Improving Performance of Mammographic Breast Positioning in an Academic Radiology Practice

Using automated software evaluation to improve the performance of breast radiographers in tomosynthesis screening

OBJECTIVE

To improve breast radiographers' individual performance by using automated software to assess the correctness of breast positioning and compression in tomosynthesis screening.

MATERIALS AND METHODS

In this retrospective longitudinal analysis of prospective cohorts, six breast radiographers with varying experience in the field were asked to use automated software to improve their performance in breast compression and positioning. The software tool automatically analyzes craniocaudal (CC) and mediolateral oblique (MLO) views for their positioning quality by scoring them according to PGMI classifications (perfect, good, moderate, inadequate) and checking whether the compression pressure is within the target range. The positioning and compression data from the studies acquired before the start of the project were used as individual baselines, while the data obtained after the training were used to test whether conscious use of the software could help the radiographers improve their performance. The percentage of views rated perfect or good and the percentage of views in target compression were used as overall metrics to assess changes in performance.

RESULTS

Following the use of the software, all radiographers significantly increased the percentage of images rated as perfect or good in both CCs and MLOs. Individual improvements ranged from 7 to 14% for CC and 10 to 16% for MLO views. Moreover, most radiographers exhibited improved compression performance in CCs, with improvements up to 16%.

CONCLUSION

Active use of a software tool to automatically assess the correctness of breast compression and positioning in breast cancer screening can improve the performance of radiographers.

CLINICAL RELEVANCE STATEMENT

This study suggests that the use of a software tool for automatically evaluating correctness of breast compression and positioning in breast cancer screening can improve the performance of radiographers on these metrics, which may ultimately lead to improved screening outcomes.

KEY POINTS

• Proper breast positioning and compression are critical in breast cancer screening to ensure accurate diagnosis. • Active use of the software increased the quality of craniocaudal and mediolateral oblique views acquired by all radiographers. • Improved performance of radiographers is expected to improve screening outcomes.

The ACR Mammography Positioning Improvement Collaborative: A Multicenter Improvement Program Within a Learning Network Framework

PURPOSE/OBJECTIVE

To share the experience and results of the first cohort of the ACR Mammography Positioning Improvement Collaborative, in which participating sites aimed to increase the mean percentage of screening mammograms meeting the established positioning criteria to 85% or greater and show at least modest evidence of improvement at each site by the end of the improvement program.

METHODS

The sites comprising the first cohort of the collaborative were selected on the basis of strength of local leadership support, intra-organizational relationships, access to data and analytic support, and experience with quality improvement initiatives. During the improvement program, participating sites organized their teams, developed goals, gathered data, evaluated their current state, identified key drivers and root causes of their problems, and developed and tested interventions. A standardized image quality scoring system was also established. The impact of the interventions implemented at each site was assessed by tracking the percentage of screening mammograms meeting overall passing criteria over time.

RESULTS

Six organizations were selected to participate as the first cohort, beginning with participation in the improvement program. Interventions developed and implemented at each site during the program resulted in improvement in the average percentage of screening mammograms meeting overall passing criteria per week from a collaborative mean of 51% to 86%, with four of six sites meeting or exceeding the target mean performance of 85% by the end of the improvement program. Afterward, all respondents to the postprogram survey indicated that the program was a positive experience.

CONCLUSION

Using a structured improvement program within a learning network framework, the first cohort of the collaborative demonstrated that improvement in mammography positioning performance can be achieved at multiple sites simultaneously and validated the hypothesis that local sites' shared experiences, insights, and learnings would not only improve performance but would also build a community of improvers collaborating to create the best experience for technologists, staff, and patients.

