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Objective: To compare positive predictive values (PPVs) of clumped vs non-clumped (homogenous and heterogeneous) internal enhancement on MRI detected linear non-mass enhancement (NME) on MRI-guided vacuum-assisted breast biopsy (MRI-VABB)., Methods: With IRB (Institutional Review Board) approval, we retrospectively reviewed 598 lesions undergoing MRI-VABB from January 2015 to April 2018 that showed linear NME. We reviewed the electronic medical records for MRI-VABB pathology, any subsequent surgery and clinical follow-up. The X 2 test was performed for univariate analysis., Results: There were 120/598 (20%) linear NME MRI-VABB lesions with clumped (52/120, 43%) vs non-clumped (68/120, 57%) internal enhancement, average size 1.8 cm (range 0.6-7.6 cm). On MRI-VABB, cancer was identified in 22/120 (18%) lesions, ductal carcinoma in situ (DCIS) was found in 18/22 (82%) and invasive cancer in 4 (18%). 3/31 (10%) high-risk lesions upgraded to DCIS at surgery, for a total of 25/120 (21%) malignancies. Malignancy was found in 12/52 (23%) clumped lesions and in 13/68 (19%) of non-clumped lesions that showed heterogeneous (5/13, 38%) or homogenous (8/13, 62%) internal enhancement. The PPV of linear NME with clumped internal enhancement (23.1%) was not significantly different from the PPV of non-clumped linear NME (19.1%) ( p = 0.597). The PPV of linear NME lesions <1 cm (33.3%) was not significantly different from the PPV of lesions ≥1 cm (18.6%) ( p = 0.157)., Conclusions: Linear NME showed malignancy in 21% of our series. Linear NME with clumped or non-clumped internal enhancement patterns, regardless of lesion size, might need to undergo MRI-VABB in appropriate populations., Advances in Knowledge: Evaluation of linear NME lesions on breast MRI focuses especially on internal enhancement pattern.

Background: To evaluate imaging characteristics, outcome of surgical excision or imaging follow-up on high-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy (MRI-VABB)., Methods: We retrospectively reviewed 598 lesions undergoing 9-gauge MRI-VABB from January 2015 to April 2018 to identify high risk breast lesions. We collected patient demographics, breast MRI BI-RADS descriptors, histopathological diagnosis at MRI-VABB and surgical excision, frequency of upgrade to malignancy and imaging follow-up of high-risk lesions. The x 2 test and Fisher exact tests were performed for univariate analysis., Results: 114 patients with 124/598 findings (20.7%) had high-risk lesions at MRI-VABB, including atypical ductal hyperplasia (ADH) (21/124, 16.9%), lobular neoplasia (40/124, 32.3%), radial scar/complex sclerosing lesion (RS/CSL) (13/124, 10.5%), papillary lesions (49/124, 39.5%), and flat epithelial atypia (FEA) (1/124, 0.8%). 84/124 (67.7%) high-risk lesions were excised. 19/84 (22.6%) were upgraded to malignancy (7 invasive cancer, 12 DCIS). The upgrade rate for ADH and lobular neoplasia was 7/18 (38.9%) and 9/31 (29.0%), respectively. The upgrade rate for RS/CSL was 1/10 (10%). Of the 25 papillary lesions excised, 2 (8%) demonstrated pathologic atypia and were upgraded to DCIS. The other 23 papillary lesions had no upgrade or atypia. Excised high-risk lesions showing upgrade varied from 0.4 to 6 cm in length (mean 1.6 cm). There was a non-significant trend (p = 0.054) between larger lesion and upgrade to malignancy; however, there were no other specific imaging features to predict malignancy upgrade., Conclusions: There were no specific MRI imaging characteristics of high-risk lesions to predict malignancy upgrade. Therefore, surgical excision is recommended for high-risk lesions, especially ADH or lobular neoplasia.

Background and Objectives: More extensive surgical treatments for early stage breast cancer are increasing. The patterns of preoperative MRI overall and by stage for this trend has not been well established., Methods: Using Breast Cancer Surveillance Consortium registry data from 2010 through 2014, we identified women with an incident non-metastatic breast cancer and determined use of preoperative MRI and initial surgical treatment (mastectomy, with or without contralateral prophylactic mastectomy (CPM), reconstruction, and breast conserving surgery ± radiation). Clinical and sociodemographic covariates were included in multivariable logistic regression models to estimate adjusted odds ratios and 95% confidence intervals., Results: Of the 13 097 women, 2217 (16.9%) had a preoperative MRI. Among the women with MRI, results indicated 32% higher odds of unilateral mastectomy compared to breast conserving surgery and of mastectomy with CPM compared to unilateral mastectomy. Women with preoperative MRI also had 56% higher odds of reconstruction., Conclusion: Preoperative MRI in women with DCIS and early stage invasive breast cancer is associated with more frequent mastectomy, CPM, and reconstruction surgical treatment. Use of more extensive surgical treatment and reconstruction among women with DCIS and early stage invasive cancer whom undergo MRI warrants further investigation., (© 2017 Wiley Periodicals, Inc.)

