Digital breast tomosynthesis: lessons learned from early clinical implementation

Digital Breast Tomosynthesis With Synthetic Mammography: Are We Missing Calcifications That Matter?

OBJECTIVE

To determine whether there are differences in the biopsy outcomes for suspicious calcifications detected with screening mammography using the digital breast tomosynthesis and synthetic 2D (DBT/SM) technique compared to calcifications detected using the full-field digital (DM) technique.

METHODS

This retrospective study was IRB approved. The records for all stereotactic biopsies performed for suspicious calcifications detected on screening mammograms using DM in 2011-2014 and DBT/SM in 2017-2020 were reviewed. We collected patient, imaging, and pathology data from the breast imaging database and from retrospective review of a subset of mammograms. The biopsy outcome results were categorized as benign, benign with upgrade potential (BWUP), and malignant based on final pathology. Frequencies and proportions of outcomes were calculated and compared using Mann-Whitney U tests and Wilcoxson signed-rank tests with P-values and 95% confidence intervals (95% CIs).

RESULTS

From 2011 to 2014 (DM), 1274 stereotactic biopsies of calcifications yielded 74.2% (945/1274) benign, 11.5% (147/1274) BWUP, and 14.3% (182/1274) malignant outcomes. From 2017 to 2020 (DBT/SM), 1049 stereotactic biopsies yielded 65.2% (684/1049) benign, 15.6% (164/1049) BWUP, and 19.2% (201/1049) malignant outcomes. With DBT/SM, benign biopsy outcomes decreased (9.0%, 95% CI 0.87-11.53, P < 0.05), whereas malignant biopsy outcomes increased (4.9%, 95% CI 0.94-8.36, P < 0.05). There was no significant difference in BWUP biopsy outcomes and total biopsy rates between techniques (P > 0.05).

CONCLUSION

Calcifications detected with screening DBT/SM technique were significantly more likely to be malignant than those found using DM. These results support using the DBT/SM technique without obtaining concurrent DM images.

Synthetic Mammography: Benefits, Drawbacks, and Pitfalls

Digital breast tomosynthesis (DBT) allows three-dimensional assessment of breast tissue; however, DBT requires a two-dimensional (2D) image for comparison with prior mammograms and accurate interpretation of calcifications. Traditionally, full-field digital mammography (FFDM) has been performed after the DBT image acquisition. Synthetic mammography (SM), the 2D reconstruction of the tomosynthesis slice dataset, has been designed to replace FFDM. Advantages of SM include decreased image acquisition time and decreased radiation exposure, with maintained or improved screening performance metrics. Because SM algorithms give extra weight to lesion-like characteristics (eg, calcifications and architectural distortions), they may enable increased visibility of these characteristics relative to that at FFDM. Although SM algorithms were designed to improve lesion identification, they have led to varied outcomes in studies reported in the literature. Compared with FFDM, SM has been reported to be associated with a higher false-positive rate for calcifications, decreased conspicuity of asymmetries, lower breast density assessments, and imaging artifacts (eg, metallic artifact, bright-band artifact, blurring of the axilla, and truncation artifact). The authors review the literature on SM, including its implementation, benefits, and artifacts. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Comparison of prone and upright, stereotactic, and tomosynthesis-guided biopsies with secondary analysis of ultrasound-occult architectural distortions

OBJECTIVES

Compare prone and upright, stereotactic, and tomosynthesis-guided vacuum-assisted breast biopsies (prone DM-VABB, prone DBT-VABB, upright DM-VABB, and upright DBT-VABB) in a community-practice setting and review outcomes of ultrasound-occult architectural distortions (AD).

METHODS

Consecutive biopsies performed at two community-based breast centers from 2016 to 2019 were retrospectively reviewed. Technical details of each procedure and patient outcomes were recorded. Separate analyses were performed for ultrasound-occult ADs. Two sample t-tests and Fisher's exact test facilitated comparisons.

RESULTS

A total of 1133 patients underwent 369 prone DM-VABB, 324 prone DBT-VABB, 437 upright DM-VABB, and 123 upright DBT-VABB with 99.2%, 100%, 99.3%, and 99.2% success, respectively (p-values > 0.25). Mean lesion targeting times were greater for prone biopsy (minutes: 6.94 prone DM-VABB, 8.54 prone DBT-VABB, 5.52 upright DM-VABB, and 5.51 upright DBT-VABB; p-values < 0.001), yielding longer total prone procedure times for prone biopsy (p < 0.001). Compared to DM-VABB, DBT-VABB used fewer exposures (p < 0.001) and more commonly targeted AD, asymmetries, or masses (p < 0.001). Malignancy rates were similar between procedures: prone DM-VABB 22.4%, prone DBT-VABB 21.9%, upright DM-VABB 22.8%, and upright DBT-VABB 17.2% (p-values > 0.19). One hundred forty of the 1133 patients underwent 145 biopsies for ultrasound-occult AD (143 DBT-VABB and 2 DM-VABB). Biopsy yielded 27 malignancies and 47 high-risk lesions (74 of 145, 51%). Malignancy rate was 20.7% after surgical upgrade of one benign-discordant and two high-risk lesions.

CONCLUSIONS

All biopsy procedure types were extremely successful. The 20.7% malignancy rate for ultrasound-occult AD confirms a management recommendation for tissue diagnosis. Upright biopsy was faster than prone biopsy, and DBT-VABB used fewer exposures than DM-VABB.

CLINICAL RELEVANCE

Our results highlight important differences between prone DM-VABB, prone DBT-VABB, upright DM-VABB, and upright DBT-VABB. Moreover, the high likelihood of malignancy for ultrasound-occult AD will provide confidence in recommending tissue diagnosis in lieu of observation or clinical follow-up.

KEY POINTS

• Upright and prone stereotactic and tomosynthesis-guided breast biopsies were safe and effective in the community-practice setting. • The malignancy rate for ultrasound-occult architectural distortion of 20.7% confirms the management recommendation for biopsy. • Upright procedures were faster than prone procedures, and tomosynthesis-guided biopsy used fewer exposures than stereotactic biopsy.

Clinical performance of digital breast tomosynthesis-guided vacuum-assisted biopsy: a single-institution experience in Japan

BACKGROUND

The purpose of this study was to evaluate the clinical performance of Digital Breast Tomosynthesis guided vacuum-assisted biopsy (DBT-VAB) for microcalcifications in the breast.

METHODS

Retrospective review of 131 mammography-guided VABs at our institution were performed. All of the targets were calcification lesion suspicious for cancer. 45 consecutive stereotactic vacuum-assisted biopsies (ST-VABs) and 86 consecutive DBT-VABs were compared. Written informed consent was obtained. Tissue sampling methods and materials were the same with both systems. Student's t-test was used to compare procedure time and the Fisher's exact test was used to compare success rate, complications, and histopathologic findings for the 2 methods.

RESULTS

The tissue sampling success rate was 95.6% for ST-VAB (43/45) and 97.7% (84/86) for DBT-VAB. Time for positioning (10.6 ± 6.4 vs. 6.7 ± 5.3 min), time for biopsy (33.4 ± 13.1 vs. 22.5 ± 13.1 min), and overall procedure time (66.6 ± 16.6 min vs. 54.5 ± 13.0 min) were substantially shorter with DBT-VAB (P < 0.0001). There were no differences in the distribution of pathological findings between the 2 groups.

