Problem-solving Breast MRI.

Breast MRI has high sensitivity and negative predictive value, making it well suited to problem solving when other imaging modalities or physical examinations yield results that are inconclusive for the presence of breast cancer. Indications for problem-solving MRI include equivocal or uncertain imaging findings at mammography and/or US; suspicious nipple discharge or skin changes suspected to represent an abnormality when conventional imaging results are negative for cancer; lesions categorized as Breast Imaging Reporting and Data System 4, which are not amenable to biopsy; and discordant radiologic-pathologic findings after biopsy. MRI should not precede or replace careful diagnostic workup with mammography and US and should not be used when a biopsy can be safely performed. The role of MRI in characterizing calcifications is controversial, and management of calcifications should depend on their mammographic appearance because ductal carcinoma in situ may not appear enhancing on MR images. In addition, ductal carcinoma in situ detected solely with MRI is not associated with a higher likelihood of an upgrade to invasive cancer compared with ductal carcinoma in situ detected with other modalities. MRI for triage of high-risk lesions is a subject of ongoing investigation, with a possible future role for MRI in decreasing excisional biopsies. The accuracy of MRI is likely to increase with the use of advanced techniques such as deep learning, which will likely expand the indications for problem-solving MRI. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Breast Cancer Screening in Survivors of Childhood Cancer.

Women who survived childhood cancers or cancers at a young age are at high risk for breast cancer later in life. The accentuated risk is notable among those treated at a young age with a high radiation dose but also extends to survivors treated with therapies other than or in addition to radiation therapy. The predisposing risk factors are complex. Advances in radiation therapy continue to curtail exposure, yet the risk of a second cancer has no dose threshold and a long latency period, and concurrent use of chemotherapy may have an additive effect on long-term risk of cancer. Early screening with annual mammography and MRI is recommended for chest radiation exposure of 10 Gy or greater, beginning 8 years after treatment or at age 25 years, whichever is later. However, there is a lack of recommendations for those at high risk without a history of radiation therapy. Because mortality after breast cancer among survivors is higher than in women with de novo breast cancer, and because there is a higher incidence of a second asynchronous breast cancer in survivors than that in the general population, regular screening is essential and is expected to improve mortality. However, awareness and continuity of care may be lacking in these young patients and is reflected in their poor screening attendance. The transition of care from childhood to adulthood for survivors requires age-targeted and lifelong strategies of education and risk prevention that are needed to improve long-term outcomes for these patients. © RSNA, 2023 See the invited commentary by Chikarmane in this issue. Quiz questions for this article are available through the Online Learning Center.

Active Surveillance for Atypical Ductal Hyperplasia and Ductal Carcinoma In Situ.

Atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) are relatively common breast lesions on the same spectrum of disease. Atypical ductal hyperblasia is a nonmalignant, high-risk lesion, and DCIS is a noninvasive malignancy. While a benefit of screening mammography is early cancer detection, it also leads to increased biopsy diagnosis of noninvasive lesions. Previously, treatment guidelines for both entities included surgical excision because of the risk of upgrade to invasive cancer after surgery and risk of progression to invasive cancer for DCIS. However, this universal management approach is not optimal for all patients because most lesions are not upgraded after surgery. Furthermore, some DCIS lesions do not progress to clinically significant invasive cancer. Overtreatment of high-risk lesions and DCIS is considered a burden on patients and clinicians and is a strain on the health care system. Extensive research has identified many potential histologic, clinical, and imaging factors that may predict ADH and DCIS upgrade and thereby help clinicians select which patients should undergo surgery and which may be appropriate for active surveillance (AS) with imaging. Additionally, multiple clinical trials are currently underway to evaluate whether AS for DCIS is feasible for a select group of patients. Recent advances in MRI, artificial intelligence, and molecular markers may also have an important role to play in stratifying patients and delineating best management guidelines. This review article discusses the available evidence regarding the feasibility and limitations of AS for ADH and DCIS, as well as recent advances in patient risk stratification.

Impact of Longitudinal Focused Academic Time on Resident Scholarly Activity.

