Screening mammography beyond breast cancer: breast arterial calcifications as a sex-specific biomarker of cardiovascular risk

Artificial Intelligence-based Software for Breast Arterial Calcification Detection on Mammograms

OBJECTIVE

The performance of a commercially available artificial intelligence (AI)-based software that detects breast arterial calcifications (BACs) on mammograms is presented.

METHODS

This retrospective study was exempt from IRB approval and adhered to the HIPAA regulations. Breast arterial calcification detection using AI was assessed in 253 patients who underwent 314 digital mammography (DM) examinations and 143 patients who underwent 277 digital breast tomosynthesis (DBT) examinations between October 2004 and September 2022. Artificial intelligence performance for binary BAC detection was compared with ground truth (GT) determined by the majority consensus of breast imaging radiologists. Area under the receiver operating curve (AUC), sensitivity, specificity, positive predictive value and negative predictive value (NPV), accuracy, and BAC prevalence rates of the AI algorithm were compared.

RESULTS

The case-level AUCs of AI were 0.96 (0.93-0.98) for DM and 0.95 (0.92-0.98) for DBT. Sensitivity, specificity, and accuracy were 87% (79%-93%), 92% (88%-96%), and 91% (87%-94%) for DM and 88% (80%-94%), 90% (84%-94%), and 89% (85%-92%) for DBT. Positive predictive value and NPV were 82% (72%-89%) and 95% (92%-97%) for DM and 84% (76%-90%) and 92% (88%-96%) for DBT, respectively. Results are 95% confidence intervals. Breast arterial calcification prevalence was similar for both AI and GT assessments.

CONCLUSION

Breast AI software for detection of BAC presence on mammograms showed promising performance for both DM and DBT examinations. Artificial intelligence has potential to aid radiologists in detection and reporting of BAC on mammograms, which is a known cardiovascular risk marker specific to women.

Breast Arterial Calcifications on Mammography: Awareness and Reporting Preferences Amongst Referring Physicians in Canada

Purpose: Breast arterial calcifications (BAC) on mammography have been correlated with increased cardiovascular risk. The Canadian Society of Breast Imaging released a position statement on BAC reporting in January 2023. This study evaluates the awareness of the clinical significance of BAC and reporting preferences of referring physicians in Canada. Methods: A 15-question survey was distributed to Canadian physicians who may review mammography results via regional and subspecialty associations and on social media following local institutional ethical approval. Responses were collected over 10 weeks from February to April 2023. Results: Seventy-two complete responses were obtained. We are unable to determine the response rate, given the means of distribution. Only 17% (12/72) of responding physicians were previously aware of the association between BAC and increased cardiovascular risk, and 51% (37/72) preferred the inclusion of BAC in the mammography report. Fifty-six percent (40/72) indicated that BAC reporting would prompt further investigation, and 63% (45/72) would inform patients that their mammogram showed evidence of BAC. Sixty-nine percent (50/72) would find grading of BAC beneficial and 71% (51/72) agreed that there is a need for national guidelines. Conclusion: Less than a quarter of responding Canadian referring physicians were previously aware of the association between BAC and cardiovascular risk, although half of respondents indicated a preference for BAC reporting on mammography. Most participating physicians would inform their patients of the presence of BAC and consider further cardiovascular risk management. There was consensus that a national BAC grading system and clinical management guidelines would be beneficial.

The impact of breast cancer radiation therapy exposure on the prevalence of breast arterial calcification

OBJECTIVES

Mammographic breast arterial calcification (BAC) is an emerging imaging biomarker of cardiovascular disease (CVD) risk in women. The purpose of this study was to assess if breast radiation therapy (RT) exposure impacts the screening utility of this imaging biomarker.

