Short communication: plain film reporting by radiographers--a feasibility study

Assessing the barriers and enablers to the implementation of the diagnostic radiographer musculoskeletal X-ray reporting service within the NHS in England: a systematic literature review

INTRODUCTION

The United Kingdom (UK) government's healthcare policy in the early 1990s paved the way adoption of the skills mix development and implementation of diagnostic radiographers' X-ray reporting service. Current clinical practice within the public UK healthcare system reflects the same pressures of increased demand in patient imaging and limited capacity of the reporting workforce (radiographers and radiologists) as in the 1990s. This study aimed to identify, define and assess the longitudinal macro, meso, and micro barriers and enablers to the implementation of the diagnostic radiographer musculoskeletal X-ray reporting service in the National Healthcare System (NHS) in England.

METHODS

Multiple independent databases were searched, including PubMed, Ovid MEDLINE; Embase; CINAHL, and Google Scholar, as well as journal databases (Scopus, Wiley), healthcare databases (NHS Evidence Database; Cochrane Library) and grey literature databases (OpenGrey, GreyNet International, and the British Library EthOS depository) and recorded in a PRISMA flow chart. A combination of keywords, Boolean logic, truncation, parentheses and wildcards with inclusion/exclusion criteria and a time frame of 1995-2022 was applied. The literature was assessed against Joanna Briggs Institute's critical appraisal checklists. With meta-aggregation to synthesize each paper, and coded using NVivo, with context grouped into macro, meso, and micro-level sources and categorised into subgroups of enablers and barriers.

RESULTS

The wide and diverse range of data (n = 241 papers) identified barriers and enablers of implementation, which were categorised into measures of macro, meso, and micro levels, and thematic categories of context, culture, environment, and leadership.

CONCLUSION

The literature since 1995 has reframed the debates on implementation of the radiographer reporting role and has been instrumental in shaping clinical practice. There has been clear influence upon both meso (professional body) and macro-level (governmental/health service) policies and guidance, that have shaped change at micro-level NHS Trust organisations. There is evidence of a shift in culturally intrenched legacy perspectives within and between different meso-level professional bodies around skills mix acceptance and role boundaries. This has helped shape capacity building of the reporting workforce. All of which have contributed to conceptual understandings of the skills mix workforce within modern radiology services.

Agreement in the reporting of General Practitioner requested musculoskeletal radiographs: Reporting radiographers and consultant radiologists compared with an index radiologist

INTRODUCTION

This study assessed the inter-observer agreement of reporting radiographers and consultant radiologists compared with an index radiologist when reporting General Practitioner (GP) requested musculoskeletal radiographs. The potential effect of discordant reports on patient management and outcome was also examined.

METHODS

Three reporting radiographers, three consultant radiologists and an index radiologist reported on a retrospective randomised sample of 219 GP requested musculoskeletal radiographs, in conditions simulating clinical practice. A speciality doctor in radiology compared the observers' reports with the index radiologist report for agreement and assessed whether any discordance between reports was clinically important.

RESULTS

Overall agreement with the index radiologist was 47.0% (95% CI, 40.5-53.6) and 51.6% (95% CI, 45.0-58.1) for the consultant radiologists and reporting radiographers, respectively. The results for the appendicular and axial skeleton were 48.6% (95% CI, 41.3-55.9) and 40.9% (95% CI, 27.7-55.6) for the radiologists, and 52.6% (95% CI, 45.2-59.8) and 47.7% (95% CI, 33.8-62.1) for the radiographers, respectively. The difference in overall observer agreement between the two professional groups with the index radiologist was not statistically significant (p = 0.34). Discordance with the index radiologist's reports was judged to be clinically important in less than 10% of the observer's reports.

CONCLUSION

Reporting radiographers and consultant radiologists demonstrate similar levels of concordance with an index radiologist when reporting GP requested musculoskeletal radiographs.

IMPLICATIONS FOR PRACTICE

These findings contribute to the wider evidence base that selected radiographers with appropriate postgraduate education and training are proficient to report on musculoskeletal radiographs, irrespective of referral source.

Clinical reporting of radiographs by radiographers: Policy and practice guidance for regional imaging networks

OBJECTIVES

Radiographer reporting is an essential component of imaging across the United Kingdom. Since the previous policy and practice guidance in 2004 the role and contribution of reporting radiographers has changed significantly. The move to imaging networks further reinforces the need for consistency in scope of practice and clinical governance for radiographer reporting.