Objective: BI-RADS for mammography and ultrasound subdivides category 4 assessments by likelihood of malignancy into categories 4A (> 2% to ≤ 10%), 4B (> 10% to ≤ 50%), and 4C (> 50% to < 95%). Category 4 is not subdivided for breast MRI because of a paucity of data. The purpose of the present study is to determine the utility of categories 4A, 4B, and 4C for MRI by calculating their positive predictive values (PPVs) and comparing them with BI-RADS-specified rates of malignancy for mammography and ultrasound., Materials and Methods: All screening breast MRI examinations performed from July 1, 2010, through June 30, 2013, were included in this study. We identified in medical records prospectively assigned MRI BI-RADS categories, including category 4 subdivisions, which are used routinely in our practice. Benign versus malignant outcomes were determined by pathologic analysis, findings from 12 months or more clinical or imaging follow-up, or a combination of these methods. Distribution of BI-RADS categories and positive predictive value level 2 (PPV2; based on recommendation for tissue diagnosis) for categories 4 (including its subdivisions) and 5 were calculated., Results: Of 860 screening breast MRI examinations performed for 566 women (mean age, 47 years), 82 with a BI-RADS category 4 assessment were identified. A total of 18 malignancies were found among 84 category 4 and 5 assessments, for an overall PPV2 of 21.4% (18/84). For category 4 subdivisions, PPV2s were as follows: for category 4A, 2.5% (1/40); for category 4B, 27.6% (8/29); for category 4C, 83.3% (5/6); and for category 4 (not otherwise specified), 28.6% (2/7)., Conclusion: Category 4 subdivisions for MRI yielded malignancy rates within BI-RADS-specified ranges, supporting their use for benefits to patient care and more meaningful practice audits.

Rationale and Objectives: The BI-RADS Atlas 5th Edition includes screening breast magnetic resonance imaging (MRI) outcome benchmarks. However, the metrics are from expert practices and clinical trials of women with hereditary breast cancer predispositions, and it is unknown if they are appropriate for routine practice. We evaluated screening breast MRI audit outcomes in routine practice across a spectrum of elevated risk patients., Materials and Methods: This Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study included all consecutive screening breast MRI examinations from July 1, 2010 to June 30, 2013. Examination indications were categorized as gene mutation carrier (GMC), personal history (PH) breast cancer, family history (FH) breast cancer, chest radiation, and atypia/lobular carcinoma in situ (LCIS). Outcomes were determined by pathology and/or ≥12 months clinical and/or imaging follow-up. We calculated abnormal interpretation rate (AIR), cancer detection rate (CDR), positive predictive value of recommendation for tissue diagnosis (PPV2) and biopsy performed (PPV3), and median size and percentage of node-negative invasive cancers., Results: Eight hundred and sixty examinations were performed in 566 patients with a mean age of 47 years. Indications were 367 of 860 (42.7%) FH, 365 of 860 (42.4%) PH, 106 of 860 (12.3%) GMC, 14 of 860 (1.6%) chest radiation, and 8 of 22 (0.9%) atypia/LCIS. The AIR was 134 of 860 (15.6%). Nineteen cancers were identified (13 invasive, 4 DCIS, two lymph nodes), resulting in CDR of 19 of 860 (22.1 per 1000), PPV2 of 19 of 88 (21.6%), and PPV3 of 19 of 80 (23.8%). Of 13 invasive breast cancers, median size was 10 mm, and 8 of 13 were node negative (61.5%)., Conclusions: Performance outcomes of screening breast MRI in routine clinical practice across a spectrum of elevated risk patients met the American College of Radiology Breast Imaging Reporting and Data System benchmarks, supporting broad application of these metrics. The indication of a personal history of treated breast cancer accounted for a large proportion (42%) of our screening examinations, with breast MRI performance in this population at least comparable to that of other screening indications., (Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Objective: Currently, dynamic contrast-enhanced (DCE) breast magnetic resonance imaging (MRI) prioritizes spatial resolution over temporal resolution given the limitations of acquisition techniques. The purpose of our intrapatient study was to assess the ability of a novel high spatial and high temporal resolution DCE breast MRI method to maintain image quality compared with the clinical standard-of-care (SOC) MRI., Materials and Methods: Thirty patients, each demonstrating a focal area of enhancement (29 benign, 1 cancer) on their SOC MRI, consented to undergo a research DCE breast MRI on a second date. For the research DCE MRI, a method (DIfferential Subsampling with Cartesian Ordering [DISCO]) using pseudorandom k-space sampling, view sharing reconstruction, 2-point Dixon fat-water separation, and parallel imaging was used to produce images with an effective temporal resolution 6 times faster than the SOC MRI (27 vs 168 seconds, respectively). Both the SOC and DISCO MRI scans were acquired with matching spatial resolutions of 0.8 × 0.8 × 1.6 mm. Image quality (distortion/artifacts, resolution, fat suppression, lesion conspicuity, perceived signal-to-noise ratio, and overall image quality) was scored by 3 radiologists in a blinded reader study., Results: Differences in image quality scores between the DISCO and SOC images were all less than 0.8 on a 10-point scale, and both methods were assessed as providing diagnostic image quality in all cases. DISCO images with the same high spatial resolution, but 6 times the effective temporal resolution as the SOC MRI scans, were produced, yielding 20 postcontrast time points with DISCO compared with 3 for the SOC MRI, over the same total time interval., Conclusions: DISCO provided comparable image quality compared with the SOC MRI, while also providing 6 times faster effective temporal resolution and the same high spatial resolution.

Purpose: We compared the frequency and sequence of breast imaging and biopsy use for the diagnostic and preoperative workup of breast cancer according to breast magnetic resonance imaging (MRI) use among older women., Materials and Methods: Using SEER-Medicare data from 2004 to 2010, we identified women with and without breast MRI as part of their diagnostic and preoperative breast cancer workup and measured the number and sequence of breast imaging and biopsy events per woman., Results: A total of 10,766 (20%) women had an MRI in the diagnostic/preoperative period, 32,178 (60%) had mammogram and ultrasound, and 10,669 (20%) had mammography alone. MRI use increased across study years, tripling from 2005 to 2009 (9%-29%). Women with MRI had higher rates of breast imaging and biopsy compared with those with mammogram and ultrasound or those with mammography alone (5.8 vs. 4.1 vs. 2.8, respectively). There were 4254 unique sequences of breast events; the dominant patterns for women with MRI were an MRI occurring at the end of the care pathway. Among women receiving an MRI postdiagnosis, 26% had a subsequent biopsy compared with 51% receiving a subsequent biopsy in the subgroup without MRI., Conclusions: Older women who receive breast MRI undergo additional breast imaging and biopsy events. There is much variability in the diagnostic/preoperative work-up in older women, demonstrating the opportunity to increase standardization to optimize care for all women.

