Breast Cancer Screening and BI-RADS Scoring Trends Before and During the COVID-19 Pandemic in an Academic Safety-Net Hospital.

BACKGROUND: Little is known about how the COVID-19 pandemic affected screening mammography rates and Breast Imaging Reporting and Data Systems (BI-RADS) categorizations within populations facing social and economic inequities. Our study seeks to compare trends in breast cancer screening and BI-RADS assessments in an academic safety-net patient population before and during the COVID-19 pandemic. PATIENTS AND METHODS: Our single-center retrospective study evaluated women ≥ 18 years old with no known breast cancer diagnosis who received breast cancer screening from March 2019-September 2020. The screening BI-RADS score, completion of recommended diagnostic imaging, and diagnostic BI-RADS scores were compared between the pre-COVID-19 era (from 1 March 2019 to 19 March 2020) and COVID-19 era (from 20 March 2020 to 30 September 2020). RESULTS: Among the 11,798 patients identified, screened patients were younger (median age 57 versus 59 years, p < 0.001) and more likely covered by private insurance (35.9% versus 32.3%, p < 0.001) during the COVID-19 era compared with the pre-COVID-19 era. During the pandemic, there was an increase in screening mammograms categorized as BI-RADS 0 compared with the pre-COVID-19 era (20% versus 14.5%, p < 0.0001). There was no statistically significant difference in rates of completion of diagnostic imaging (81.6% versus 85.4%, p = 0.764) or assignment of suspicious BI-RADS scores (BI-RADS 4-5; 79.9% versus 80.8%, p = 0.762) between the two eras. CONCLUSIONS: Although more patients were recommended to undergo diagnostic imaging during the pandemic, there were no significant differences in race, completion of diagnostic imaging, or proportions of mammograms categorized as suspicious between the two time periods. These findings likely reflect efforts to maintain equitable care among diverse racial groups served by our safety-net hospital.

Breast Imaging Fellowship Training in the United States: A National Survey of Fellowship Program Directors.

OBJECTIVE: To provide an updated characterization of breast imaging fellowship programs in the United States to identify opportunities for improvement and standardization. METHODS: An anonymous survey was e-mailed to program directors of breast imaging fellowship programs listed on the Society of Breast Imaging website. The survey was open from April 23, 2021, through May 27, 2021. The survey was deemed exempt by the IRB. RESULTS: Forty-seven of 80 (59%) program directors responded, of which 36/47 (77%) represented programs dedicated 100% to breast imaging, and 11/47 (23%) represented programs dedicated 50%-75% to breast imaging. Common elements to most programs include tumor boards (47/47, 100%), journal clubs (39/47, 83%), case-based teaching sessions (35/47, 74%), didactic lectures (40/47, 85%), and participation in radiology-pathology conferences (29/47, 62%). Mammography Quality and Standards Act audit training (22/47, 47%), mammography quality control training (22/47, 47%), and formal communication training (19/47, 40%) were less common. Most programs provide exposure to wire (42/47, 89%) and wire-free localization procedures (45/47, 96%), but exposure to contrast-enhanced mammography (13/47, 28%) and molecular breast imaging (4/47, 9%) was limited. A small majority of programs (25/47, 53%) do not require weekday call; however, more (31/47, 66%) have weekend call responsibilities. Many programs (29/47, 62%) offer at least 3 weeks of elective time, which may be clinical or nonclinical. CONCLUSION: Breast imaging fellowship programs vary in curricula, modality exposure, and academic policies. The results of this survey can help guide further efforts to standardize and optimize fellowship training.

Imaging Preferences in Women With a History of Breast Cancer Receiving Contrast-Enhanced Mammography.