KEY FINDINGS

This guidance provides a consistent, evidence-based template for planning a reporting service, resourcing, clinical governance, preceptorship, volume and frequency of reporting, a peer learning framework and expected standards.

CONCLUSION

Developed for North Central and East London, this framework and standards will help reduce unwarranted variation.

IMPLICATIONS FOR PRACTICE

Consistency in practice could help maximise the contribution of radiographer reporting.

A study to determine the added value of 740 screening panoramic radiographs compared to intraoral radiography in the management of adult (>18 years) dentate patients in a primary care setting

OBJECTIVES

To measure the added value of panoramic radiography in new dentate patients attending for routine treatment.

METHODS

Thirty-seven general dental practitioners using panoramic radiographs routinely were recruited. Twenty dentate patients were identified prospectively by each participating dentist if they were new to the practice, attending for an examination and requesting any treatment deemed necessary. A panoramic radiograph was taken with appropriate intraoral radiographs in line with national guidelines. Each dentist completed a radiological report for the panoramic radiograph only and these 20 reports were forwarded to the researchers along with the 20 panoramic radiographs, their accompanying bitewing and periapical radiographs and twenty completed clinical assessment sheets.

RESULTS

740 panoramic, 1418 bitewing and 325 periapical radiographs were assessed by the researchers. Only 32 panoramic films provided any additional diagnostic value when compared to intraoral films when guidelines had been observed resulting from the poor technical and processing quality of the accompanying intraoral films. Assessment of the number of caries and periapical lesions and the degree of periodontal bone loss from the intraoral films provided a greater diagnostic yield at the p<0.001 level of significance. The research found that dentists underestimated the number of caries lesions present and level of periodontal bone loss when compared to the researchers but overestimated the presence of periapical pathology, at the level of significance at p<0.001.

CONCLUSIONS

The study found that there was no support for the use of panoramic radiographs in routine screening as there was no net diagnostic benefit to the patient.

Evidence of reference standard related bias in studies of plain radiograph reading performance: a meta-regression

The aim is to determine the effect of reference standard related bias on estimates of plain radiograph reading performance using studies conducted in clinical practice. Data were extracted on study eligibility, clinical and reference standard characteristics and reading performance. The choice of reference standards and the prevalence of bias are presented descriptively. Associations between bias and reading performance are estimated using a regression model that produces relative diagnostic odds ratios (RDOR) with 95% confidence intervals (CIs). Three of the 20 eligible studies addressed all five reference standard related biases; 15 studies addressed three or more. When the reference standard report is influenced by knowledge of an observer's opinion this is associated with a significant overestimation in reading performance (RDOR, 3.7; 95% CI, 1.6 to 8.3; p = 0.01). There is limited evidence that reading performance is inflated when the observer is aware of the reference standard report before commenting on the radiograph (RDOR, 1.7; 95% CI, 0.6 to 5.1) and deflated when a less valid reference standard is used (RDOR, 0.5; 95% CI, 0.1 to 2.5). There is no evidence that reading performance is affected by application of the reference standard depending on an observer's opinion and using different reference standards in the same study. In conclusion we found variation in the choice and application of reference standards in studies of plain radiograph reading performance, but only when reference standards report in the knowledge of an observer's opinion does this contribute to a significant overestimation in reading performance.

The use of additionally trained sonographers as ultrasound practitioners: our first-year experience

OBJECTIVE

Two sonographers were trained to help manage an abrupt, permanent increase in the number of ultrasound examinations in our department. Called "ultrasound practitioners," they functioned as physician assistants and triaged 20 to 30 cases per day, allowing the cases to be batch read at a formal reading at day's end. We report our first-year experience with this program.

METHODS

Two sonographers with 10 and 30 years of experience, respectively, were trained to triage and dictate cases. Once trained, they triaged the cases of 20 to 30 patients per day. Reports were predictated with voice recognition technology. A radiologist was always readily available to provide support, and consultation with a radiologist was always obtained for the infrequent verbal reports that were requested. Reports from the practitioner were graded subjectively on a 4-point scale for the first year, according to the modification required at formal readout (A, no change; B, minor change not affecting patient care; C, moderate change not affecting care in a dramatic way; and D, major change markedly affecting care).