METHODS

This cross-sectional study included women ages 40-75 years who underwent index screening mammography between January 1, 2011 and December 31, 2012. Chart review was performed to extract data on the breast cancer RT exposure and CVD risk factors. Mammograms were reviewed for the presence of BAC. Multivariate logistic regression was used to examine breast RT exposure and BAC, with adjustment for age, body mass index, smoking status, hypertension, Type 2 diabetes, statin medication use, and antihypertensive medication use.

RESULTS

Of the 1155 women included in this analysis, 222 (19.2%) had mammographic evidence of BAC, 122 (10.6%) had a history of RT exposure, and 39 (32%) women with RT exposure had mammographic BAC. Women with breast RT exposure had higher odds of BAC compared to women without (odds ratio: 2.18, 95% CI: 1.43, 3.28; P-value = .0008). However, this association became non-significant after multivariable adjustment, with the maximally adjusted model demonstrating an odds ratio of 1.52 (95% CI: 0.95, 2.40; P-value = .07).

CONCLUSIONS

Our findings suggest that breast RT exposure does not impact the prevalence of mammographic BAC. Therefore, it does not affect its utility as an imaging biomarker of CVD risk.

ADVANCES IN KNOWLEDGE

This is the first observational study addressing the knowledge gap pertaining to the influence of breast RT exposure on BAC.

Incidental Breast Arterial Calcifications and Assessment of Coronary Artery Disease Risk: A Review and Recommendation

Coronary artery disease (CAD) continues to be the leading cause of morbidity and mortality in women, contributing to about 20%, or nearly 400,000, of female deaths annually in the United States. Despite their significant burden from CAD, women have been traditionally underrepresented in trials, and therefore, there is still much to be studied regarding the sex-based variations that have been reported regarding the pathophysiology, clinical presentation, efficacy of diagnostic workup, and response to therapy in CAD. Previous studies have reported that breast arterial calcifications, commonly found incidentally on screening mammography, may be associated with risk of CAD; however, there are currently no specific guidelines concerning reporting and quantification practices, as well as further workup recommendations for patients who are found to have vascular calcifications. Thus, the question remains whether breast arterial calcifications can serve as a sex-specific marker for CAD, and whether there is enough evidence to support the use of mammography as a screening tool for CAD in women. In this review, we will summarize the current understanding of cardiovascular disease in women, the existing literature regarding breast arterial calcifications and current reporting practices, and the association of vascular calcifications with CAD risk; based on the collected evidence, we will make a recommendation whether screening mammography and breast arterial calcifications should be used to assess CAD risk, and if so, what additional workup, if any, we recommend in women found to have breast arterial calcifications on imaging.

Deep transfer learning for detection of breast arterial calcifications on mammograms: a comparative study

INTRODUCTION

Breast arterial calcifications (BAC) are common incidental findings on routine mammograms, which have been suggested as a sex-specific biomarker of cardiovascular disease (CVD) risk. Previous work showed the efficacy of a pretrained convolutional network (CNN), VCG16, for automatic BAC detection. In this study, we further tested the method by a comparative analysis with other ten CNNs.

MATERIAL AND METHODS

Four-view standard mammography exams from 1,493 women were included in this retrospective study and labeled as BAC or non-BAC by experts. The comparative study was conducted using eleven pretrained convolutional networks (CNNs) with varying depths from five architectures including Xception, VGG, ResNetV2, MobileNet, and DenseNet, fine-tuned for the binary BAC classification task. Performance evaluation involved area under the receiver operating characteristics curve (AUC-ROC) analysis, F1-score (harmonic mean of precision and recall), and generalized gradient-weighted class activation mapping (Grad-CAM++) for visual explanations.

RESULTS

The dataset exhibited a BAC prevalence of 194/1,493 women (13.0%) and 581/5,972 images (9.7%). Among the retrained models, VGG, MobileNet, and DenseNet demonstrated the most promising results, achieving AUC-ROCs > 0.70 in both training and independent testing subsets. In terms of testing F1-score, VGG16 ranked first, higher than MobileNet (0.51) and VGG19 (0.46). Qualitative analysis showed that the Grad-CAM++ heatmaps generated by VGG16 consistently outperformed those produced by others, offering a finer-grained and discriminative localization of calcified regions within images.