OBJECTIVE: There is interest in contrast-enhanced mammography (CEM) to screen breast cancer survivors, yet it is unclear whether they would accept CEM as their annual exam. The purpose of this study was to understand patient preferences to guide CEM implementation for screening. METHODS: Consecutive women with breast cancer history who had CEM as their annual mammogram from July 2020 to August 2021 at a single academic institution completed an 18-question survey regarding prior contrast imaging, CEM experience, and comparison to other breast imaging exams. Response proportions were calculated, and chi-square or Fisher's exact test were used to evaluate associations of demographics with responses. RESULTS: A total of 78% (104/133) of women undergoing CEM provided results. Most were satisfied with CEM (99%, 103/104), had nothing to complain about (87%, 90/104), did not find CEM anxiety provoking (69%, 72/104), felt comfortable having contrast for annual imaging (94%, 98/104), were willing to accept the small risk of a contrast reaction if CEM would find their cancer (93%, 97/104), and would like to have CEM for their exam next year (95%, 99/104). Compared with mammography, 23% (24/104) reported CEM was a better experience, and 63% (66/104) reported CEM was about the same. Of those who had prior MRI, the majority reported CEM was better (53%, 29/55) and would prefer CEM if both MRI and CEM had an equal chance of detecting cancer (73%, 41/56). Most preferences did not differ significantly according to demographics. CONCLUSION: Most women surveyed considered CEM to be satisfactory and preferred compared to other breast screening modalities.

Comparison of Contrast-enhanced Mammography with MRI Utilizing an Enriched Reader Study: A Breast Cancer Study (CONTRRAST Trial).

Background Despite growing interest in using contrast-enhanced mammography (CEM) for breast cancer screening as an alternative to breast MRI, limited literature is available. Purpose To determine whether CEM is noninferior to breast MRI or abbreviated breast MRI (AB MRI) and superior to two-dimensional mammography in an asymptomatic population simulating those who would present for screening and then undergo diagnostic work-up. Materials and Methods This enriched reader study used CEM and MRI data prospectively collected from asymptomatic individuals at a single institution from December 2014 to March 2020. Case sets were obtained at screening, as part of work-up for a screening-detected finding, or before biopsy of a screening-detected abnormality. All images were anonymized and randomized, and all 12 radiologists interpreted them. For CEM interpretation, readers were first shown low-energy images as a surrogate for digital mammography and asked to give a forced Breast Imaging Reporting and Data System score for up to three abnormalities. The highest score was used as the case score. Readers then reviewed the full CEM examination and scored it similarly. After a minimum 1-month washout, the readers similarly interpreted AB MRI and full MRI examinations. Receiver operating characteristic analysis, powered to test CEM noninferiority to full MRI, was performed. Results The study included 132 case sets (14 negative, 74 benign, and 44 malignant; all female participants; mean age, 54 years ± 12 [SD]). The mean areas under the receiver operating characteristic curve (AUCs) for digital mammography, CEM, AB MRI, and full MRI were 0.79, 0.91, 0.89, and 0.91, respectively. CEM was superior to digital mammography (P < .001). No evidence of a difference in AUC was found between CEM and AB MRI and MRI. Conclusion In an asymptomatic study sample, CEM was noninferior to full MRI and AB MRI and was superior to digital mammography. Clinical trial registration no. NCT03482557 and NCT02275871 © RSNA, 2023 Supplemental material is available for this article.

Imaging and Management of Radial Scars and Complex Sclerosing Lesions.

Radial scars and complex sclerosing lesions, often collectively referred to as radial sclerosing lesions (RSLs), are breast lesions characterized by sclerotic stroma with entrapped epithelial elements. RSLs have imaging features that overlap with those of breast malignancy and often become the target of imaging-guided biopsy given their suspicious imaging appearance. These can be identified in isolation or can also be associated with atypia or other high-risk lesions that have intrinsic malignant potential, increasing the risk of carcinoma and affecting prognosis and management of RSLs. Because of this, management of these lesions remains controversial. Traditional management has been surgical excisional biopsy. However, as more RSLs are identified (because digital breast tomosynthesis allows identification of more architectural distortions), optimal management is evolving. Physicians in some practices are using a multidisciplinary approach to the management of RSLs when deciding on surgical excision of these lesions versus imaging follow-up. These discussions also incorporate individual patient risk factors and greater patient informed medical decision making. Reported upgrade rates of RSLs at core needle biopsy vary and can depend on the sampling method, number of samples, gauge of the needle, target being sampled, and radiologic-pathologic concordance or discordance. A precise sampling technique also allows greater accuracy of diagnosis and lower upgrade rates for these lesions, with radiologic-pathologic correlation as an integral component for further management decisions. The authors review the overall histopathologic, clinical, and imaging features of RSLs and discuss appropriate management based on currently available data regarding upgrade rates. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Impact of imaging nurse navigation on breast interventions: Direct and closed-loop patient communication and documentation.

