Intra-individual comparison of patient acceptability of multidetector-row CT colonography and double-contrast barium enema

CTC service heterogeneity and design of a workforce calculator

AIM

To determine the level of heterogeneity in delivery of computed tomography (CT) colonography services and develop a workforce calculator that accommodates the variation identified.

MATERIALS AND METHODS

A national survey, based on the "WHO workforce indicators of staffing need", established activity standards for essential tasks in delivery of the service. From these data a workforce calculator was designed to guide the required staffing and equipment resource by service size.

RESULTS

Activity standards were established as mode responses >70%. Service homogeneity was greater in areas where professional standards and guidance were available. The mean service size was 1,101. Did not attend (DNA) rates were lower where direct booking was available (p<0.0001). Service sizes were larger where radiographer reporting was embedded in reporting paradigms (p<0.024).

CONCLUSION

The survey identified benefits of radiographer-led direct booking and reporting. The workforce calculator derived from the survey provides a framework to guide the resourcing of expansion while maintaining standards.

Model-based Iterative Reconstruction in Low-radiation-dose Computed Tomography Colonography: Preoperative Assessment in Patients with Colorectal Cancer

RATIONALE AND OBJECTIVES

To assess the effect of model-based iterative reconstruction (MBIR) on image quality and diagnostic performance of low-radiation-dose computed tomography colonography (CTC) in the preoperative assessment of colorectal cancer.

MATERIALS AND METHODS

This study included 30 patients with colorectal cancer referred for surgical treatment. All patients underwent CTC with a standard dose (SD) protocol in the supine position and a low-dose (LD; radiation dose reduction of approximately 85%) protocol in the prone position. The SD protocol images were post-processed using filtered back projection (FBP), whereas the LD protocol images were post-processed using FBP and MBIR. Objective and subjective image quality parameters were compared among the three different methods. Preoperative evaluations, including site, length, and tumor and node staging were performed, and the findings were compared to the postsurgical findings.

RESULTS

The mean image noise of SD-FBP, LD-FBP, and LD-MBIR images was 17.3 ± 3.2, 40.5 ± 10.9, and 11.2 ± 2.0 Hounsfield units, respectively. There were significant differences for all comparison combinations among the three methods (P < .01). For image noise, the mean visual scores were significantly higher for SD-FBP and LD-MBIR than for LD-FBP, and the scores for SD-FBP and LD-MBIR were equivalent (3.9 ± 0.3 [SD-FBP], 2.0 ± 0.5 [LD-FBP], and 3.7 ± 0.3 [LD-MBIR]). Preoperative information was more accurate under SD-FBP and LD-MBIR than under LD-FBP, and the information was comparable between SD-FBP and LD-MBIR.

CONCLUSION

MBIR can yield significantly improved image quality on low-radiation-dose CTC and provide preoperative information equivalent to that of standard-radiation-dose protocol.

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.

CT-colonography in the follow-up of acute diverticulitis: patient acceptance and diagnostic accuracy

OBJECTIVE

The aim of this study was to assess CT-colonography (CTC) in the follow-up of diverticulitis regarding patient acceptance and diagnostic accuracy for diverticular disease, adenomas and cancer, with colonoscopy as a reference standard.

METHODS

A prospective comparative study where half of the patients underwent colonoscopy first, followed immediately by CTC. The other half had the examinations in the reverse order. Patient experiences and findings were registered after every examination, blinded to the examiner.

RESULTS

Of a total of 110 consecutive patients, 108 were included in the study, with a median age of 56 years (range 27-84). The success rate was 91% for colonoscopy and 86% for CTC. Examination time was 25 min for both methods. The mean time for CTC evaluation was 20 min. Eighty-three per cent of the patients received sedation during colonoscopy. Despite this, patients experienced colonoscopy as more painful (p < 0.001) and uncomfortable (p < 0.001). Diverticulosis and polyps were detected in 94% and 20% with colonoscopy and in 94% and 29% with CTC, respectively. Sensitivity and specificity for CTC in the detection of diverticulosis was 99% and 67%, with a good agreement (κ = 0.71). Regarding detection of polyps, the sensitivity and specificity were 47% and 75%, with a poor agreement (κ = 0.17). No cancer was found.

CONCLUSION

CTC was less painful and unpleasant and can be used for colonic investigation in the follow-up of diverticulitis. CTC detected diverticulosis with good accuracy while the detection accuracy of small polyps was poor. CTC is a viable alternative, especially in case of incomplete colonoscopy or in a situation with limited colonoscopy resources.