RATIONALE AND OBJECTIVES: Meeting the Accreditation Council for Graduate Medical Education scholarly activity requirement can be challenging for residents. Time to engage in research is one of the commonly perceived barriers. To address this barrier, our residency program implemented a focused academic time initiative of a half day per week that can be taken while on rotation. At the end of the third year of implementation, we assessed the effectiveness of this initiative on the productivity of resident scholarly activity. MATERIALS AND METHODS: Radiology resident scholarly activity submitted to the Accreditation Council for Graduate Medical Education web-based Accreditation Data System were reviewed and compared to the three academic years before (July 1, 2012-June 30, 2015) and three academic years after (July 1, 2015-June 30, 2018) implementing the focused research time. The types of scholarly activity, which consisted of peer-reviewed journal publications, national conference presentations, and textbook chapters were captured. PubMed-Indexed for MEDLINE (PMID) number was used to confirm publications. Descriptive statistics were used to analyze the data. RESULTS: The total number of residents per year, ranging between 37-40, was similar between the academic years 2012-2015 (116 residents total) and 2015-2018 (117 residents total). After initiating focused academic time, the number of publications increased from 45 to 75 (67%), presentations at conferences increased from 112 to 128 (14%), the number of textbook chapters increased from 4 to 15 (275%), and total number of first author publications by residents increased from 21 to 28 (33% increase). CONCLUSION: Longitudinal focused academic time of half a day per week increased productivity of scholarly activity among our radiology residents.

Differences between human and machine perception in medical diagnosis.

Deep neural networks (DNNs) show promise in image-based medical diagnosis, but cannot be fully trusted since they can fail for reasons unrelated to underlying pathology. Humans are less likely to make such superficial mistakes, since they use features that are grounded on medical science. It is therefore important to know whether DNNs use different features than humans. Towards this end, we propose a framework for comparing human and machine perception in medical diagnosis. We frame the comparison in terms of perturbation robustness, and mitigate Simpson's paradox by performing a subgroup analysis. The framework is demonstrated with a case study in breast cancer screening, where we separately analyze microcalcifications and soft tissue lesions. While it is inconclusive whether humans and DNNs use different features to detect microcalcifications, we find that for soft tissue lesions, DNNs rely on high frequency components ignored by radiologists. Moreover, these features are located outside of the region of the images found most suspicious by radiologists. This difference between humans and machines was only visible through subgroup analysis, which highlights the importance of incorporating medical domain knowledge into the comparison.

Incorporation of a Social Virtual Reality Platform into the Residency Recruitment Season.

RATIONALE AND OBJECTIVES: The Covid-19 pandemic ushered a sudden need for residency programs to develop innovative socially distant and remote approaches to effectively promote their program. Here we describe our experience using the social virtual reality (VR) platform Mozilla Hubs for the pre-interview social during the 2020-2021 radiology residency virtual recruitment season, provide results of a survey sent to assess applicants' attitudes towards the VR pre-interview social, and outline additional use-cases for the emerging technology. MATERIALS AND METHODS: A VR Meeting Hall dedicated to the pre-interview social was designed in Mozilla Hubs. To assess applicants' impressions of the Mozilla Hubs pre-interview social, applicants were sent an optional web-based survey. Survey respondents were asked to respond to a series of eleven statements using a five-point Likert scale of perceived agreement: Strongly Agree, Agree, Neutral, Disagree, Strongly Disagree. Statements were designed to gauge applicants' attitudes towards the Mozilla Hubs pre-interview social and its usefulness in helping them learn about the residency program, particularly in comparison with pre-interview socials held on conventional video conferencing software (CVCS). RESULTS: Of the 120 residency applicants invited to the Mozilla Hubs pre-interview social, 111 (93%) attended. Of these, 68 (61%) participated in the anonymous survey. Most applicants reported a better overall experience with Mozilla Hubs compared to CVCS (47/68, 69%), with 10% (7/68) reporting a worse overall experience, and 21% (14/68) neutral. Most applicants reported the Mozilla Hubs pre-interview social allowed them to better assess residency culture than did pre-interview socials using CVCS (41/68, 60%). Seventy-two percent of applicants reported that the Mozilla Hubs pre-interview social positively impacted their decision to strongly consider the residency program (49/68). CONCLUSION: Radiology residency applicants overall preferred a pre-interview social hosted on a social VR platform, Mozilla Hubs, compared to those hosted on CVCS. Applicants reported the use of a social VR platform reflected positively on the residency and positively impacted their decision to strongly consider the program.