RESULTS

Practitioner 1 monitored the examinations of 2858 patients. The graded report results were as follows: A, 96.2%; B, 3.5%; C, 0.3%; and D, 0.00%. Practitioner 2 monitored the examinations of 2825 patients. The graded report results were as follows: A, 96.1%; B, 3.6%; C, 0.2%; and D, 0.00%. There were no category D reports.

CONCLUSIONS

The results far exceeded expectations, with a very low rate of category B and C reports and an absence of category D reports. The practitioners allowed the cases of 20 to 30 patients to be batch read by the existing radiologist staff at the end of the day.

The effect of introducing radiographer reporting on the availability of reports for Accident and Emergency and General Practitioner examinations: a time-series analysis

This study explores whether the introduction of selectively trained radiographers reporting Accident and Emergency (A&E) X-ray examinations of the appendicular skeleton affected the availability of reports for A&E and General Practitioner (GP) examinations at a typical district general hospital. This was achieved by analysing monthly data on A&E and GP examinations for 1993-1997 using structural time-series models. Parameters to capture stochastic seasonal effects and stochastic time trends were included in the models. The main outcome measures were changes in the number, proportion and timeliness of A&E and GP examinations reported. Radiographer reporting X-ray examinations requested by A&E was associated with a 12% (p=0.050) increase in the number of A&E examinations reported and a 37% (p</=0.001) decrease in the time taken to report on these examinations. Radiographer reporting of A&E X-ray examinations was also associated with a 14% (p=0.067) decrease in the time taken for GP examinations to be reported. That is, radiographer reporting A&E X-ray examinations allowed an increase in the time available to radiologists to report on examinations requested by GPs. An increase in the proportion of GP examinations reported by radiologists was associated with longer reporting times for A&E examinations. In conclusion, selectively trained radiographers reporting on A&E X-ray examinations significantly improved the availability of reports for A&E and GP examinations.

The costs and effects of introducing selectively trained radiographers to an A&E reporting service: a retrospective controlled before and after study

The costs and effects of introducing selectively trained radiographers reporting accident and emergency (A&E) radiographs of the appendicular skeleton in a district general hospital were assessed using a retrospective controlled before and after design. Reference standard reports were compared with a random stratified sample of 200 A&E and 200 general practitioner (GP) reports before and after the intervention. GP reports were used as a non-intervention, non-equivalent control group. An A&E specialist registrar judged whether incorrect A&E reports might have a clinically important effect on patient management. The effect of incorrect A&E reports on outcome was assessed by patient re-attendance to the hospital because of missed abnormalities. The annual, average and incremental costs of radiographers and radiologists reporting A&E radiographs were calculated and a sensitivity analysis was undertaken. The introduction of the radiographers resulted in a 1% (95% CI -7.9 to 5.9) fall in A&E radiograph reporting accuracy and 11% (95% CI -33.7 to 11.3) reduction of cases in which incorrect A&E reports might have a clinically important effect on patient management. Only two A&E reports (one before and one after the intervention) affected patient outcome in that a fracture missed at the first visit resulted in patient re-attendance to the X-ray Department. There was a saving of 361 pounds per annum to the X-ray Department. In conclusion this study provides further evidence that selectively trained radiographers can accurately report A&E plain radiographs and at no additional cost.

Radiographers and radiologists reporting plain radiograph requests from accident and emergency and general practice

AIM

To assess selectively trained radiographers and consultant radiologists reporting plain radiographs for the Accident and Emergency Department (A&E) and general practitioners (GPs) within a typical hospital setting.

METHODS

Two radiographers, a group of eight consultant radiologists, and a reference standard radiologist independently reported under controlled conditions a retrospectively selected, random, stratified sample of 400 A&E and 400 GP plain radiographs. An independent consultant radiologist judged whether the radiographer and radiologist reports agreed with the reference standard report. Clinicians then assessed whether radiographer and radiologist incorrect reports affected confidence in their diagnosis and treatment plans, and patient outcome.

RESULTS

For A&E and GP plain radiographs, respectively, there was a 1% (95% confidence interval (CI) -2 to 5) and 4% (95% CI -1 to 8) difference in reporting accuracy between the two professional groups. For both A&E and GP cases there was an 8% difference in the clinicians' confidence in their diagnosis based on radiographer or radiologist incorrect reports. For A&E and GP cases, respectively, there was a 2% and 8% difference in the clinicians' confidence in their management plans based on radiographer or radiologist incorrect reports. For A&E and GP cases, respectively, there was a 1% and 11% difference in effect on patient outcome of radiographer or radiologist incorrect reports.