CONCLUSION

Deep transfer learning showed promise in automated BAC detection on mammograms, where relatively shallow networks demonstrated superior performances requiring shorter training times and reduced resources.

RELEVANCE STATEMENT

Deep transfer learning is a promising approach to enhance reporting BAC on mammograms and facilitate developing efficient tools for cardiovascular risk stratification in women, leveraging large-scale mammographic screening programs.

KEY POINTS

• We tested different pretrained convolutional networks (CNNs) for BAC detection on mammograms. • VGG and MobileNet demonstrated promising performances, outperforming their deeper, more complex counterparts. • Visual explanations using Grad-CAM++ highlighted VGG16's superior performance in localizing BAC.

Detection and quantification of breast arterial calcifications on mammograms: a deep learning approach

OBJECTIVE

Breast arterial calcifications (BAC) are a sex-specific cardiovascular disease biomarker that might improve cardiovascular risk stratification in women. We implemented a deep convolutional neural network for automatic BAC detection and quantification.

METHODS

In this retrospective study, four readers labelled four-view mammograms as BAC positive (BAC+) or BAC negative (BAC-) at image level. Starting from a pretrained VGG16 model, we trained a convolutional neural network to discriminate BAC+ and BAC- mammograms. Accuracy, F1 score, and area under the receiver operating characteristic curve (AUC-ROC) were used to assess the diagnostic performance. Predictions of calcified areas were generated using the generalized gradient-weighted class activation mapping (Grad-CAM++) method, and their correlation with manual measurement of BAC length in a subset of cases was assessed using Spearman ρ.

RESULTS

A total 1493 women (198 BAC+) with a median age of 59 years (interquartile range 52-68) were included and partitioned in a training set of 410 cases (1640 views, 398 BAC+), validation set of 222 cases (888 views, 89 BAC+), and test set of 229 cases (916 views, 94 BAC+). The accuracy, F1 score, and AUC-ROC were 0.94, 0.86, and 0.98 in the training set; 0.96, 0.74, and 0.96 in the validation set; and 0.97, 0.80, and 0.95 in the test set, respectively. In 112 analyzed views, the Grad-CAM++ predictions displayed a strong correlation with BAC measured length (ρ = 0.88, p < 0.001).

CONCLUSION

Our model showed promising performances in BAC detection and in quantification of BAC burden, showing a strong correlation with manual measurements.

CLINICAL RELEVANCE STATEMENT

Integrating our model to clinical practice could improve BAC reporting without increasing clinical workload, facilitating large-scale studies on the impact of BAC as a biomarker of cardiovascular risk, raising awareness on women's cardiovascular health, and leveraging mammographic screening.

KEY POINTS

• We implemented a deep convolutional neural network (CNN) for BAC detection and quantification. • Our CNN had an area under the receiving operator curve of 0.95 for BAC detection in the test set composed of 916 views, 94 of which were BAC+ . • Furthermore, our CNN showed a strong correlation with manual BAC measurements (ρ = 0.88) in a set of 112 views.

Associations of Breast Arterial Calcifications with Cardiovascular Disease

Cardiovascular diseases (CVD), including coronary artery disease (CAD), continue to be the leading cause of global mortality among women. While traditional CVD/CAD prevention tools play a significant role in reducing morbidity and mortality among both men and women, current tools for preventing CVD/CAD rely on traditional risk factor-based algorithms that often underestimate CVD/CAD risk in women compared with men. In recent years, some studies have suggested that breast arterial calcifications (BAC), which are benign calcifications seen in mammograms, may be linked to CVD/CAD. Considering that millions of women older than 40 years undergo annual screening mammography for breast cancer as a regular activity, innovative risk prediction factors for CVD/CAD involving mammographic data could offer a gender-specific and convenient solution. Such factors that may be independent of, or complementary to, current risk models without extra cost or radiation exposure are worthy of detailed investigation. This review aims to discuss relevant studies examining the association between BAC and CVD/CAD and highlights some of the issues related to previous studies' design such as sample size, population types, method of assessing BAC and CVD/CAD, definition of cardiovascular events, and other confounding factors. The work may also offer insights for future CVD risk prediction research directions using routine mammograms and radiomic features other than BAC such as breast density and macrocalcifications.