MRI in the Setting of Neoadjuvant Treatment of Breast Cancer.

Neoadjuvant therapy may reduce tumor burden preoperatively, allowing breast conservation treatment for tumors previously unresectable or requiring mastectomy without reducing disease-free survival. Oncologists can also use the response of the tumor to neoadjuvant chemotherapy (NAC) to identify treatment likely to be successful against any unknown potential distant metastasis. Accurate preoperative estimations of tumor size are necessary to guide appropriate treatment with minimal delays and can provide prognostic information. Clinical breast examination and mammography are inaccurate methods for measuring tumor size after NAC and can over- and underestimate residual disease. While US is commonly used to measure changes in tumor size during NAC due to its availability and low cost, MRI remains more accurate and simultaneously images the entire breast and axilla. No method is sufficiently accurate at predicting complete pathological response that would obviate the need for surgery. Diffusion-weighted MRI, MR spectroscopy, and MRI-based radiomics are emerging fields that potentially increase the predictive accuracy of tumor response to NAC.

Artificial intelligence system reduces false-positive findings in the interpretation of breast ultrasound exams.

Though consistently shown to detect mammographically occult cancers, breast ultrasound has been noted to have high false-positive rates. In this work, we present an AI system that achieves radiologist-level accuracy in identifying breast cancer in ultrasound images. Developed on 288,767 exams, consisting of 5,442,907 B-mode and Color Doppler images, the AI achieves an area under the receiver operating characteristic curve (AUROC) of 0.976 on a test set consisting of 44,755 exams. In a retrospective reader study, the AI achieves a higher AUROC than the average of ten board-certified breast radiologists (AUROC: 0.962 AI, 0.924 ± 0.02 radiologists). With the help of the AI, radiologists decrease their false positive rates by 37.3% and reduce requested biopsies by 27.8%, while maintaining the same level of sensitivity. This highlights the potential of AI in improving the accuracy, consistency, and efficiency of breast ultrasound diagnosis.

Impact on Participants of Family Connect, a Novel Program Linking COVID-19 Inpatients' Families With the Frontline Providers.

PURPOSE: With clinical volumes decreased, radiologists volunteered to participate virtually in daily clinical rounds and provide communication between frontline physicians and patients with coronavirus disease 2019 (COVID-19) and their families affected by restrictive hospital visitation policies. The purpose of this survey-based assessment was to demonstrate the beneficial effects of radiologist engagement during this pandemic and potentially in future crises if needed. METHODS: After the program's completion, a survey consisting of 13 multiple-choice and open-ended questions was distributed to the 69 radiologists who volunteered for a minimum of 7 days. The survey focused on how the experience would change future practice, the nature of interaction with medical students, and the motivation for volunteering. The electronic medical record system identified the patients who tested positive for or were suspected of having COVID-19 and the number of notes documenting family communication. RESULTS: In all, 69 radiologists signed or cosigned 7,027 notes. Of the 69 radiologists, 60 (87.0%) responded to the survey. All found the experience increased their understanding of COVID-19 and its effect on the health care system. Overall, 59.6% agreed that participation would result in future change in communication with patients and their families. Nearly all (98.1%) who worked with medical students agreed that their experience with medical students was rewarding. A majority (82.7%) chose to participate as a way to provide service to the patient population. CONCLUSION: This program provided support to frontline inpatient teams while also positively affecting the radiologist participants. If a similar situation arises in the future, this communication tool could be redeployed, especially with the collaboration of medical students.

Screening Breast MRI Primer: Indications, Current Protocols, and Emerging Techniques.