Acceptability of oral iodinated contrast media: a head-to-head comparison of four media

OBJECTIVE

To assess the palatability of iodinated oral contrast media commonly used in abdominopelvic CT and CT colonography (CTC).

METHODS

80 volunteers assessed the palatability of a 20-ml sample of a standard 30 mg ml(-1) dilution of Omnipaque® (iohexol; GE Healthcare, Cork, Ireland), Telebrix® (meglumine ioxithalamate; Guerbet, Aulnay-sous-Bois, France), Gastromiro® (iopamidol; Bracco, High Wycombe, UK) and Gastrografin® (sodium diatrizoate and meglumine diatrizoate; Bayer, Newbury, UK) in a computer-generated random order.

RESULTS

Gastrografin is rated significantly less palatable than the remaining media (p<0.005). Omnipaque and Telebrix are significantly more palatable than Gastromiro. No difference existed between Omnipaque and Telebrix. 39% of participants would refuse to consume the quantities of Gastrografin required for a CTC examination compared with Telebrix (7%) and Omnipaque (9%) (p<0.05).

CONCLUSION

Omnipaque and Telebrix are significantly more palatable than both Gastromiro and Gastrografin, with participants more willing to ingest them in larger quantities as well as being less expensive.

ADVANCES IN KNOWLEDGE

Omnipaque and Telebrix are significantly more palatable iodinated oral contrast media than both Gastromiro and Gastrografin, which has potential implications in compliance with both abdominopelvic CT and CTC.

Computed tomographic colonography versus barium enema for diagnosis of colorectal cancer or large polyps in symptomatic patients (SIGGAR): a multicentre randomised trial

BACKGROUND

Barium enema (BE) is widely available for diagnosis of colorectal cancer despite concerns about its accuracy and acceptability. Computed tomographic colonography (CTC) might be a more sensitive and acceptable alternative. We aimed to compare CTC and BE for diagnosis of colorectal cancer or large polyps in symptomatic patients in clinical practice.

METHODS

This pragmatic multicentre randomised trial recruited patients with symptoms suggestive of colorectal cancer from 21 UK hospitals. Eligible patients were aged 55 years or older and regarded by their referring clinician as suitable for radiological investigation of the colon. Patients were randomly assigned (2:1) to BE or CTC by computer-generated random numbers, in blocks of six, stratified by trial centre and sex. We analysed the primary outcome-diagnosis of colorectal cancer or large (≥10 mm) polyps-by intention to treat. The trial is an International Standard Randomised Controlled Trial, number 95152621.

FINDINGS

3838 patients were randomly assigned to receive either BE (n=2553) or CTC (n=1285). 34 patients withdrew consent, leaving for analysis 2527 assigned to BE and 1277 assigned to CTC. The detection rate of colorectal cancer or large polyps was significantly higher in patients assigned to CTC than in those assigned to BE (93 [7.3%] of 1277 vs 141 [5.6%] of 2527, relative risk 1.31, 95% CI 1.01-1.68; p=0.0390). CTC missed three of 45 colorectal cancers and BE missed 12 of 85. The rate of additional colonic investigation was higher after CTC than after BE (283 [23.5%] of 1206 CTC patients had additional investigation vs 422 [18.3%] of 2300 BE patients; p=0.0003), due mainly to a higher polyp detection rate. Serious adverse events were rare.

INTERPRETATION

CTC is a more sensitive test than BE. Our results suggest that CTC should be the preferred radiological test for patients with symptoms suggestive of colorectal cancer.

FUNDING

NIHR Health Technology Assessment Programme, NIHR Biomedical Research Centres funding scheme, Cancer Research UK, EPSRC Multidisciplinary Assessment of Technology Centre for Healthcare, and NIHR Collaborations for Leadership in Applied Health Research and Care.

Evaluation of two minimal-preparation regimes for CT colonography: optimising image quality and patient acceptability

OBJECTIVE

To compare a 2 day bowel preparation regime of barium, iodine and a mild stimulant laxative with a 1 day iodine-only regime for CT colonography (CTC).