Development of a Subtraction Processing Technology for Assistance in the Comparative Interpretation of Mammograms

A comparative interpretation of mammograms has become increasingly important, and it is crucial to develop subtraction processing and registration methods for mammograms. However, nonrigid image registration has seldom been applied to subjects constructed with soft tissue only, such as mammograms. We examined whether subtraction processing for the comparative interpretation of mammograms can be performed using nonrigid image registration. As a preliminary study, we evaluated the results of subtraction processing by applying nonrigid image registration to normal mammograms, assuming a comparative interpretation between the left and right breasts. Mediolateral-oblique-view mammograms were taken from noncancer patients and divided into 1000 cases for training, 100 cases for validation, and 500 cases for testing. Nonrigid image registration was applied to align the horizontally flipped left-breast mammogram with the right one. We compared the sum of absolute differences (SAD) of the difference of bilateral images (Difference Image) with and without the application of nonrigid image registration. Statistically, the average SAD was significantly lower with the application of nonrigid image registration than without it (without: 0.0692; with: 0.0549 (p < 0.001)). In four subgroups using the breast area, breast density, compressed breast thickness, and Difference Image without nonrigid image registration, the average SAD of the Difference Image was also significantly lower with nonrigid image registration than without it (p < 0.001). Nonrigid image registration was found to be sufficiently useful in aligning bilateral mammograms, and it is expected to be an important tool in the development of a support system for the comparative interpretation of mammograms.

Sustaining Mammography Image Quality With a Technologist Coaching Program in the Era of the Enhancing Quality Using the Inspection Program (EQUIP)

OBJECTIVE

To evaluate the ability of a long-term technologist coaching program to sustain gains in mammography quality made by a previously implemented quality improvement (QI) initiative.

METHODS

Mammography quality metrics from July 2014 to June 2020 were reviewed. Numbers of screening mammograms performed/audited, monthly average mammogram overall quality pass rates, changes in facilities/staffing, and technical recall rates were evaluated. Performance metrics at baseline (July 2013), during the improvement (July 2014 to January 2015), postimprovement (February 2015 to August 2015), and sustained coaching periods (after initiation of the technologist coaching model, from September 2015 to June 2020) were compared.

RESULTS

During the postimprovement and sustained coaching periods, 93% (501/541) and 90% (8902/9929) of audited mammograms, respectively, met overall passing criteria, achieving or exceeding the QI goal of 90%, and results for both periods were significantly higher than that during the improvement period (74%, 1098/1489), at P < 0.0001 and P < 0.0001, respectively. The technical recall rates during the improvement and postimprovement periods were 2.6% (85/3321) and 1.7% (54/3236), respectively; the rate during the sustained coaching period was significantly lower than these, at 1.2% (489/40 440) (P < 0.0001 and P = 0.0232, respectively). Sustained quality passing rates and lower technical recall rates were observed despite statistically significantly increases in screening volumes.

CONCLUSION

A technologist coaching program resulted in sustained high mammographic quality for almost 5 years.

Impact of Artificial Intelligence-driven Quality Improvement Software on Mammography Technical Repeat and Recall Rates

Poor positioning decreases mammography sensitivity and is arguably the single most important contributor to image quality (IQ). Inadequate IQ may subject patients to technical repeat views during the examination or return for technical recalls. Artificial intelligence (AI) software can objectively evaluate breast positioning and compression metrics for all images and technologists. This study assessed whether implementation of AI software across the authors' institution improved IQ and reduced rates of technical repeats and recalls (TR). From April 2019 to March 2022, TR was retrospectively evaluated for 40 technologists (198 054 images; Centricity electronic medical record system, GE HealthCare), and AI IQ metrics were available for 42 technologists (211 821 images; Analytics, Volpara Health Technologies). Diagnostic and digital breast tomosynthesis images and implant cases were excluded. Kolmogorov-Smirnov, χ2, and paired t tests were used to evaluate whether AI IQ metrics and TR rates improved between the initial and most recent 12-month periods following AI software implementation (ie, baseline [April 2019 to March 2020] vs current [April 2021 to March 2022]). Comparing baseline with current periods, TR significantly reduced from 0.77% (788 of 102 953 images) to 0.17% (160 of 95 101 images), respectively (P < .001), and overall mean quality score improved by 6% ([2.42 - 2.28]/2.28; P = .001), demonstrating the potential of AI software to improve IQ and reduce patient TR. Keywords: Mammography, Breast, Oncology, QA/QC, Screening, Technology Assessment © RSNA, 2023.

Development and validation of a novel measure of adverse patient positioning in mammography

PURPOSE

The primary aim was to develop and validate a novel mammography positioning measure, specifically incorporating parameters which might relate to mammography pain. We then explored relationships between the new adverse positioning score and (1) pain; (2) patient and technique factors.