OBJECTIVE: A breast imaging nurse navigator (NN) was established with the goals to enhance the patient experience after biopsy, improve care timeliness, accuracy, and coordination, facilitate direct communication to patients, and increase care retention within our system. Our aim was to determine the impact of NN on patient care time metrics, communication, documentation, compliance, and care retention at our institution after breast biopsy. METHODS: Retrospective review of a six-month period before (5/1/17-10/31/17) and after (5/1/19-10/31/19) establishment of a nurse navigator in our breast imaging department was performed, including 498 patients in the pre-navigation (pre-NN) group and 526 patients in the post-navigation (post-NN) group. Data was gathered from the electronic medical record and collected using REDCap. RESULTS: Biopsy pathology results were communicated directly to the patient more often post-NN (71%, 374/526) compared to pre-NN (4%, 21/498) (p < 0.0001), without change in overall time of result communication (p = 0.08). Due to factors outside of imaging, most care time metrics were longer post-NN, including days from biopsy to pathology report (p < 0.001), result communication to initiation of care (p < 0.001), and biopsy to surgery (p < 0.001). There was no difference and high compliance (p = 1) and care retention (p = 0.015) in both groups. There was improved documentation of pathology results, recommendations, and communication post-NN (0/526 vs 10/498, p = 0.001). CONCLUSION: Imaging nurse navigation added greatest value by communicating breast biopsy results and recommendations directly to patients and ensuring documentation. Compliance and retention were high in both groups. Factors outside of Radiology influenced time metrics, requiring further investigation of multidisciplinary collaboration.

Management of Mammographic Architectural Distortion Based on Contrast-enhanced MRI and US Correlation.

OBJECTIVE: The objective was to evaluate outcomes of mammographic architectural distortion (AD) with and without MRI and US correlates. METHODS: A retrospective review of unexplained mammographic AD with subsequent MRI from January 1, 2007 to September 30, 2017 was performed using a reader-based study design. Mammographic, MRI, and US features and outcomes were documented. Truth was based on biopsy results or minimum two-year imaging follow-up. Measures of diagnostic accuracy were calculated. RESULTS: Fifty-six cases of AD were included: 29 (51.8%) detected on 2D mammogram and 27 (48.2%) detected on digital breast tomosynthesis. Of 35.7% (20/56) with MRI correlate, 40.0% (8/20) were enhancing masses, 55.0% (11/20) were non-mass enhancement (NME), and 5.0% (1/20) were nonenhancing AD. Of eight enhancing masses, 75.0% (6/8) were invasive cancers, and 25.0% (2/8) were high-risk lesions. Of 11 NME, 18.2% (2/11) were ductal carcinoma in situ, 36.4% (4/11) were high-risk lesions, and 45.4% (5/11) were benign. Of 64.3% (36/56) without MRI correlate, 94.4% (34/36) were benign by pathology or follow-up, one (2.8%, 1/36) was a 4-mm focus of invasive cancer with US correlate, and one (1/36, 2.8%) was a high-risk lesion. Of cases without MRI and US correlates, one (3.0%, 1/33) was a high-risk lesion and 97.0% (32/33) were benign. The negative predictive value of mammographic AD without MRI correlate was 97.2% (35/36) and without both MRI and US correlates was 100.0% (33/33). CONCLUSION: Mammographic AD without MRI or US correlate was not cancer in our small cohort and follow-up could be considered, reducing interventions.

