Comparison of the Diagnostic Accuracy of Mammogram-based Deep Learning and Traditional Breast Cancer Risk Models in Patients Who Underwent Supplemental Screening with MRI.

Background Access to supplemental screening breast MRI is determined using traditional risk models, which are limited by modest predictive accuracy. Purpose To compare the diagnostic accuracy of a mammogram-based deep learning (DL) risk assessment model to that of traditional breast cancer risk models in patients who underwent supplemental screening with MRI. Materials and Methods This retrospective study included consecutive patients undergoing breast cancer screening MRI from September 2017 to September 2020 at four facilities. Risk was assessed using the Tyrer-Cuzick (TC) and National Cancer Institute Breast Cancer Risk Assessment Tool (BCRAT) 5-year and lifetime models as well as a DL 5-year model that generated a risk score based on the most recent screening mammogram. A risk score of 1.67% or higher defined increased risk for traditional 5-year models, a risk score of 20% or higher defined high risk for traditional lifetime models, and absolute scores of 2.3 or higher and 6.6 or higher defined increased and high risk, respectively, for the DL model. Model accuracy metrics including cancer detection rate (CDR) and positive predictive values (PPVs) (PPV of abnormal findings at screening [PPV1], PPV of biopsies recommended [PPV2], and PPV of biopsies performed [PPV3]) were compared using logistic regression models. Results This study included 2168 women who underwent 4247 high-risk screening MRI examinations (median age, 54 years [IQR, 48-60 years]). CDR (per 1000 examinations) was higher in patients at high risk according to the DL model (20.6 [95% CI: 11.8, 35.6]) than according to the TC (6.0 [95% CI: 2.9, 12.3]; P < .01) and BCRAT (6.8 [95% CI: 2.9, 15.8]; P = .04) lifetime models. PPV1, PPV2, and PPV3 were higher in patients identified as high risk by the DL model (PPV1, 14.6%; PPV2, 32.4%; PPV3, 36.4%) than those identified as high risk with the TC (PPV1, 5.0%; PPV2, 12.7%; PPV3, 13.5%; P value range, .02-.03) and BCRAT (PPV1, 5.5%; PPV2, 11.1%; PPV3, 12.5%; P value range, .02-.05) lifetime models. Conclusion Patients identified as high risk by a mammogram-based DL risk assessment model showed higher CDR at breast screening MRI than patients identified as high risk with traditional risk models. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Bae in this issue.

Evidence-Based Pragmatic Approach to the Management of Borderline or High-Risk Breast Lesions.

The management of borderline or high-risk breast lesions (HRLs) remains controversial. We propose a pragmatic evidence-based approach based on lesion type. For lobular carcinoma in situ with pleomorphism, papilloma with atypia, atypical ductal hyperplasia, and fibroepithelial lesions, surgical consultation and excision are recommended. Patients with other borderline or HRLs are referred for surgical consultation to discuss excision versus surveillance. Our recommendations align with American Society of Breast Surgeons guidelines, which aim to reduce unnecessary surgery and ensure appropriate follow-up.

Artificial Intelligence (AI) for Screening Mammography, From the AJR Special Series on AI Applications.

Artificial intelligence (AI) applications for screening mammography are being marketed for clinical use in the interpretative domains of lesion detection and diagnosis, triage, and breast density assessment and in the noninterpretive domains of breast cancer risk assessment, image quality control, image acquisition, and dose reduction. Evidence in support of these nascent applications, particularly for lesion detection and diagnosis, is largely based on multireader studies with cancer-enriched datasets rather than rigorous clinical evaluation aligned with the application's specific intended clinical use. This article reviews commercial AI algorithms for screening mammography that are currently available for clinical practice, their use, and evidence supporting their performance. Clinical implementation considerations, such as workflow integration, governance, and ethical issues, are also described. In addition, the future of AI for screening mammography is discussed, including the development of interpretive and noninterpretive AI applications and strategic priorities for research and development.

Disparities in Same-Day Diagnostic Imaging in Breast Cancer Screening: Impact of an Immediate-Read Screening Mammography Program Implemented During the COVID-19 Pandemic.