Breast dynamic contrast-enhanced MRI (DCE-MRI) is the most sensitive imaging modality for the detection of breast cancer. Screening MRI is currently performed predominantly in patients at high risk for breast cancer, but it could be of benefit in patients at intermediate risk for breast cancer and patients with dense breasts. Decreasing scan time and image interpretation time could increase cost-effectiveness, making screening MRI accessible to a larger group of patients. Abbreviated breast MRI (Ab-MRI) reduces scan time by decreasing the number of sequences obtained, but as multiple delayed contrast enhanced sequences are not obtained, no kinetic information is available. Ultrafast techniques rapidly acquire multiple sequences during the first minute of gadolinium contrast injection and provide information about both lesion morphology and vascular kinetics. Diffusion-weighted imaging is a noncontrast MRI technique with the potential to detect mammographically occult cancers. This review article aims to discuss the current indications of breast MRI as a screening tool, examine the standard breast DCE-MRI technique, and explore alternate screening MRI protocols, including Ab-MRI, ultrafast MRI, and noncontrast diffusion-weighted MRI, which can decrease scan time and interpretation time.

Assessing the impact of an orientation week on acclimation to radiology residency.

PURPOSE: Acclimating residents to radiology residency requires attention to new responsibilities, educational material, and social cohesion. To this end, we instituted a structured orientation week for incoming residents and assessed its impact. PROCEDURES: During the first weeks of July 2016 and 2017, first year residents attended a five day orientation free of clinical duties, consisting of didactics, hands-on training sessions, and social events. After two orientation cohorts, residents who completed orientation week, and two cohorts who had not, were given a voluntary, anonymous survey using Likert scale questions (1 [worst] to 5 [best]) regarding preparedness for responsibilities, learning, and social cohesion. Residents were asked which components were or would have been helpful. Independent samples t-tests were performed to evaluate differences between the two groups (two-tailed p < 0.05). FINDINGS: 21/37 (57%) residents participated. Higher percentages of residents who participated in the orientation week gave scores ≥4 when asked about preparedness for rotations (70% vs. 36%), learning new material (80% vs. 36%), and class cohesiveness (90% vs. 70%). Mean scores on these questions were also higher for these residents with regards to: preparedness for new responsibilities (3.7 vs. 2.9), learning new material (3.8 vs. 2.9), and class cohesiveness (4.5 vs. 3.8), with differences approaching significance (p = 0.09-0.15). Individual components receiving most votes of ≥4 were social outings, resident lunches, didactic lectures, and PACS training. CONCLUSION: A weeklong orientation program free of clinical duties was valued by residents and contributed to acclimation to new responsibilities, education, and social cohesion.

Breast Imaging in Transgender Patients: What the Radiologist Should Know.

Transgender is the umbrella term for individuals whose gender identity and/or gender expression differs from their assigned sex at birth. With the rise in patients undergoing gender-affirming hormone therapy and gender-affirming surgery, it is increasingly important for radiologists to be aware of breast imaging considerations for this population. While diagnostic imaging protocols for transgender individuals are generally similar to those for cisgender women, screening guidelines are more variable. Currently, several professional and institutional guidelines have been created to address breast cancer screening in the transgender population, specifically screening mammography in transfeminine individuals who undergo hormone therapy. This article defines appropriate terminology with respect to the transgender population, reviews evidence for breast cancer risk and screening in transgender individuals, considers diagnostic breast imaging approaches, and discusses special considerations and challenges with regard to health care access and public education for these individuals. ©RSNA, 2019.

Frequency and outcomes of biopsy-proven fibroadenomas recommended for surgical excision.

Our aim was to investigate the outcomes of fibroadenomas recommended for surgical excision due to large size (>2cm) or interval growth. A retrospective review of our institutional radiology database from 2007 to 2015 was performed. We identified 167 biopsy-proven fibroadenomas recommended for surgical consultation. Of these, 75 (45%) cases actually underwent excision, 7 (9%, 95% CI: 4-18%) of which were upgraded to phyllodes tumors upon histopathological examination. Our results support the current recommendation to surgically excise breast lesions diagnosed as fibroadenomas with size >2cm or with interval growth due to the considerable risk of finding phyllodes tumors.