Objective: Among vulnerable women, unequal access to advanced breast imaging modalities beyond screening mammography may lead to delays in cancer diagnosis and unfavourable outcomes. We aimed to compare on-site availability of advanced breast imaging services (ultrasound, magnetic resonance imaging [MRI], and image-guided biopsy) between imaging facilities serving vulnerable patient populations and those serving non-vulnerable populations., Setting: 73 imaging facilities across five Breast Cancer Surveillance Consortium regional registries in the United States during 2011 and 2012., Methods: We examined facility and patient characteristics across a large, national sample of imaging facilities and patients served. We characterized facilities as serving vulnerable populations based on the proportion of mammograms performed on women with lower educational attainment, lower median income, racial/ethnic minority status, and rural residence.We performed multivariable logistic regression to determine relative risks of on-site availability of advanced imaging at facilities serving vulnerable women versus facilities serving non-vulnerable women., Results: Facilities serving vulnerable populations were as likely (Relative risk [RR] for MRI = 0.71, 95% Confidence Interval [CI] 0.42, 1.19; RR for MRI-guided biopsy = 1.07 [0.61, 1.90]; RR for stereotactic biopsy = 1.18 [0.75, 1.85]) or more likely (RR for ultrasound = 1.38 [95% CI 1.09, 1.74]; RR for ultrasound-guided biopsy = 1.67 [1.30, 2.14]) to offer advanced breast imaging services as those serving non-vulnerable populations., Conclusions: Advanced breast imaging services are physically available on-site for vulnerable women in the United States, but it is unknown whether factors such as insurance coverage or out-of-pocket costs might limit their use., (© The Author(s) 2015.)

Background: Breast cancer in the U.S. - estimated at 232,670 incident cases in 2014 - has the highest aggregate economic burden of care relative to other female cancers. Yet, the amount of cost attributed to diagnostic/preoperative work up has not been characterized. We examined the costs of imaging and biopsy among women enrolled in Medicare who did and did not receive diagnostic/preoperative Magnetic Resonance Imaging (MRI)., Methods: Using Surveillance, Epidemiology and End Results (SEER)- Medicare data, we compared the per capita costs (PCC) based on amount paid, between diagnosis date and primary surgical treatment for a breast cancer diagnosis (2005-2009) with and without diagnostic/preoperative MRI. We compared the groups with and without MRI using multivariable models, adjusting for woman and tumor characteristics., Results: Of the 53,653 women in the cohort, within the diagnostic/preoperative window, 20 % (N = 10,776) received diagnostic/preoperative MRI. Total unadjusted median costs were almost double for women with MRI vs. without ($2,251 vs. $1,152). Adjusted costs were higher among women receiving MRI, with significant differences in total costs ($1,065), imaging costs ($928), and biopsies costs ($138)., Conclusion: Costs of diagnostic/preoperative workups among women with MRI are higher than those without. Using these cost estimates in comparative effectiveness models should be considered when assessing the benefits and harms of diagnostic/preoperative MRI.

Background: Screening MRI is recommended for individuals at high risk for breast cancer, based on genetic risk or family history (GFH); however, there is insufficient evidence to support screening MRI for women with a personal history (PH) of breast cancer. We compared screening MRI performance in women with PH vs GFH of breast cancer., Methods: We analyzed case-series registry data, collected at time of MRI and at 12-month follow-up, from our regional Clinical Oncology Data Integration project. MRI performance was compared in women with PH with those with GFH. Chi-square testing was used to identify associations between age, prior history of MRI, and clinical indication with MRI performance; logistic regression was used to determine the combined contribution of these variables in predicting risk of a false-positive exam. All statistical tests were two-sided., Results: Of 1521 women who underwent screening MRI from July 2004 to November 2011, 915 had PH and 606 had GFH of breast cancer. Overall, MRI sensitivity was 79.4% for all cancers and 88.5% for invasive cancers. False-positive exams were lower in the PH vs GFH groups (12.3% vs 21.6%, P < .001), specificity was higher (94.0% vs 86.0%, P < .001), and sensitivity and cancer detection rate were not statistically different (P > .99). Age (P < .001), prior MRI (P < .001), and clinical indication (P < .001) were individually associated with initial false-positive rate; age and prior MRI remained statistically significant in multivariable modeling (P = .001 and P < .001, respectively)., Conclusion: MRI performance is superior in women with PH compared with women with GFH. Screening MRI warrants consideration as an adjunct to mammography in women with a PH of breast cancer., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Preoperative breast magnetic resonance imaging (MRI) use among Medicare beneficiaries with breast cancer has substantially increased from 2005 to 2009. We sought to identify factors associated with preoperative breast MRI use among women diagnosed with ductal carcinoma in situ (DCIS) or stage I-III invasive breast cancer (IBC). Using Surveillance, Epidemiology, and End Results and Medicare data from 2005 to 2009 we identified women ages 66 and older with DCIS or stage I-III IBC who underwent breast-conserving surgery or mastectomy. We compared preoperative breast MRI use by patient, tumor and hospital characteristics stratified by DCIS and IBC using multivariable logistic regression. From 2005 to 2009, preoperative breast MRI use increased from 5.9% to 22.4% of women diagnosed with DCIS and 7.0% to 24.3% of women diagnosed with IBC. Preoperative breast MRI use was more common among women who were younger, married, lived in higher median income zip codes and had no comorbidities. Among women with IBC, those with lobular disease, smaller tumors (<1 cm) and those with estrogen receptor negative tumors were more likely to receive preoperative breast MRI. Women with DCIS were more likely to receive preoperative MRI if tumors were larger (>2 cm). The likelihood of receiving preoperative breast MRI is similar for women diagnosed with DCIS and IBC. Use of MRI is more common in women with IBC for tumors that are lobular and smaller while for DCIS MRI is used for evaluation of larger lesions., (© 2015 Wiley Periodicals, Inc.)