BACKGROUND. The need for second visits between screening mammography and diagnostic imaging contributes to disparities in the time to breast cancer diagnosis. During the COVID-19 pandemic, an immediate-read screening mammography program was implemented to reduce patient visits and decrease time to diagnostic imaging. OBJECTIVE. The purpose of this study was to measure the impact of an immediate-read screening program with focus on disparities in same-day diagnostic imaging after abnormal findings are made at screening mammography. METHODS. In May 2020, an immediate-read screening program was implemented whereby a dedicated breast imaging radiologist interpreted all screening mammograms in real time; patients received results before discharge; and efforts were made to perform any recommended diagnostic imaging during the visit (performed by different radiologists). Screening mammographic examinations performed from June 1, 2019, through October 31, 2019 (preimplementation period), and from June 1, 2020, through October 31, 2020 (postimplementation period), were retrospectively identified. Patient characteristics were recorded from the electronic medical record. Multivariable logistic regression models incorporating patient age, race and ethnicity, language, and insurance type were estimated to identify factors associated with same-day diagnostic imaging. Screening metrics were compared between periods. RESULTS. A total of 8222 preimplementation and 7235 postimplementation screening examinations were included; 521 patients had abnormal screening findings before implementation, and 359 after implementation. Before implementation, 14.8% of patients underwent same-day diagnostic imaging after abnormal screening mammograms. This percentage increased to 60.7% after implementation. Before implementation, patients who identified their race as other than White had significantly lower odds than patients who identified their race as White of undergoing same-day diagnostic imaging after receiving abnormal screening results (adjusted odds ratio, 0.30; 95% CI, 0.10-0.86; p = .03). After implementation, the odds of same-day diagnostic imaging were not significantly different between patients of other races and White patients (adjusted odds ratio, 0.92; 95% CI, 0.50-1.71; p = .80). After implementation, there was no significant difference in race and ethnicity between patients who underwent and those who did not undergo same-day diagnostic imaging after receiving abnormal results of screening mammography (p > .05). The rate of abnormal interpretation was significantly lower after than it was before implementation (5.0% vs 6.3%; p < .001). Cancer detection rate and PPV1 (PPV based on positive findings at screening examination) were not significantly different before and after implementation (p > .05). CONCLUSION. Implementation of the immediate-read screening mammography program reduced prior racial and ethnic disparities in same-day diagnostic imaging after abnormal screening mammograms. CLINICAL IMPACT. An immediate-read screening program provides a new paradigm for improved screening mammography workflow that allows more rapid diagnostic workup with reduced disparities in care.

Screening Mammography Recovery After COVID-19 Pandemic Facility Closures: Associations of Facility Access and Racial and Ethnic Screening Disparities.

BACKGROUND. Screening mammography facilities closed during the COVID-19 pandemic in spring 2020. Recovery of screening volumes has varied across patient subgroups and facilities. OBJECTIVE. We compared screening mammography volumes and patient and facility characteristics between periods before COVID-19 and early and later postclosure recovery periods. METHODS. This retrospective study included screening mammograms performed in the same 2-month period (May 26-July 26) in 2019 (pre-COVID-19), 2020 (early recovery), and 2021 (late recovery after targeted interventions to expand access) and across multiple facility types (urban, suburban, community health center). Suburban sites had highest proportion of White patients and the greatest scheduling flexibility and expanded appointments during initial reopening. Findings were compared across years. RESULTS. For White patients, volumes decreased 36.6% from 6550 in 2019 (4384 in 2020) and then increased 61.0% to 6579 in 2021; for patients with races other than White, volumes decreased 53.9% from 1321 in 2019 (609 in 2020) and then increased 136.8% to 1442 in 2021. The percentage of mammograms in patients with races other than White was 16.8% in 2019, 12.2% in 2020, and 18.0% in 2021. The proportion performed at the urban center was 55.3% in 2019, 42.2% in 2020, and 45.9% in 2021; the proportion at suburban sites was 34.0% in 2019, 49.2% in 2020, and 43.5% in 2021. Pre-COVID-19 volumes were reached by the sixth week after reopening for suburban sites but were not reached during early recovery for the other sites. The proportion that were performed on Saturday for suburban sites was similar across periods, whereas the proportion performed on Saturday for the urban site was 7.6% in 2019, 5.3% in 2020, and 8.8% in 2021; the community health center did not offer Saturday appointments during recovery. CONCLUSION. After reopening, screening shifted from urban to suburban settings, with a disproportionate screening decrease in patients with races other than White. Initial delayed access at facilities serving underserved populations exacerbated disparities. Interventions to expand access resulted in late recovery volumes exceeding prepandemic volumes in patients with races other than White. CLINICAL IMPACT. Interventions to support equitable access across facilities serving diverse patient populations may mitigate potential widening disparities in breast cancer diagnosis during the pandemic.