Prospective Evaluation of the Cost of Performing Breast Imaging Examinations Using a Time-Driven Activity-Based Costing Method: A Single-Center Study.

OBJECTIVE: Measuring the cost of performing breast imaging is difficult in healthcare systems. The purpose of our study was to evaluate this cost using time-driven activity-based costing (TDABC) and to evaluate cost drivers for different exams. METHODS: An IRB-approved, single-center prospective study was performed on 80 female patients presenting for breast screening, diagnostic or biopsy exams from July 2020 to April 2021. Using TDABC, data were collected for each exam type. Included were full-field digital mammography (FFDM), digital breast tomosynthesis (DBT), contrast-enhanced mammography (CEM), US and MRI exams, and stereotactic, US-guided and MRI-guided biopsies. For each exam type, mean cost and relative contributions of equipment, personnel and supplies were calculated. RESULTS: Screening MRI, CEM, US, DBT, and FFDM costs were $249, $120, $83, $28, and $30. Personnel was the major contributor to cost (60.0%-87.0%) for all screening exams except MRI where equipment was the major contributor (62.2%). Diagnostic MRI, CEM, US, and FFDM costs were $241, $123, $70, and $43. Personnel was the major contributor to cost (60.5%-88.6%) for all diagnostic exams except MRI where equipment was the major contributor (61.8%). Costs of MRI-guided, stereotactic and US-guided biopsy were $1611, $826, and $356. Supplies contributed 40.5%-49.8% and personnel contributed 30.7%-55.6% to the total cost of biopsies. CONCLUSION: TDABC provides assessment of actual costs of performing breast imaging. Costs and contributors varied across screening, diagnostic and biopsy exams and modalities. Practices may consider this methodology in understanding costs and making changes directed at cost savings.

Enhancement Type at Contrast-enhanced Mammography and Association with Malignancy.

Background Despite the increasing use of contrast-enhanced mammography (CEM), there are limited data on the evaluation of findings on recombined images and the association with malignancy. Purpose To determine the rates of malignancy of enhancement findings on CEM images in the presence or absence of low-energy findings using the Breast Imaging Reporting and Data System (BI-RADS) lexicon developed for mammography and MRI. Materials and Methods All diagnostic CEM examinations performed at one academic institution between December 2015 and December 2019 had low-energy and recombined images retrospectively. Data were independently reviewed by three breast imaging radiologists with 5-25 years of experience using the BI-RADS mammography and MRI lexicon. Outcome was determined with pathologic analysis or 1-year imaging or clinical follow-up. The χ2 and Fisher exact tests were used for analysis. Results A total of 371 diagnostic CEM studies were performed in 371 women (mean age, 54 years ± 11[SD]). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value of enhancement on CEM images was 95% (104 of 109 [95% CI: 90, 98]), 67% (176 of 262 [95% CI: 61, 73]), 55% (104 of 190 [95% CI: 47, 62]), and 97% (176 of 181 [95% CI: 94, 99]), respectively. Among 190 CEM studies with enhancing findings, enhancing lesions were more likely to be malignant when associated with low-energy findings (26% vs 59%, P < .001). Among enhancement types, mass enhancement composed 71% (99 of 140) of all malignancies with PPV of 63% when associated with low-energy findings. Foci, non-mass enhancement, and mass enhancement without low-energy findings had PPV of 6%, 24%, and 38%, respectively. Neither background parenchymal enhancement nor density was associated with enhancement type (P = .19 and P = .28, respectively). Conclusion Mass enhancement on recombined images using CEM was most commonly associated with malignancy, especially when associated with low-energy findings. Enhancement types were more likely to be benign when not associated with low-energy findings; however, they should still be viewed with suspicion, given the high association with malignancy. © RSNA, 2022 Online supplemental material is available for this article.

Characterization of True and False Positive Findings on Contrast-Enhanced Mammography.