Objective: The purpose of this study was to evaluate concordance between BI-RADS assessments and management recommendations for breast MRI in community practice., Materials and Methods: Breast MRI data were collected from four regional Breast Cancer Surveillance Consortium registries from 2005 to 2011 for women who were 18-79 years old. Assessments and recommendations were compared to determine concordance according to BI-RADS guidelines. Concordance was compared by assessment category as well as by year of examination and clinical indication., Results: In all, 8283 MRI examinations were included in the analysis. Concordance was highest (93% [2475/2657]) in examinations with a BI-RADS category 2 (benign) assessment. Concordance was also high in examinations with category 1 (negative) (87% [1669/1909]), category 0 (incomplete) (83% [348/417]), category 5 (highly suggestive of malignancy) (83% [208/252]), and category 4 (suspicious) (74% [734/993]) assessments. Examinations with categories 3 (probably benign) and 6 (known biopsy-proven malignancy) assessments had the lowest concordance rates (36% [302/837] and 56% [676/1218], respectively). The most frequent discordant recommendation for a category 3 assessment was routine follow-up. The most frequent discordant recommendation for a category 6 assessment was biopsy. Concordance of assessments and management recommendations differed across clinical indications (p < 0.0001), with the lowest concordance in examinations to assess disease extent., Conclusion: Breast MRI BI-RADS management recommendations were most concordant for assessments of negative, incomplete, suspicious, and highly suggestive of malignancy. Lower concordance for assessments of probably benign and known biopsy-proven malignancy and for examinations performed to assess disease extent highlight areas for interventions to improve breast MRI reporting.

The purpose of this study was to determine magnetic resonance imaging (MRI) screening recommendations and the subsequent outcomes in women with increased risk for breast cancer evaluated by oncology subspecialists at an academic center. Patients evaluated between 1/1/2007 and 3/1/2011 under diagnosis codes for family history of breast or ovarian cancer, genetic syndromes, lobular carcinoma in situ or atypical hyperplasia were included. Patients with a history of breast cancer were excluded. Retrospective review of prospectively acquired demographics, lifetime risk of breast cancer, and screening recommendations were obtained from the medical record. Retrospective review of the results of prospectively interpreted breast imaging examinations and image-guided biopsies were analyzed. 282 women were included. The majority of patients were premenopausal with a median age of 43. Most (69%) were referred due to a family history of breast or ovarian cancers. MRI was recommended for 84% of patients based on a documented lifetime risk >20%. Most women referred for MRI screening (88%) were compliant with this recommendation. A total of 299 breast MRI examinations were performed in 146 patients. Biopsy was performed for 32 (11%) exams and 10 cancers were detected for a positive predictive value (PPV) of 31% (based on biopsy performed) and an overall per exam cancer yield of 3.3%. Three cancers were detected in patients who did not undergo screening MRI. The 13 cancers were Stage 0-II; all patients were without evidence of disease with a median follow-up of 22 months. In a cohort of women seen by breast subspecialty providers, screening breast MRI was recommended according to guidelines, and used primarily in premenopausal women with a family history or genetic predisposition to breast cancer. Adherence to MRI screening recommendations was high and cancer yield from breast MRI was similar to that in clinical trials., (© 2015 Wiley Periodicals, Inc.)

Rationale and Objectives: To determine whether quantitative dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) magnetic resonance imaging (MRI) features can discriminate malignant from benign axillary lymph nodes (ALNs) identified as suspicious on clinical breast MRI in patients newly diagnosed with breast cancer., Materials and Methods: After approval from institutional review board, all clinical breast MR examinations performed from March 2006 through January 2010 describing at least one morphologically suspicious ipsilateral ALN in patients with newly diagnosed breast cancer were identified. Each suspicious ALN underwent ultrasound-guided core needle biopsy, and nodes with benign results were subsequently sampled surgically. Quantitative DCE and DW MRI parameters (diameters, volume, enhancement kinetics, and apparent diffusion coefficients [ADC]) were measured for each suspicious ALN and a representative contralateral normal node, and each feature was compared between the ALN groups (normal, benign, and malignant)., Results: Thirty-four suspicious ALNs (18 malignant and 16 benign) and 34 contralateral normal-appearing ALNs were included. Suspicious malignant and benign nodes exhibited larger size, greater volume, and lower ADCs than normal ALNs (P < .05). Among suspicious ALNs, the only quantitative measure that discriminated between malignant from benign outcome was percent of ALN demonstrating washout kinetics (P = .02)., Conclusions: In ALNs deemed morphologically suspicious on breast MRI, quantitative MRI features show little value in identifying those with malignant etiology., (Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.)