CONCLUSION

Depth information and stable visibility of the target provided by DBT images led to quick decisions about target coordinates and improved the clinical performance of microcalcification biopsies.

Digital tomosynthesis spot view in architectural distortions: outcomes in management and radiation dose

PURPOSE

To evaluate if digital breast tomosynthesis spot compression view (DBT-SCV) could be an additional projection to confirm or deny architectural distortions (ADs) detected by digital breast tomosynthesis (DBT) while assessing the average glandular radiation dose.

METHODS

This is a retrospective cohort study enrolling 8864 DBT exams, of which only cases detecting primary AD and with BI-RADS 2-5 score were considered. Seventy-one AD cases examined with DBT-SCV, US and MRI were evaluated for correlation in terms of BI-RADS score; variables among exams were assessed for inter-relationships.

RESULTS

Of all ADs identified at DBT, biopsy yielded malignancy in only 38%. PPV in identifying malignancy of ADs was higher for DBT-SCV than DBT (p < 0.05); the NPV of DBT-SCV was 94%. The difference between DBT and DBT-SCV in the detection of benign ADs was statistically significant (p < 0.05). AD without US or MRI confirmation was less likely to represent malignancy (p < 0.05). In detecting malignant cases of ADs, both DBT and DBT-SCV were strongly correlated with US and RM (Kappa > 0.90). In identifying benign cases of ADs, DBT-SCV was poorly/moderately correlated with US and RM (Kappa 0.25 and 0.66); DBT was negatively correlated with US and MRI.

CONCLUSION

DBT-SCV could be useful to better characterize AD firstly identified by DBT, keeping dose levels within the reference limits. If AD is detected by DBT without an US or MRI correlate, that is not confirmed by DBT-SCV, a "wait and see" approach can be applied to reduce unnecessary biopsy.

Mammography and Digital Breast Tomosynthesis in Granulomatous and Nongranulomatous Mastitis

INTRODUCTION

Digital Mammography (DM) is extensively used for breast imaging however, lesion visibility is often limited by overlapping tissues, which affects lesion characterization. Digital breast tomosynthesis (DBT) reduces the effect of overlapping tissues and helps in revealing obscured findings. We aimed to describe the mammographic findings in granulomatous and non-granulomatous mastitis and assess the utility of adjunctive DBT in lesion characterization.

MATERIALS AND METHODS

DM and DBT images of histo-pathologically diagnosed cases of granulomatous (GM) and non-granulomatous mastitis (NGM) were reviewed according to the BI-RADS lexicon. Presence of contiguous/ interconnected lesions, tubular densities, interspersed hypodensities/fat densities within the involved areas were also assessed. The perceived utility of adjunct DBT was scored from 0-2.

RESULTS

Of 33 reviewed patients (24 GM, 9 NGM; median age 39 years, range 24-78); 13/33 (39.4%) were under 35 years of age. DBT detected masses in 24/33 (72.7%), whereas only 15/33 (45.4%) were visible on DM alone. Contiguous or inter-connected lesions were found in 10/33 (30.3%) cases. Tubular extensions were seen in 14 cases and interspersed hypodensities in 15. None of the enlarged lymph nodes had irregular shape or indistinct margins or loss of fatty hilum. DBT was able to categorize more lesions as BIRADS 4a or below, as compared to DM alone.

CONCLUSIONS

Mammographic presence of multiple contiguous iso-dense masses, reniform contour of axillary lymph nodes with preserved fatty hilum despite a large area of breast involvement favour a benign etiology; especially if DBT reveals tubular extensions or lesions with inhomogenous low density areas within.

Digital Breast Tomosynthesis versus MRI as an Adjunct to Full-Field Digital Mammography for Preoperative Evaluation of Breast Cancer according to Mammographic Density

OBJECTIVE

To compare digital breast tomosynthesis (DBT) and MRI as an adjunct to full-field digital mammography (FFDM) for the preoperative evaluation of women with breast cancer based on mammographic density.

MATERIALS AND METHODS

This retrospective study enrolled 280 patients with breast cancer who had undergone FFDM, DBT, and MRI for preoperative local tumor staging. Three radiologists independently sought the index cancer and additional ipsilateral and contralateral breast cancers using either FFDM alone, DBT plus FFDM, or MRI plus FFDM. Diagnostic performances across the three radiologists were compared among the reading modes in all patients and subgroups with dense (n = 186) and non-dense breasts (n = 94) according to mammographic density.

RESULTS

Of 280 patients, 46 (16.4%) had 48 additional (39 ipsilateral and nine contralateral) cancers in addition to the index cancer. For index cancers, both DBT plus FFDM and MRI plus FFDM showed sensitivities of 100% in the non-dense group. In the dense group, DBT plus FFDM showed lower sensitivity than that of MRI plus FFDM (94.6% vs. 99.6%, p < 0.001). For additional ipsilateral cancers, DBT plus FFDM showed specificity and positive predictive value (PPV) of 100% in the non-dense group, but sensitivity and negative predictive value (NPV) were not statistically different from those of MRI plus FFDM (p > 0.05). In the dense group, DBT plus FFDM showed higher specificity (98.2% vs. 94.1%, p = 0.005) and PPV (83.1% vs. 65.4%; p = 0.036) than those of MRI plus FFDM, but lower sensitivity (59.9% vs. 75.3%; p = 0.049). For contralateral cancers, DBT plus FFDM showed higher specificity than that of MRI plus FFDM (99.0% vs. 96.7%, p = 0.014), however, the other values did not differ (all p > 0.05) in the dense group.

CONCLUSION

DBT plus FFDM showed an overall higher specificity than that of MRI plus FFDM regardless of breast density, perhaps without substantial loss in sensitivity and NPV in the diagnosis of additional cancers. Thus, DBT may have the potential to be used as a preoperative breast cancer staging tool.

Synthetic Mammography: Review of Benefits and Drawbacks in Clinical Use

Digital breast tomosynthesis (DBT) has been widely adopted as a breast cancer screening tool, demonstrating decreased recall rates and other improved screening performance metrics when compared to digital mammography (DM) alone. Drawbacks of DBT when added to 2D DM include the increased radiation dose and longer examination time. Synthetic mammography (SM), a 2D reconstruction from the tomosynthesis slices, has been introduced to eliminate the need for a separate acquisition of 2D DM. Data show that the replacement of 2D DM by SM, when used with DBT, maintains the benefits of DBT, such as decreased recall rates, improved cancer detection rates, and similar positive predictive values. Key differences between SM and 2D DM include how the image is acquired, assessment of breast density, and visualization of mammographic findings, such as calcifications. Although SM is approved by the Food and Drug Administration and has been shown to be non-inferior when used with DBT, concerns surrounding SM include image quality and artifacts. The purpose of this review article is to review the benefits, drawbacks, and screening performance metrics of SM versus DBT.

2D or Synthetic 2D? A Reader Study of Visualization of Amorphous Calcifications

OBJECTIVE

Some vendors have created algorithms that generate synthetic 2D (s2D) images from a digital breast tomosynthesis (DBT) dataset to reduce the radiation from obtaining a separate 2D digital mammography (DM). This study evaluated the visibility of amorphous calcifications on 2D DM versus s2D on screening mammography.