RATIONALE AND OBJECTIVES: The purpose of this paper is to characterize true and false positive findings on contrast-enhanced mammography (CEM) and correlate enhancement pattern and method of detection with pathology outcomes. MATERIALS AND METHODS: This was an IRB-approved retrospective review of diagnostic CEM performed from December 2015 through December 2019 for which biopsy was recommended. Background parenchymal enhancement, tissue density, finding features, pathologic/clinical outcomes, and method of detection were captured. CEM includes low-energy images (LE), similar to standard 2D mammography, and recombined images (RI) that show enhancement. 'MG-detected' findings were identified on mammography or LE. 'RI-detected' findings were identified due to enhancement on RI. The positive predictive value (PPV2) was calculated on a per-case and a per-finding level. Comparisons were performed using Pearson chi-square and Fisher exact tests. RESULTS: One hundred sixty CEM cases with 220 findings were evaluated with a case PPV2 of 58.1%. 32.3% (71/220) of lesions were RI-detected.  The PPV2 of RI-detected enhancement was 40.8% with subanalysis revealing PPV2 of 22.2%, 32%, and 51.4% for foci, NME, and masses, respectively. The PPV2 of MG-detected enhancement was 73.5% with subanalysis revealing PPV2 of 50%, 54.1%, and 83.8% for foci, NME, and masses, respectively. There were 100 false positives findings, 42 of which were RI-detected. CONCLUSION: PPV2 of diagnostic CEM is within the range of other diagnostic breast imaging exams. However false positives remain a challenge, especially for RI-detected findings. Additional efforts to improve specificity of RI-detected findings are worthwhile.

Patient preferences regarding use of contrast-enhanced imaging for breast cancer screening.

RATIONALE AND OBJECTIVES: Our purpose is to understand patient preferences towards contrast-enhanced imaging such as CEM or MRI for breast cancer screening. METHODS AND MATERIALS: An anonymous survey was offered to all patients having screening mammography at a single academic institution from December 27 th 2019 to March 6 th 2020. Survey questions related to: (1) patients' background experiences (2) patients' concern for aspects of MRI and CEM measured using a 5-point Likert scale, and (3) financial considerations. RESULTS: 75% (1011/1349) patients completed the survey. 53.0% reported dense breasts and of those, 47.6% had additional screening. 49.6% had experienced a callback, 29.0% had a benign biopsy, and 13.7% had prior CEM/MRI. 34.7% were satisfied with mammography for screening. A majority were neutral or not concerned with radiation exposure, contrast allergy, IV line placement, claustrophobia, and false positive exams. 54.7% were willing to pay at least $250-500 for screening MRI. Those reporting dense breasts were less satisfied with mammography for screening (p<0.001) and willing to pay more for MRI (p<0.001). If patients had prior CEM/MRI, there was less concern for an allergic reaction (p<0.001), IV placement (p=0.025), and claustrophobia (p=0.006). There was less concern for false positives if they had a prior benign biopsy (p=0.029) or prior CEM/MRI (p=0.005) and less concern for IV placement if they had dense breasts (p=0.007) or a previous callback (p=0.013). CONCLUSION: The screening population may accept CEM or MRI as a screening exam despite its risks and cost, especially patients with dense breasts and patients who have had prior CEM/MRI.

Upgrade Rates of Pure, Radiology-Pathology Concordant Lobular Neoplasia Diagnosed on Breast Core Needle Biopsy: Is Surgical Excision Warranted?