Objectives: While 3T breast magnetic resonance imaging has increased in use over the past decade, there is little data comparing its use for assessing ductal carcinoma in situ (DCIS) versus 1.5 T. We sought to compare the accuracies of DCIS extent of disease measures on pre-operative 3T versus 1.5 T MRI., Methods: This institutional review board-approved prospective study included 20 patients with ductal carcinoma in situ diagnosed by core needle biopsy (CNB) who underwent pre-operative breast MRI at both 3T (resolution=0.5 mm×0.5 mm×1.3 mm) and 1.5 T (0.85 mm×0.85 mm×1.6 mm). All patients provided informed consent, and the study was HIPPA compliant. Lesion sizes and imaging characteristics (morphologic and kinetic enhancement) were recorded for the 3 T and 1.5 T examinations. Lesion size measures at both field strengths were correlated to final pathology, and imaging characteristics also were compared., Results: Of the initial cohort of 20 patients with CNB-diagnosed DCIS, 19 underwent definitive surgery. Median DCIS sizes of these 19 patients were 6mm (range: 0-67 mm) on 3T, 13 mm (0-60 mm) on 1.5 T, and 6mm (0-55 mm) on surgical pathology. Size correlation between MRI and pathology was higher for 3T (Spearman's ρ=0.66, p=0.002) than 1.5 T (ρ=0.36, p=0.13). In 10 women in which a residual area of suspicious enhancement was identified on both field strengths, there was agreement of morphologic description (NME vs. mass) in nine, and no significant difference in dynamic contrast enhanced kinetics at 3T compared to 1.5 T., Conclusions: Pre-operative breast MRI at 3T provided higher correlation with final pathology size of DCIS lesions compared to 1.5 T, and may be more accurate for assessment of disease extent prior to definitive surgery., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Rationale and Objectives: As breast magnetic resonance imaging (MRI) use grows, benchmark performance parameters are needed for auditing and quality assurance purposes. We describe the variation in breast MRI abnormal interpretation rates (AIRs) by clinical indication among a large sample of US community practices., Materials and Methods: We analyzed data from 41 facilities across five Breast Cancer Surveillance Consortium imaging registries. Each registry obtained institutional review board approval for this Health Insurance Portability and Accountability Act compliant analysis. We included 11,654 breast MRI examinations conducted in 2005-2010 among women aged 18-79 years. We categorized clinical indications as 1) screening, 2) extent of disease, 3) diagnostic (eg, breast symptoms), and 4) other (eg, short-interval follow-up). We characterized assessments as positive (ie, Breast Imaging Reporting and Data System [BI-RADS] 0, 4, and 5) or negative (ie, BI-RADS 1, 2, and 6) and provide results with BI-RADS 3 categorized as positive and negative. We tested for differences in AIRs across clinical indications both unadjusted and adjusted for patient characteristics and registry and assessed for changes in AIRs by year within each clinical indication., Results: When categorizing BI-RADS 3 as positive, AIRs were 21.0% (95% confidence interval [CI], 19.8-22.3) for screening, 31.7% (95% CI, 29.6-33.8) for extent of disease, 29.7% (95% CI, 28.3-31.1) for diagnostic, and 27.4% (95% CI, 25.0-29.8) for other indications (P < .0001). When categorizing BI-RADS 3 as negative, AIRs were 10.5% (95% CI, 9.5-11.4) for screening, 21.8% (95% CI, 19.9-23.6) for extent of disease, 17.7% (95% CI, 16.5-18.8) for diagnostic, and 13.3% (95% CI, 11.6-15.2) for other indications (P < .0001). The significant differences in AIRs by indication persisted even after adjusting for patient characteristics and registry (P < .0001). In addition, for most indications, there were no significant changes in AIRs over time., Conclusions: Breast MRI AIRs differ significantly by clinical indication. Practices should stratify breast MRI examinations by indication for quality assurance and auditing purposes., (Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess which patient and magnetic resonance (MR) imaging factors are associated with the likelihood of contralateral prophylactic mastectomy (CPM) in patients with newly diagnosed breast cancer., Materials and Methods: The American College of Radiology Imaging Network 6667 trial was compliant with HIPAA; institutional review board approval was obtained at each site. All patients provided written informed consent. This study was a retrospective review of data from 934 women enrolled in the trial who did not have a known contralateral breast cancer at the time of surgical planning. The authors assessed age, menopausal status, index breast cancer histologic results, contralateral breast histologic results, breast density, family history, race and/or ethnicity, MR imaging Breast Imaging Reporting and Data System (BI-RADS) assessment, and number of MR imaging lesions for association with CPM by using the Fisher exact test, exact χ(2) test, and multivariate logistic regression analyses., Results: Eighty-six of the 934 (9.2%) women underwent CPM and were more likely to be younger (mean age, 48 years [range, 27-78 years] vs mean age, 54 years [range, 25-86 years]; P < .0001), be premenopausal (55 of 86 [64%] vs 349 of 845 [41%], P < .0001), have ductal carcinoma in situ (DCIS) in the index breast (31% [27 of 86] vs 19% [164 of 848], P = .02), have greater breast density (71 of 86 [83%] vs 572 of 848 [68%], P = .004), and have a family history of breast cancer (44 of 86 [30%] vs 150 of 488 [18%], P = .01) than those who did not undergo CPM. Distributions of race and/or ethnicity, contralateral lesion pathologic results, and number of MR imaging lesions were similar in both groups. With multivariate modeling, younger age, greater breast density, DCIS index cancer, and family history remained significant, whereas menopausal status did not. Positive MR imaging assessments were not significantly more frequent in the CPM group than in the group of women who did not undergo CPM (14 of 86 [16.3%] vs 113 of 848 [13.3%], P = .43)., Conclusion: In patients with newly diagnosed breast cancer who underwent breast MR imaging at which a contralateral breast cancer was not identified, patient factors and not breast MR imaging BI-RADS scores were chief determinants in decisions regarding CPM. Online supplemental material is available for this article., (© RSNA, 2014.)