Mammography biomarkers of cardiovascular and musculoskeletal health: A review

Breast density (BD) and breast arterial calcifications (BAC) can expand the role of mammography. In premenopause, BD is related to body fat composition: breast adipose tissue and total volume are potential indicators of fat storage in visceral depots, associated with higher risk of cardiovascular disease (CVD). Women with fatty breast have an increased likelihood of hypercholesterolemia. Women without cardiometabolic diseases with higher BD have a lower risk of diabetes mellitus, hypertension, chest pain, and peripheral vascular disease, while those with lower BD are at increased risk of cardiometabolic diseases. BAC, the expression of Monckeberg sclerosis, are associated with CVD risk. Their prevalence, 13 % overall, rises after menopause and is reduced in women aged over 65 receiving hormonal replacement therapy. Due to their distinct pathogenesis, BAC are associated with hypertension but not with other cardiovascular risk factors. Women with BAC have an increased risk of acute myocardial infarction, ischemic stroke, and CVD death; furthermore, moderate to severe BAC load is associated with coronary artery disease. The clinical use of BAC assessment is limited by their time-consuming manual/visual quantification, an issue possibly solved by artificial intelligence-based approaches addressing BAC complex topology as well as their large spectrum of extent and x-ray attenuations. A link between BD, BAC, and osteoporosis has been reported, but data are still inconclusive. Systematic, standardised reporting of BD and BAC should be encouraged.

Relationship between Arterial Calcifications on Mammograms and Cardiovascular Events: A Twenty-Three Year Follow-Up Retrospective Cohort Study

PURPOSE

Breast arterial calcifications (BAC) have been associated with cardiovascular diseases. We aimed to examine whether the presence of BAC could predict the development of cardiovascular events in the very long term, as evidence has suggested.

PATIENTS AND METHODS

We conducted a 23-year follow-up retrospective cohort study considering women specifically studied for breast cancer. After reviewing the mammograms of 1759 women, we selected 128 patients with BAC and an equal number of women without BAC.

RESULTS

Women with BAC had higher relative risk (RR) for cardiovascular events, globally 1.66 (95% CI): 1.31-2.10 vs. 0.53 (0.39-0.72), and individually for ischemic heart disease 3.25 (1.53-6.90) vs. 0.85 (0.77-0.94), hypertensive heart disease 2.85 (1.59-5.09) vs. 0.79 (0.69-0.89), valvular heart disease 2.19 (1.28-3.75) vs. 0.83 (0.73-0.94), congestive heart failure 2.06 (1.19-3.56) vs. 0.85 (0.75-0.96), peripheral vascular disease 2.8 (1.42-5.52) vs. 0.85 (0.76-0.94), atrial fibrillation 1.83 (1.09-3.08) vs. 0.86 (0.76-0.98), and lacunar infarction 2.23 (1.21-4.09) vs. 0.86 (0.77-0.96). Cox's multivariate analysis, also considering classical risk factors, indicated that this BAC was significantly and independently associated with survival (both cardiovascular event-free and specific survival; 1.94 (1.38-2.73) and 6.6 (2.4-18.4)).

CONCLUSIONS

Our data confirm the strong association of BAC on mammograms and the development cardiovascular events, but also evidence the association of BAC with cardiovascular event-free and specific survival.

