A retrospective 5-year study on the accuracy of the barium enema examination performed by radiographers

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.

Evaluation of a radiographer-provided barium enema service

AIM

Radiographers performed and reported 5516 double contrast barium enemas (RDCBEs) over 4 years to October 2001. This study was undertaken to assess the accuracy of RDCBE and the sensitivity for diagnosing colorectal cancer (CRC).

METHOD

A total of 224 consecutive outpatient RDCBEs were reported; normal (C1), diverticulosis (C2), diverticulosis with filling defect (C3), diverticulosis & other pathology (C4) and abnormal (C5). RDCBEs were then reported by a radiologist (AL, NS) and the two reports compared. Of 450 CRCs, 153 had undergone DCBE; 152 RDCBEs. Reports were analysed to establish concurrence between radiographer and radiologist and final CRC diagnosis.

RESULTS

By category: C1 - 37%, C2 - 31%, C3 - 21%, C4 - 11%, C5 - 0%. C4s included polyps (50%), cancer (12.5%), disrupted anastomosis (8%) and colitis (4%). There was no discrepancy between RDCBE and radiologist reports. Radiology and CRC diagnosis agreed in 145 of 152 DCBEs. There were three exclusions: DCBEs occurred outside the study period (2), one only with raised possibility of malignancy. Of eight remaining RDCBEs, seven were false negatives and one false positive. Sensitivity score for RDCBE was 94.5%. Double reporting by a radiologist did not improve sensitivity.

CONCLUSION

RDCBEs are as accurate as those performed by radiologists and have a very high sensitivity for CRC. In a time of ever increasing demands for complex staging investigations for CRC and interventional radiology, the ACPGBI needs to reconsider its guidelines on radiographers not only performing but also reporting DCBE.

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.

Comparison of radiologists and technologists in the performance of air-contrast barium enemas

OBJECTIVE

The purpose of this study was to determine whether the rate of polyp detection and the quality of air-contrast barium enema (ACBE) procedures performed by technologists differ from those performed by radiologists.

CONCLUSION

Our results showed that well-trained certified technologists can perform ACBE similar in overall quality and accuracy to ACBE performed by attending physicians and residents. Training technologists to perform ACBE may help to alleviate the radiology staffing shortage in the United States.

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.

Complications from radiographer-performed double contrast barium enemas

AIM

To determine the types and rates of complications encountered by radiographers when performing double contrast barium enemas (DCBE).

MATERIALS AND METHODS

Seven hundred and forty-one questionnaires were posted to radiographers who had in the last 5 years attended one of the biannual barium enema training courses.

RESULTS

Of 741 questionnaires posted 407 (54.9%) were returned completed. Approximately 348,000 barium enema examinations had been performed. Fifty-nine radiographers reported 89 complications, including 13 intra-peritoneal and 11 extra-peritoneal perforations. There were five deaths (mortality 1 in 70,000). Deaths resulted from two of 24 (10%) perforations, two of 45 (5%) cardiac events and one cerebrovascular accident that occurred during an examination.

CONCLUSIONS

Radiographers have been regularly performing DCBEs for almost a decade. The mortality for radiographer-performed DCBE is similar to that previously reported for radiologists, although a slightly higher rate of perforation is noted and so this is an area where radiographer training should be targeted.

Barium enema: use of increased copper filtration to optimize dose and image quality

The purpose of this study was to determine and validate the optimum copper filtration for adult double contrast barium enema examinations. Entrance surface dose rates to polymethyl methacrylate slabs and corresponding image intensifier input kermas, were measured for various added copper filters. Image contrast was assessed using a Leeds TO.10 test object. Copper filter thickness of 0.3 mm was chosen, as this reduced entrance surface dose rate by 56%, without substantially degrading image contrast due to kV and mA saturation. 20 sets of clinical films taken with each of 0.3 mm copper, 0.1 mm copper and no copper were reviewed following randomization, by a specialist gastrointestinal radiologist. Each set of digital spot and conventional films was allocated a score for each of three regions of the bowel, on a scale of 0-3 for perceived barium coating. The Kruskal-Wallis test showed no significant difference in perceived coating between the three groups (Digital spot: sigmoid colon p=0.207, splenic flexure p=0.103, hepatic flexure p=0.894. Screen-film: left colon p=0.803, right colon p=0.487, transverse colon p=0.905). All examinations but one were classified as diagnostic. The remaining one was classified indeterminate, due to poor distension of the colon. On adding 0.3 mm copper filtration, the mean dose-area product per examination was reduced by 57%, from 17.7 Gy cm(2) to 7.6 Gy cm(2). The estimated reduction in effective dose was 11%, from 3.0 mSv to 2.7 mSv. X-ray tube loading increased by 30%, but this caused no overheating with our local examination protocol and schedule. Additional filtration of 0.3 mm copper for adult double contrast barium enemas has now been implemented in routine clinical use at our hospital.