METHODS

This IRB-approved, retrospective, reader study included screening mammograms from 36 women who received screening DBT exams where both 2D DM and s2D images were obtained: 28 screening mammograms that were eventually given BI-RADS category 4 or 5 for amorphous calcifications and 8 BI-RADS category 1 or 2 screening exams. Two rounds of interpretation were conducted with a six-week washout period. Cases were randomized to display either the 2D DM or s2D images, which were then alternated in the second round. Four fellowship-trained breast radiologists determined whether a study merited recall for calcifications. If so, they rated calcification visibility on a scale of 1 to 5. McNemar chi-square tests were conducted to assess differences in recall rates and Wilcoxon signed rank tests were used to examine shifts in visibility.

RESULTS

There was no difference in detection rates of amorphous calcifications between 2D DM and s2D, which were 75.9% and 75.0%, respectively (P = 1.000). Collectively, amorphous calcifications were more visible on s2D than 2D DM, with mean visibility scores of 3.4 versus 3.0, respectively (P = 0.005).

CONCLUSION

Synthetic 2D did not change identification of amorphous calcifications compared to 2D DM, and readers considered them more visible on average.

Variation in digital breast tomosynthesis image quality at differing heights above the detector

Introduction

The aim of this preliminary work was to determine if image quality in digital breast tomosynthesis (DBT) changes when tomosynthesis image slices were obtained at differing heights above the detector and in differing breast thicknesses.

Methods

A CIRS Model 020 BR3D breast imaging phantom was used to obtain the DBT images. The images were also acquired at different tube voltages, and each exposure was determined by the automatic exposure control system. Contrast‐to‐noise ratio (CNR) and figure‐of‐merit (FOM) values were obtained and compared.

Results

At a phantom thickness of 5 cm or greater, there was a significant reduction (P ≤ 0.05) of image CNR values obtained from the images near the top of the phantom to those obtained near the bottom of the phantom. When the phantom thickness was 4 cm, there was no significant difference in CNR values between DBT images acquired at any height in the phantom. FOM values generally showed no difference when images were obtained at differing heights above the detector.

Conclusion

Image quality, as measured by the CNR, was reduced when tomosynthesis slice image heights were at the top of the phantom and when the thickness of the phantom was more than 4 cm. From this preliminary work, clinicians need to be aware that DBT images obtained near the top of the breast, when breast thickness is greater than 4 cm, may have reduced image quality. Further work is needed to fully assess any DBT image quality changes when images are obtained near the top of the breast.

Upright Tomosynthesis-guided Breast Biopsy: Tips, Tricks, and Troubleshooting

The advent and implementation of digital breast tomosynthesis (DBT) have had a significant effect on breast cancer detection and image-guided breast procedures. DBT has been shown to improve the visualization of architectural distortions and noncalcified masses. With the incorporation of DBT imaging, biopsy of those findings seen only with DBT is feasible, and the need for localization and surgical excision to determine the pathologic diagnosis is avoided. The additional benefits of reduced procedural time, better localization, and increased technical success support the use of DBT for breast biopsy. DBT-guided biopsy can be performed with the patient prone or upright, depending on the table or unit used. Upright positioning enables improved patient comfort, particularly in patients who have restricted mobility, weight-related limitations, and/or difficulty lying prone for an extended period. Upright DBT-guided breast procedures require a cohesive team approach with overlapping radiologist and technologist responsibilities. Since this is a common breast procedure, the radiologist should be familiar with preprocedural considerations, patient preparations, and use of the biopsy equipment. The basic principles of upright DBT-guided breast biopsy are described in this comprehensive review. The various procedural components, including alternative approaches and techniques, are discussed. Tips and tricks for navigating the biopsy procedure to minimize complications, imaging examples of crucial steps, and supporting diagrams are provided. In addition, the challenges of performing upright DBT-guided biopsy, with troubleshooting techniques to ensure a successful procedure, are reviewed. ^©RSNA, 2021.

Estimated risk of radiation-induced cancer following breast screening employing tomosynthesis and digital mammography

The objective of this study was to estimate the risk of radiation-induced injury to the organs due to ionizing radiation following breast screening recommendations employing digital breast tomosynthesis (DBT) and digital mammography (DM). Using the Monte Carlo method, absorbed doses in the tissues and organs were calculated on an adult female phantom, considering two-view craniocaudal (CC) and mediolateral oblique (MLO) projections for each breast. The results showed differences in the total effective risk due to DM (CC + MLO) and DBT (CC + MLO) examinations in Brazil, ranging from 20.73 cases 10^-5(DM) to 27.19 cases 10^-5(DBT). Significant differences were also observed in the total effective risk of cancer incidence in the lungs due to DM (CC + MLO) and DBT (CC + MLO), ranging from 1.75×10^-01cases 10^-5(DM) to 1.76×10^-01cases 10^-5(DBT). The results indicate that the total effective risk of incidence should be considered as an additional parameter for the evaluation of DBT or DBT + DM program performance.

Breast cancer screening in women with and without implants: retrospective study comparing digital mammography to digital mammography combined with digital breast tomosynthesis

OBJECTIVES

Compare four groups being screened: women without breast implants undergoing digital mammography (DM), women without breast implants undergoing DM with digital breast tomosynthesis (DM/DBT), women with implants undergoing DM, and women with implants undergoing DM/DBT.

METHODS

Mammograms from February 2011 to March 2017 were retrospectively reviewed after 13,201 were excluded for a unilateral implant or prior breast cancer. Patients had been allowed to choose between DM and DM/DBT screening. Mammography performance metrics were compared using chi-square tests.

RESULTS

Six thousand forty-one women with implants and 91,550 women without implants were included. In mammograms without implants, DM (n = 113,973) and DM/DBT (n = 61,896) yielded recall rates (RRs) of 8.53% and 6.79% (9726/113,973 and 4204/61,896, respectively, p < .001), cancer detection rates per 1000 exams (CDRs) of 3.96 and 5.12 (451/113,973 and 317/61,896, respectively, p = .003), and positive predictive values for recall (PPV1s) of 4.64% and 7.54% (451/9726 and 317/4204, respectively, p < .001), respectively. In mammograms with implants, DM (n = 6815) and DM/DBT (n = 5138) yielded RRs of 5.81% and 4.87% (396/6815 and 250/5138, respectively, p = .158), CDRs of 2.49 and 2.92 (17/6815 and 15/5138, respectively, p > 0.999), and PPV1s of 4.29% and 6.0% (17/396 and 15/250, respectively, p > 0.999), respectively.

CONCLUSIONS

DM/DBT significantly improved recall rates, cancer detection rates, and positive predictive values for recall compared to DM alone in women without implants. DM/DBT performance in women with implants trended towards similar improvements, though no metric was statistically significant.

KEY POINTS

• Digital mammography with tomosynthesis improved recall rates, cancer detection rates, and positive predictive values for recall compared to digital mammography alone for women without implants. • Digital mammography with tomosynthesis trended towards improving recall rates, cancer detection rates, and positive predictive values for recall compared to digital mammography alone for women with implants, but these trends were not statistically significant - likely related to sample size.

Digital Breast Tomosynthesis: an Overview

Breast cancer is emerging as the most common malignancy in Indian women. Mammography is one of the few screening modalities available to the modern world that has proved itself of much use by aiding early detection and treatment of non-palpable, node-negative breast cancers. However, due to its two-dimensional nature, many cases of malignancies are still missed, to be detected at a later date or by an alternate modality. In 2011, FDA approved the supplemental use of digital breast tomosynthesis (DBT) in screening and diagnostic set ups. The acquisition of multiple low-dose projection images of the compressed parenchyma provided a 'third' dimension to the mammogram whereby the breast tissue could be seen layer by layer on the workstation. It improves cancer detection rate, and reduces recall rate and false-positive findings by improving lesion characterization. The current review discusses the principle of DBT with a comprehensive study of the literature.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-021-01310-y.

