Colonoscopically detected colorectal cancer missed on barium enema

Added value of double reading in diagnostic radiology,a systematic review

Objectives

Double reading in diagnostic radiology can find discrepancies in the original report, but a systematic program of double reading is resource consuming. There are conflicting opinions on the value of double reading. The purpose of the current study was to perform a systematic review on the value of double reading.

Methods

A systematic review was performed to find studies calculating the rate of misses and overcalls with the aim of establishing the added value of double reading by human observers.

Results

The literature search resulted in 1610 hits. After abstract and full-text reading, 46 articles were selected for analysis. The rate of discrepancy varied from 0.4 to 22% depending on study setting. Double reading by a sub-specialist, in general, led to high rates of changed reports.

Conclusions

The systematic review found rather low discrepancy rates. The benefit of double reading must be balanced by the considerable number of working hours a systematic double-reading scheme requires. A more profitable scheme might be to use systematic double reading for selected, high-risk examination types. A second conclusion is that there seems to be a value of sub-specialisation for increased report quality. A consequent implementation of this would have far-reaching organisational effects.

Key Points

• In double reading, two or more radiologists read the same images.

• A systematic literature review was performed.

• The discrepancy rates varied from 0.4 to 22% in various studies.

• Double reading by sub-specialists found high discrepancy rates.

Electronic supplementary material

The online version of this article (10.1007/s13244-018-0599-0) contains supplementary material, which is available to authorised users.

Critical analysis of the performance of double-contrast barium enema for detecting colorectal polyps > or = 6 mm in the era of CT colonography

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 > or = 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 > or = 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 A(z) 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 > or = 10 mm, a 0.121-per-patient 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 > or = 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 > or = 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 > or = 6 mm.

National audit of the sensitivity of double-contrast barium enema for colorectal carcinoma, using control charts

AIM

To audit the sensitivity of double-contrast barium enema (DCBE) for colorectal carcinoma, as currently practised in UK departments of radiology.

METHODS

As part of its programme of national audits, the Royal College of Radiologists Clinical Radiology Audit Sub-Committee undertook a retrospective audit of the sensitivity of DCBE for colorectal carcinoma during 2002. The following targets were set: demonstration of a lesion > or =95%; correct identification as a carcinoma > or =90%.

RESULTS

Across the UK, 131 departments took part in the audit, involving 5454 examinations. The mean demonstration rate was 92.9% and the diagnosis rate was 85.9%, slightly below the targets set. The equivocal rate (lesion demonstrated, but not defined as malignant) was 6.9%, the perception failure rate was 2.8% and the technical failure rate was 4.4%. Control-chart methodology was used to analyze the data and to identify any departments whose performance was consistent with special-cause variation.

CONCLUSION

When compared with the diagnosis rate (84.6%) and demonstration rate (92.7%) reported in the Wessex Audit 1995, [Thomas RD, Fairhurst JJ, Frost RA. Wessex regional audit: barium enema in colo-rectal carcinoma. Clin Radiol 1995;50:647-50.] a similar level of performance was observed in the NHS today, implying that the basic process for undertaking and reporting DCBE has remained relatively unchanged over the last few years. Improvement in the future will require fundamental changes to the process of reporting DCBE, in order to minimize the perception failure rate and accurately to describe lesions, so reducing the equivocal rate. Control-chart methodology has a useful role in identifying strategies to deliver continual improvement.

The evaluation of rectal bleeding in adults. A cost-effectiveness analysis comparing four diagnostic strategies

BACKGROUND

Though primary care patients commonly present with rectal bleeding, the optimal evaluation strategy remains unknown.

OBJECTIVE

To compare the cost-effectiveness of four diagnostic strategies in the evaluation of rectal bleeding.

DESIGN

Cost-effectiveness analysis using a Markov decision model.

DATA SOURCES

Systematic review of the literature, Medicare reimbursement data, Surveillance, Epidemiology, and End Results (SEER) Cancer Registry.

