Increase in perceived case suspiciousness due to local contrast optimisation in digital screening mammography.

OBJECTIVES: To determine the influence of local contrast optimisation on diagnostic accuracy and perceived suspiciousness of digital screening mammograms. METHODS: Data were collected from a screening region in the Netherlands and consisted of 263 digital screening cases (153 recalled,110 normal). Each case was available twice, once processed with a tissue equalisation (TE) algorithm and once with local contrast optimisation (PV). All cases had digitised previous mammograms. For both algorithms, the probability of malignancy of each finding was scored independently by six screening radiologists. Perceived case suspiciousness was defined as the highest probability of malignancy of all findings of a radiologist within a case. Differences in diagnostic accuracy of the processing algorithms were analysed by comparing the areas under the receiver operating characteristic curves (A(z)). Differences in perceived case suspiciousness were analysed using sign tests. RESULTS: There was no significant difference in A(z) (TE: 0.909, PV 0.917, P = 0.46). For all radiologists, perceived case suspiciousness using PV was higher than using TE more often than vice versa (ratio: 1.14-2.12). This was significant (P <0.0083) for four radiologists. CONCLUSIONS: Optimisation of local contrast by image processing may increase perceived case suspiciousness, while diagnostic accuracy may remain similar. KEY POINTS: Variations among different image processing algorithms for digital screening mammography are large. Current algorithms still aim for optimal local contrast with a low dynamic range. Although optimisation of contrast may increase sensitivity, diagnostic accuracy is probably unchanged. Increased local contrast may render both normal and abnormal structures more conspicuous.

Consequences of digital mammography in population-based breast cancer screening: initial changes and long-term impact on referral rates.

OBJECTIVES: To investigate the referral pattern after the transition to full-field digital mammography (FFDM) in a population-based breast cancer screening programme. METHODS: Preceding the nationwide digitalisation of the Dutch screening programme, an FFDM feasibility study was conducted. Detection and referral rates for FFDM and screen-film mammography (SFM) were compared for first and subsequent screens. Furthermore, radiological characteristics of referrals in digital screening were assessed. RESULTS: A total of 312,414 screening mammograms were performed (43,913 digital and 268,501 conventional), with 4,473 consecutive referrals (966 following FFDM). Initially the FFDM referral rate peaked, and many false-positive results were noted as a consequence of pseudolesions and increased detection of (benign) microcalcifications. A higher overall referral rate was observed in FFDM screening in both first and subsequent examinations (p < .001), with a significant increase in cancer detection (p = .010). CONCLUSION: As a result of initial inexperience with digital screening images implementing FFDM in a population-based breast cancer screening programme may lead to a strong, but temporary increase in referral. Dedicated training in digital screening for radiographers and screening radiologists is therefore recommended. Referral rates decrease and stabilise (learning curve effect) at a higher level than in conventional screening, yet with significantly enhanced cancer detection.

Breast arterial calcifications are correlated with subsequent development of coronary artery calcifications, but their aetiology is predominantly different.

OBJECTIVE: To study whether calcifications in breast arteries, as seen on mammograms, predict future development of coronary artery calcifications. METHODS: We studied 499 women, aged 49-70 years, participating in a breast cancer screening program and investigated whether arterial calcifications in the breast (BAC) are associated with coronary arterial calcifications (CAC) after 9 years follow-up. Mammograms were reviewed for the presence of BAC. CAC was assessed by multi slice computed tomography (MSCT). With logistic regression analysis the independent effect of various risk factors on BAC and CAC was measured. RESULTS: BAC was present in 58 of 499 women (12%) and CAC score>0 was present in 262 of 499 women (53%). BAC was strongly associated with CAC (OR 3.2, 95% CI 1.71-6.04) and this remained significant after adjustment for age at baseline and the duration of follow-up (OR 2.1, 95% CI 1.10-4.23). Most CV risk factors were associated with CAC but not with BAC. Only parity was significantly associated with both increased CAC (OR 2.1, 95% CI 1.21-3.60) and increased BAC (OR 5.3, 95% CI 1.23-22.43). Breastfeeding was associated with BAC (OR 3.4, 95% CI 1.40-8.23) but not with CAC (OR 1.3, 95% CI 0.84-1.93). CONCLUSION: Breast arterial calcifications are predictive of subsequent development of calcifications in the coronary arteries.

Vitamin K intake and calcifications in breast arteries.

OBJECTIVES: Vitamin K is an important co-factor in the production of proteins that inhibit vascular calcification. A low dietary Vitamin K intake has been associated with aortic and coronary calcifications and an elevated cardiovascular risk. Calcifications in the arteries of the breasts have also been associated with cardiovascular risk, but whether there is a relation with a low Vitamin K intake has not yet been studied. METHODS: We conducted a cross-sectional study among 1689 women, aged 49-70 years. Dietary Vitamins K1 and K2 intake was calculated from a validated food frequency questionnaire. Breast arterial calcifications (BAC) were assessed on standard screening mammograms by two independent radiologists. With a general linear model mean Vitamins K1, K2 and Vitamin K2 subtypes were calculated for women with BAC and without, adjusted for age, smoking, diabetes, intake of saturated fat, mono-unsaturated fat, poly-unsaturated fat and protein- and calcium-intake. RESULTS: BAC was less common in the highest (9%) quartile of Vitamin K2 intake, compared to the lowest (13%) (OR 0.7, 95% CI 0.5-1.1) and not different across quartiles of Vitamin K1 intake. Mean Vitamin K2 levels and mean levels of Vitamin K2 subtypes MK-5 through MK-10 were lower in the participants with BAC (p=0.01) compared to participants without BAC. However, after adjustment for aging, smoking, diabetes and dietary factors the association of mean Vitamin K2 intake with BAC was no longer significant. CONCLUSION: Calcifications in breast arteries are not associated with a lower dietary intake of Vitamin K.

Arterial calcifications seen on mammograms: cardiovascular risk factors, pregnancy, and lactation.

PURPOSE: To retrospectively assess if mammographic calcium deposits are related to coronary heart disease (CHD) risk factors and reproductive factors in a subset of women participating in the European Prospective Investigation into Cancer and Nutrition study. MATERIALS AND METHODS: The study was approved by the institutional review board of the University Medical Center Utrecht; informed consent was obtained. Mammograms were evaluated by two radiologists for the presence of breast arterial calcifications (BAC) in the Prospect cohort, a breast cancer screening population of women aged 49-70 years (mean, 57 years) within the European Prospective Investigation into Cancer and Nutrition study. Cardiovascular risk factors and reproductive factors were examined for independent effects on the prevalence of BAC. Logistic regression analysis was performed. RESULTS: BAC was present in 194 of 1699 (11%) women and increased with age to 20% in the highest quartile of age (mean, 66 years). The odds ratio was 4.7 in the highest versus the lowest quartile of age (95% confidence interval [CI], 2.9, 7.6). After adjustment for age, no significant association was found between BAC and traditional cardiovascular risk factors. Current smoking was inversely related to BAC (odds ratio, 0.6; 95% CI: 0.4, 0.9). BAC was prevalent in 2.5% of nulliparous women, in 9% of women with one or two children, and in 17% of women with three or more children (odds ratio, 7.2; 95% CI: 2.9, 18.0). Breast feeding after pregnancy was significantly associated with BAC in women who ever were pregnant (odds ratio, 2.2; 95% CI: 1.4, 3.6). CONCLUSION: Calcifications in arteries on mammograms are associated with increasing age, pregnancy, and lactation but not with various cardiovascular risk factors.