Evaluation of microcalcification contrast in clinical images for digital mammography and synthetic mammography

PURPOSE

The aim of this work was to compare, in a clinical study, digital mammography and synthetic mammography imaging by evaluating the contrast in microcalcifications of different sizes.

METHODS

A retrospective review of microcalcifications from 46 patients was undertaken. A Hologic 3-Dimensions mammography system and a HD Combo protocol was used for simultaneous acquisition of the digital and synthetic images. Microcalcifications were classified in accordance with their size, and patient breast images were classified in accordance with their density as adipose, moderately dense and dense. The contrast of the microcalcifications was measured and the contrast ratio between synthetic and digital images was compared. An additional qualitative assessment of the images was presented to correlate the conspicuity of the microcalcifications with the suppression of the structure noise.

RESULTS

Microcalcifications in adipose background always exhibit a comparable or better contrast on synthetic images, regardless their size. For moderately dense background, synthetic images show a better contrast in 91.2 % of cases for small microcalcifications and in 90.9 % of cases for large microcalcifications. For a dense background, better contrast is seen in 89.5 % of cases for small microcalcifications, and in 85.7 % of cases for large microcalcifications. The contrast ratio increases with increasing breast glandularity. The suppression of structure noise also contributes to the enhancement of microcalcifications in the synthetic images.

CONCLUSIONS

Synthetic mammography imaging is superior to digital mammography imaging in terms of microcalcification contrast, regardless their size and breast density.

Impact of digital breast tomosynthesis (DBT) on finding types leading to true-positive and false-positive examinations

PURPOSE

To investigate the frequencies of finding types with combined digital breast tomosynthesis (DBT) and digital mammography (DM) leading to true-positive (TP) and false-positive (FP) examinations.

MATERIALS AND METHODS

Consecutive screening mammograms at an academic medical center from March 2008 to February 2011 (DM group) and from January 2013 to December 2017 (DBT/DM group) were retrospectively reviewed. Multivariable logistic regression models were used to compare the proportions of mammographic finding types leading to TP and FP examinations between the two groups.

RESULTS

The DM group had 554 TP and 7278 FP examinations, and the DBT/DM group had 1271 TP and 14,544 FP examinations. The finding type of calcifications led to a lower proportion of TP examinations in the DBT/DM than DM group (34.3% versus 47.7%, p < 0.001) but also a lower proportion of FP examinations (18.7% versus 21.7%, p < 0.001). Mass led to a higher proportion of TP examinations in the DBT/DM than DM group (5.7% versus 1.3%, p < 0.001) but also a higher proportion of FP examinations (4.6% versus 0.3%, p < 0.001). Asymmetry led to a higher proportion of TP examinations in the DBT/DM than DM group (58.3% versus 50.4%, p = 0.03) and a lower proportion of FP examinations (75.9% versus 77.6%, p < 0.001). Architectural distortion led a similar proportion of TP examinations in the DBT/DM and DM groups (1.7% versus 0.7%, p = 0.12) but a higher proportion of FP examinations (0.8% versus 0.4%, p = 0.007).

CONCLUSIONS

Mammographic findings leading to TP and FP examinations have shifted with the addition of DBT to DM.

Comparison of Mass Size Measurements: Synthesized Mammography Versus Full-Field Digital Mammography

OBJECTIVES

To compare mass size measurements between synthesized mammography (SM) and full-field digital mammography (FFDM), and to assess interobserver agreement for those measurements.

MATERIALS AND METHODS

One hundred and forty-three patients who underwent FFDM and digital breast tomosynthesis acquisitions during the same compression session were included in the study. Two observers with four-and 1-year experience with digital breast tomosynthesis and SM images, respectively, measured mass sizes independently in two different sessions that were 2 weeks apart, and were blinded to each other. The first session included only FFDM images, and the second session included only SM images. Largest dimension of masses was measured in millimeters. Paired t test was used to compare differences in size measurements between FFDM and SM images. Intraclass correlation coefficient test was used to analyze interobserver agreement. Bland-Altman analyses were performed to evaluate agreements between the imaging techniques and between the observers.

RESULTS

The mean mass sizes on FFDM and SM images were 20.27 ± 14.10 and 18.50 ± 13.05 mm, respectively, for the first observer and 21.56 ± 14.84 and 19.89 ± 13.68 mm, respectively, for the second observer. The mass size measurements were significantly different between FFDM and SM for both observers (p < 0.001). Range of measurement errors, defined as 95% limits of agreements between two imaging techniques for observers 1 and 2 were ±1.96*1.36 mm, and ±1.96*1.53 mm, respectively. Range of measurement errors, defined as 95% limits of agreements between two observers for SM and FFDM were ±1.96*3.68 mm, and ±1.96*3.35 mm, respectively.

CONCLUSION

The measured mass sizes were significantly smaller on SM than FFDM images, and the interobserver differences for both of the imaging techniques were greater than the differences measured between FFDM and SM images.

Accuracy and Effectiveness of Mammography versus Mammography and Tomosynthesis for Population-Based Breast Cancer Screening: A Systematic Review and Meta-Analysis

We proposed to compare the accuracy and effectiveness of digital breast tomosynthesis (DBT), plus digital or synthetic mammography, with digital mammography alone in women attending population-based breast cancer screenings. We performed a systematic review and included controlled studies comparing DBT with digital mammography for breast cancer screening. Search strategies were applied to the MEDLINE, Embase, LILACS, and CENTRAL databases. With moderate quality of evidence, in 1,000 screens, DBT plus digital mammography increased the overall and invasive breast cancer rates by 3 and 2 (RR 1.36, 95% CI 1.18 to 1.58 and RR 1.51, 95% CI 1.27 to 1.79, respectively). DBT plus synthetic mammography increased both overall and invasive breast cancer rates by 2 (RR 1.38, 95% CI 1.24 to 1.54 and RR 1.37, 95% CI 1.22 to 1.55, respectively). DBT did not improve recall, false positive and false negative rates. However due to heterogeneity the quality of evidence was low. For women attending population-based breast cancer screenings, DBT increases rates of overall and invasive breast cancer. There is no evidence with high or moderate quality showing that DBT compared with digital mammography decreases recall rates, as well as false positive and false negative rates.