OBJECTIVE: To determine upgrade rates of lobular neoplasia (LN) to malignancy and evaluate factors that may predict upgrade. METHODS: From 5/1/2003 to 12/30/2015, breast lesions diagnosed as LN (atypical lobular hyperplasia [ALH] or classic lobular carcinoma in-situ [LCIS]) on core biopsy that underwent surgical excision or at least 2 years imaging follow-up were identified. A subspecialty trained breast radiologist and pathologist reviewed imaging and pathology slides to confirm diagnosis and to determine if LN represented the target lesion, part of the target lesion, or an incidental finding. Imaging features, original BI-RADS final assessment category, biopsy method, biopsy device and final pathologic diagnosis were documented. Cases with both ALH and LCIS were classified as LCIS for analysis. Reason for biopsy of BI-RADS 2-3 was patient or referring physician preference. Upgrade rates to malignancy were determined for all cases. RESULTS: In this study 73.7% (115/156) lesions were ALH and 26.3% (41/156) were LCIS+/-ALH. Surgical excision and imaging follow-up were performed in 71.2% (111/156) and 28.8% (45/156), respectively. Upgrade rates for ALH and LCIS were 0.0% (0/115) and 7.3% (3/41), respectively. Cancer developed at a site separate from core biopsy in 1.7% (2/115) ALH and 7.3% (3/41) LCIS cases. We found no association of upgrade rate with biopsy type, BI-RADS or target/part of target lesion versus incidental. CONCLUSION: Our study supports consideration of excision for LCIS, given 7.3% upgrade rate. Conversely, imaging surveillance might be appropriate following diagnosis of ALH alone.

Cancer Conspicuity on Low-energy Images of Contrast-enhanced Mammography Compared With 2D Mammography.

OBJECTIVE: Low-energy (LE) images of contrast-enhanced mammography (CEM) have been shown to be noninferior to digital mammography. However, our experience is that LE images are superior to 2D mammography. Our purpose was to compare cancer appearance on LE to 2D images. METHODS: In this IRB-approved retrospective study, seven breast radiologists evaluated 40 biopsy-proven cancer cases on craniocaudal (CC) and mediolateral oblique (MLO) LE images and recent 2D images for cancer visibility, confidence in margins, and conspicuity of findings using a Likert scale. Objective measurements were performed using contrast-to-noise ratio (CNR) estimated from regions of interest placed on tumor and background parenchyma. Reader agreement was evaluated using Fleiss kappa. Per-reader comparisons were performed using Wilcoxon test and overall comparisons used three-way analysis of variance. RESULTS: Low-energy images showed improved performance for visibility (CC LE 4.0 vs 2D 3.5, P < 0.001 and MLO LE 3.7 vs 2D 3.5, P = 0.01), confidence in margins (CC LE 3.2 vs 2D 2.8, P < 0.001 and MLO LE 3.1 vs 2D 2.9, P < 0.008), and conspicuity compared to tissue density compared to 2D mammography (CC LE 3.6 vs 2D 3.2, P < 0.001 and MLO LE 3.5 vs 2D 3.2, P < 0.001). The average CNR was significantly higher for LE than for digital mammography (CC 2.1 vs 3.2, P < 0.001 and MLO 2.1 vs 3.4, P < 0.001). CONCLUSION: Our results suggest that cancers may be better visualized on the LE CEM images compared with the 2D digital mammogram.

Tips for Successful Career Transitions in Breast Imaging.

Whether beginning a new career in breast imaging or switching into a different breast imaging practice for personal or professional advancement, a leadership opportunity, a need to relocate geographically, or simply a better opportunity, it is critical to transition between positions as smoothly as possible. Thoroughly reflecting on your career priorities and goals is essential prior to undertaking any career transition. Once the decision has been made to move to a new position, it is imperative to learn about the dynamics of the new practice and practice environment. Here, we provide suggestions on how to hit the ground running when joining a new breast imaging practice.

Development of a novel framework to evaluate the localization accuracy of tomosynthesis-guided breast biopsy units.