Cardiovascular Disease Screening in Women: Leveraging Artificial Intelligence and Digital Tools

Cardiovascular disease remains the leading cause of death in women. Given accumulating evidence on sex- and gender-based differences in cardiovascular disease development and outcomes, the need for more effective approaches to screening for risk factors and phenotypes in women is ever urgent. Public health surveillance and health care delivery systems now continuously generate massive amounts of data that could be leveraged to enable both screening of cardiovascular risk and implementation of tailored preventive interventions across a woman's life span. However, health care providers, clinical guidelines committees, and health policy experts are not yet sufficiently equipped to optimize the collection of data on women, use or interpret these data, or develop approaches to targeting interventions. Therefore, we provide a broad overview of the key opportunities for cardiovascular screening in women while highlighting the potential applications of artificial intelligence along with digital technologies and tools.

Breast arterial calcifications on mammography: a new marker of cardiovascular risk in asymptomatic middle age women?

OBJECTIVES

To determine whether breast arterial calcification (BAC) detected on mammography can predict the presence of coronary artery calcification (CAC) on CT in women.

METHODS

Women explored with both mammography and thoracic CT from 2009 to 2018 were retrospectively included. Women were separated in 3 categories (no BAC, few BAC, and marked BAC) using a specific 12-point scale. Similar scale was used to evaluate the amount of CAC on CT. The mean sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of BAC for the detection of CAC were calculated. Statistical significance was assessed with Pearson's chi-squared test and Fisher's exact test as appropriate.

RESULTS

A total of 507 women (mean age: 62 years ± 16) were included. Patients with high amount of BAC were older (72 ± 11 vs. 59 ± 15 years old; p < .0001), were more frequently hypertensive (66% vs. 31%; p < .0001), and had more frequently renal failure (21% vs. 6%; p < .0003) than patients without BAC. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy of BAC for the detection of women with marked CAC were 53.1%, 87.6%, 55.0%, 86.7%, and 79.9%, respectively. The highest diagnostic accuracy was obtained in patients under 60 years: 84.2% for detection of CAC and 93.2% for detection of women with marked CAC.

CONCLUSION

The presence of BAC on mammography was linked to the presence of CAC and may be used as a cardiovascular marker in patient less than 60 years.

KEY POINTS

• The diagnostic accuracy of breast arterial calcification (BAC) to detect the presence of coronary artery calcification (CAC) was 70.4% and reached to 79.9% to detect women with high amount of CAC. • Highest diagnostic accuracy of BAC to detect CAC (93.2%) was noticed in women under 60 years. • The presence of BAC on mammography may be used as a cardiovascular risk marker in women, especially under 60 years.

Reporting and Perceptions of Breast Arterial Calcification on Mammography: A Survey of ACR Radiologists

RATIONALE AND OBJECTIVES

The ACR Breast Commission conducted a member survey to evaluate current practices of reporting breast arterial calcification (BAC) on mammography and to determine perceptions about the value of BAC communication and follow-up recommendations among radiologists.

MATERIALS AND METHODS

In September 2020, an 18-item online survey was emailed to radiologist members of the American College of Radiology (ACR). Questions included radiologist demographics, current BAC reporting practices, follow-up recommendations, and perceptions about BAC. Five-point Likert scales were used and multivariate analysis was performed.

RESULTS

Of 598 completed survey responses, up to 87% (522/598) of ACR radiologist members include BAC in mammogram reports. However, only 41% (212/522) of respondents report BAC 'always' or 'most of the time'. Radiologist factors significantly associated with BAC reporting include years in practice and fellowship training with those in practice longer more likely to report BAC (OR 1.10, 95% CI, [1.01-1.20], p = 0.023) and those with fellowship training less likely to report BAC (OR 0.63, 95% CI, [0.42-0.94], p = 0.024). When BAC is reported, 69% (360/522) simply indicate the presence of BAC, 23% (121/522) provide a subjective grading of BAC burden, and 1% (6/522) calculate a BAC score. Among the radiologists reporting BAC, 58% (301/522) make no subsequent recommendations, while the remainder recommend primary care follow-up (39%; 204/522), cardiology evaluation (13%; 68/522), and/or coronary calcium scoring CT (11%; 59/522). Overall, there was agreement from 66% (392/598) of respondents that BAC is a cardiovascular risk factor. However, there was no consensus on whether patients and/or providers should be informed about BAC or whether reporting of BAC should become a standardized practice in breast imaging. Older and more experienced radiologists are more likely to agree that BAC is a cardiovascular risk factor (p = 0.022), providers should be informed about BAC (p = 0.002 and 0.006), BAC reporting should be a standardized practice (p = 0.004 and 0.001), and feel more comfortable informing patients about BAC (p = 0.001 and 0.003).