Performance of 2D Synthetic Mammography Versus Digital Mammography in the Detection of Microcalcifications at Screening

OBJECTIVE. The purpose of this study is to compare the performance of 2D synthetic mammography (SM) to that of full-field digital mammography (FFDM) in the detection of microcalcifications and to evaluate radiologists' preference between the two imaging modalities for assessing calcifications. MATERIALS AND METHODS. A fully crossed, mode-balanced, paired-case (n = 160), retrospective, multireader (n = 3) performance study was implemented to compare screening mammograms acquired with digital breast tomosynthesis and both FFDM and SM between 2015 and 2017. The study cohort included 70 patients with mammograms recalled for microcalcifications (35 with malignant findings and 35 with benign findings) and was supplemented with 90 patients with mammograms with negative findings. In separate sessions, readers interpreted SM or FFDM images by recording a BI-RADS assessment and the probability of malignancy. In a final session that included 70 mammograms with microcalcifications, readers recorded their subjective assessment of microcalcification conspicuity and diagnostic confidence. RESULTS. There was no difference in diagnostic accuracy as assessed by comparing the likelihood of malignancy based on the AUC of plotted ROCs, with AUCs of 91% (95% CI, 83-97%) and 88% (95% CI, 79-95%) observed for SM and FFDM, respectively (p = 0.392), and with noninferiority of SM compared with FFDM (p = 0.011). No significant difference was observed between SM and FFDM in terms of sensitivity (77% vs 73%, respectively; p = 0.366) or negative predictive value (84% vs 82%, respectively; p = 0.598). The specificity and positive predictive value of SM were lower than those of FFDM (91% vs 98%, respectively [p = 0.034], and 87% vs 96%, respectively [p = 0.034]). All readers found calcifications to be more conspicuous on SM (p < 0.0001); however, no significant difference in subjective diagnostic confidence was seen. CONCLUSION. SM is noninferior to FFDM in the detection of microcalcifications. Despite the increased conspicuity of microcalcifications on SM, the subjective diagnostic confidence in the two modalities is comparable.

A method for the automated classification of benign and malignant masses on digital breast tomosynthesis images using machine learning and radiomic features

In digital mammography, which is used for the early detection of breast tumors, oversight may occur due to overlap between normal tissues and lesions. However, since digital breast tomosynthesis can acquire three-dimensional images, tissue overlapping is reduced, and, therefore, the shape and distribution of the lesions can be easily identified. However, it is often difficult to distinguish between benign and malignant breast lesions on images, and the diagnostic accuracy can be reduced due to complications from radiological interpretations, owing to acquisition of a higher number of images. In this study, we developed an automated classification method for diagnosing breast lesions on digital breast tomosynthesis images using radiomics to comprehensively analyze the radiological images. We extracted an analysis area centered on the lesion and calculated 70 radiomic features, including the shape of the lesion, existence of spicula, and texture information. The accuracy was compared by inputting the obtained radiomic features to four classifiers (support vector machine, random forest, naïve Bayes, and multi-layer perceptron), and the final classification result was obtained as an output using a classifier with high accuracy. To confirm the effectiveness of the proposed method, we used 24 cases with confirmed pathological diagnosis on biopsy. We also compared the classification results based on the presence or absence of dimension reduction using least absolute shrinkage and a selection operator (LASSO). As a result, when the support vector machine was used as a classifier, the correct identification rate of the benign tumors was 55% and that of malignant tumors was 84%, with best results. These results indicate that the proposed method may help in more accurately diagnosing cases that are difficult to classify on images.

Correlation of digital mammography and digital breast tomosynthesis features of self-detected breast cancers with human epidermal growth factor receptor type 2/neu status

Context:

Breast cancer is a heterogeneous disease with several histological subtypes. Its prognosis and management are influenced by human epidermal growth factor receptor type 2 (HER2/neu) expression. Varying grades of HER2/neu overexpression are likely to have different morphological features. Digital breast tomosynthesis (DBT) enhances lesion visibility and hence that it may reveal features closer to histomorphological findings.

Aims:

The aim of this study is to correlate digital mammography (DM) and DBT findings of self-detected tumors with HER2/neu status, to determine whether differences in imaging features can help predict the degrees of HER2/neu overexpression.

Settings and Design:

Prospective study conducted in a tertiary care hospital.

Methods:

For 100 consecutive patients with self-detected lumps, DM and DBT data were reviewed by two radiologists who were blinded to histopathology. Of these, 63 patients with histologically proven breast cancer were recruited and their DM and DBT findings compared and correlated with HER2neu status (scores 0–3+).

Statistical Analysis:

Pearson's Chi-squared test and Fisher's exact test were used (SPSS version 22.0, IBM).

Results:

Morphology of lesions at both DM and DBT varied with HER2/neu status (P = 0.04 and 0.015, respectively). HER2-0 tumors mostly presented as masses without microcalcifications (88.8%), while most of HER2-3+ tumors as masses or asymmetries with microcalcifications (61.9%). The presence or absence of calcifications varied significantly with HER2/neu status. Breast imaging-reporting and data system (BI-RADS) scoring varied significantly (P < 0.001) with higher HER2 signal, more frequently associated with BI-RADS 5 score.

Conclusion:

DM and DBT features vary with the intensity of HER2 immunostaining. Higher BI-RADS scores, microcalcifications, and spiculated margins are frequently associated with HER2/neu 3+ lesions.

Digital Breast Tomosynthesis: Physics, Artifacts, and Quality Control Considerations

As digital breast tomosynthesis (DBT) becomes widely used, radiologists must understand the basic principles of (a) image acquisition, (b) artifacts, and (c) quality control (QC) that are specific to DBT. Standard acquisition parameters common to both full-field digital mammography (FFDM) and DBT are combinations of x-ray tube voltage, current exposure time, and anode target and filter combinations. Image acquisition parameters specific to DBT include tube motion, sweep angle, and number of projections. Continuous tube motion or x-ray emission decreases imaging time but leads to focal spot blurring when compared with step-and-shoot techniques. The sweep angle and number of projections determines resolution. Wider sweep angles allow greater out-of-plane (z-axis) resolution, improving visualization of masses and architecture distortion. A greater number of projections increases in-plane or x-y axis resolution, improving visualization of microcalcifications. Artifacts related to DBT include blurring-ripple, truncation, and loss of skin and superficial tissue resolution. Motion artifacts are difficult to recognize because of inherent out-of-plane blurring. To maintain optimal image quality and an "as low as reasonably achievable" (ALARA) radiation dose, regular QC must be performed. DBT is considered a new imaging modality; therefore, breast imaging facilities are required to obtain a separate certification in addition to that in FFDM, and all personnel (radiologists, technologists, and medical physicists) are mandated to complete initial DBT training and maintain appropriate continuing medical education credits. ^©RSNA, 2019.

Calcifications at Digital Breast Tomosynthesis: Imaging Features and Biopsy Techniques

Full-field digital mammography (FFDM), the standard of care for breast cancer screening, has some limitations. With the advent of digital breast tomosynthesis (DBT), improvements including decreased recall rates and increased cancer detection rates have been observed. The quasi-three-dimensional capability of DBT reduces breast tissue overlap, a significant limitation of FFDM. However, early studies demonstrate that a few cancers detected at FFDM may not be diagnosed at DBT-only screening, and lesions with calcifications as the dominant feature may look less suspicious at DBT or not be visible at all. These findings support the use of combined FFDM and DBT protocols to optimize screening performance. However, this combination would approximately double the patient's radiation exposure. The development of computer algorithms that generate two-dimensional synthesized mammography (SM) views from DBT has improved calcification conspicuity and sensitivity. Therefore, SM may substitute for FFDM in screening protocols, reducing radiation exposure. DBT plus SM demonstrates significantly better performance than that of FFDM alone, although there are reports of missed malignant calcifications. Thus, some centers continue to perform FFDM with DBT. Use of DBT in breast imaging has also necessitated the development of DBT-guided biopsy. DBT-guided biopsy may have a higher success rate than that of stereotactic biopsy, with a shorter procedure time. While DBT brings substantial improvements to breast cancer imaging, it is important to be aware of its strengths and limitations regarding detection of calcifications. This article reviews the imaging appearance of breast calcifications at DBT, discusses calcification biopsy techniques, and provides an overview of the current literature. Online supplemental material is available for this article. ^©RSNA, 2019 An earlier incorrect version of this article appeared online. This article was corrected on February 13, 2019.