PURPOSE: To develop a scheme to quantitatively assess localization accuracy of tomosynthesis-guided vacuum-assisted breast biopsy apparatus. METHODS: A phantom containing a metallic pellet on a flexible plastic shaft was constructed and was tested in cranio-caudal (CC) and lateral (LAT) arm biopsy geometries following the standard clinical breast biopsy workflow. Three points were manually digitized on tomosynthesis images including: the center of the target, and the tip of the needle in pre- and postfire positions. The needle trajectory was determined and four error metrics were defined: (1) stroke length error (difference between the nominal and measured stroke lengths); (2) Euclidian distance between the target and center of trough (i.e., aperture); (3) longitudinal distance between target and center of trough; and (4) lateral distance between target and needle. The proposed methodology was also evaluated on a breast gel phantom and the complete biopsy procedure, including vacuum-assisted biopsy was performed. RESULTS: Three biopsy geometries were investigated: (i) LAT arm on a prone table unit (Hologic, Affirm Prone), (ii) CC- and (iii) LAT arm in an upright unit (Hologic Affirm Upright). Both biopsy units passed the vendor-provided daily localization accuracy test, with <1 mm nominal error in each dimension. The aforementioned error metrics (1) to (4) were (0.6, 1.8, 0.4, 1.7) mm, (0.4, 4.2, 4.1, 1.1) mm, and (0.3, 2.4, 0.7, 2.3) mm, respectively, for geometry-I, -II, and -III. The gel phantom was tested on the upright unit with lateral arm and the error metrics (1) to (4) were 0.4, 2.5, 0.8, and 2.4 mm respectively. CONCLUSIONS: A framework was developed to evaluate the tomosynthesis-guided breast biopsy localization error, allowing quantitative comparisons between different systems and biopsy configurations. The proposed framework can also be extended to the stereotactic breast biopsy units. We suggest that a quantitative tolerance level for localization accuracy of breast biopsy units be established.

Histopathologic Correlates of Nonmass Enhancement Detected by Breast Magnetic Resonance Imaging.

CONTEXT.­: Dynamic, contrast-enhanced magnetic resonance imaging (MRI) is a highly sensitive imaging modality used for screening and diagnostic purposes. Nonmass enhancement (NME) is commonly seen on MRI of the breast. However, the pathologic correlates of NME have not been extensively explored. Consequently, concordance between MRI and pathologic findings in such cases may be uncertain and this uncertainty may cause the need for additional procedures. OBJECTIVE.­: To examine the histologic alterations that correspond to NME on MRI. DESIGN.­: We performed a retrospective search for women who underwent breast MRI between March 2014 and December 2016 and identified 130 NME lesions resulting in biopsy. The MRI findings and pathology slides for all cases were reviewed. The follow-up findings on any subsequent excisions were also noted. RESULTS.­: Among the 130 cases, the core needle biopsy showed 1 or more benign lesions without atypia in 80 cases (62%), atypical lesions in 21 (16%), ductal carcinoma in situ in 22 (17%), and invasive carcinoma in 7 (5%). Review of the imaging features demonstrated some statistically significant differences in lesions that corresponded to malignant lesions as compared with benign alterations, including homogeneous or clumped internal enhancement, type 3 kinetics, and T2 dark signal; however, there was considerable overlap of features between benign and malignant lesions overall. Of 130 cases, 54 (41.5%) underwent subsequent excision with only 6 cases showing a worse lesion on excision. CONCLUSIONS.­: This study illustrates that NME can be associated with benign, atypical, and/or malignant pathology and biopsy remains indicated given the overlap of radiologic features.

Factors Associated With Background Parenchymal Enhancement on Contrast-Enhanced Mammography.

OBJECTIVE. The purpose of this study was to determine the relationship between background parenchymal enhancement (BPE) on contrast-enhanced mammography (CEM) and breast tissue density, menstrual status, endocrine therapy, and risk factors for breast cancer and also to evaluate interreader agreement on classification of BPE on CEM. MATERIALS AND METHODS. Five subspecialty-trained breast radiologists independently and blindly graded tissue density (with fatty tissue and scattered fibroglandular tissue classified as nondense tissue and with heterogeneously dense and extremely dense classified as dense tissue) and BPE (with minimal or mild BPE categorized as low BPE and moderate or marked BPE categorized as high BPE) on CEM examinations performed from 2014 to 2018. Electronic medical charts were reviewed for information on menstrual status, endocrine therapy, history of breast surgery, and other risk factors for breast cancer. Comparisons were performed using the Kruskal-Wallis test, Mann-Whitney test, and Spearman rank correlation. Interreader agreement was estimated using the Fleiss kappa test. RESULTS. A total of 202 patients (mean [± SD] age, 54 ± 10 years; range, 25-84 years) underwent CEM. Tissue density was categorized as fatty in two patients (1%), scattered fibroglandular in 67 patients (33%), heterogeneously dense in 117 patients (58%), and extremely dense in 16 patients (8%). Among the 202 patients, BPE was minimal in 77 (38%), mild in 80 (40%), moderate in 31 (15%), and marked in 14 (7%). Dense breasts, younger age, premenopausal status, no history of endocrine therapy, and no history of breast cancer were significantly associated with high BPE. Among premenopausal patients, no association was found between BPE and time from last menstrual period to CEM. Overall interreader agreement on BPE was moderate (κ = 0.41; 95% CI, 0.40-0.42). Interreader agreement on tissue density was substantial (κ = 0.67; 95% CI, 0.66-0.69). CONCLUSION. Women with dense breasts, premenopausal status, and younger age are more likely to have greater BPE. Targeting CEM to the last menstrual period is not indicated.

