Physicians' opinions on the delivery of mammographic screening services: immediate interpretation versus double reading

Blinded comparison of computer-aided detection with human second reading in screening mammography

OBJECTIVE

The purpose of this study was to compare a human second reader with computer-aided detection (CAD) for the reduction of false-negative cases by a primary radiologist. We retrospectively reviewed our clinical practice.

MATERIALS AND METHODS

We found that 6,381 consecutive screening mammograms were interpreted by a primary reader. This radiologist then reinterpreted the studies using CAD ("CAD reader"). A second human reader who was blinded to the CAD results but knowledgeable of the primary reader's findings reviewed the studies, looking for abnormalities not seen by the first reader.

RESULTS

Two cancers were called back by the second human reader that were not called back by the CAD reader; however, the CAD system had marked the findings, but they were dismissed by the primary reader. Because of the small numbers, the difference between the CAD and second human reader was not statistically significant. The CAD and human second readers increased the recall rates 6.4% and 7.2% (p = 0.70), respectively, and the biopsy rates 10% and 14.7%. The positive predictive value was 0% (0/3) for the CAD reader and was 40% (2/5) for the human second reader. The relative increases in the cancer detection rate compared with the primary reader's detection rate were 0% for the CAD reader and 15.4% (2/13) for the human second reader (p = 0.50).

CONCLUSION

A human second reader or the use of a CAD system can increase the cancer detection rate, but we found no statistical difference between the two because of the small sample size. A possible benefit from a human second reader is that CAD systems can only point to possible abnormalities, whereas a human must determine the significance of the finding. Having two humans review a study may increase detection rates due to interpreter--hence, perceptual--variability and not just increased detection.

Comparison of recall and cancer detection rates for immediate versus batch interpretation of screening mammograms

PURPOSE

To retrospectively compare recall and cancer detection rates between immediate and subsequent batch methods for interpretation of screening mammograms.

MATERIALS AND METHODS

Institutional review board approval was obtained, and informed consent was waived. Retrospective analysis was performed for 8698 screening mammograms obtained between January 1 and October 31, 2001, which were interpreted either immediately (n = 4113) or subsequently with batch method (n = 4585). Data were collected from data reporting system and patient billing records. Patients with high risk factors were excluded; 3441 patients were in the immediate group, and 3932 were in the batch group. The two groups were compared with respect to age, breast density, and availability of comparison films with Wilcoxon rank sum test. Recall rates and cancer detection rates for each group were determined and compared with Pearson chi(2) test; false-negative rates were compared with Fischer exact test.

RESULTS

A significant difference (P < .001) was noted in recall rates between immediate (18%) and batch (14%) groups; however, no significant difference (P = .7) was noted in cancer detection rates (immediate, 0.5%; batch, 0.4%). Mean age of patients was 56.8 years (age range, 21-96 years) in the immediate group and 56.2 years (age range 24-98 years) in the batch group (P = .02). Comparison of breast densities between groups indicates no statistically significant difference (P = .4). The batch group had significantly fewer comparison mammograms (3106 [79%]) available than the immediate group (2856 [83%]) (P < .001). There was no significant difference in false-negative rates between the immediate group (0.1%) and the batch group (0.1%) (P > .99).

CONCLUSION

Immediate interpretation of screening mammograms resulted in a statistically significant increase in recalls and additional clinical work-ups of perceived abnormalities; however, no significant difference in cancer detection rate was detected between groups.

Computer-aided detection (CAD) in mammography: Does it help the junior or the senior radiologist?

OBJECTIVES

To evaluate the impact of a computer-aided detection (CAD) system on the ability of a junior and senior radiologist to detect breast cancers on mammograms, and to determine the potential of CAD as a teaching tool in mammography.

METHODS

Hundred biopsy-proven cancers and 100 normal mammograms were randomly analyzed by a CAD system. The sensitivity (Se) and specificity (Sp) of the CAD system were calculated. In the second phase, to simulate daily practice, 110 mammograms (97 normal or with benign lesions, and 13 cancers) were examined independently by a junior and a senior radiologist, with and without CAD. Interpretations were standardized according to BI-RADS classification. Sensitivity, Specificity, positive and negative predictive values (PPV, NPV) were calculated for each session.

RESULTS

For the senior radiologist, Se slightly improved from 76.9 to 84.6% after CAD analysis (NS) (one case of clustered microcalcifications case overlooked by the senior radiologist was detected by CAD). Sp, PPV and PNV did not change significantly. For the junior radiologist, Se improved from 61.9 to 84.6% (significant change). Three cancers overlooked by the junior radiologist were detected by CAD. Sp was unchanged.

CONCLUSION

CAD mammography proved more useful for the junior than for the senior radiologist, improving sensitivity. The CAD system may represent a useful educational tool for mammography.