CONCLUSION

Radiologists' reporting practices and perceptions regarding BAC are not homogeneous. Although many radiologists report BAC to varying degrees, it is not routinely reported or recommended for follow-up in mammogram reports. Experienced radiologists are more likely to include and value BAC in their breast imaging practice.

Breast Arterial Calcifications: Reporting Preferences and Impact on Screening for Coronary Artery Disease

OBJECTIVE

Breast arterial calcifications (BAC) have been shown to correlate with measures of coronary artery disease risk stratification, although reporting of BAC is optional by BI-RADS guidelines. The purpose of this study is to determine referring provider preferences in BAC reporting on mammography reports and if such reporting has any impact on patient management.

METHODS

This study was approved by the local institutional review board. A voluntary eight-question survey regarding the preferences and outcomes of BAC reporting on mammography was distributed to 1085 primary care physicians, obstetrics and gynecologists, medical oncologists, and breast and general surgeons in our health system via a secure online platform. Data analysis including Pearson chi-square was performed with a P-value of <0.05 for significance.

RESULTS

A response rate of 19.1% (207/1085) was attained, with 21/207 (10.1%) of respondents indicating they do not routinely order mammograms excluded from further analysis. A total of 62.4% (116/186) of ordering physicians indicated a preference for reporting of BAC in both the body and impression of the radiology report, with 82.3% (153/186) of respondents placing importance on the quantity of atherosclerotic calcifications. Most participants (148/186, 79.6%) reported that the presence of BAC would prompt further investigation for coronary artery disease and associated risk factors.

CONCLUSION

The majority of responding physicians indicated a preference for detailed reporting of BAC and that such reporting would impact patient care. Understanding referring provider preferences regarding ancillary findings of BAC will allow for improved communication and value in mammography.

Assessment of the Severity of Breast Artery Calcification on a Mammogram: Intraoperator and Interoperator Reproducibility

Purpose. To study approaches to the quantitative assessment of breast arterial calcification (BAC) – a new surrogate marker of high cardiovascular risk in women, to determine the most detailed way to quantify BAC and to assess the reproducibility of these parameters.

Material and methods. Mammograms of 1,078 women were analyzed for the presence of BAC. The intraoperator reproducibility of the assessment of the severity of BAC using a 12-point scale (Margolies L et al., 2016) was studied by analyzing 20 mammograms by the same operator twice with an interval of at least 2 weeks. Inter-operator reproducibility was studied by analyzing 99 mammograms by two independent operators.

Results. When assessing the intraoperative reproducibility of the total score for each mammary gland, the exact coincidence of the results was noted in 70% (95% confidence interval [CI] 53.5-83.4), in cases of difference of no more than 1 point – in 27.5% (95%CI 14.6-43.9), only in 1 case the difference in assessments was 2 points. No systematic error was found between the two measurements (p=1.0), the correlation coefficient was rs=0.973. The assessment of inter-operator reproducibility showed that the exact coincidence of indicators was present in 48.5% (95%CI 41.3-55.7), in 91.4% (95% CI 86.6-94.9) cases, the total score for each the mammary gland differed by no more than 1 point. There was no systematic error between the measurements of the two experts (p=0.438), the correlation coefficient was rs=0.942.