CONCLUSION

There is the potential to extend the reporting role of selectively trained radiographers to include plain radiographs for all A&E and GP patients. Further research conducted during clinical practice at a number of sites is recommended.

Accuracy of radiographer plain radiograph reporting in clinical practice: a meta-analysis

AIM

To determine the accuracy of radiographer plain radiograph reporting in clinical practice.

MATERIALS AND METHODS

Studies were identified from electronic sources and by hand searching journals, personal communication and checking reference lists. Eligible studies assessed radiographers' plain radiograph reporting in clinical practice compared with a reference standard, and provided accuracy data to construct 2 x 2 contingency tables. Data were extracted on study eligibility and characteristics, quality and accuracy. Summary estimates of sensitivity and specificity and receiver operating characteristic curves were used to pool the accuracy data.

RESULTS

Radiographers compared with a reference standard, report plain radiographs in clinical practice at 92.6% (95% CI: 92.0-93.2) and 97.7% (95% CI: 97.5-97.9) sensitivity and specificity, respectively. Studies that compared selectively trained radiographers and radiologists of varying seniority against a reference standard showed no evidence of a difference between radiographer and radiologist reporting accuracy of accident and emergency plain radiographs. Selectively trained radiographers were also found to report such radiographs as accurately as those not solely from accident and emergency, although some variation in reporting accuracy was found for different body areas. Training radiographers improved their accuracy when reporting normal radiographs.

CONCLUSION

This study systematically synthesizes the literature to provide an evidence-base showing that radiographers can accurately report plain radiographs in clinical practice.

Confidence intervals and sample size calculations for studies of film-reading performance

The relaxation of restrictions on the type of professions that can report films has resulted in radiographers and other healthcare professionals becoming increasingly involved in image interpretation in areas such as mammography, ultrasound and plain-film radiography. Little attention, however, has been given to sample size determinations concerning film-reading performance characteristics such as sensitivity, specificity and accuracy. Illustrated with hypothetical examples, this paper begins by considering standard errors and confidence intervals for performance characteristics and then discusses methods for determining sample size for studies of film-reading performance. Used appropriately, these approaches should result in studies that produce estimates of film-reading performance with adequate precision and enable investigators to optimize the sample size in their studies for the question they seek to answer.

Accident and emergency and general practitioner plain radiograph reporting by radiographers and radiologists: a quasi-randomized controlled trial

Two specially trained radiographers at York District Hospital have been reporting appendicular plain radiograph X-ray examinations for Accident and Emergency (A&E) patients since February 1995. This study explores the potential for further expanding their reporting role. This was achieved by assessing the two radiographers' and a group of consultant radiologists' ability to report on a retrospectively selected random stratified sample of 400 A&E and General Practitioner (GP) plain radiograph X-ray examinations for all body areas. Using receiver operating characteristic (ROC) curve analyses there was no statistically significant difference at the 5% level between the area under the ROC curves for the radiographers and consultant radiologists when reporting A&E or GP plain radiographs. It may be feasible to expand the reporting role of suitably trained radiographers to include plain radiograph X-ray examinations for all A&E patients and for GP patients, with no detriment to the quality of reports.

Review article: methodological standards in radiographer plain film reading performance studies

The objectives of this paper are to raise awareness of the methodological standards that can affect the quality of radiographer plain-film reading performance studies and to determine the frequency with which these standards are fulfilled. Multiple search methods identified 30 such studies from between 1971 and the end of June 1999. The percentage of studies that fulfilled criteria for the 10 methodological standards were as follows. (1) Performance of a sample size calculation, 3%; (2) definition of a normal and abnormal report, 97%; (3) description of the sequence of events through which films passed before reporting, 94%; (4) analysis of individual groups of observers within a combination of groups, 50% (5) appropriate choice of reference standard, 80%; (6) appropriate choice of arbiter, 57%; (7) appropriate use of a control, 22%; (8) analysis of pertinent clinical subgroups, e.g. body areas, patient type, 44%; (9) availability of data for re-calculation, 59%; and (10) presentation of indeterminate results, 69%. These findings indicate variation in the application of the methodological standards to studies of radiographer's film reading performance. Careful consideration of these standards is an essential component of study quality and hence the validity of the evidence base used to underpin radiographic reporting policy.