Colorectal cancer screening: scientific review

CONTEXT

Screening for colorectal cancer clearly reduces colorectal cancer mortality, yet many eligible adults remain unscreened. Several screening tests are available, and various professional organizations have differing recommendations on which screening test to use. Clinicians are challenged to ensure that eligible patients undergo colorectal cancer screening and to guide patients in choosing what tests to receive.

OBJECTIVE

To critically assess the evidence for use of the available colorectal cancer screening tests, including fecal occult blood tests, sigmoidoscopy, colonoscopy, double-contrast barium enema, and newer tests, such as virtual colonoscopy and stool-based molecular screening.

DATA SOURCES

All relevant English-language articles were identified using PubMed (January 1966-August 2002), published meta-analyses, reference lists of key articles, and expert consultation.

DATA EXTRACTION

Studies that evaluated colorectal cancer screening in healthy individuals and assessed clinical outcomes were included. Evidence from randomized controlled trials was considered to be of highest quality, followed by observational evidence. Diagnostic accuracy studies were evaluated when randomized controlled trials and observational studies were not available or did not provide adequate evidence. Studies were excluded if they did not evaluate colorectal screening tests and if they did not evaluate average-risk individuals.

DATA SYNTHESIS

Randomized controlled trials have shown that fecal occult blood testing can reduce colorectal cancer incidence and mortality. Case-control studies have shown that sigmoidoscopy is associated with a reduction in mortality, and observational studies suggest colonoscopy is effective as well. Combining fecal occult blood testing and sigmoidoscopy may decrease mortality and can increase diagnostic yield.

CONCLUSION

The recommendation that all men and women aged 50 years or older undergo screening for colorectal cancer is supported by a large body of direct and indirect evidence. At present, the available evidence does not currently support choosing one test over another.

Reducing dose at barium enema: radiographers do it digitally

It has been previously shown that, whilst radiographers in our hospital can undertake barium enema examinations with the same degree of diagnostic accuracy as consultant radiologists, there was a dose penalty to the patient arising from the use of a restrictive protocol requiring radiographers to take a series of plain radiographs for reporting purposes. For the past 3 years radiographers at this hospital have worked to a new protocol that replaces all routine radiographs with digital spot films. In the present study, dose-area product (DAP) measurements for 801 barium enema examinations performed by consultant radiologists and radiographers, using the revised protocol, were analysed and compared to ascertain whether there were still significant differences in radiation dose to the patient depending on the category of staff performing the examination. All examinations were reported by a consultant radiologist. The radiologists' reports were analysed against the known outcomes to compare the diagnostic accuracy of the examination when carried out by the two categories of staff. This study shows that using a modified protocol, in which digital spot films replace the series of overcouch radiographs for reporting, our radiographers are able to perform barium enemas without dose penalty to the patient, and without compromizing diagnostic accuracy. Means with 95% confidence intervals for DAP in the two groups were 9.8 Gycm(2) (9.4-10.3 Gycm(2)) and 10.7 Gycm(2) (10.2-11.1 Gycm(2)) for radiographers and radiologists, respectively.

Double contrast barium enema sensitivity: a comparison of studies by radiographers and radiologists

PURPOSE

A retrospective study of histologically proven cases of colorectal cancer (CRC) was performed to assess whether the sensitivity of the radiographer-performed double contrast barium enema (DCBE) differed from that of the radiologist-performed study.

MATERIALS AND METHODS

Histologically proven cases of CRC were reviewed over a 3-year period to ascertain whether: the diagnosis had been made by DCBE in the 3 years before histological diagnosis; the lesion had been correctly diagnosed; the examination had been performed by a radiologist or radiographer.