Conclusion. A good intraoperator and interoperator reproducibility of indicators of the severity of BAC on a 12-point scale has been shown, which makes it possible to recommend it for use in science and practice.

Assessing the Stress Echocardiography in Women With Breast Arterial Calcification

Objective: breast arterial calcification (BAC) is one of the most prevalent mammographic findings and has been debated as a marker of cardiovascular disease (CVDs). The present study aimed to assess the findings of stress echo in women with BAC. Materials and methods: This cross-sectional study was conducted on women who undergo mammography for routine breast cancer screening at Imam Reza hospital, western Iran from March 2018 to July 2018. The patients underwent stress echocardiography to evaluate the probability of myocardial ischemia (MI). Chi-square and independent t-tests were used to assess the differences between subgroups. Results: BAC was present in 61 (15.2%) women. The mean age of the patients with BAC was significantly higher than the patients without BAC (58.59± 7.82 vs. 55.32±6.57, p =0.003). Prevalence rates of the menopause (88.5% vs. 71.1%, p=0.009), hypertension (29.5% vs. 17.7%, p=0.032), and hypercholesterolemia (24.6% vs. 13.0, p=0.018) were significantly higher in the patients with BAC compared to the patients without BAC. The prevalence rate of MI symptoms in the patients with BAC was equal to 24.6%. Significantly, more women with BAC were positive for myocardial ischemia compared to the women without BAC (24.6% vs. 8.5%, p<0.001). The prevalence rates of the diabetes mellitus, hypertension, hypercholesterolemia, and history of CVDs were significantly higher in the patients who were positive for MI. Conclusion: It was found that BACs are correlated with an increased occurrence rate of CVDs. Our results illustrated that the patients who were positive for MI were more plausible to be diabetic, hyperlipidemic, hypertensive, and having a history of CVDs.

Semiquantitative score of breast arterial calcifications on mammography (BAC-SS): intra- and inter-reader reproducibility

Background

Breast arterial calcifications (BAC), representing Mönckeberg's sclerosis of the tunica media of breast arteries, are an imaging biomarker for cardiovascular risk stratification in the female population. Our aim was to estimate the intra- and inter-reader reproducibility of a semiquantitative score for BAC assessment (BAC-SS).

Methods

Consecutive women who underwent screening mammography at our center from January 1^st to January 31^st, 2018 were retrieved and included according to BAC presence. Two readers (R1 and R2) independently applied the BAC-SS to medio-lateral oblique views, obtaining a BAC score by summing: (I) number of calcified vessels (from 0 to n); (II) vessel opacification, i.e., the degree of artery coverage by calcium bright pixels (0 or 1); and (III) length class of calcified vessels (from 0 to 4). R1 repeated the assessment 2 weeks later. Scoring time was recorded. Cohen's κ statistics and Bland-Altman analysis were used.

Results

Among 408 women, 57 (14%) had BAC; 114 medio-lateral oblique views were assessed. Median BAC score was 4 [interquartile range (IQR): 3-6] for R1 and 4 (IQR: 2-6) for R2 (P=0.417) while median scoring time was 156 s (IQR: 99-314 s) for R1 and 191 s (IQR: 137-292 s) for R2 (P=0.743). Bland-Altman analysis showed a 77% intra-reader reproducibility [bias: 0.193, coefficient of repeatability (CoR): 0.955] and a 64% inter-reader reproducibility (bias: 0.211, CoR: 1.516). Cohen's κ for BAC presence was 0.968 for intra-reader agreement and 0.937 for inter-reader agreement.

Conclusions

Our BAC-SS has a good intra- and inter-reader reproducibility, within acceptable scoring times. A large-scale study is warranted to test its ability to stratify cardiovascular risk in women.