Predictors of Reexcision following Breast-Conserving Surgery for Ductal Carcinoma In Situ.

BACKGROUND: Reexcision following breast-conserving surgery (BCS) in women with ductal carcinoma in situ (DCIS) results in adjuvant treatment delays, higher health care costs, and undesirable cosmetic outcomes. The purpose of this study is to determine patient, imaging, pathological, and surgical predictors of reexcision following BCS for DCIS. PATIENTS AND METHODS: A retrospective review of women with DCIS who had BCS from 2007 to 2016 was conducted. Patient, imaging, pathological, and surgical features, in addition to surgical outcomes, were collected from medical records. Standard statistical tests were used to compare features between patients who did and did not undergo at least one reexcision. A multivariable logistic regression model was fit to assess features associated with reexcision. RESULTS: A total of 547 women (mean age 59 years; range 30-88 years) diagnosed with DCIS at core needle biopsy underwent BCS. Of all women, 31.6% (173/547) had at least one reexcision. With multivariable analysis, features associated with reexcision included younger patient age (adjusted odds ratio [aOR] 0.98, 95% confidence interval [CI] 0.97-1.0, p = 0.049), African-American race (aOR 2.66, 95% CI 1.13-6.26, p = 0.03), biopsy modality of ultrasound (aOR 2.35, 95% CI 1.22-4.53, p = 0.01), and earlier year of surgery (aOR 0.92, 95% CI 0.86-0.98, p = 0.01). No pathological features of DCIS were associated with reexcision risk. CONCLUSIONS: In our cohort of nearly 550 women with DCIS who underwent BCS, 31.6% had at least one reexcision. Features associated with reexcision include younger patient age, African-American race, biopsy modality of ultrasound, and earlier year of surgery.

Mitigating the Impact of Coronavirus Disease (COVID-19) Vaccinations on Patients Undergoing Breast Imaging Examinations: A Pragmatic Approach.

Reports of patients with axillary adenopathy identified on breast imaging after coronavirus disease (COVID-19) vaccination are rising. We propose a pragmatic management approach based on clinical presentation, vaccination delivery, and imaging findings. In the settings of screening mammography, screening MRI, and diagnostic imaging workup of breast symptoms, with no imaging findings beyond unilateral axillary adenopathy ipsilateral to recent (within the past 6 weeks) vaccination, we report the adenopathy as benign with no further imaging indicated if no nodes are palpable 6 weeks after the last dose. For patients with palpable axillary adenopathy in the setting of ipsilateral recent vaccination, clinical follow-up of the axilla is recommended. In all these scenarios, axillary ultrasound is recommended if clinical concern persists 6 weeks after vaccination. In patients with a recent breast cancer diagnosis in the pre- or peritreatment setting, prompt recommended imaging is encouraged as well as vaccination (in the thigh or contralateral arm). Our recommendations align with the ACR BI-RADS Atlas and aim to reduce patient anxiety, provider burden, and costs of unnecessary evaluation of enlarged nodes in the setting of recent vaccinations and, also, to avoid further delays in vaccinations and breast cancer screening during the pandemic.

Retrospective Review of Preoperative Radiofrequency Tag Localization of Breast Lesions in 848 Patients.