Rationale and Objectives: Breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) scanning protocols vary widely. The purpose of this study was to determine the effects of postcontrast timing on delayed-phase lesion kinetics assessment and ability to discriminate malignant from benign lesions., Materials and Methods: Following institutional review board approval, we retrospectively reviewed all lesions assessed on magnetic resonance examinations from April 2005 to June 2006. DCE-MRI was performed with 90-second temporal resolution. Delayed-phase kinetic parameters including percentages of persistent, plateau, and washout, and categorizations of predominant and worst curve type were compared between 4.5 and 7.5 minutes postcontrast. Ability to discriminate benign and malignant lesions based on delayed-phase kinetic parameters was compared between postcontrast timings by receiver operating characteristic (ROC) analysis., Results: Two hundred eighty consecutive breast lesions (206 malignant and 74 benign) were evaluated in 228 women. Comparing kinetics assessments at 7.5 versus 4.5 minutes: volume percentage of washout increased in malignancies by a mean of 9.4% (P<.0001) and increased slightly in benign lesions (mean 3.2%, P=.007); predominant curve type categorizations changed significantly only for malignancies (P<.0001); and worst curve categorizations did not change significantly for either benign or malignant lesions (P>.05). There were no significant differences between timings in area under ROC curves for delayed-phase kinetic parameters., Conclusions: The choice of delayed postcontrast timing more strongly affects the kinetics assessments for malignancies than benign breast lesions, but our results suggest that a shortened breast DCE-MRI protocol may not significantly impact diagnostic accuracy. Furthermore, worst curve type classifications are least affected by postcontrast timing and may provide reliable assessment of delayed-phase kinetics across protocols., (Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.)

Importance: Breast magnetic resonance imaging (MRI) is increasingly used for breast cancer screening, diagnostic evaluation, and surveillance. However, we lack data on national patterns of breast MRI use in community practice., Objective: To describe patterns of breast MRI use in US community practice during the period 2005 through 2009., Design, Setting, and Participants: Observational cohort study using data collected from 2005 through 2009 on breast MRI and mammography from 5 national Breast Cancer Surveillance Consortium registries. Data included 8931 breast MRI examinations and 1,288,924 screening mammograms from women aged 18 to 79 years., Main Outcomes and Measures: We calculated the rate of breast MRI examinations per 1000 women with breast imaging within the same year and described the clinical indications for the breast MRI examinations by year and age. We compared women screened with breast MRI to women screened with mammography alone for patient characteristics and lifetime breast cancer risk., Results: The overall rate of breast MRI from 2005 through 2009 nearly tripled from 4.2 to 11.5 examinations per 1000 women, with the most rapid increase from 2005 to 2007 (P = .02). The most common clinical indication was diagnostic evaluation (40.3%), followed by screening (31.7%). Compared with women who received screening mammography alone, women who underwent screening breast MRI were more likely to be younger than 50 years, white non-Hispanic, and nulliparous and to have a personal history of breast cancer, a family history of breast cancer, and extremely dense breast tissue (all P < .001). The proportion of women screened using breast MRI at high lifetime risk for breast cancer (>20%) increased during the study period from 9% in 2005 to 29% in 2009., Conclusions and Relevance: Use of breast MRI for screening in high-risk women is increasing. However, our findings suggest that there is a need to improve appropriate use, including among women who may benefit from screening breast MRI.

Purpose: The ACR Education Center's Breast MR With Guided Biopsy course is designed to provide radiologists with an intensive, hands-on experience in interpreting breast MR. The aim of this study was to describe radiologists' performance in breast MR interpretation by case clinical indication, lesion type, and BI-RADS(®) assessment to inform future educational efforts., Methods: Data from 16 consecutive courses held from 2009 to 2012 at the ACR Education Center were analyzed. For each MR case, the clinical indication (screening vs diagnostic), background parenchymal enhancement, and lesion type (mass vs nonmass enhancement) were recorded. Participant case BI-RADS assessments were categorized as either correct or incorrect in relation to expert-opinion BI-RADS assessments. Participants' interpretive accuracy on the basis of study indication, lesion type, and background parenchymal enhancement is reported., Results: Data from 745 course participants over 3 years were analyzed. Of the 96 MR cases included in the analysis, 58% (n = 50) were indicated for screening and 42% (n = 46) for diagnostic purposes. Participants provided correct BI-RADS assessments for 79% of screening cases (32,399 of 41,249) and 74% of diagnostic cases (20,888 of 28,106). Participants more accurately assessed screening compared with diagnostic MR cases (P < .0001) and masses compared with nonmass enhancement (P < .0001). There was no statistically significant difference in performance on the basis of background parenchymal enhancement., Conclusions: Practicing radiologists perform more accurately on screening compared with diagnostic MR and when evaluating masses as opposed to areas of nonmass enhancement. Future case-based breast MR education efforts should emphasize strategies for interpreting diagnostic breast MR cases and evaluating nonmass enhancement., (Copyright © 2013 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Although there are multiple variations in acquisition protocols for breast magnetic resonance (MR) imaging, there is agreement that components of high-quality technique include a bilateral acquisition obtained with a dedicated breast coil. Further, key pulse sequences should be included and spatial and temporal resolution should be sufficiently high to assess lesion morphology and kinetics. Artifacts must be recognized and avoided. The American College of Radiology Breast MRI Accreditation Program requirements provide minimum standards to guide facilities in technique. MR imaging at 3 T is increasingly available and offers signal-to-noise ratio advantages over 1.5 T but also some technical challenges., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to compare the diagnostic accuracy and interpretation times of breast MRI with and without use of a computer-aided detection (CAD) system by novice and experienced readers., Subjects and Methods: A reader study was undertaken with 20 radiologists, nine experienced and 11 novice. Each radiologist participated in two reading sessions spaced 6 months apart that consisted of 70 cases (27 benign, 43 malignant), read with and without CAD assistance. Sensitivity, specificity, negative predictive value, positive predictive value, and overall accuracy as measured by the area under the receiver operating characteristic curve (AUC) were reported for each radiologist. Accuracy comparisons across use of CAD and experience level were examined. Time to interpret and report on each case was recorded., Results: CAD improved sensitivity for both experienced (AUC, 0.91 vs 0.84; 95% CI on the difference, 0.04, 0.11) and novice readers (AUC, 0.83 vs 0.77; 95% CI on the difference, 0.01, 0.10). The increase in sensitivity was statistically higher for experienced readers (p = 0.01). Diagnostic accuracy, measured by AUC, for novices without CAD was 0.77, for novices with CAD was 0.79, for experienced readers without CAD was 0.80, and for experienced readers with CAD was 0.83. An upward trend was noticed, but the differences were not statistically significant. There were no significant differences in interpretation times., Conclusion: MRI sensitivity improved with CAD for both experienced readers and novices with no overall increase in time to evaluate cases. However, overall accuracy was not significantly improved. As the use of breast MRI with CAD increases, more attention to the potential contributions of CAD to the diagnostic accuracy of MRI is needed.