TARGET POPULATION

Patients over age 40 with otherwise asymptomatic rectal bleeding.

TIME HORIZON

The patient's lifetime.

PERSPECTIVE

Modified societal perspective.

INTERVENTIONS

Watchful waiting, flexible sigmoidoscopy, flexible sigmoidoscopy followed by air contrast barium enema (FS+ACBE), and colonoscopy.

OUTCOME MEASURES

Incremental cost-effectiveness ratio.

RESULTS OF BASE-CASE ANALYSIS

The incremental cost-effectiveness ratio for colonoscopy compared with flexible sigmoidoscopy was 5,480 dollars per quality-adjusted year of life saved (QALY). Watchful waiting and FS+ACBE were more expensive and less effective than colonoscopy.

RESULTS OF SENSITIVITY ANALYSES

The cost of colonoscopy was reduced to 1,686 dollars per QALY when age at entry was changed to 45. Watchful waiting became the least expensive strategy when community procedure charges replaced Medicare costs, when age at entry was maximized to 80, or when the prevalence of polyps was lowered to 7%, but the remaining strategies provided greater life expectancy at relatively low cost. The strategy of FS+ACBE remained more expensive and less effective in all analyses. In the remaining sensitivity analyses, the incremental cost-effectiveness of colonoscopy compared with flexible sigmoidoscopy never rose above 34,000 dollars.

CONCLUSIONS

Colonoscopy is a cost-effective method to evaluate otherwise asymptomatic rectal bleeding, with a low cost per QALY compared to other strategies.

Screening CT colonography

CT colonography (Virtual Colonoscopy) was first introduced in 1994 as a novel imaging technique for the detection of colorectal polyps and cancer. It is currently proposed as a new screening tool for colorectal carcinoma that may be more acceptable to patients than current methods. There are a growing number of published studies evaluating all aspects of CT colonography, including technique, imaging displays, interpretation methods, patient acceptance, and lesion detection accuracy. While there are multiple studies that have found excellent CT colonography results for the detection of larger polyps in high risk or symptomatic patient cohorts, there are very few published studies evaluating the performance of CT colonography in asymptomatic screening patients. Although we do not have the results of large, randomized, controlled trials documenting the performance of CT colonography in screening-type patients, this technique is currently employed at some sites as a screening tool for colorectal carcinoma. Thus, CT colonography has become a part of the controversy surrounding total body CT screening. In this article, the current techniques for colonic preparation and distention will be discussed, as well as the optimum CT protocol, and the recommended use of image displays for time-efficient interpretation. The results of the larger and newer studies will be presented, as well as some of the current clinical uses of CT colonography. Issues specific to the use of CT colonography as a screening test will also be discussed.

The double contrast barium enema: a retrospective single centre audit of the detection of colorectal carcinomas

AIM

To determine retrospectively the sensitivity and specificity of the double contrast barium enema (DCBE) as performed in one institution for the detection of colorectal carcinoma.

SUBJECTS AND METHODS

Eight hundred and eighty barium enema reports were reviewed of consecutive adult patients who underwent DCBE and also had hospital case notes with a minimum follow up of two years, a later diagnostic colonoscopy, or operative and histological findings.

RESULTS

Seventy-four true positive cases of colorectal carcinoma diagnosed at DCBE were confirmed at surgery and histological examination. There were four false positive diagnoses of carcinoma at DCBE. Eight false negative cases at DCBE were demonstrated within a two-year follow-up period. The sensitivity of the DCBE for detecting colorectal carcinoma was therefore 90.2% and the specificity was 99.5%.

CONCLUSION

DCBE is a sensitive and highly specific investigation for the detection of colorectal carcinoma.

Why barium enemas fail to identify colorectal cancers

BACKGROUND

The aim of the present study was to determine the cause and clinicopathological factors associated with the failure of barium enemas to detect colorectal cancers.