Measuring the effects of image interpretation: an evaluative framework

The relaxing of restrictions on reporting films has resulted in radiographers and other health care professionals becoming increasingly involved in the interpretation of images in areas such as mammography, ultrasound and plain film radiography. However, errors and variation in the interpretation of images now represents the weakest area of clinical imaging. This has been highlighted by the difficulty of establishing standards to measure the film reading performance of radiographers as part of role extension initiatives. Despite a growing literature of studies that evaluate the film reading performance of different health care professionals, there is a paucity of evidence of the subsquent effects on the referring clinician's diagnosis, management plans and patient outcome. This paper proposes an evaluative framework that can be used to measure the chain of events from the initial technical assessment of observers' potential to interpret images using search behaviour techniques, through to the potential costs and benefits to society. Evaluating the wider implications of alternative or complementary reporting policies is essential for generating the evidence base to comprehensively underpin policy and practice and direct future research. Brealey, S.(2001). Clinical Radiology56, 341-347.

Bias in plain film reading performance studies

Radiographers and other healthcare professionals are becoming increasingly involved in radiological reporting, for instance plain radiographs, mammography and ultrasound. Systematic reviews of research evidence can help to assimilate a knowledge base by ordering and evaluating the available evidence on the reporting accuracy of different professional groups. This article reviews the biases that can undermine the results of plain film reading performance studies. These biases are subdivided into three categories. The first category refers to the selection of subjects, including both films and professionals, and covers the validity of generalizing results beyond the study population. The other two categories are concerned with study design and the interpretation both of films and of reports and the effect on study validity. An understanding of these biases is essential when designing such studies and when interpreting the results of existing studies.

The role of preliminary interpretation of chest radiographs by radiographers in the management of acute medical problems within a cardiothoracic centre

Radiographic staff in a regional cardiothoracic centre were asked to assess all pre- and post-operative chest radiographs over a 6-month period. Radiographs showing new, acute changes were noted and a red dot placed on the film. Medical staff were notified of radiographs with red dots, and these were subsequently reported by radiologists. Using reports by radiologists as the gold standard, an audit was performed of the radiographers' accuracy in identifying new abnormalities. The absence of a necessary red dot as well as inappropriate use were noted. To enhance the accuracy of radiograph interpretation, a series of lectures on the chest radiograph and a protocol for red dot use were developed by senior radiologists. During this 6-month period 8614 chest radiographs were taken; red dots were applied to 464 (5%). These red dots were considered incorrect in 100 radiographs. Radiographers misinterpreted or missed potentially important changes in 38 of the remaining 8150 radiographs without red dots (sensitivity and specificity of 90% and 99%, respectively). Radiographers appeared to err on the side of caution when confronted with an abnormal chest radiograph, especially when previous radiographs and reports were unavailable. This resulted is a relatively high false positive rate. Future audits will show whether this rate can be reduced by continued training. Subtle interpretation is crucial to distinguish between an abnormal chest radiograph needing urgent medical attention and an abnormal chest radiograph with normal post-operative changes. The opinion of the experienced and trained radiographer is immediate and may be invaluable to the diagnostic care of the patient.

[Significance of simple radiography of the abdomen in nephritic colic]

BASIS

The utility of the abdominal plain film in the emergency department to evaluate urolithiasis is questionable. Between another things, there are influence of the different formation of distinct examinators.

METHODS

A retrospective study in 65 patients referrals to urology in 1997 and 1998 by suspicion of renal colic was carried out. The radiography of abdomen took in the emergency room the day of the income is reviewed with a protocol, by a resident of Familiar and Community Medicine and by the urologist, separately and without information of the medical records.

RESULTS

We have excluded three patients. At last, we diagnose 49 patients as renal colic with certainty, 6 patients with doubtful diagnosis and 7 patients with distinct diagnosis. The urologist achieved the most adequate reading in 11 cases; in 7 was best the resident, to equal in 31, and in 13 the differences were not important. The resident obtained of radiography a sensitivity of the 67% and a specificity of the 42% and the urologist 71% and 57% respectively.

CONCLUSIONS

There are few differences of reading, at least when the resident dispose a protocol of interpretation. Despite to the almost null diagnostic utility of the radiography, supply additional ation, and permit to value the evolution with a few aggressive technique.