Practice Management Performance Indicators in Academic Radiology Departments

PURPOSE

To determine the management performance indicators most frequently utilized in academic radiology departments in the United States.

MATERIALS AND METHODS

This investigation met the criteria for an exemption from institutional review board approval. A cross-sectional study in which a validated national survey was sent to members of the Society of Chairmen of Academic Radiology Departments (SCARD) was conducted. The survey was designed to examine the following six categories of 28 performance indicators: (a) general organization, (b) volume and productivity, (c) radiology reporting, (d) access to examinations, (e) customer satisfaction, and (f) finance. A total of 158 variables were included in the analysis. Summary statistics, the chi(2) test, rank correlation, multiple regression analysis, and analysis of variance were used.

RESULTS

A response rate of 42% (55 of 132 SCARD members) was achieved. The mean number of performance indicators used by radiology departments was 16 +/- 6.35 (standard deviation). The most frequently utilized performance indicators were as follows: (a) productivity, in terms of examination volume (78% [43 departments]) and examination volume per modality (78% [43 departments]); (b) reporting, in terms of report turnaround (82% [45 departments]) and transcription time (71% [39 departments]); (c) access, in terms of appointment access to magnetic resonance imaging (80% [44 departments]); (d) satisfaction, in terms of number of patient complaints (84% [46 departments]); and (e) finance, in terms of expenses (67% [37 departments]). Regression analysis revealed that the numbers of performance indicators in each category were statistically significant in predicting the total number of performance indicators used (P < .001 for all). Numbers of productivity and financial indicators were moderately correlated (r = 0.51). However, there were no statistically significant correlations between the numbers of performance indicators used and hospital location, hospital size, or department size (P > .4 for all).

CONCLUSION

Assessing departmental performance with a wide range of management indicators is not yet an established and standardized practice in academic radiology departments in the United States. Among all indicators, productivity indicators are the most frequently used.

Effectiveness and cost-effectiveness of double reading of mammograms in breast cancer screening: findings of a systematic review

There is a lack of direct evidence on the effectiveness of double reading of breast screening mammograms within the context of national screening programmes even though about half of the countries that use mammography screening have implemented double reading. A systematic review was conducted to compare double reading with single reading of mammograms for screening accuracy, patient outcomes and costs. We searched an extensive range of electronic databases, bibliographies of studies were scanned and experts were contacted. Data extraction and quality assessment was undertaken independently by two reviewers. Estimates of the diagnostic accuracy were calculated for those studies with follow-up to identify interval cancers. Only 10 cohort studies met the inclusion criteria with reported extractable data on the effectiveness of double compared to single reading. The mix of methodologies meant that few conclusions could be drawn about the effect of double reading independent of number of views, or effects on size and type of tumours detected. Overall, double reading increases the cancer detection rate by 3-11 per 10,000 women screened and has a double impact on recall rates depending on the recall policy used. The benefit could be mainly in the detection of small cancers, and could be greatest where two readers have different strengths and weaknesses, or where readers are less experienced. Double reading can improve accuracy as compared with single reading. In particular, double reading by consensus or arbitration achieves an increase in cancer detection rate together with a reduction in the rate of women recalled for assessment. Further research should quantify the relative benefit from double reading according to recall policy and number of mammographic views, and estimate the impact on patient outcome.

Patient expectations and costs of immediate reporting of screening mammography: talk isn't cheap

OBJECTIVE

Our purpose was to determine whether patients prefer immediate or delayed results of screening mammography and to determine the cost of immediate reporting at our institution.

MATERIALS AND METHODS

A survey was anonymously and randomly distributed to 129 women who were 35-70 years old during a visit to their primary care physician, asking the women's preference for receiving mammography results by one of two systems: by letter with a return visit for any additional tests; or by speaking at once with the radiologist, with the option of additional tests being performed during the same visit. Patients' willingness to pay for the latter service was also determined. A cost identification model was constructed using commercially available software. We considered the impact on radiologists' and technologists' time and the need for additional equipment and space, and we analyzed the effect on the cost of immediate reporting.

RESULTS

One hundred twenty (93%) surveys were completed. Eighty women (67%) preferred immediate reporting, and 62 (78%) of these 80 patients would wait 30-60 min. The additional cost of immediate reporting is $28.22 per patient. Only 11% of patients were willing to pay this additional cost. When new equipment and space were not required, the cost would increase by $4.38. This cost was most influenced by the time required to give patients normal results.

CONCLUSION

Most surveyed patients preferred speaking with a radiologist immediately but were unwilling to pay additional fees. Radiologists, hospital administrators, and health care planners must be aware of the costs of immediate reporting and must factor these costs into any change in hospital or national policy.

Focal arterial injuries of the proximal extremities: helical CT arteriography as the initial method of diagnosis

PURPOSE

To present our experience with helical computed tomographic (CT) arteriography as the initial diagnostic examination in patients suspected to have focal arterial injuries of the proximal extremities.