METHODS

100 consecutive patients underwent CTC. The first 50 patients (Regime 1) ingested 1 bisacodyl tablet twice a day 3 days before CTC and 1 dose each of 50 ml of barium and 20 ml of iodinated contrast per day starting 2 days before CTC. The second 50 patients (Regime 2) ingested 3 doses of iodinated contrast over 24 h prior to CTC. Volumes of residual stool and fluid, and the effectiveness of stool and fluid tagging, were graded according to methods established by Taylor et al (Taylor S, Slaker A, Burling D, Tam E, Greenhalgh R, Gartner L, et al. CT colonography: optimisation, diagnostic performance and patient acceptability of reduced-laxative regimens using barium-based faecal tagging. Eur Radiol 2008; 18: 32-42). A 3 day low-residue diet was taken by both cohorts. Questionnaires rating the side-effects and burden of the bowel preparation were compared to a control cohort of patients undergoing barium enema.

RESULTS

The proportion of colons producing none/scattered stool (score 1) was 90.3% with Regime 1 and 65.0% with Regime 2 (p<0.005). Any residual stool was significantly better tagged with Regime 1 (score 5), with 91.7% of Regime 1 exhibiting optimum tagging vs 71.3% of Regime 2 (p<0.05). No significant differences in side-effects between the bowel preparation regimes for CTC were elicited. Bowel preparation for barium enema was tolerated significantly worse than both of the CTC bowel preparation regimes.

CONCLUSION

Regime 1, containing a 3 day preparation of a mild laxative, barium and iodine, produced a significantly better prepared colon, with no difference in patient acceptability.

Preferences for CT colonography and colonoscopy as diagnostic tests for colorectal cancer: a discrete choice experiment

OBJECTIVE

Computed tomography colonography (CTC) is an alternative diagnostic test to colonoscopy for colorectal cancer and polyps. The aim of this study was to determine test characteristics important to patients and to examine trade-offs in attributes that patients are willing to accept in the context of the diagnosis of colorectal cancer.

METHODS

A discrete choice study was used to assess preferences of patients with clinical indications suspicious of colorectal cancer who experienced both CTC and colonoscopy as part of a diagnostic accuracy study in South Australia. Results were analyzed by using a mixed logit model and presented as odds ratios (ORs) for preferring CTC over colonoscopy.

RESULTS

Colonoscopy was preferred over CTC as the need for a second procedure after CTC increased (OR of preferring CTC to colonoscopy = 0.013), as the likelihood of missing cancers or polyps increased (OR of preferring CTC to colonoscopy = 0.62), and as CTC test cost increased (OR of preferring CTC to colonoscopy = 0.65-0.80). CTC would be preferred to colonoscopy if a minimal bowel preparation was available (OR = 1.7). Some patients were prepared to trade off the diagnostic and therapeutic advantage of colonoscopy for a CTC study with a less intensive bowel preparation. Preferences also varied significantly with sociodemographic characteristics.

CONCLUSIONS

Despite CTC's often being perceived as a preferred test, this may not always be the case. Informed decision making for diagnostic tests for colorectal cancer should include discussion of the benefits, downsides, and uncertainties associated with alternative tests, as patients are willing and able to make trade-offs between what they perceive as the advantages and disadvantages of these diagnostic tests.

Two-year audit of computed tomographic colonography in a teaching hospital: are we meeting the standard?

OBJECTIVE

We aimed to determine whether adopting the published recommendations has led to successful implementation of computed tomographic colonography (CTC) in a teaching hospital setting outside the context of a clinical trial.

METHOD

An audit of all the CTC examinations between April 2005 and June 2007 was conducted to determine the following: adequacy of bowel preparation, CTC indications and findings (compared with available colonoscopy), complications and experience of reporting radiologist.

RESULTS

The most common indications for the 111 CTC patients reviewed included exclusion of synchronous colonic tumours, incomplete colonoscopy and altered bowel habit. Only 16% of ascending colon/caecal segments was clear of faecal or fluid contamination. The rectum and sigmoid colon were free of contamination in 78% and 74% of cases respectively. Appropriately trained radiologists reported 91% of studies. Thirty-two percent of studies were normal. The most common positive findings were diverticular disease or a rectal tumour. Sensitivity, specificity and positive predictive value were 89%, 94% and 90% respectively (all polyps) with a sensitivity of 98.5% for lesions > 5 mm in size. Twenty-five percent of patients had extra colonic abnormalities. There were no recorded complications.

CONCLUSION

Our CTC practice is within accepted published guidelines. Bowel preparation is suboptimal in a significant proportion of cases and faecal tagging is being implemented.