Predictors of mammographic microcalcifications

We examined the association between established risk factors for breast cancer and microcalcification clusters and their asymmetry. A cohort study of 53 273 Swedish women aged 30 to 80 years, with comprehensive information on breast cancer risk factors and mammograms, was conducted. Total number of microcalcification clusters and the average mammographic density area were measured using a Computer Aided Detection system and the STRATUS method, respectively. A polygenic risk score for breast cancer, including 313 single nucleotide polymorphisms, was calculated for those women genotyped (N = 7387). Odds ratios (ORs) and 95% confidence intervals (CIs), with adjustment for potential confounders, were estimated. Age was strongly associated with microcalcification clusters. Both high mammographic density (>40 cm2 ), and high polygenic risk score (80-100 percentile) were associated with microcalcification clusters, OR = 2.08 (95% CI = 1.93-2.25) and OR = 1.22 (95% CI = 1.06-1.48), respectively. Among reproductive risk factors, life-time breastfeeding duration >1 year was associated with microcalcification clusters OR = 1.22 (95% CI = 1.03-1.46). The association was confined to postmenopausal women. Among lifestyle risk factors, women with a body mass index ≥30 kg/m2 had the lowest risk of microcalcification clusters OR = 0.79 (95% CI = 0.73-0.85) and the association was stronger among premenopausal women. Our results suggest that age, mammographic density, genetic predictors of breast cancer, having more than two children, longer duration of breast-feeding are significantly associated with increased risk of microcalcification clusters. However, most lifestyle risk factors for breast cancer seem to protect against presence of microcalcification clusters. More research is needed to study biological mechanisms behind microcalcifications formation.

Breast arterial calcifications as a biomarker of cardiovascular risk: radiologists' awareness, reporting, and action. A survey among the EUSOBI members

Objectives

To investigate the knowledge of radiologists on breast arterial calcifications (BAC) and attitude about BAC reporting, communication to women, and subsequent action.

Methods

An online survey was offered to EUSOBI members, with 17 questions focused on demographics, level of experience, clinical setting, awareness of BAC association with cardiovascular risk, mammographic reporting, modality of BAC assessment, and action habits. Descriptive statistics were used.

Results

Among 1084 EUSOBI members, 378 (34.9%) responded to the survey, 361/378 (95.5%) radiologists, 263 females (69.6%), 112 males (29.6%), and 3 (0.8%) who did not specify their gender. Of 378 respondents, 305 (80.7%) declared to be aware of BAC meaning in terms of cardiovascular risk and 234 (61.9%) to routinely include BAC in mammogram reports, when detected. Excluding one inconsistent answer, simple annotation of BAC presence was declared by 151/233 (64.8%), distinction between low versus extensive BAC burden by 59/233 (25.3%), and usage of an ordinal scale by 22/233 (9.5%) and of a cardinal scale by 1/233 (0.4%). Among these 233 radiologists reporting BAC, 106 (45.5%) declared to orally inform the woman and, in case of severe BAC burden, 103 (44.2%) to investigate cardiovascular history, and 92 (39.5%) to refer the woman to a cardiologist.

Conclusion

Among EUSOBI respondents, over 80% declared to be aware of BAC cardiovascular meaning and over 60% to include BAC in the report. Qualitative BAC assessment predominates. About 40% of respondents who report on BAC, in the case of severe BAC burden, investigate cardiovascular history and/or refer the woman to a cardiologist.

Key Points

• Of 1084 EUSOBI members, 378 (35%) participated: 81% of respondents are aware of breast arterial calcification (BAC) cardiovascular meaning and 62% include BAC in the mammogram report.

• Of those reporting BAC, description of presence was declared by 65%, low versus extensive burden distinction by 25%, usage of an ordinal scale by 10%, and of a cardinal scale by 0.4%; 46% inform the woman and, in case of severe BAC burden, 44% examine cardiovascular history, and 40% refer her to a cardiologist.

• European breast radiologists may be ready for large-scale studies to ascertain the role of BAC assessment in the comprehensive framework of female cardiovascular disease prevention.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07136-6) contains supplementary material, which is available to authorized users.