MATERIALS AND METHODS

During 19 months, 142 arterial segments in the proximal portions of the extremities of 139 patients with trauma were evaluated with helical CT arteriography. CT arteriograms were interpreted on site by the radiologist in charge of emergency procedures and retrospectively with consensus interpretation between two radiologists. CT study quality and the presence of arterial injuries were noted. CT arteriographic findings were compared with those of surgery, conventional arteriography, and/or clinical follow-up.

RESULTS

Five (3.6%) patients had nondiagnostic studies and underwent conventional arteriography. In the remaining 137 arterial segments in 134 patients, helical CT arteriography demonstrated arterial injuries in 61 segments and normal arteries in 76 segments. These segments were treated initially with surgery (55 segments) or endovascular intervention (four segments) or were observed (78 segments); 77 of the 78 observed segments remained stable at 3-18 months (mean follow-up, 5.2 months). There were no differences between the on-site and consensus interpretations (kappa = 1.0). The sensitivity of CT arteriography was 95.1%, and the specificity was 98.7%.

CONCLUSION

Helical CT arteriography can be performed as the initial diagnostic method in most patients suspected to have focal arterial injuries of the proximal portions of the extremities.

Helical CT in emergency radiology

Today, a wide range of traumatic and nontraumatic emergency conditions are quickly and accurately diagnosed with helical computed tomography (CT). Many traditional emergency imaging procedures have been replaced with newer helical CT techniques that can be performed in less time and with greater accuracy, less patient discomfort, and decreased cost. The speed of helical technology permits CT examination of seriously ill patients in the emergency department, as well as patients who might not have been taken to CT previously because of the length of the examinations of the past. Also, helical technology permits multiple, sequential CT scans to be quickly obtained in the same patient, a great advance for the multiple-trauma patient. Higher quality CT examinations result from decreased respiratory misregistration, enhanced intravenous contrast material opacification of vascular structures and parenchymal organs, greater flexibility in image reconstruction, and improved multiplanar and three-dimensional reformations. This report summarizes the role and recommended protocols for the helical CT diagnosis of thoracic aortic trauma; aortic dissection; pulmonary embolism; acute conditions of the neck soft tissues; abdominal trauma; urinary tract stones; appendicitis; diverticulitis; abdominal aortic aneurysm; fractures of the face, spine, and extremities; and acute stroke.

Medical radiologic technologist review: effects on a population-based breast cancer screening program

PURPOSE

To evaluate the effects of medical radiologic technologist review of mammograms in a population-based breast cancer screening program.

MATERIALS AND METHODS

A technologist review pilot project was incorporated into the Regina, Saskatchewan, Canada, reading center. Technologists received special training in mammographic interpretation. They reviewed all 27,863 mammograms obtained at the center from July 1995 to September 1996 that were reviewed by a radiologist and selected cases for second blind reading by another radiologist. When the two radiologists' readings were in agreement, the report was sent. When the readings differed, a third opinion was obtained from the program's consulting radiologist. Changes in the number of mammograms interpreted as abnormal and the number of cancers detected were assessed.

RESULTS

The technologist review was responsible for the detection of nine cancers missed at the first radiologist's interpretation. Technologists were very discriminating; only 391 cases (1.4%) were sent for double reading. The positive predictive value of screening did not change significantly (7.5% without review, 8.1% with review; P > .20).

CONCLUSION

A substantial number of cancers were found with the technologist review. The number of mammograms interpreted as abnormal was reduced slightly. The technologist review proved to be a cost-effective alternative to double reading by two radiologists.

Patient satisfaction with screening mammography: online vs off-line interpretation

RATIONALE AND OBJECTIVES

The purpose of this study was to determine patient satisfaction with online and off-line methods of interpreting screening mammograms and to determine those characteristics that most influence patient preferences.

MATERIALS AND METHODS

A survey consisting of 17 questions assessing satisfaction and demographics was distributed to women whose screening mammograms were read in one of two ways at the same facility: (a) the "online" method, in which all additional requested studies are completed and results are immediately communicated, and (b) the "off-line" method, in which mammograms are read in batches the next day, results are communicated at a later time, and patients return for diagnostic studies. To ensure statistical power, at least 174 surveys were collected from each group.

RESULTS

Of 192 women whose mammograms were interpreted online, 188 (97%) responded, and of 247 women whose mammograms were interpreted off-line, 181 (73%) responded. Overall mean satisfaction with the mammographic experience and with the time it took to receive results differed significantly between the two groups (P < .002). Analysis of the subgroup of very satisfied respondents disclosed that 92% of patients in the online group and 59% of patients in the off-line group were very satisfied with their mammography experience. If allowed to choose the method of interpretation, 97% of patients in the online group and 91% of patients in the off-line group would choose online interpretation.

CONCLUSION

Patients preferred online mammographic interpretation of screening studies.