METHODS

A histopathological database was used to identify all patients with a diagnosis of colorectal cancer between 1991 and 1995. These records were matched with the records from patients who underwent barium enema examinations between 1990 and 1995. Those patients who had a colorectal cancer histologically diagnosed within 24 months of a barium enema in which no carcinoma was seen, were identified. Where possible the radiology was reviewed. Failure to identify a carcinoma was then attributed to either simple failure, technical, interpretive or perceptive difficulties.

RESULTS

There were 967 patients with colorectal cancers treated in Christchurch Hospital during the study period 1991-1995. Matching of these patient details with all barium enema records revealed 313 patients who had barium enemas and histologically proven colorectal cancer. There were 21 (6.7%) patients in whom a carcinoma was missed. Of these, 18 had a barium enema within 8 months of surgery, and three were performed outside this timespan (15, 18 and 28 months, respectively). On review, 11 carcinomas could not be identified (nine due to technical error: poor coating (n = 1), overlapping loops (n = 3), single-contrast enema (n = 4), faecal residue (n = 1)); and seven could be seen on review of the films (two interpretation errors, one technical and perceptive error, and four perceptive errors). In three cases films could not be found for review. In 16 of the 21 missed lesions the patient had a double-contrast barium enema (DCBE) while five patients had single-contrast barium enema (SCBE). The site and stage of missed tumours is presented.

CONCLUSIONS

The most common reason for missed tumours was technical. The percentage of missed tumours in each region of the bowel correlates with the known incidence of tumours in each region and with a normal Dukes stage distribution, except in the caecum where the number of missed lesions was higher than expected.

Colorectal neoplasia: performance characteristics of CT colonography for detection in 300 patients

PURPOSE

To determine the sensitivity and specificity of computed tomographic (CT) colonography for colorectal polyp and cancer detection by using colonoscopy as the reference standard.

MATERIALS AND METHODS

Three hundred patients underwent CT colonography followed by standard colonoscopy. Bowel preparation consisted of magnesium citrate and polyethylene glycol. After colonic air insufflation, patients underwent scanning in the supine and prone positions with 3-mm collimation during a single breath hold. The transverse CT images, sagittal and coronal reformations, and three-dimensional endoluminal images were interpreted by two radiologists independently, and then a consensus reading was performed. CT colonographic findings were correlated with standard colonoscopic and histologic findings.

RESULTS

The overall sensitivity and specificity of CT colonography for polyp detection were 90.1% (164 of 182) and 72.0% (85 of 118), respectively. By using direct polyp matching, the overall sensitivity was 69.7% (365 of 524). The sensitivity was 90% (74 of 82) for the detection of polyps 10 mm or larger, 80.1% (113 of 141) for polyps 5.0-9.9 mm, and 59.1% (178 of 301) for polyps smaller than 5 mm. The sensitivity was 94% (64 of 68) for the detection of adenomas 10 mm or larger, 82% (72 of 88) for adenomas 5.0-9.9 mm, and 66.9% (95 of 142) for adenomas smaller than 5 mm. CT colonography was used to identify all eight carcinomas.

CONCLUSION

CT colonography has excellent sensitivity for the detection of clinically important colorectal polyps and cancer.

Barium enema and endoscopy for the detection of colorectal neoplasia: sensitivity, specificity, complications and its determinants

AIM

To analyse sensitivity, specificity and complication rate of endoscopy, and barium enema for the detection of colorectal neoplasia.

MATERIALS AND METHODS

A MEDLINE search was performed (1980-2000) directed at the endoscopic and radiologic literature on barium enema. Articles were selected based on the type of study, availability of sensitivity and specificity values in sizeable patient groups, and reports on complications. Sixty articles were included in the analysis.

RESULTS

Endoscopy proved to have superior sensitivity for polyps in patients at high-risk for colorectal neoplasia. The role of endoscopy and radiology in average-risk screening populations is not known. Sensitivity and specificity rates ranged widely, probably due to bias. For the detection of small polyps endoscopy has superior performance, whereas sensitivity is similar for endoscopy and barium enema for the detection of larger (>1 cm) polyps and tumours. Overall, endoscopy is associated with a higher complication rate.