Association between digital breast tomosynthesis and molecular subtypes of breast cancer

In recent years, with increasing prevalence, particularly in young patients, breast cancer is considered to be one of the most common malignancies. The aim of the present study was to evaluate the clinical value of digital breast tomosynthesis (DBT) in diagnosing molecular subtypes of breast cancer. The present study retrospectively analyzed 134 cases of breast cancer with data regarding surgery, complete pathology and immunohistochemistry, which were collected at The Second Clinical College of Fujian Medical University (Quanzhou, China) between May 2013 and October 2014. The patients were divided into the four following molecular subtypes: Luminal A, luminal B, triple-negative and human epidermal growth factor receptor 2 (HER-2) overexpression, according to the expression of estrogen receptor, progesterone hormone receptor, HER-2 and Ki67. The association between clinical characteristics of each molecular subtype and characteristics of DBT were assessed. Calcification scores and lymph node size were the indicators that exhibited a significant difference following comparison between the four molecular subtypes. The subgroup analysis based on tumor size, calcification scores and lymph node size identified a significant difference in the distribution between patients with breast cancer with lymph node size of ≥1.5 and <1.5 cm. The analysis also revealed that the molecular subtypes of breast cancer were significantly associated with variables of calcification scores and lymph node size. In conclusion, the diagnostic imaging features, including calcification score and lymph node size, determined using DBT could be used as assistant diagnostic markers of breast cancer molecular subtypes.

Impact of Advancing Technology on Diagnosis and Treatment of Breast Cancer

New emerging breast imaging techniques have shown great promise in breast cancer screening, evaluation of extent of disease, and response to neoadjuvant therapy. Tomosynthesis, allows 3-dimensional imaging of the breast, and increases breast cancer detection. Fast abbreviated MRI has reduced time and costs associated with traditional breast MRI while maintaining cancer detection. Diffusion-weighted imaging is a functional MRI technique that does not require contrast and has shown potential in screening, lesion characterization and also evaluation of treatment response. New image-guided preoperative localizations are available that have increased patient satisfaction and decreased operating room delays.

Strengths and Weaknesses of Synthetic Mammography in Screening

Synthetic mammography (SM) consists of two-dimensional images reconstructed from digital breast tomosynthesis (DBT) data. Unlike standard full-field digital mammography (FFDM), SM does not require additional radiation exposure. SM is being introduced in breast imaging centers because early clinical data demonstrate that synthetic images are comparable to FFDM in cancer detection, positive predictive values, and recall rates. SM has completely replaced FFDM in some practices. Thus, an understanding of SM and its strengths and weaknesses compared with those of FFDM is essential. The artifacts of SM include blurring subcutaneous tissue, loss of resolution in the axilla on mediolateral oblique views, pseudocalcifications, and decreased resolution near foreign bodies (eg, biopsy markers). SM's strengths include a reduced radiation dose, shorter acquisition time compared with a combined FFDM/DBT screening examination (with potentially less motion artifact), and increased conspicuity of calcifications, spiculated margins, and architectural distortion. The weaknesses of SM include the potential for false positives due to pseudocalcifications and the difficulty in assessing for motion artifact. This article reviews SM and its role in screening and presents clinical cases to highlight SM's strengths, weaknesses, and artifacts. ^©RSNA, 2017.

Impact of Addition of Digital Breast Tomosynthesis to Digital Mammography in Lesion Characterization in Breast Cancer Patients

Context:

Digital breast tomosynthesis (DBT) is a new development in mammography technology which reduces the effect of overlapping tissue.

Aims:

The aim is to interrogate whether addition of DBT to digital mammography (DM) helps in better characterization of mammographic abnormalities in breast cancer patients in general and in different breast compositions.

Settings and Design:

Retrospective, analytical cross-sectional study.

Subjects and Methods:

Mammographic findings in 164 patients with 170 pathologically proven lesions were evaluated by using first DM alone and thereafter with addition of DBT to DM. The perceived utility of adjunct DBT was scored using a rating of 0–2. A score of 0 indicating that DM plus DBT was comparable to DM alone, 1 indicating that DM plus DBT was slightly better, and 2 indicating that DM plus DBT was definitely better.

Statistical Analysis:

McNemar Chi-squares test, Fisher's exact test.

Results:

On DM, 149 lesions were characterized mass with or without calcifications, 18 asymmetries with or without calcifications, 2 as architectural distortion, and 1 as microcalcification alone. Adjunct DBT helped in better morphological characterization of 17 lesions, with revelation of underlying masses in 16 asymmetries and one architectural distortion. Adjunct DBT was perceived to be slightly better than DM alone in 44.7% lesions, and definitely better in 22.9% lesions. Lesions showing score 1 or 2 improvement were significantly higher in heterogeneously and extremely dense breasts (P < 0.001).

Conclusions:

Adjunct DBT improves morphological characterization of lesions in patients with breast cancer. It highlights more suspicious features of lesions that indicate the presence of cancer, particularly in dense breasts.

Characterization of invisible breast cancers in digital mammography and tomosynthesis: radio-pathological correlation

OBJECTIVE

To review the radio-pathologic features of symptomatic breast cancers not detected at digital mammography (DM) and digital breast tomosynthesis (DBT).

MATERIAL AND METHODS

Retrospective analysis of 169 lesions from symptomatic patients with breast cancer that were studied with DM, DBT, ultrasound (US) and magnetic resonance (MR). We identified occult lesions (true false negatives) in DM and DBT. Clinical data, density, US and MR findings were analyzed as well as histopathological results.

RESULTS

We identified seven occult lesions in DM and DBT. 57% (4/7) of the lesions were identified in high-density breasts (type c and d), and the rest of them in breasts of density type b. Six carcinomas were identified at US and MR (BI-RADS 4 masses); the remaining lesion was only identified at MR. The tumor size was larger than 3cm at MRI in 57% of the lesions. All tumors were ductal infiltrating carcinomas, six of them with high stromal proportion. According to molecular classification, we found only one triple-negative breast cancer, the other lesions were luminal-type. We analyzed the tumor margins of two resected carcinomas that were not treated with neoadjuvant chemotherapy, both lesions presented margins that displaced the adjacent parenchyma without infiltrating it.

CONCLUSION

Occult breast carcinomas in DM and DBT accounted for 4% of lesions detected in patients with symptoms. They were mostly masses, all of them presented the diagnosis of infiltrating ductal carcinoma (with predominance of the luminal immunophenotype) and were detected in breasts of density type b, c and d.

Added Value of Digital Breast Tomosynthesis Combined with Digital Mammography According to Reader Agreement: Changes in BI-RADS Rate and Follow-Up Management

BACKGROUND

The aim of this study was to evaluate the added value of digital breast tomosynthesis (DBT) when combined with digital mammography (DM) in BI-RADS assessment and follow-up management.

METHODS

From February 2014 to January 2015, 214 patients underwent DM and DBT, acquired with a Siemens Mammomat Inspiration unit. 2 expert readers independently reviewed the studies in 2 steps: DM and DM+DBT, according to BI-RADS rate. Patients with BI-RADS 0, 3, 4, and 5 were recalled for work-up. Inter-reader agreement for BI-RADS rate and work-up rate were evaluated using Cohen's kappa.