Interpretation of selected accident and emergency radiographic examinations by radiographers: a review of 11000 cases

Two specially trained radiographers took part in the radiologists' rota for "cold" reporting skeletal radiographs of patients who attended the Accident and Emergency (A&E) Department at times when there was no "hot" reporting service operating, and who were not admitted for treatment or referred to fracture clinics for follow-up. These radiographs had initially been seen by A&E medical staff. At the end of an 18 month period during which the two radiographers reported on 11,322 skeletal examinations, a retrospective search was made to detect interpretive errors. The radiological history of all 11,322 patients was reviewed over a follow-up period of at least 3 months subsequent to the attendance reported by the radiographers. 48% of patients did not re-attend, 42% re-attended for unrelated examinations, and 10% re-attended for repeat examinations of the same anatomical area, or for different procedures (bone scintigraphy or CT) related to the original injury. The second (or subsequent) report was discrepant with that of the first attendance in only 29 cases out of 1103. Of these 29 patients, 13 had occult fractures which were undetectable at first attendance even in retrospect, six had new injuries accounting for the new findings, six had been the subject of false positive calls at an earlier visit, one had a fracture of the hamate missed at first attendance, and in three cases no consensus could be reached as to the cause of the discrepancy, owing to incomplete films or insufficient clinical data. Analysis of the patients' postcodes showed at least 89% were of local origin and only 1% were from outside Yorkshire, suggesting that the review should have identified the great majority of erroneous reports. It is concluded that appropriately trained and supervised radiographers can successfully undertake diagnostic reporting of selected skeletal examinations on A&E patients.

Variation between experienced observers in the interpretation of accident and emergency radiographs

Skill mix and role extension initiatives have highlighted the difficulty of establishing quality standards for the accuracy of plain film reporting. An acceptable performance might be one which is indistinguishable from that of a group of experienced consultant radiologists. In order to assess the feasibility of setting such a standard, the variation between experienced observers must first be established. This study examines the variation found between three observers with the three major types of plain film examination. 402 plain film examinations (205 skeletal, 100 chest and 97 abdominal) performed on accident and emergency patients were reported retrospectively and independently by three experienced radiologists. The clinical data supplied on the request cards were available to the readers. Each examination was categorized by each reader as being normal, as showing significant abnormality relevant to the current clinical problem, or as showing insignificant or irrelevant abnormality. Concordance between all three readers was found in 51%, 61% and 74% of abdominal, chest and skeletal radiographs, respectively. Weighted kappa values confirmed that the level of agreement between pairs of observers was higher with skeletal radiographs (kappa w = 0.76-0.77) than with chest (kappa w = 0.63-0.68), or abdominal (kappa w = 0.50-0.78) examinations. However, the frequency of major disagreements (at least one reader reporting "normal" and one reporting "relevant abnormality") was similar for abdominal (11%), chest (12%) and skeletal (10%) radiographs. When the reports were reclassified into only two groups--either significantly abnormal or not--pairs of observers disagreed on 9-10% of skeletal, 11-19% of chest and 8-18% of abdominal cases. The average incidence of errors per observer was estimated to be in the range 3-6%. The magnitude of interobserver variation in plain film reporting is considerable, and must be taken into account when designing assessment techniques and setting quality standards for this activity.

Radiology's Achilles' heel: error and variation in the interpretation of the Röntgen image

The performance of the human eye and brain has failed to keep pace with the enormous technical progress in the first full century of radiology. Errors and variations in interpretation now represent the weakest aspect of clinical imaging. Those interpretations which differ from the consensus view of a panel of "experts" may be regarded as errors; where experts fail to achieve consensus, differing reports are regarded as "observer variation". Errors arise from poor technique, failures of perception, lack of knowledge and misjudgments. Observer variation is substantial and should be taken into account when different diagnostic methods are compared; in many cases the difference between observers outweighs the difference between techniques. Strategies for reducing error include attention to viewing conditions, training of the observers, availability of previous films and relevant clinical data, dual or multiple reporting, standardization of terminology and report format, and assistance from computers. Digital acquisition and display will probably not affect observer variation but the performance of radiologists, as measured by receiver operating characteristic (ROC) analysis, may be improved by computer-directed search for specific image features. Other current developments show that where image features can be comprehensively described, computer analysis can replace the perception function of the observer, whilst the function of interpretation can in some cases be performed better by artificial neural networks. However, computer-assisted diagnosis is still in its infancy and complete replacement of the human observer is as yet a remote possibility.