Ductal Carcinoma In Situ: The Whole Truth.

OBJECTIVE: Ductal carcinoma in situ (DCIS) is a noninvasive malignant breast disease traditionally described as a precursor lesion to invasive breast cancer. With screening mammography, DCIS now accounts for approximately 20% of newly diagnosed cancer cases. DCIS is not well understood because of its heterogeneous nature. CONCLUSION: Studies have aimed to assess prognostic factors to characterize its risk of invasive potential; however, there still remains a lack of uniformity in workup and treatment. We summarize current knowledge of DCIS and the ongoing controversies.

Comparison between qualitative and quantitative assessment of background parenchymal enhancement on breast MRI.

BACKGROUND: Potential clinical implications of the level of background parenchymal enhancement (BPE) on breast MRI are increasing. Currently, BPE is typically evaluated subjectively. Tests of concordance between subjective BPE assessment and computer-assisted quantified BPE have not been reported. PURPOSE OR HYPOTHESIS: To compare subjective radiologist assessment of BPE with objective quantified parenchymal enhancement (QPE). STUDY TYPE: Cross-sectional observational study. POPULATION: Between 7/24/2015 and 11/27/2015, 104 sequential patients (ages 23 - 81 years, mean 49 years) without breast cancer underwent breast MRI and were included in this study. FIELD STRENGTH/SEQUENCE: 3T; fat suppressed axial T2, axial T1, and axial fat suppressed T1 before and after intravenous contrast. ASSESSMENT: Four breast imagers graded BPE at 90 and 180 s after contrast injection on a 4-point scale (a-d). Fibroglandular tissue masks were generated using a phantom-validated segmentation algorithm, and were co-registered to pre- and postcontrast fat suppressed images to define the region of interest. QPE was calculated. STATISTICAL TESTS: Receiver operating characteristic (ROC) analyses and kappa coefficients (k) were used to compare subjective BPE with QPE. RESULTS: ROC analyses indicated that subjective BPE at 90 s was best predicted by quantified QPE ≤20.2 = a, 20.3-25.2 = b, 25.3-50.0 = c, >50.0 = d, and at 180 s by quantified QPE ≤ 32.2 = a, 32.3-38.3 = b, 38.4-74.5 = c, >74.5 = d. Agreement between subjective BPE and QPE was slight to fair at 90 s (k = 0.20-0.36) and 180 s (k = 0.19-0.28). At higher levels of QPE, agreement between subjective BPE and QPE significantly decreased for all four radiologists at 90 s (P ≤ 0.004) and for three of four radiologists at 180 s (P ≤ 0.004). DATA CONCLUSION: Radiologists were less consistent with QPE as QPE increased. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1685-1691.

Magnetic Resonance Imaging-Directed Ultrasound Imaging of Non-Mass Enhancement in the Breast: Outcomes and Frequency of Malignancy.

OBJECTIVES: This study was performed to determine the frequency, predictors, and outcomes of ultrasound (US) correlates for non-mass enhancement. METHODS: From January 2005 to December 2011, a retrospective review of 5837 consecutive breast magnetic resonance imaging examinations at our institution identified 918 non-mass enhancing lesions for which follow-up or biopsy was recommended. Retrospective review of the images identified 879 of 918 lesions (96%) meeting criteria for non-mass enhancement. Patient demographics, pathologic results, and the presence of an adjacent landmark were recorded. Targeted US examinations were recommended for 331 of 879 cases (38%), and 284 of 331 women (86%) underwent US evaluations. RESULTS: The US correlate rate for non-mass enhancement was 23% (64 of 284). An adjacent landmark was significantly associated with a US correlate (P < .001). Biopsy was recommended for 43 of 64 correlates (67%). Ultrasound-guided biopsy was performed on 39 of 43 (91%); 7 of 39 (18%) were malignant. No correlate was seen for 220 of 284 lesions (77%). At magnetic resonance imaging-guided biopsy, 14 of 117 (12%) were malignancies. For all biopsied non-mass enhancements, the malignancy rate was 18% (55 of 308) and was significantly more prevalent in the setting of a known index cancer (P < .001), older age (P < .001), the presence of a landmark (P = .002), and larger lesion size (P = .019). CONCLUSIONS: Non-mass enhancement with an adjacent landmark is more likely to have a US correlate compared to non-mass enhancement without an adjacent landmark. Non-mass enhancement in the setting of a known index cancer, older age, a landmark, and larger lesion size is more likely to be malignant. However, no statistical difference was detected in the rate of malignancy between non-mass enhancement with (18%) or without (12%) a correlate. Absence of a correlate does not obviate the need to biopsy suspicious non-mass enhancement.