METHODS

A 15-item instrument incorporating positioning features with potential to relate to mammography pain was developed. Participants' mammograms (n = 310) were reviewed for presence of these features. Validity was investigated using the Rasch model. Scores produced by the resultant measure were investigated for associations with patients' pain scores and relevant patient and technique factors, using Pearson correlation, analysis of variance, and multiple linear regression.

RESULTS

Statistical indices within the Rasch measurement framework provided good evidence that the measure reflected a coherent construct of adverse positioning. Thus, the scores produced with the measurement instrument were valid for use in further statistical analysis. There is, however, scope for improvement of the measure's discriminatory properties. Adverse positioning scores were higher for greater breast volumes (r = 0.12, p=.0391) and body mass index (BMI) (r = 0.13, p=.0349), and varied by mammographer (F(11,298) 2.38, p = .0078). The relationships with BMI and mammographer persisted in regression modelling. No relationship was found between adverse positioning and pain.

CONCLUSIONS

Evidence from Rasch analysis suggests that this novel measure is valid for quantifying a coherent "adverse positioning" construct in mammography. Adverse positioning scores varied by mammographer and were related to higher patient BMI but not to mammography pain. The measure warrants expansion, further refinement, and testing in larger studies.

Evaluation of the quality of mammographic breast positioning: a quality improvement study

BACKGROUND

Although there are concerns that inadequate breast positioning in mammographic examinations may lead to cancers being missed, few studies have examined the quality of breast positioning, especially in the Canadian context. Our objective was to assess the quality of breast positioning in mammographic examinations in a Quebec-wide representative sample of technologists.

METHODS

This quality improvement study was part of a professional inspection launched by the Ordre des technologues en imagerie médicale, en radio-oncologie et en électrophysiologie médicale du Québec among its members. The inspection was conducted between May and July 2017 on a proportionate stratified random sample of all active technologists certified in mammography in Quebec. Each technologist provided images from 15 consecutive mammographic examinations they performed in the previous 6 months. The quality of positioning was then evaluated by senior technologists using a quality assessment tool specifically developed for this inspection. A technologist was deemed to have failed the professional inspection when at least 7 of the 15 mammographic examinations were scored as critical failures. Proportions were calculated accounting for sampling weights and correction for finite population.

RESULTS

Among the 520 technologists certified in mammography in Quebec, 76 technologists (14.6%) were randomly selected for the professional inspection and contributed images from 1127 mammographic examinations. Thirty-eight technologists (weighted percentage 50.3%, 95% confidence interval [CI] 37.6% to 63.0%) failed the professional inspection. Overall, 492 mammographic examinations (43.7%, 95% CI 38.6% to 48.8%) had at least 1 image scored as a critical failure.

INTERPRETATION

Half of the technologists performing mammographic examinations in Quebec who participated in this study failed the inspection, and a substantial proportion of their mammographic examinations demonstrated critical failures in breast positioning. Overall, our findings are concordant with those of previous studies and highlight the need for additional investigations assessing the quality of breast positioning in mammographic examinations in other jurisdictions.

Variability in Mammography Quality Assessment After Implementation of Enhancing Quality Using the Inspection Program (EQUIP)

OBJECTIVE

Analyze mammography quality and deficiencies, including variability in quality assessment among subspecialized breast radiologists, after implementing the Enhancing Quality Using the Inspection Program (EQUIP).

METHODS

After IRB approval, this single institution study retrospectively queried data prospectively entered into our automated reporting software after implementing EQUIP (October 2017-March 2019). Screening and diagnostic combination (digital mammography with tomosynthesis) mammograms were reviewed by seven breast radiologists. Quality was assessed as excellent, good, adequate, or problems found. Of those with problems found, the deficiency and corrective action were evaluated. The interpreting radiologist, EQUIP radiologist, and performing technologist were recorded. P values were calculated using Fisher exact test and chi-square analyses.