The use of breast MRI at 3 tesla (T) has increased in use substantially in recent years. Potential benefits of moving to higher field strength MRI include improved morphologic and kinetic assessment of breast lesions through higher spatial and temporal resolution dynamic contrast-enhanced MR examinations. Furthermore, higher field strength holds promise for the development of superior advanced breast MRI techniques, such as diffusion weighted imaging and MR spectroscopy. To fully realize the benefits of moving to 3T, a thorough understanding of the technical and safety challenges of higher field strength imaging specific to breast MRI is paramount. Through the use of advanced coil technology, parallel imaging, dual-source parallel radiofrequency excitation, and image-based shimming techniques, many of these limiting technical factors can be overcome to achieve high quality breast MRI at 3T., (Copyright © 2012 Wiley Periodicals, Inc.)

Objective: The purpose of this study was to compare the differences in kinetic assessments of lesions at breast MRI performed with higher and lower temporal resolution., Materials and Methods: All consecutively evaluated BI-RADS category 4, 5, and 6 lesions imaged with breast MRI and pathologically confirmed from October 2005 to August 2009 were identified. Patients underwent MRI with one of two dynamic contrast-enhanced protocols: one with 90-second (October 2005-June 2006) and another with 180-second (July 2006-August 2009) temporal resolution. Studies were processed with a computer-aided evaluation system with initial and delayed contrast-enhanced time points with the k-space centered 90 and 450 seconds after contrast injection. Initial-phase peak enhancement, delayed-phase predominant curve type, and worst curve type were recorded and compared for benign and malignant lesions across protocols., Results: The analysis set comprised 993 lesions: 145 imaged with the 90-second acquisition (17 benign, 28 ductal carcinoma in situ [DCIS], 100 invasive cancer) and 848 imaged with the 180-second acquisition (212 benign, 145 DCIS, 491 invasive cancer). Peak enhancement was significantly higher for both benign lesions (p = 0.01) and invasive cancers (p = 0.0008) with the 180-second protocol. Peak enhancement of DCIS was similar in the two protocols (p = 0.88). Delayed-phase kinetics were similar for the two protocols for both benign and malignant lesions when defined by predominant or worst curve type., Conclusion: Although it has lower temporal resolution, a 180-second acquisition may be preferable because it allows higher spatial resolution and captures higher initial-phase peak enhancement without loss of delayed-phase kinetic information.

Purpose: To evaluate the positive predictive values (PPVs) of Breast Imaging and Reporting Data Systems (BI-RADS) assessment categories for breast magnetic resonance (MR) imaging and to identify the BI-RADS MR imaging lesion features most predictive of cancer., Materials and Methods: This institutional review board-approved HIPAA-compliant prospective multicenter study was performed with written informed consent. Breast MR imaging studies of the contralateral breast in women with a recent diagnosis of breast cancer were prospectively evaluated. Contralateral breast MR imaging BI-RADS assessment categories, morphologic descriptors for foci, masses, non-masslike enhancement (NMLE), and kinetic features were assessed for predictive values for malignancy. PPV of each imaging characteristic of interest was estimated, and logistic regression analysis was used to examine the predictive ability of combinations of characteristics., Results: Of 969 participants, 71.3% had a BI-RADS category 1 or 2 assessment; 10.9%, a BI-RADS category 3 assessment; 10.0%, a BI-RADS category 4 or 5 assessment; and 7.7%, a BI-RADS category 0 assessment on the basis of initial MR images. Thirty-one cancers were detected with MR imaging. Overall PPV for BI-RADS category 4 and 5 lesions was 0.278, with 17 cancers in patients with a BI-RADS category 4 lesion (PPV, 0.205) and 10 cancers in patients with a BI-RADS category 5 lesion (PPV, 0.714). Of the cancers, one was a focus, 17 were masses, and 13 were NMLEs. For masses, irregular shape, irregular margins, spiculated margins, and marked internal enhancement were most predictive of malignancy. For NMLEs, ductal, clumped, and reticular or dendritic enhancement were the features most frequently seen with malignancy. Kinetic enhancement features were less predictive of malignancy than were morphologic features., Conclusion: Standardized terminology of the BI-RADS lexicon enables quantification of the likelihood of malignancy for MR imaging-detected lesions through careful evaluation of lesion features. In particular, BI-RADS assessment categories and morphologic descriptors for masses and NMLE were useful in estimating the probability of cancer., (© RSNA, 2012.)

