there has been opposition to incorporating CTC as an accepted screening instrument, especially by gastroenterologists. Heretofore, optical colonoscopy has been the mainstay in this screening. We discuss these issues and the continuing controversies concerning CTC.

Current status on performance of CT colonography and clinical indications

CT colonography (CTC) is a robust and reliable imaging test of the colon. Accuracy for the detection of colorectal cancer (CRC) is as high as conventional colonoscopy (CC). Identification of polyp is size dependent, with large lesions (≥10mm) accurately detected and small lesions (6-9mm) identified with moderate to good sensitivity. Recent studies show good sensitivity for the identification of nonpolypoid (flat) lesions as well. Current CTC indications include the evaluation of patients who had undergone a previous incomplete CC or those who are unfit for CC (elderly and frail individuals, patients with underlying severe clinical conditions, or with contraindication to sedation). CTC can also be efficiently used in the assessment of diverticular disease (excluding patients with acute diverticulitis, where the exam should be postponed), before laparoscopic surgery for CRC (to have an accurate localization of the lesion), in the evaluation of colonic involvement in the case of deep pelvic endometriosis (replacing barium enema). CTC is also a safe procedure in patients with colostomy. For CRC screening, CTC should be considered an opportunistic screening test (not available for population, or mass screening) to be offered to asymptomatic average-risk individuals, of both genders, starting at age 50. The use in individuals with positive family history should be discussed with the patient first. Absolute contraindication is to propose CTC for surveillance of genetic syndromes and chronic inflammatory bowel diseases (in particular, ulcerative colitis). The use of CTC in the follow-up after surgery for CRC is achieving interesting evidences despite the fact that literature data are still relatively weak in terms of numerosity of the studied populations. In patients who underwent previous polypectomy CTC cannot be recommended as first test because debate is still open. It is desirable that in the future CTC would be the first-line and only diagnostic test for colonic diseases, leaving to CC only a therapeutic role.

CT colonography without cathartic preparation: positive predictive value and patient experience in clinical practice

OBJECTIVE

To determine the positive predictive value (PPV) for polyps ≥ 6 mm detected at CT colonography (CTC) performed without cathartic preparation, with low-dose iodine faecal tagging regimen and to evaluate patient experience.

METHODS

1920 average-risk patients underwent CTC without cathartic preparation. Faecal tagging was performed by diatrizoate meglumine and diatrizoate sodium at a total dose of 60 ml (22.2 g of iodine).The standard interpretation method was primary 3D with 2D problem solving. We calculated per-patient and per-polyp PPV in relation to size and morphology. All colonic segments were evaluated for image quality (faecal tagging, amount of liquid and solid residual faeces and luminal distension). Patients completed a questionnaire before and after CTC to assess preparation and examination experience.

RESULTS

Per-polyp PPV for detected lesions of ≥ 6 mm, 6-9 mm, ≥ 10 mm and ≥ 30 mm were 94.3%, 93.1%, 94.7% and 98%, respectively. Per-polyp PPV, according to lesion morphology, was 94.6%, 97.3% and 85.1% for sessile, pedunculated and flat polyps, respectively. Per-patient PPV was 92.8%. Preparation without frank cathartics was reported to cause minimal discomfort by 78.9% of patients.

CONCLUSION

CTC without cathartic preparation and low-dose iodine faecal tagging may yield high PPVs for lesions ≥ 6 mm and is well accepted by patients.

KEY POINTS

• Computed tomographic colonography (CTC) without cathartic preparation is well accepted by patients • Cathartic-free faecal tagging CTC yields high positive predictive values • CTC without cathartic preparation could improve uptake of colorectal cancer screening.

Yearly diagnostic yield of colonoscopy in patients age 80 years or older, with a special interest in colorectal cancer

AIM

A high diagnostic yield of colonoscopy has been reported in elderly patients, but there is no data on the yearly yield. Our aim was to detect the yearly yield of colonoscopy in elderly patients.

METHODS

All consecutive endoscopies in the years 1992-2009 were included. Important endoscopic diagnoses were defined as colorectal cancer (CRC), polyps, diverticuli and inflammation.

RESULTS

In total, 19 569 endoscopies were performed, of which 1706 (8.7%) were in patients age 80 years or older. The number of women was significantly higher (P < 0.001). The percentage of patients who were 80 years or older was higher than in the general population and remained stable during the study period, though there has been a proportional increase of elderly people in the general population. Inconclusive procedures were present in 106 (6.2%) elderly patients compared with 277 (1.6%) patients under 80 years of age (P < 0.001). There were no significant changes in the consecutive years. A procedure revealing no endoscopic diagnosis was observed less often in patients who were 80 years or older (P < 0.001). CRC was diagnosed in 221 (19.6%) older patients. This figure remained more or less constant each year. Polyps were seen in 448 (8.8%) patients 80 years of age or older. The percentage of patients with diverticuli and inflammation was constant. The number of patients 80 years or older with CRC and polyps rose at a lower rate than the number of older people in the general population.

CONCLUSION

The yield of colonoscopy in patients 80 years or older was high and constant over the years. The number of tumors rose less than expected compared to the increase of elderly in the general population.

Reduced cathartic bowel preparation for CT colonography: prospective comparison of 2-L polyethylene glycol and magnesium citrate

PURPOSE

To prospectively compare adequacy of colonic cleansing, adequacy of solid stool and fluid tagging, and patient acceptance by using reduced-volume, 2-L polyethylene glycol (PEG) versus magnesium citrate bowel preparations for CT colonography.