RESULTS

In the 3-year period there were 478 cases with histologically proven CRC. Of these, 239 (50%) had undergone DCBE as the initial radiological investigation of the colon. Sixty-four examinations had been performed by radiographers. A correct diagnosis was made in 58 cases (90.6%), the report was equivocal in one case (1.6%), there were four false-negatives (6.25%), and one case was abandoned (1.6%). One hundred and seventy-five examinations were performed by radiologists. A correct diagnosis was made in 157 cases (89.7%), the report was equivocal in one case (0.6%), there were 16 false-negatives (9.1%), and one case was abandoned (0.6%).

CONCLUSION

A sensitivity of 90.6% for radiographer-performed studies compared favourably with 89.7% for radiologist-performed studies and supports the practice of radiographers undertaking barium enemas.

Cost-effectiveness of barium enemas performed by radiographers

AIM

To assess the cost-effectiveness of barium enemas performed by radiographers compared to those performed by consultant radiologists.

METHOD

Prospective study of 200 barium enemas carried out by a senior radiographer and a consultant radiologist. The sample was a consecutive sample of adult out-patients over a 3-month period, with no exclusion. The length of time of the enema and the numbers and grades of staff involved in the procedure were recorded. This was translated into staffing costs using the appropriate pay scales.

RESULTS

The barium enemas performed by the superintendent radiographer were more cost-effective than those performed by the consultant radiologist (pound 1406 for 100 radiographer-performed barium enemas compared to pound 1787 for 100 carried out by the consultant radiologist).

CONCLUSION

In terms of staffing costs, radiographers performing barium enemas not only liberates radiologist time, it is also a cost-effective method of providing an out-patient barium enema service.

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.

Diagnostic angiography performed by nurses

The aim of this study was to assess the feasibility of a nurse performing diagnostic angiography. After a theoretical and practical training course on the techniques of arterial catheterization, the nurse performed diagnostic angiography under supervision on 68 patients. Patients with impalpable femoral pulses or scarred groins as well as obese patients were excluded. Successful arterial catheterization was achieved in 58 (85%) patients. Complications were limited to a severe haematoma requiring surgery in one patient and seven minor self-limiting haematomas. On this evidence, it is feasible and safe for appropriately trained nurses to perform angiography in radiology departments that have limited radiology staffing levels and no non-invasive alternations to catheter-based angiography.

Feasibility of instructing radiology technologists in the performance of gastrointestinal fluoroscopy

OBJECTIVE

We sought to determine if dedicated gastrointestinal technologists could be trained to properly perform esophagography and double-contrast barium enema examinations.

SUBJECTS AND METHODS

Ninety-four patients undergoing double-contrast barium enema examinations and 123 patients undergoing esophagographic examinations were included in the study. The study was conducted over a 4-month period, with examinations performed by eight gastrointestinal technologists, 10 radiology residents, and four staff radiologists. Four random lists were generated for each set of examinations. Each staff gastrointestinal radiologist, who was unaware of who had performed the examination, independently scored the representative radiographs.

RESULTS

For the double-contrast barium enema examinations, no statistically significant differences were found between the technologists and residents for amount of barium used, degree of distention, cecal opacification, and quality of spot radiographs. The technologist-performed examinations had a statistically significant lower mean fluoroscopy time (3.2 min, compared with 4.0 min for staff radiologists and 5.7 min for residents). For the esophagrams, no statistically significant differences between technologists and residents were found for single-contrast esophagrams; radiographs of the gastric cardia; assessment of motility, reflux, and transit of a solid bolus; and fluoroscopy time. Double-contrast esophagrams obtained by technologists received a better mean score than did those of the residents.

CONCLUSION

Radiology technologists can be trained to perform high-quality esophagography and double-contrast barium enema examinations without an unacceptably high radiation dose.

1999 RCR Audit Poster PrizewinnersExamination Dose and Screening Time of Radiographer Performed Barium Enemas

Robertson, M. A. (2000). Clinical Radiology55, 896. Copyright 2000 The Royal College of Radiologists.

Hospital radiology: today and tomorrow

Of all the medical specialties, radiology has developed most rapidly throughout this century to a point where it is central to the management of the majority of hospital patients. The papers in this issue's symposium illustrate the role of radiology in four diverse fields, but are just a sample which could be expanded right across the spectrum of medical practice.