Contrast-enhanced Mammography: A Guide to Setting Up a New Clinical Program.

Contrast-enhanced mammography (CEM) is gaining rapid traction following the U.S. Food and Drug Administration approval for diagnostic indications. Contrast-enhanced mammography is an alternative form of mammography that uses a dual-energy technique for image acquisition after the intravenous administration of iodinated contrast material. The resulting exam includes a dual set of images, one that appears similar to a routine 2D mammogram and one that highlights areas of contrast uptake. Studies have shown improved sensitivity compared to mammography and similar performance to contrast-enhanced breast MRI. As radiology groups incorporate CEM into clinical practice they must first select the indications for which CEM will be used. Many practices initially use CEM as an MRI alternative or in cases recommended for biopsy. Practices should then define the CEM clinical workflow and patient selection to include ordering, scheduling, contrast safety screening, and managing imaging on the day of the exam. The main equipment requirements for performing CEM include CEM-capable mammography equipment, a power injector for contrast administration, and imaging-viewing capability. The main staffing requirements include personnel to place the intravenous line, perform the CEM exam, and interpret the CEM. To safely and appropriately perform CEM, staff must be trained in their respective roles and to manage potential contrast-related events. Lastly, informing referring colleagues and patients of CEM through marketing campaigns is helpful for successful implementation.

Injected Breast Materials: Review of Imaging Features and Characteristics.

In the United States, silicone and saline breast implants with their familiar radiologic appearance are the mainstays of breast augmentation. However, less well-known sequelae of unconventional injected materials introduced for cosmetic and noncosmetic purposes may also be encountered on breast imaging-for example, free silicone, paraffin and/or oil, polyacrylamide gel, autologous fat, and hyaluronic acid, which are encountered in the setting of breast augmentation. Breast injection of go-yak is not cosmetic but also results in characteristic imaging findings. Breast changes due to extravasation of chemotherapy or interstitial brachytherapy can mimic the appearance of injected noncosmetic materials. Because many of these materials can mimic or obscure imaging findings of breast cancer, it is important to recognize their varied appearances and the limitations of imaging alone in delineating breast injection material from cancer. Given the relatively uncommon incidence of injected materials into the breast, this article aims to review the imaging appearance in order to aid radiologists in maximizing cancer detection and ensuring optimal patient management.

A Roadmap for a Successful Breast Imaging Fellowship.

Breast imaging is an important field within radiology, having made significant strides in helping reduce morbidity and mortality from breast cancer. Historically, breast imaging radiologists learned mammography and ultrasound skills on the job as a part of general radiology training. However, breast imaging as a subspecialty has grown over time with the emergence of breast imaging fellowships across the country. Despite this growth, breast imaging fellowships remain nonaccredited through the American College of Graduate Medical Education, and as a result, there are significant variations in training programs throughout the country. In this article, we will provide guidelines on organizing a breast imaging fellowship to help standardize the experience of fellows entering the breast imaging community. This will include guidelines regarding providing adequate clinical exposure, developing a fund of knowledge, fostering extra-clinical interests, and providing constructive feedback for ongoing improvement.