Comparison of CT colonography vs. conventional colonoscopy in mapping the segmental location of colon cancer before surgery

Once presence of a colorectal cancer has been diagnosed, a key factor for patient's prognosis in view of surgical intervention is the correct segmental localization and resection of the tumor. The aim of this work was to compare the accuracy of the current gold standard technique, conventional colonoscopy (CC), to computed tomography colonography (CTC) in the segmental localization of tumor. Sixty-five patients (mean age 64; 45 female and 19 male) with colorectal cancer diagnosed at colonoscopy underwent CTC before surgery. In 45 out of 65 cases (69%), patients were referred to CTC after incomplete CC. Reasons were patient intolerance to CC or presence of stenosing cancer, with consistent difficulties in crossing the tract of the colon involved by the lesion. CTC allowed the complete colonic examination in 63/65 cases, since in 2 patients with an obstructing lesion of the sigmoid colon, pneumocolon could not be obtained. However, per patient and per lesion sensitivity of CTC was 100%. Difference from colonoscopy was statistically significant (P < 0.05). In terms of segmental localization of masses, CTC located precisely all lesions, while colonoscopy failed in 16/67 (24%) lesions, though six were missed for incomplete colonoscopy (9%). In the remaining 10/67 (15%) lesions, detected by colonoscopy but incorrectly located, the mismatch occurred in the rectum (n = 3), sigmoid (n = 2), descending (n = 1), transverse (n = 2), ascending colon, and cecum. Agreement between CTC and CC was fair (k value 0.62). Sensitivity, specificity, positive predictive value and negative predictive value of CTC in determining the precise location of colonic masses were respectively 100%, 96%, 85%, and 100%. CT detected hepatic (6/65 patients) and lung metastases (3/65 patients). CT colonography has better performance in the identification of colonic masses (diameter > 3 cm), in the completion of colonic evaluation and in the segmental localization of tumor. CTC should replace colonoscopy for preoperative staging of colorectal cancer.

Use of modified multidetector CT colonography for the evaluation of acute and subacute colon obstruction caused by colorectal cancer: a feasibility study

PURPOSE

This study was designed to evaluate the feasibility of using CT colonography with a modified procedural protocol for diagnosis and cancer staging in patients with suspected acute or subacute colon obstruction caused by colorectal cancer.

METHODS

Following colonic cleansing with lukewarm water enemas, thin-collimation CT colonography was performed on 47 patients (15 women and 32 men, mean age, 68 years) in the precontrast prone position and in the supine position after the intravenous administration of a contrast agent. The surgical and pathologic findings served as a reference standard.

RESULTS

In 44 of 47 patients, colon distention was caused by obstruction, and pathologic examination confirmed colorectal cancer in 41 of these 44 patients. CT colonography correctly located all tumors and successfully identified noncancerous causes of colon distention in five patients. The overall accuracy of staging was 97.6 percent for the T category, 73.2 percent for N, and 100 percent for M. Two synchronous colorectal cancers were correctly identified.

CONCLUSIONS

When appropriate protocol modifications regarding colon cleansing and air insufflation are made to take the clinical situation into account, CT colonography is a technically feasible, accurate, and well-tolerated method for tumor evaluation and cancer staging in patients with acute and subacute colon obstruction.

Considering double contrast barium enema and its demise: a case for systematic videorecording of colonoscopy

Double contrast barium enema (DCBE) continues its decline. One area where DCBE and CT colonography surpass colonoscopy is in documentation. Colonoscopy could improve documentation by systematic videorecording of examinations (or at least of the withdrawal portions). Investigation of the impact of systematic videorecording of colonoscopy on quality, cost, and medical-legal risk is warranted.

Racial/ethnic differences in patient experiences with and preferences for computed tomography colonography and optical colonoscopy

BACKGROUND & AIMS

Racial/ethnic minorities are less likely than whites to undergo colorectal cancer (CRC) screening. Although computed tomography colonography (CTC) is a less invasive alternative to optical colonoscopy (OC), it is not known whether CTC will increase acceptance of CRC screening in minorities.

METHODS

Patients undergoing OC for clinically indicated reasons had CTC followed by same-day OC. After the sedation from the OC had worn off, a questionnaire was administered to assess pain, discomfort, bloating, embarrassment, anxiety, and patient satisfaction using a 10-point scale (1 = least, 10 = greatest).