BACKGROUND. Advantages of radiofrequency tags for preoperative breast lesion localization include decoupling of tag placement from surgical schedules and improved patient comfort. OBJECTIVE. The purpose of this study was to evaluate the feasibility of a preoperative localization radiofrequency tag system for breast lesions requiring surgical excision. METHODS. The cohort for this retrospective study included consecutive patients who underwent image-guided needle localization with radiofrequency tags before surgical excision from July 12, 2018, to July 31, 2019. Images and medical records were reviewed to evaluate the pathologic diagnoses serving as indications for tag placement, imaging guidance for tag placement, number of tags placed, and target lesion type. Tag placement technical accuracy rate (defined as deployment of the tag within 1 cm of the edge of the target), success (defined as technical accuracy without complication), and surgical margin and reexcision status were evaluated. RESULTS. A total of 1013 tags were placed under imaging guidance in 848 patients (mean age, 60 years; range, 23-96 years) and 847 subsequently underwent surgical excision. Tags were most commonly placed for invasive carcinoma (537/1013, 53.0%), ductal carcinoma in situ (138/1013, 13.6%), and high-risk lesions (289/1013, 28.5%). A total of 673 (66.4%) tags were deployed under mammographic guidance, whereas 340 (33.6%) were placed under sonographic guidance. Two or more tags were placed in 149 of 848 patients (17.6%). Targeted lesion types primarily included masses (448/1013, 44.2%), biopsy clip markers (331/1013, 32.7%), and calcifications (155/1013, 15.3%). Technical accuracy of placement was achieved in 1004 (99.1%) tags. Of the nine inaccurate tag placements, seven (77.8%) required an additional tag or wire placement. Seven (0.7%) biopsy clip markers were displaced within the breast or removed by the tag device during placement. No complications were reported intraoperatively. Therefore, success was achieved in 997 (98.4%) tags. Tags were successfully retrieved in all 847 patients who underwent surgery. Of the 568 patients with a preoperative diagnosis of carcinoma, 86 (15.1%) had positive or close surgical margins requiring surgical reexcision. CONCLUSION. Preoperative image-guided localization with radiofrequency tags is a safe and feasible technique for breast lesions requiring surgery. CLINICAL IMPACT. Radiofrequency tag localization is an acceptable alternative to needle or wire localization, offering the potential for improved patient workflow and experience.

Node-Positive Patients Treated with Neoadjuvant Chemotherapy Can Be Spared Axillary Lymph Node Dissection with Wireless Non-Radioactive Localizers.

BACKGROUND: Targeted axillary dissection (TAD) involves sentinel lymph node biopsy (SLNB) and excision of a biopsy-proven node marked by a clip. This study evaluates the feasibility of non-radioactive wireless localizers for targeted excision of clipped axillary lymph nodes. METHODS: We identified biopsy-proven, node-positive breast cancer patients treated with neoadjuvant therapy (NAT) and TAD from 2016 to 2020, and included those with a clipped node localized using SAVI SCOUT, Magseed, or RFID Tag. Primary outcome measures were (1) successful localization (ultrasound or mammographic-guided placement < 10 mm from target), and (2) retrieval of the clipped node during TAD, documented by specimen radiography or gross visualization. Secondary outcomes included rates of completion axillary lymph node dissection (cALND) and complications. RESULTS: Overall, 57 patients were included; 1 (1.8%) patient had no clip visible at the time of localization, and no radiographic confirmation of clip placement at the time of biopsy, and was therefore excluded. In the remaining 56 patients, localization was successful in 53 (94.6%) patients and the clipped node was retrieved during TAD in 51 (91.1%) patients. Twenty-three of 27 (85.2%) ypN0 patients were spared cALND; 3 (11.1%) patients had cALND for failed clipped node retrieval during TAD, and 1 (3.7%) for false-positive frozen section. In patients with TAD alone, the rates of axillary seroma and infection were 20.0% and 8.6%, respectively. CONCLUSIONS: Wireless non-radioactive localizers are feasible for axillary localization after NAT, with high success rates of retrieving clipped nodes. The lack of signal decay is an advantage of these devices, allowing flexibility in timing of placement.

Frequency and Cancer Yield of BI-RADS Category 3 Lesions Detected at High-Risk Screening Breast MRI.