RESULTS

Inter-reader agreement (κ value) for BI-RADS classification was 0.58 for DM and 0.8 for DM+DBT. DM+DBT increased the number of BI-RADS 1, 2, 4, 5 and reduced the number of BI-RADS 0 and 3 for both readers compared to DM alone. Regarding work-up rate agreement, κ was poor for DM and substantial (0.7) for DM+DBT. DM+DBT also reduced the work-up rate for both Reader 1 and Reader 2.

CONCLUSION

DM+DBT increased the number of negative and benign cases (BI-RADS 1 and 2) and suspicious and malignant cases (BI-RADS 4 and 5), while it reduced the number of BI-RADS 0 and 3. DM+DBT also improved inter-reader agreement and reduced the overall recall for additional imaging or short-interval follow-up.

Digital breast tomosynthesis versus full-field digital mammography-Which modality provides more accurate prediction of margin status in specimen radiography?

OBJECTIVES

To evaluate the reliability of tumor margin assessment in specimen radiography (SR) using digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) in comparison to postoperative histopathology margin status as the gold standard.

METHODS

After ethics committee approval, 102 consecutive patients who underwent breast conservative surgery for nonpalpable proven breast cancer were prospectively included. All patients underwent ultrasound/mammography-guided wire localization of their lesions. After excision, each specimen was marked for orientation and imaged using FFDM and DBT. Two blinded radiologists (R1, R2) independently analyzed images acquired with both modalities. Readers identified in which direction the lesion was closest to the specimen margin and to measure the margin width. Their findings were compared with the final histopathological analysis. True positive margin status was defined as a margin measuring <1mm for invasive cancer and 5mm for ductal carcinoma in situ (DCIS) at imaging and pathology.

RESULTS

For FFDM, correct margin direction was identified in 45 cases (44%) by R1 and in 37 cases (36%) by R2. For DBT, 69 cases (68%) were correctly identified by R1 and 70 cases (69%) by R2. Overall accuracy was 40% for FFDM and 69% for DBT; the difference was statistically significant (p<0.0001). Sensitivity in terms of correct assessment of margin status was significantly better for DBT than FFDM (77% versus 62%).

CONCLUSION

SR using DBT is significantly superior to FFDM regarding identification of the closest margin and sensitivity in assessment of margin status.

Benefit of adding digital breast tomosynthesis to digital mammography for breast cancer screening focused on cancer characteristics: a meta-analysis

PURPOSE

We evaluated the benefit of adding digital breast tomosynthesis (DBT) to full-field digital mammography (FFDM) compared to FFDM alone for breast cancer detection, focusing on cancer characteristics.

METHODS

We searched electronic databases and relevant references for published studies comparing DBT plus FFDM to FFDM alone for breast cancer screening. Pooled risk ratios (RRs) for various pathologic findings were determined using random effects models.

RESULTS

Eleven eligible studies were included. Pooled RRs showed a greater cancer detection for DBT plus FFDM than for FFDM alone for invasive cancer (1.327; 95% CI, 1.168-1.508), stage T1 (1.388; 95% CI, 1.137-1.695), nodal-negative (1.451; 95% CI, 1.209-1.742), all histologic grades (grade I, 1.812; grade II/III, 1.403), and histologic types of invasive cancer (ductal, 1.437; lobular, 1.901). However, adding DBT did not increase for detection of carcinoma in situ (1.198; 95% CI, 0.942-1.524), stage ≥T2 (1.391; 95% CI, 0.895-2.163), or nodal-positive cancer (1.336; 95% CI, 0.921-1.938). Heterogeneity among studies was not significant in any subset analysis.

CONCLUSIONS

Adding DBT to FFDM enabled detection of early invasive breast cancer that might have been missed with FFDM alone. Knowing which cancer characteristic DBT detects may allow it to play a complementary role in predicting long-term patient outcomes and facilitate treatment planning.

Impact of the Addition of Digital Breast Tomosynthesis (DBT) to Standard 2D Digital Screening Mammography on the Rates of Patient Recall, Cancer Detection, and Recommendations for Short-term Follow-up

RATIONALE AND OBJECTIVES

The addition of digital breast tomosynthesis (DBT) to digital screening mammography (DM) has been shown to decrease recall rates and improve cancer detection rates, but there is a lack of data regarding the impact of DBT on rates of short-term follow-up. We assessed possible changes in performance measures with the introduction of DBT at our facility.

MATERIALS AND METHODS

In our observational study, databases were used to compare rates of recall, short-term follow-up, biopsy, and cancer detection between women undergoing DM without (n = 10,477) and women undergoing DM with (n = 2304) the addition of DBT. Regression analysis was performed to determine associations with patient age, breast density, and availability of comparison examinations.

RESULTS

The addition of DBT resulted in significantly lower recall rates (16%-14%, P = .017), higher rates of biopsy (12.7%-19.1%, P < .01), and increased detection of ductal carcinoma in situ, with a difference of 2.3 cases per 1000 screens (P = .044). A 33% increase in cancer detection rates was observed with DBT, which did not reach statistical significance. Short-term follow-up of probably benign findings was 80% higher in the DBT group (odds ratio = 1.80, 95% confidence interval = 1.38-2.36, P < .001).

CONCLUSIONS

To our knowledge, we are the first to study the impact of DBT on rates of short-term follow-up, and observed an 80% increase over the DM group. Further research is needed to determine the malignancy rate of Breast Imaging Reporting and Data System 3 lesions detected with DBT, and establish appropriate follow-up to maximize cancer detection while minimizing expense and patient anxiety.

Strategies to Increase Cancer Detection: Review of True-Positive and False-Negative Results at Digital Breast Tomosynthesis Screening

Digital breast tomosynthesis (DBT) represents a valuable addition to breast cancer screening by decreasing recall rates while increasing cancer detection rates. The increased accuracy achieved with DBT is due to the quasi-three-dimensional format of the reconstructed images and the ability to "scroll through" breast tissue in the reconstructed images, thereby reducing the effect of tissue superimposition found with conventional planar digital mammography. The margins of both benign and malignant lesions are more conspicuous at DBT, which allows improved lesion characterization, increased reader confidence, and improved screening outcomes. However, even with the improvements in accuracy achieved with DBT, there remain differences in breast cancer conspicuity by mammographic view. Early data suggest that breast cancers may be more conspicuous on craniocaudal (CC) views than on mediolateral oblique (MLO) views. While some very laterally located breast cancers may be visualized on only the MLO view, the increased conspicuity of cancers on the CC view compared with the MLO view suggests that DBT screening should be performed with two-view imaging. Even with the improved conspicuity of lesions at DBT, there may still be false-negative studies. Subtle lesions seen on only one view may be discounted, and dense and/or complex tissue patterns may make some cancers occult or extremely difficult to detect. Therefore, radiologists should be cognizant of both perceptual and cognitive errors to avoid potential pitfalls in lesion detection and characterization. ^©RSNA, 2016 Online supplemental material is available for this article.

Is the false-positive rate in mammography in North America too high?