MATERIALS AND METHODS

This study was approved by the institutional Committee on Human Research and was compliant with HIPAA; all patients provided written consent. In this randomized, investigator-blinded study, 50 patients underwent oral preparation with either a 2-L PEG or a magnesium citrate solution, tagging with oral contrast agents, and subsequent CT colonography and segmentally unblinded colonoscopy. The residual stool (score 0 [best] to 3 [worst]) and fluid (score 0 [best] to 4 [worst]) burden and tagging adequacy were qualitatively assessed. Residual fluid attenuation was recorded as a quantitative measure of tagging adequacy. Patients completed a tolerance questionnaire within 2 weeks of scanning. Preparations were compared for residual stool and fluid by using generalized estimating equations; the Mann-Whitney test was used to compare the qualitative tagging score, mean residual fluid attenuation, and adverse effects assessed on the patient experience questionnaire.

RESULTS

The mean residual stool (0.90 of three) and fluid burden (1.05 of four) scores for PEG were similar to those for magnesium citrate (0.96 [P = .58] and 0.98 [P = .48], respectively). However, the mean fecal and fluid tagging scores were significantly better for PEG (0.48 and 0.28, respectively) than for magnesium citrate (1.52 [P < .01] and 1.28 [P < .01], respectively). Mean residual fluid attenuation was higher for PEG (765 HU) than for magnesium citrate (443 HU, P = .01), and mean interpretation time was shorter for PEG (14.8 minutes) than for magnesium citrate (18.0 minutes, P = .04). Tolerance ratings were not significantly different between preparations.

CONCLUSION

Reduced-volume PEG and magnesium citrate bowel preparations demonstrated adequate cleansing effectiveness for CT colonography, with better tagging and shorter interpretation time observed in the PEG group. Adequate polyp detection was maintained but requires further validation because of the small number of clinically important polyps.

[CT colonography: what radiologists need to know]

In 2008, CT colonography was approved by the American Cancer Society as a technique for screening for colorectal cancer. This approval should be considered an important step in the recognition of the technique, which although still relatively new is already changing some diagnostic algorithms. This update about CT colonography reports the quality parameters necessary for a CT colonographic study to be diagnostic and reviews the technical innovations and colonic preparation for the study. We provide a brief review of the signs and close with a discussion of the current indications for and controversies about the technique.

Patient acceptability of CT colonography compared with double contrast barium enema: results from a multicentre randomised controlled trial of symptomatic patients

OBJECTIVES

To determine patient acceptability of barium enema (BE) or CT colonography (CTC).

METHODS

After ethical approval, 921 consenting patients with symptoms suggestive of colorectal cancer who had been randomly assigned and completed either BE (N = 606) or CTC (N = 315) received a questionnaire to assess experience of the clinical episode including bowel preparation, procedure and complications. Satisfaction, worry and physical discomfort were assessed using an adapted version of a validated acceptability scale. Non-parametric methods assessed differences between the randomised tests and the effect of patient characteristics.

RESULTS

Patients undergoing BE were significantly less satisfied (median 61, interquartile range [IQR] 54-67 vs. median 64, IQR 56-69; p = 0.003) and experienced more physical discomfort (median 40, IQR 29-52 vs. median 35.5, IQR 25-47; p < 0.001) than those undergoing CTC. Post-test, BE patients were significantly more likely to experience 'abdominal pain/cramps' (68% vs. 57%; p = 0.007), 'soreness' (57% vs. 37%; p < 0.001), 'nausea/vomiting' (16% vs. 8%; p = 0.009), 'soiling' (31% vs. 23%; p = 0.034) and 'wind' (92% vs. 84%; p = 0.001) and in the case of 'wind' to also rate it as severe (27% vs. 15%; p < 0.001).

CONCLUSION

CTC is associated with significant improvements in patient experience. These data support the case for CTC to replace BE.

Computed tomographic colonography: ready for prime time?

Computed tomographic (CT) colonography is a noninvasive method to evaluate the colon and has received considerable attention in the last decade as a colon-imaging tool. The technique has also been proposed as a potential primary colon cancer-screening method in the United States. The accuracy of the technique for the detection of large lesions seems to be high, perhaps in the range of colonoscopy. Overall, the field is rapidly evolving. Available data suggest that CT colonography, although a viable colon cancer screening modality in the United States, is not ready for widespread implementation, largely because of the lack of standards for training and reading and the limited number of skilled readers.

Guidelines for colorectal cancer screening--a puzzle of tests and strategies

Colorectal cancer (CRC) is a leading cause of cancer death around the World. An effective way to reduce colorectal cancer mortality is to screen for it and its precursor, the adenoma. In industrialized countries the mortality related to CRC is decreasing probably due to better screening programmes in average-risk individuals as well as changes in risk factors. Screening procedures are various including faecal screening tests--which primarily detect colon cancer--and structural tests (endoscopy--flexible sigmoidoscopy or colonoscopy--, Barium enema, Computed Tomography Colonography) that may detect not only cancer but also its precursors. Video-colon capsule is a new tool for exploring the colon but needs further studies before becoming a screening test. The choice of a screening test includes several factors as cost, invasiveness, acceptability, adherence to repeat testing and acceptance referral for colonoscopy for positive tests as well as local financial resources. Every screening programme has advantages and limitations. Enhancing use and quality of CRC screening programmes is mandatory.