RESULTS

Of the 272 patients enrolled, there were 134 whites, 71 blacks, 53 Hispanics, and 14 who self-identified their race/ethnicity as other. Although the proportion of subjects who preferred CTC over OC was not significantly different (52.9% vs 47.1%, P = .36), racial/ethnic minorities were significantly less likely than whites to prefer CTC over OC (whites, 65.7%; blacks, 45.1%; Hispanics, 35.8%; and other, 35.7%; P < .001). Racial/ethnic minorities were less satisfied with CTC (whites, 8.4 +/- 1.7; blacks, 7.8 +/- 1.7; Hispanics, 7.4 +/- 1.8; and other, 7.5 +/- 2.1; P = .001) and were significantly less willing to undergo CTC again in the future (whites, 95.5%; blacks, 80.3%; Hispanics, 84.9%; and other, 85.7%; P = .006).

CONCLUSIONS

Compared with white patients, OC is better tolerated and is preferred over CTC for evaluation of the colon among racial/ethnic minorities. Although CTC is less invasive than OC, our findings suggest that CTC is unlikely to overcome racial/ethnic disparities in CRC screening.

European Society of Gastrointestinal and Abdominal Radiology (ESGAR): consensus statement on CT colonography

Rapid clinical dissemination of CT colonography (CTC) is occurring in parallel with continued research into technique optimisation and diagnostic performance. A need exists therefore for current guidance as to basic prerequisites for effective clinical implementation. A questionnaire detailing CTC technique, analysis, training and clinical implementation was developed by the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) CTC committee and circulated to all faculty members of previous ESGAR "hands-on" CTC training courses. Responses were collated and a consensus statement produced. Of 27 invited to participate, 24 responded. Reasonable consensus was reached on bowel preparation, colonic distension, patient positioning, use of IV contrast and optimal scan parameters. Both primary 2D and primary 3D analysis were advocated equally, with some evidence that more experienced readers prefer primary 2D. Training was universally recommended, although there was no consensus regarding minimum requirements. CTC was thought superior to barium enema, although recommended for screening only in the presence of validated local experience. There was consensus that polyps 4 mm or less could be ignored assuming agreement from local gastroenterological colleagues. There is increasing consensus amongst European experts as to the current best practice in CTC.

CT colonography versus colonoscopy in the follow-up of patients after diverticulitis - a prospective, comparative study

AIM

To assess whether computed tomography colonography (CTC) is a viable alternative to colonoscopy or double contrast barium enema in the follow-up of patients after diverticulitis.

MATERIAL AND METHODS

Fifty patients underwent CTC followed immediately by colonoscopy. Results were blinded to the examiners. Findings of diverticular disease and patient acceptance were evaluated.

RESULTS

Bowel preparation and distension were good in the majority of CTC and colonoscopy examinations. Diverticular disease was found in 96% of patients at CTC and in 90% at colonoscopy. The rate of agreement between CTC and colonoscopy for diverticular findings in the sigmoid colon was good (kappa=0.64). No complications were seen. Patients found colonoscopy more uncomfortable (p<0.03), more painful (p<0.001), and more difficult (p<0.01) than CTC. Of the patients favouring one examination, 74% preferred CTC.

CONCLUSION

CTC appears to have a better diagnostic potential for imaging of diverticular disease-specific findings, when compared with colonoscopy. Also, CTC was less uncomfortable and was preferred by a majority of patients. CTC seems to be a reasonable alternative in follow-up of patients with symptomatic diverticular disease.

Virtual colonoscopy training and accreditation: a national survey of radiologist experience and attitudes in the UK

AIM

Expert consensus recommends directed training and possibly in the future, formal accreditation before independent virtual colonoscopy (VC) reporting. We surveyed radiologists' experience of VC training, compared with barium enema, and assessed attitudes towards accreditation.

MATERIALS AND METHODS

A questionnaire was sent to 78 consultant radiologists from 72 centres (65 National Health Service hospitals; seven independent primary screening centres) offering a VC service.

RESULTS

Fifty-four (69%) eligible radiologists responded. They had interpreted 18,152 examinations (range 3-1500) in total versus 232,350 (13 times more) barium enemas. Twenty-two (41%) deemed their VC training as inadequate [including five (45%) of screening centre radiologists], and only 14 (26%) had attended a training workshop due to lack of availability (54%) or financial/study leave constraints (24%). Eleven (20%) radiologists routinely double-reported VC examinations versus 37 (69%) barium enemas, yet 21 (39%) considered requirements for VC training were greater than barium enema. Thirty-eight (70%) favoured accreditation beyond internal audit for VC versus 15(28%) for barium enema. Of these 38, seven (18%) favoured "one-off," and 18 (47%) periodic testing, with 16 (42%) favouring external audit alone or in combination with testing. Overall, 42 (78%) considered specific accreditation for reporting screening examinations appropriate and 45 (83%) respondents preferred a national radiological organization to regulate such a scheme.