Clinical applicability and relevance of fibroglandular tissue segmentation on routine T1 weighted breast MRI.

PURPOSE: To evaluate clinical applicability of fibroglandular tissue (FGT) segmentation on routine T1 weighted breast MRI and compare FGT quantification with radiologist assessment. METHODS: FGT was segmented on 232 breasts and quantified, and was assessed qualitatively by four breast imagers. RESULTS: FGT segmentation was successful in all 232 breasts. Agreement between radiologists and quantified FGT was moderate to substantial (kappa=0.52-0.67); lower quantified FGT was associated with disagreement between radiologists and quantified FGT (P≤0.002). CONCLUSIONS: FGT segmentation was successful using routine T1 weighted breast MRI. Radiologists were less consistent with quantified results in breasts with lower quantified FGT.

Metastatic carcinoid tumor to the breast: report of two cases and review of the literature.

The breast is an unusual site for carcinoid metastasis. Due to increasing survival rates for carcinoid tumors, however, awareness of their rare complications is important. Carcinoid metastasis to the breast typically presents as a palpable breast mass or a mass on screening mammogram. Because imaging findings are nonspecific, the diagnosis is established through histological findings of neuroendocrine features corresponding with the known primary carcinoid pathology. Correctly distinguishing metastatic carcinoid from primary breast carcinoma is crucial to avoid more invasive procedures required for the latter. Two cases of metastatic carcinoid to the breast are presented with review of the literature.

Frequency and Outcomes of Incidental Breast Lesions Detected on Abdominal MRI Over a 7-Year Period.

OBJECTIVE: Our aim was to evaluate the frequency and outcomes of incidental breast lesions detected on abdominal MRI examinations. MATERIALS AND METHODS: Abdominal MRI reports for 11,462 women imaged at our institution from November 2007 through December 2014 were reviewed to identify those reporting an incidental breast lesion. Available breast imaging and pathology results were assessed to identify outcomes in these lesions. RESULTS: Incidental breast lesions were described in the MRI reports of 292 (3%) patients who underwent abdominal MRI during the study period; breast imaging was recommended for 192 of these 292 (66%) patients. Sixty-three of the 192 (33%) patients for whom follow-up breast imaging was recommended underwent such imaging at our institution. Twenty-one of these 63 (33%) lesions underwent biopsy or surgery; histologic sampling of these lesions yielded seven incidental cancers (invasive ductal, n = 6; invasive lobular, n = 1) and 14 benign diagnoses. Three additional cancers (invasive ductal, n = 2; invasive lobular, n = 1) and three benign diagnoses were discovered at pathology at outside institutions. Of the remaining 165 patients without a histologic diagnosis, the lesions in 95 (58%) patients were presumed to be benign because of stability over time. Seven of the 10 patients with a diagnosis of incidental cancer (age range, 53-86 years; mean ± SD, 67.0 ± 10.6 years) had not undergone screening mammography at our institution. The frequency of incidental breast cancer was 11% of patients subsequently undergoing follow-up breast imaging at our institution, 3% of all patients with reported breast lesions, and 0.09% of patients undergoing abdominal MRI examinations. CONCLUSION: Although incidental breast lesions were rarely detected on abdominal MRI, a considerable number of these lesions were found to represent breast cancer, particularly when leading to a recommendation for follow-up breast imaging. Therefore, it is important for radiologists interpreting abdominal MRI examinations to carefully evaluate for the presence of breast abnormalities.