OBJECTIVE. The purpose of this study was to evaluate the frequency and cancer yield of BI-RADS category 3 lesions in baseline versus nonbaseline (those with at least one prior) MRI screening examinations. MATERIALS AND METHODS. Consecutive MRI screening examinations performed from 2011 through 2015 were reviewed. Pearson and Wilcoxon tests were used to examine differences in age, breast density, screening indication, background parenchymal enhancement, and cancer yield between baseline and nonbaseline MRI BI-RADS category 3 assessments. Multivariate logistic regression models based on generalized estimating equations were used to assess the odds of receiving a BI-RADS 3 assessment as a function of the variables. RESULTS. Of 6672 MRI screening examinations of 3214 patients, 202 examinations (3%) were assessed BI-RADS category 3. Among baseline examinations, 8% (82/983) were assessed BI-RADS 3, compared with 2% (120/5689) of nonbaseline examinations (p < 0.001). Among the total BI-RADS 3 examinations, 6% (13/202) yielded malignancy of the lesion that had been assessed BI-RADS 3; 12 of 13 cancers were stage 0 or I at diagnosis. The cancer yield of BI-RADS 3 at baseline examinations was 2% (2/82), compared with 9% (11/120) for nonbaseline examinations (p = 0.056). Ten of 13 examinations were upgraded at or before 6-month follow-up MRI. CONCLUSION. Baseline screening breast MRI examinations are associated with a significantly higher rate of BI-RADS category 3 assessments than are nonbaseline examinations. Most cancers diagnosed at follow-up of BI-RADS 3 lesions are in an early stage and are diagnosed at or before the 6-month follow-up examination. When used judiciously, short-interval follow-up MRI is an appropriate method for identifying early-stage breast cancer while avoiding unnecessary biopsies with benign findings.

Missed Breast Cancer: Effects of Subconscious Bias and Lesion Characteristics.

Medical errors are a substantial cause of morbidity and mortality and the third leading cause of death in the United States. Errors resulting in missed breast cancer are the most common reason for medical malpractice lawsuits against all physicians. Missed breast cancers are breast malignancies that are detectable at retrospective review of a previously obtained mammogram that was prospectively reported as showing negative, benign, or probably benign findings. Investigators in prior studies have found that up to 35% of both interval cancers and screen-detected cancers could be classified as missed. As such, in conjunction with having awareness of the most common misleading appearances of breast cancer, it is important to understand the cognitive processes and unconscious biases that can impact image interpretation, thereby helping to decrease the number of missed breast cancers. The various cognitive processes that lead to unconscious bias in breast imaging, such as satisfaction of search, inattention blindness, hindsight, anchoring, premature closing, and satisfaction of reporting, are outlined in this pictorial review of missed breast cancers. In addition, strategies for reducing the rates of these missed cancers are highlighted. The most commonly missed and misinterpreted lesions, including stable lesions, benign-appearing masses, one-view findings, developing asymmetries, subtle calcifications, and architectural distortion, also are reviewed. This information will help illustrate why and how breast cancers are missed and aid in the development of appropriate minimization strategies in breast imaging. ©RSNA, 2020.

Breast pain and cancer: should we continue to work-up isolated breast pain?

PURPOSE: To assess the cancer detection rate (CDR) in patients presenting with isolated breast pain. METHODS: A retrospective review was performed of consecutive patients presenting to a large tertiary care academic center or an affiliated hospital with isolated breast pain from October 1, 2013 to September 30, 2015. Medical records were reviewed for patient demographics, pain characteristics, imaging findings, and outcome. RESULTS: The study cohort was comprised of 971 exams in 953 patients, with a median age of 50 years. A total of 62.5% (607/971) of the cases were assessed by mammography and ultrasound, 24.4% (237/971) by ultrasound only, and 13.1% (127/971) by mammography only. Including the abnormalities detected in the asymptomatic breast, 88.7% (861/971) of the cases were negative or had benign findings (BI-RADS 1 and 2), 6.8% (66/971) were probably benign (BI-RADS 3), 3.9% (38/971) were suspicious (BI-RADS 4), and 0.6% (6/971) were highly suggestive of malignancy (BI-RADS 5). CDR on initial work-up was 0.8% (8/953), of which 0.6% (4/690) was in average-risk patients while 1.5% (4/263) was in higher-than-average risk patients. CONCLUSIONS: CDR in patients presenting with isolated breast pain overall was low, comparable to the expected incidence of breast cancer in asymptomatic women. Work-up for isolated breast pain may therefore be unnecessary and lead to overutilization of healthcare resources. Routine screening mammography should be encouraged and higher-than-average risk patients may benefit from additional tests.