CONCLUSION

Endoscopy is the preferred detection method in high-risk patients. The role of endoscopy and radiology in a screening setting requires evaluation. This review provides the test characteristics of endoscopy and radiology which are relevant for a cost-effectiveness analysis. Double-contrast barium enema may play an important role for screening purposes, owing to its good sensitivity for detecting larger (>1 cm) polyps and its lack of major complications. de Zwart, I. M.et al. (2001). Clinical Radiology56, 401-409.

Clinical governance in action: radiology

Articles and conferences on clinical governance abound, but much of the content is theoretical. This article describes how clinical governance may be introduced in a busy radiology department in a straightforward and practical way, with benefits to both the radiologist and patient.

Colon cancer at barium enema examination and colonoscopy: a study from the county of Hordaland, Norway

PURPOSE

To evaluate the efficacy of barium enema examination as routinely performed in the detection of colon cancer in the inhabitants of a well-defined and circumscribed geographic region.

MATERIALS AND METHODS

The study comprised 571 patients with histopathologically verified colon cancer during 1990-1993 from the county of Hordaland. The barium enema examination results were reviewed retrospectively.

RESULTS

The correct diagnosis was reached in 351 cases (sensitivity, 90.9%) in 386 tumor locations on the basis of the results of 381 barium enema examinations. Cancer or an important precancerous lesion was overlooked in 26 cases (6.7%), and the examination was not feasible in nine cases (2.3%). The correct diagnosis was reached in 172 cases (sensitivity, 80.0%) in patients with 215 tumor locations on the basis of the results of 213 colonoscopies. Cancer or an important precancerous lesion was overlooked in 13 cases (6.0%). The examination was technically not successful (i.e., the affected area was not reached with the scope) in 30 cases (13.9%).

CONCLUSION

Barium enema examination is valuable in the diagnosis of colon cancer and compares favorably with colonoscopy. The main reason for missed radiologic diagnosis is failure to observe important lesions visible on the radiographs.

Audit of barium enema examinations in the diagnosis of colorectal carcinoma

Barium enema is a commonly used technique. A number of papers have been published describing its accuracy in the diagnosis of colorectal carcinoma. A retrospective comparison of pathology and radiology reports was made to determine rates of demonstration and reporting of colorectal carcinoma on barium enema examinations for a 12-month period.

The role of the barium enema in the diagnosis of colorectal neoplasia

The recent interest in guidelines for colorectal cancer diagnosis, management and in screening has important implications for radiologists. The present article reviews the role of the barium enema in colorectal neoplasia diagnosis in symptomatic patients, and in the context of screening programmes.

Wessex regional radiology audit: barium enema in colo-rectal carcinoma

In the first Wessex regional radiology audit, a retrospective comparison of pathology and radiology reports was made to determine rates of demonstration and reporting of colo-rectal carcinoma on barium enema. Barium enema films were analysed by peer review in cases of discrepancy. The standard set was 100% demonstration and 100% diagnosis of colo-rectal carcinoma on a barium enema undertaken in the 12 months preceding histological diagnosis. The carcinoma demonstration rate was 97% and carcinoma reporting rate 85%. Of 1351 patients with carcinoma, 557 had a barium enema in the preceding 12 months. Four hundred and seventy-one enema reports satisfactorily recorded the malignant lesion (85%). The reasons for non-reporting of a carcinoma were failure to demonstrate the lesion (18 cases, 3%), failure to perceive a demonstrated lesion (23 cases, 4%) and failure to analyse a perceived lesion (45 cases, 8%). Any improvement in demonstration cannot be estimated, but 94% of carcinomas should be reported when improved reporting techniques are instituted and the audit loop is closed.