The practice of investigating pathological abnormalities in the breasts of females who are asymptomatic is primarily employed using X-ray mammography. The importance of breast screening is reflected in the mortality-based benefits observed among females who are found to possess invasive breast carcinoma prior to the manifestation of clinical symptoms. It is estimated that population-based screening constitutes a 17% reduction in the breast cancer mortality rate among females affected by invasive breast carcinoma. In spite of the significant utility that screening confers in those affected by invasive cancer, limitations associated with screening manifest as potential harms affecting individuals who are free of invasive disease. Disease-free and benign tumour-bearing individuals who are subjected to diagnostic work-up following a screening examination constitute a population of cases referred to as false positives (FPs). This article discusses factors contributing to the FP rate in mammography and extends the discussion to an assessment of the consequences associated with FP reporting. We conclude that the mammography FP rate in North America is in excess based upon the observation of overtreatment of in situ lesions and the disproportionate distribution of detriment and benefit among the population of individuals recalled for diagnostic work-up subsequent to screening. To address the excessive incidence of FPs in mammography, we investigate solutions that may be employed to remediate the current status of the FP rate. Subsequently, it can be suggested that improvements in the breast-screening protocol, medical litigation risk, image interpretation software and the implementation of image acquisition modalities that overcome superimposition effects are promising solutions.

Dedicated Three-dimensional Breast Computed Tomography: Lesion Characteristic Perception by Radiologists

Objectives:

To assess radiologist confidence in the characterization of suspicious breast lesions with a dedicated three-dimensional breast computed tomography (DBCT) system in comparison to diagnostic two-dimensional digital mammography (dxDM).

Materials and Methods:

Twenty women were recruited who were to undergo a breast biopsy for a Breast Imaging-Reporting and Data System (BI-RADS) 4 or 5 lesion evaluated with dxDM in this Institutional Review Board-approved study. The enrolled subjects underwent imaging of the breast(s) of concern using DBCT. Seven radiologists reviewed the cases. Each reader compared DBCT to the dxDM and was asked to specify the lesion type and BI-RADS score for each lesion and modality. They also compared lesion characteristics: Shape for masses or morphology for calcifications; and margins for masses or distribution for calcifications between the modalities using confidence scores (0–100).

Results:

Twenty-four biopsied lesions were included in this study: 17 (70.8%) masses and 7 (29.2%) calcifications. Eight (33.3%) lesions were malignant, and 16 (66.7%) were benign. Across all lesions, there was no significant difference in the margin/distribution (Δ = −0.99, P = 0.84) and shape/morphology (Δ = −0.10, P = 0.98) visualization confidence scores of DBCT in relation to dxDM. However, analysis by lesion type showed a statistically significant increase in reader shape (Δ =11.34, P = 0.013) and margin (Δ =9.93, P = 0.023) visualization confidence with DBCT versus dxDM for masses and significant decrease in reader morphology (Δ = −29.95, P = 0.001) and distribution (Δ = −28.62, P = 0.002) visualization confidence for calcifications.

Conclusion:

Reader confidence in the characterization of suspicious masses is significantly improved with DBCT, but reduced for calcifications. Further study is needed to determine whether this technology can be used for breast cancer screening.

Significance and Application of Digital Breast Tomosynthesis for the BI-RADS Classification of Breast Cancer

BACKGROUND

Full-field digital mammography (FFDM) with dense breasts has a high rate of missed diagnosis, and digital breast tomosynthesis (DBT) could reduce organization overlapping and provide more reliable images for BI-RADS classification. This study aims to explore application of COMBO (FFDM+DBT) for effect and significance of BI-RADS classification of breast cancer.

MATERIALS AND METHODS

In this study, we selected 832 patients who had been treated from May 2013 to November 2013. Classify FFDM and COMBO examination according to BI-RADS separately and compare the differences for glands in the image of the same patient in judgment, mass characteristics display and indirect signs. Employ Paired Wilcoxon rank sum test was used in 79 breast cancer patients to find differences between two examine methods.

RESULTS

The results indicated that COMBO pattern is able to observe more details in distribution of glands when estimating content. Paired Wilcoxon rank sum test showed that overall classification level of COMBO is higher significantly compared to FFDM to BI-RADS diagnosis and classification of breast (P<0.05). The area under FFDM ROC curve is 0.805, while that is 0.941 in COMBO pattern. COMBO shows relation of mass with the surrounding tissues, the calcification in the mass, and multiple foci clearly in breast cancer tissues. The optimal sensitivity of cut-off value in COMBO pattern is 82.9%, which is higher than that in FFDM (60%). They share the same specificity which is both 93.2%.

CONCLUSIONS

Digital Breast Tomosynthesis (DBT) could be used for the BI-RADS classification in breast cancer in clinical.

Awareness, Interest, and Preferences of Primary Care Providers in Using Point-of-Care Cancer Screening Technology

Well-developed point-of-care (POC) cancer screening tools have the potential to provide better cancer care to patients in both developed and developing countries. However, new medical technology will not be adopted by medical providers unless it addresses a population’s existing needs and end-users’ preferences. The goals of our study were to assess primary care providers’ level of awareness, interest, and preferences in using POC cancer screening technology in their practice and to provide guidelines to biomedical engineers for future POC technology development. A total of 350 primary care providers completed a one-time self-administered online survey, which took approximately 10 minutes to complete. A $50 Amazon gift card was given as an honorarium for the first 100 respondents to encourage participation. The description of POC cancer screening technology was provided in the beginning of the survey to ensure all participants had a basic understanding of what constitutes POC technology. More than half of the participants (57%) stated that they heard of the term “POC technology” for the first time when they took the survey. However, almost all of the participants (97%) stated they were either “very interested” (68%) or “somewhat interested” (29%) in using POC cancer screening technology in their practice. Demographic characteristics such as the length of being in the practice of medicine, the percentage of patients on Medicaid, and the average number of patients per day were not shown to be associated with the level of interest in using POC. These data show that there is a great interest in POC cancer screening technology utilization among this population of primary care providers and vast room for future investigations to further understand the interest and preferences in using POC cancer technology in practice. Ensuring that the benefits of new technology outweigh the costs will maximize the likelihood it will be used by medical providers and patients.

Monte-Carlo simulation of a slot-scanning digital mammography system for tomosynthesis

BACKGROUND

Digital breast tomosynthesis (DBT) reconstructs planar slices of the breast based on two-dimensional angular projections. Early studies and clinical trials show that DBT is an improvement over full field digital mammography (FFDM) because it provides the radiologist with better image quality and more information.

OBJECTIVE

This paper presents a simulation system to model the performance of a slot-scanning FFDM and DBT system.

METHODS

A tissue-equivalent three dimensional (3D) breast phantom was constructed, validated for slot-scanning digital mammography and used in simulating digital breast tomosynthesis. The simulation system was validated by comparing images acquired with a slot-scanning mammography machine with simulated phantom images, using the edge-test method and image quality metrics modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE). Different two-dimensional (2D) projections of the 3D phantom were simulated and the phantom was reconstructed using filtered backprojection.

RESULTS

Image quality metrics showed equivalence between simulated and real images.

CONCLUSIONS

The simulation tool is suitable for slot-scanning FFDM and DBT and may be used for the design and comparison of mammography systems.

Tubular Carcinoma of the Breast: Advantages and Limitations of Breast Tomosynthesis

Tubular carcinoma of the breast is a rare variant of invasive ductal carcinoma. We report a case of 42-year-old asymptomatic female with a histopathological proven multifocal tubular carcinoma, studied by mammography, Tomosynthesis, Ultrasound, and Magnetic Resonance. Herein, we discuss the advantages and limitations of Tomosynthesis, an emerging imaging technique, in this particular case.