Evaluation of a Nonradioactive Magnetic Marker Wireless Localization Program.

OBJECTIVE: The purpose of this study is to evaluate the feasibility and effectiveness of a nonradioactive magnetic marker wireless localization technique. MATERIALS AND METHODS: A retrospective review was performed of consecutive patients who underwent image-guided needle localization with nonradioactive magnetic markers and subsequent surgical excision from March to August 2017. Indications for marker placement, lesion type, imaging guidance used for marker placement, postprocedure mammographic imaging and reports, surgical reports, and surgical margin status were reviewed. RESULTS: A total of 188 patients (mean age, 59 years; range, 22-89 years) underwent image-guided localization with 213 magnetic markers and subsequent surgical excision. The indications for marker placement included invasive carcinoma (96 markers [45.1%]), ductal carcinoma in situ (41 markers [19.2%]), and high-risk lesions (71 markers [33.3%]). Localization markers were most commonly placed for masses (96 markers [45.1%]) and were deployed under mammographic guidance (160 markers [75.1%]) or sonographic guidance (53 markers [24.9%]). Technical success, which was defined as placement of the magnetic marker within 1 cm of the target, was achieved for 206 of 213 markers (96.7%). All 213 markers were successfully retrieved at surgery. Of 137 cases of in situ or invasive carcinoma, 30 (21.9%) had tumor-positive or close surgical margins that required reexcision. No major or minor complications were observed during marker placement, intraoperatively, or postoperatively. CONCLUSION: Image-guided needle localization with magnetic markers is a safe, feasible, and effective method for localizing breast lesions. Magnetic marker localization has the potential to replace conventional wire needle localization and radioactive seed needle localization for lesions that require surgical excision.

Pathologic Outcomes of Architectural Distortion on Digital 2D Versus Tomosynthesis Mammography.

OBJECTIVE: The purpose of this study is to compare the risk of malignancy associated with architectural distortion detected on 2D digital mammography (DM) versus digital breast tomosynthesis (DBT). MATERIALS AND METHODS: We performed a retrospective review of architectural distortion cases recommended for biopsy from September 2007 to February 2011, the period before DBT integration (hereafter known as the DM group), and from January 2013 to June 2016, the period after DBT integration (hereafter known as the DBT group). Medical records were reviewed for imaging findings and pathology results. RESULTS: Architectural distortion was more commonly detected in the DBT group than the DM group (0.14% [274/202,438 examinations] vs 0.07% [121/166,661 examinations]; p < 0.001). The positive predictive value of architectural distortion for malignancy was significantly lower in the DBT group than the DM group (50.7% [139/274 cases] vs 73.6% [89/121 cases]; p < 0.001). Radial scar was the most common nonmalignant finding in both groups, but it was more common in the DBT group (33.2% [91/274] vs 11.6% [14/121]; p < 0.001). In the DBT group, architectural distortion without correlative findings on ultrasound was less likely to represent malignancy than was architectural distortion with correlative findings on ultrasound (29.2% [31/106] vs 66.5% [105/158]; p < 0.001). CONCLUSION: Architectural distortion is more commonly detected on DBT than DM and is less likely to represent malignancy on DBT. Architectural distortion on DBT is less likely to represent malignancy if there is no sonographic correlate; however, biopsy is warranted even in the absence of a sonographic correlate, given the nearly 30% risk of malignancy in this setting.

Incidence, Timing, and Long-Term Outcomes of COVID-19 Vaccine-Related Lymphadenopathy on Screening Mammography.