RESULTS

Of 17 312 mammograms, 529 (3%) underwent EQUIP review. Of 43 (8%) with problems found, 23 (53%) did not include sufficient tissue, 9 (21%) had motion degradation, 3 (7%) had artifacts, 2 each (4.7% each) had the nipple not in profile or skin folds, and 4 (9%) were categorized as "other." Nine (9/529, 1.7%) required recall for repeat imaging. The lead interpreting physician (LIP) was more likely to categorize mammograms as technically inadequate compared to other radiologists (P < 0.00001), and there were also statistically significant differences in how the remaining radiologists stratified cases (P < 0.00001) even when excluding the LIP.

CONCLUSION

Insufficient tissue was the most common problem identified in the EQUIP-reviewed mammograms with deficiencies. Significant variability was present among radiologist EQUIP designations. Ongoing review of clinical image quality with EQUIP allows for opportunities to provide corrective feedback.

Assessment of breast positioning criteria in mammographic screening: Agreement between artificial intelligence software and radiographers

OBJECTIVES

To determine the agreement between artificial intelligence software (AI) and radiographers in assessing breast positioning criteria for mammograms from standard digital mammography and digital breast tomosynthesis.

METHODS

Assessment of breast positioning was performed by AI and by four radiographers in pairs of two on 156 examinations of women screened in Bergen, April to September 2019, as part of BreastScreen Norway. Ten criteria were used; three for craniocaudal and seven for mediolateral-oblique view. The criteria evaluated the appearance of the nipple, breast rotation, pectoral muscle, inframammary fold and pectoral nipple line. Intraclass correlation and Cohen's kappa coefficient (κ) were used to investigate the correlation and agreement between the radiographer's assessments and AI.

RESULTS

The intraclass correlation for the pectoral nipple line between the radiographers and AI was >0.92. A substantial to almost perfect agreement (κ > 0.69) was observed between the radiographers and AI on the nipple in profile criterion. We observed a slight to moderate agreement for the other criteria (κ = 0.06-0.52) and generally a higher agreement between the two pairs of radiographers (mean κ = 0.70) than between the radiographers and AI (mean κ = 0.41).

CONCLUSIONS

AI has great potential in evaluating breast position criteria in mammography by reducing subjectivity. However, varying agreement between radiographers and AI was observed. Standardized and evidence-based criteria for definitions, understandings and assessment methods are needed to reach optimal image quality in mammography.

Effect of the EQUIP initiative on additional images performed at screening mammography: a pilot study

PURPOSE

The Enhancing Quality Using the Inspection Program (EQUIP) initiative was launched to improve clinical image quality. The purpose of this study was to determine if the implementation of the EQUIP reporting system resulted in an increased number of extra views performed at the technologists' discretion during screening mammography.

MATERIALS AND METHODS

Following IRB approval at a single comprehensive cancer center, patients who underwent screening mammography with combination full-field digital mammography plus digital breast tomosynthesis during a 6-month period before (January 2017 to June 2017) and after (January 2018 to June 2018) EQUIP implementation were identified. For each patient, both screening mammograms were retrospectively reviewed by 1 of 3 subspecialized breast radiologists (3-10 years of experience). The following data were recorded: demographics, breast density, surgical history, technologist, number and type of extra views, final BI-RADS assessment, radiologist-assigned indication for the view, and radiologist-assigned necessity of the view. McNemar's test for paired data was computed with p value of <0.05 considered statistically significant.

RESULTS

Of 820 patients, 370 (45%) had additional views in 2018 compared to 317 (39%) in 2017. After EQUIP, patients were 38% more likely to have additional views (OR = 1.38, 95% CI = 1.11-1.73). The total number of additional views in 2018 was 636 compared to 530 in 2017 (20% increase). Among patients with extra views in both years, the number of additional views per patient did not significantly increase post EQUIP implementation (OR = 1.18, 95% CI = 0.73-1.92). The most common extra view was exaggerated craniocaudal lateral, and the most common reason cited by the reviewing radiologist was lateral fibroglandular tissue at the edge of the images. Most of the extra views performed in 2018 were not performed in 2017 and over half were deemed unnecessary. Eight of eleven technologists demonstrated an increased frequency of screening mammograms with extra views performed post EQUIP.

CONCLUSION

Following EQUIP implementation, screening mammography patients were significantly more likely to have extra views performed at the technologists' discretion. Our findings emphasize the importance of ongoing technologist education and radiologist feedback.