Radiology in the detection and prevention of colorectal cancer

Imaging techniques available for detection of colorectal cancer include barium enema, endoscopy, computed tomography (CT), ultrasound, magnetic resonance (MR) and immunoscintigraphy. Technical advances continue rapidly and prompt frequent re-evaluation of the optimal approach to management of these patients. Barium enema and colonoscopy are the main techniques for evaluation of symptomatic patients, although CT may well assume the predominant role within a few years. Variation in quality of barium enemas and colonoscopy poses a challenge for continuing medical education (CME) activities. Screening of asymptomatic individuals has to be considered separately for high, moderate and low risk population. Recommendations have to be made at present in the absence of evidence of effectiveness. Staging of disease pre-operatively is of limited value. Follow-up after surgery should be primarily clinical although endoscopy, CT, MR, ultrasound and immunoscintigraphy all have specific roles in the evaluation of patients suspected of harbouring recurrent disease.

A combined flexible sigmoidoscopy and double-contrast barium enema service: initial experience

BACKGROUND

A service has been instituted offering a combined single-stage procedure of flexible sigmoidoscopy and double-contrast barium enema (FS/DCBE). The results have been reviewed in the first 80 patients to undergo this examination (45 male: 35 female; mean age 61.4 years).

METHODS

Indications for investigation were abdominal pain or suspected diverticular disease (22 patients), altered bowel habit (19), rectal bleeding (17), iron deficiency anemia (6), and miscellaneous (16). FS was followed immediately by DCBE. Radiographs were reviewed by two radiologists unaware of the FS findings.

RESULTS

The extent of FS was to the proximal sigmoid or sigmoid descending colon or splenic flexure in 12.5%, and mid or distal sigmoid in 37.5%. Biopsies were performed at FS in 26 patients (33%). In 67 (84%) of DCBEs the barium coating was assessed as satisfactory or better. FS yielded pathological findings not seen at DCBE in 21 patients (26%). DCBE demonstrated additional abnormalities within the range of the FS examination in 15 patients (19%), almost entirely due to its increased sensitivity for diverticular disease.

CONCLUSION

FS/DCBE is feasible as a one-stage combined procedure. The quality of DCBE following FS is satisfactory, and the extra yield of FS and its potential for biopsy make the combined FS/DCBE a useful technique in the investigation of large bowel disease.

Changes in diagnostic imaging routines of the stomach and the large bowel during the period between 1975 and 1992

In a retrospective study on diagnostic imaging of the stomach and large bowel, we evaluated the examination routines in six Norwegian hospitals for the period between 1975 and 1992. For both organ systems, a shift in routines from radiological examination toward endoscopy was observed. For the stomach there was a significant correlation between an increase in the use of endoscopy and a decrease in the use of X-ray examinations. Additionally, the total number of stomach examinations had declined. For the large bowel, the total number of endoscopic and radiological examinations had increased for all hospitals studied. While not as prominent as for the stomach, an obvious shift from X-ray examinations toward endoscopy was observed. These results should be considered when planning new imaging departments and hospitals in Norway.

Contemporary radiological examination of the lower gastrointestinal tract

The morphological spectrum of colonic disease is wide. Various treatment modalities may influence the macroscopic aspect of colonic lesions and render a pathological differential diagnosis occasionally difficult or impossible. Before starting therapy in patients suspected of having colonic disease, a physician should undertake a thorough radiological and endoscopic evaluation of the extent and severity of disease activity in the large bowel (Ruderman and Farmer, 1987). DCBE and colonoscopy are complementary imaging modalities, each test has its own intrinsic advantages and merits (Lichtenstein and Rothstein, 1991). DCBE remains the cornerstone in the detection of fistulas, strictures, perforations and estimating depth of ulcerations. Colonoscopy and biopsy remain the most sensitive imaging modalities to identify mucosal involvement (Dijkstra, 1992). The main clinically relevant discrepancies between colonoscopy and DCBE consist of inflammatory lesions without distortion of the mucosal relief and inflammation in the form of small, superficial erosions and ulcers (Dijkstra, 1992).