CONCLUSION

There is wide variability in reporting experience and recommendations for VC training have not been widely adopted, in part due to limited access to dedicated workshops. UK radiologists are generally in favour of VC accreditation, governed by a national radiology organization.

CT colonography: Results and limitations

Meta-analysis of data from studies of CT colonography suggests that it has excellent per-patient average sensitivity and average specificity for detection of adenomatous polyps and cancer. However, while its potential as a screening test is undoubted, there are several current limitations that will need to be overcome before it can be considered seriously by health policy makers. These revolve around issues of generalisability, which is inhibited most by a lack of trained observers and access to CT scanners, and a paucity of data relating to cost-effectiveness. Whether offering CT colonography as an alternative to competing strategies will genuinely enhance compliance also needs further and more detailed attention.

Frequency and impact of extracolonic findings detected at computed tomographic colonography in a symptomatic population

Background

Extracolonic findings are frequently recognized alongside colonic pathology at computed tomographic colonography (CTC). This study assessed the clinical impact of extracolonic findings in a symptomatic population at high risk of colorectal cancer.

Methods

CTC was performed in a consecutive cohort of patients assessed in a fast-track colorectal cancer clinic as being at high risk of colorectal cancer. A review of CTC findings and case notes was undertaken. Patients with extracolonic findings were followed up for at least 12 months.

Results

Thirty-one (13·8 per cent) of 225 patients investigated by CTC had colorectal cancer. Extracolonic findings were identified in 81 (53·3 per cent) of 152 patients with normal or non-neoplastic bowel findings, compared with 27 (37 per cent) of 73 patients with colorectal neoplasia (P = 0·025). Twenty-four patients (10·7 per cent) with extracolonic findings underwent further investigation or treatment. The median duration of investigation was 19·5 weeks. Seventy-five clinical events were recorded, including 14 surgical procedures.

Conclusion

A prospective cost–benefit analysis of diagnostic CTC should be performed before it is established as a first-line investigation for colonic symptoms.

Resources and costs associated with incidental extracolonic findings from CT colonogaphy: a study in a symptomatic population

CT colonography (CTC) is increasingly used to detect colonic polyps and cancers, but its impact in practice is also influenced by frequent detection of extracolonic lesions. We have previously documented the frequency and nature of such lesions. The current study was performed to assess the clinical resources and costs associated with the investigation and treatment of extracolonic lesions. We reviewed the reports of 225 consecutive CTC examinations carried out on patients with symptoms of bowel cancer. 116 of the 225 were reported to have one or more extracolonic findings. All 116 patients with an abnormality were followed up for 12-24 months. 24 patients underwent further actions (outpatient attendance, investigations, or surgical procedures) as a result of previously undiagnosed lesions unrelated to bowel cancer. The costs of these further actions were derived from the NHS Reference Costs manual 2004. The total cost for further investigations and interventions was 34,329 pounds sterling and the mean cost over the sample of 225 patients was 153 pounds sterling--more than the cost of the CTC itself. The costs were mainly generated by surgical procedures. Resources consumed as a result of extracolonic findings approximately doubled the costs of diagnostic CTC. These costs, along with inconvenience, anxiety, morbidity and occasionally even mortality suffered by patients, must be offset by the good done to some of those with sub-clinical but potentially lethal diseases.

Minimal preparation CT for the diagnosis of suspected colorectal cancer in the frail and elderly patient

Colorectal cancer is a common malignancy with an increased incidence in the elderly population. Traditional methods of evaluating this disease have included double contrast barium enema and colonoscopy. Unfortunately, in the frail and elderly patient, these investigations can be difficult to perform and are often not tolerated. Minimal preparation computed tomography (MPCT) of the colon has been suggested as an alternative in this patient population. In this technique, no bowel preparation is used apart from the administration of oral contrast medium. The patient is imaged only in the supine position, without per rectal insufflation of gas or barium. This article reviews the experience to date of MPCT in detecting colonic tumours, and compares its efficacy to the traditional methods. A meta-analysis of the studies allowed estimation of the pooled sensitivity of MPCT to be 83% (95% confidence interval: 76-89%), and pooled specificity to be 90% (95% CI: 85-94%). An added advantage of MPCT is the ability to identify extra-colonic pathology, and this aspect is also reviewed. In addition, the common radiological features and pitfalls in identifying colonic tumours by MPCT are discussed.