OBJECTIVE: To determine the incidence, timing, and long-term outcomes of unilateral axillary lymphadenopathy ipsilateral to vaccine site (UIAL) on screening mammography after COVID-19 vaccination. METHODS: This retrospective, multisite study included consecutive patients undergoing screening mammography February 8, 2021, to January 31, 2022, with at least 1 year of follow-up. UIAL was typically considered benign (BI-RADS 1 or 2) in the setting of recent (≤6 weeks) vaccination or BI-RADS 0 (ultrasound recommended) when accompanied by a breast finding or identified >6 weeks postvaccination. Vaccination status and manufacturer were obtained from regional registries. Lymphadenopathy rates in vaccinated patients with and without UIAL were compared using Pearson's χ2 test. RESULTS: There were 44,473 female patients (mean age 60.4 ± 11.4 years) who underwent screening mammography at five sites, and 40,029 (90.0%) received at least one vaccine dose. Ninety-four (0.2%) presented with UIAL, 1 to 191 days postvaccination (median 13.5 [interquartile range: 5.0-31.0]). Incidence declined from 2.1% to 0.9% to ≤0.5% after 1, 2, and 3 weeks and persisted up to 36 weeks (P < .001). UIAL did not vary across manufacturer (P = .15). Of 94, 77 (81.9%) were BI-RADS 1 or 2 at screening. None were diagnosed with malignancy at 1-year follow-up. Seventeen (18.1%) were BI-RADS 0 at screening. At diagnostic workup, 13 (76.5%) were BI-RADS 1 or 2, 2 (11.8%) were BI-RADS 3, and 2 (11.8%) were BI-RADS 4. Both BI-RADS 4 patients had malignant status and ipsilateral breast malignancies. Of BI-RADS 3 patients, at follow-up, one was biopsied yielding benign etiology, and one was downgraded to BI-RADS 2. DISCUSSION: Isolated UIAL on screening mammography performed within 6 months of COVID-19 vaccination can be safely assessed as benign.

Breast imaging with an ultra-low field MRI scanner: a pilot study.

Breast cancer screening is necessary to reduce mortality due to undetected breast cancer. Current methods have limitations, and as a result many women forego regular screening. Magnetic resonance imaging (MRI) can overcome most of these limitations, but access to conventional MRI is not widely available for routine annual screening. Here, we used an MRI scanner operating at ultra-low field (ULF) to image the left breasts of 11 women (mean age, 35 years ±13 years) in the prone position. Three breast radiologists reviewed the imaging and were able to discern the breast outline and distinguish fibroglandular tissue (FGT) from intramammary adipose tissue. Additionally, the expert readers agreed on their assessment of the breast tissue pattern including fatty, scattered FGT, heterogeneous FGT, and extreme FGT. This preliminary work demonstrates that ULF breast MRI is feasible and may be a potential option for comfortable, widely deployable, and low-cost breast cancer diagnosis and screening.

Contralateral breast cancer after curative-intent treatment for ductal carcinoma in situ: Rate and associated clinicopathological and imaging risk factors.

PURPOSE: Patients who have ductal carcinoma in situ (DCIS) are undergoing bilateral mastectomy at increasing rates. One of the reasons is to minimize contralateral breast cancer (CBC) risk. The purpose of this study is to determine the rate of and risk factors associated with CBC in women treated for DCIS. METHODS: A retrospective study was performed of women with DCIS at surgery from 2007 to 2014 who had at least five-year follow-up. Patient attributes, imaging findings, histopathology results, and surgical and long-term outcomes were collected. Features associated with a CBC were assessed with multivariable logistic regression models. RESULTS: 613 women (mean 56 years, range 30-87) with DCIS underwent breast-conserving surgery (BCS) (n = 426), unilateral mastectomy (n = 101), or bilateral mastectomy (n = 86), with mean follow-up of 7.9 years. Of the 527 women who had BCS or unilateral mastectomy, 7.4% (n = 39) developed a CBC (DCIS in 12 and invasive cancer in 27). 4.1% (5/122) of women treated with adjuvant endocrine therapy developed a CBC, compared to 8.4% (34/405) who were not treated (p = .11). Features associated with CBC risk were younger age at menarche (adjusted odds ratio [aOR] of 0.76, p = .03) and low nuclear grade of DCIS (aOR of 5.43 for grade 1 versus 3, p = .01). CONCLUSION: In women treated for DCIS, the overall rate of CBC was low at 7.4%. Younger age at menarche and low nuclear grade of DCIS had significant associations with higher CBC risk.