Purpose: To compare breast MRI B(1) homogeneity at 3 Tesla (T) with and without dual-source parallel radiofrequency (RF) excitation., Materials and Methods: After institutional review board approval, we evaluated 14 consecutive breast MR examinations performed at 3T that included three-dimensional B(1) maps created separately with conventional single-source and dual-source parallel RF excitation techniques. We measured B(1) values (expressed as % of intended B(1) ) on each B(1) map at nipple level in multiple bilateral locations: anterior, lateral, central, medial, and posterior. Mean whole breast and location specific B(1) values were calculated and compared between right and left breasts using paired t-test., Results: Mean whole breast B(1) values differed significantly between right and left breasts with standard single-source RF excitation (difference L-R, Δ = 9.2%; P < 0.001) but not with dual-source parallel RF excitation (Δ = 2.3%; P = 0.085). Location specific B(1) values differed significantly between right and left on single-source in the lateral (P = 0.014), central (P = 0.0001), medial (P = 0.0013), and posterior (P < 0.0001) locations. Conversely, mean B(1) values differed significantly on dual-source parallel RF excitation for only the anterior (P = 0.030) and lateral (P = 0.0003) locations., Conclusion: B(1) homogeneity is improved with dual-source parallel RF excitation on 3T breast MRI when compared with standard single-source RF excitation technique., (Copyright © 2012 Wiley Periodicals, Inc.)

Objective: Breast density is documented to reduce sensitivity and specificity of mammography. However, little is known regarding the effect of normal background parenchymal enhancement on accuracy of breast MRI. The purpose of this study was to evaluate the effect of background parenchymal enhancement on MRI diagnostic performance., Materials and Methods: A review of our established MRI data identified all women undergoing breast MRI from March 1, 2006, through June 30, 2007. Prospectively reported background parenchymal enhancement categories of minimal, mild, moderate, or marked (anticipated BI-RADS MRI lexicon definitions) and assessments were extracted from the database for each patient. Outcomes were determined by pathologic analysis, imaging, and linkage with the regional tumor registry with a minimum of 24 months of follow-up. Patients were dichotomized into categories of minimal or mild versus moderate or marked background parenchymal enhancement. Associations with patient age, abnormal interpretation rate, positive biopsy rate, cancer yield, sensitivity, and specificity were compared using chi-square and z score tests., Results: The study cohort included 736 women. Moderate or marked background parenchymal enhancement was significantly more frequent among patients younger than 50 years compared with those 50 years old and older (39.7% vs 18.9%; p < 0.0001). Moderate or marked background parenchymal enhancement was also associated with a higher abnormal interpretation rate compared with minimal or mild background parenchymal enhancement (30.5% vs 23.3%; p = 0.046). Positive biopsy rate, cancer yield, sensitivity, and specificity were not significantly different according to background parenchymal enhancement category., Conclusion: Increased background parenchymal enhancement on breast MRI is associated with younger patient age and higher abnormal interpretation rate. However, it is not related to significant differences in positive biopsy rate, cancer yield, sensitivity, or specificity of MRI.

Objectives: To predict the probability of malignancy for MRI-detected breast lesions with a multivariate model incorporating patient and lesion characteristics., Methods: Retrospective review of 2565 breast MR examinations from 1/03-11/06. BI-RADS 3, 4 and 5 lesions initially detected on MRI for new cancer or high-risk screening were included and outcomes determined by imaging, biopsy or tumor registry linkage. Variables were indication for MRI, age, lesion size, BI-RADS lesion type and kinetics. Associations with malignancy were assessed using generalized estimating equations and lesion probabilities of malignancy were calculated., Results: 855 lesions (155 malignant, 700 benign) were included. Strongest associations with malignancy were for kinetics (washout versus persistent; OR 4.2, 95% CI 2.5-7.1) and clinical indication (new cancer versus high-risk screening; OR 3.0, 95% CI 1.7-5.1). Also significant were age > = 50 years, size > = 10 mm and lesion-type mass. The most predictive model (AUC 0.70) incorporated indication, size and kinetics. The highest probability of malignancy (41.1%) was for lesions on MRI for new cancer, > = 10 mm with washout. The lowest (1.2%) was for lesions on high-risk screening, <10 mm with persistent kinetics., Conclusions: A multivariate model shows promise as a decision support tool in predicting malignancy for MRI-detected breast lesions.

Breast magnetic resonance imaging (MRI) is routinely used as a problem-solving tool, but its benefit for this indication remains unclear. The records of 3001 consecutive breast MR examinations between January 1, 2003 and June 6, 2007 were reviewed to identify all those performed for the clinical indication of problem solving. Details of clinical presentation, mammography and ultrasound (US) findings, follow-up recommendations, and pathology outcomes were recorded. Benign versus malignant outcomes were determined by biopsy or 12 months of follow-up imaging and linkage with the regional tumor registry. Problem solving was the clinical indication for 204 of 3001 (7%) of all examinations. Forty-two of 204 examinations (21%) had suspicious or highly suspicious MRI assessments with recommendation for biopsy and 62 of 204 (79%) examinations were assessed as negative, benign, or probably benign. Thirty-six biopsies were performed based on MRI findings and 14 cancers were diagnosed. Biopsy was indicated for 11 of 14 (79%) cancers based on suspicious mammographic or US findings identified prior to MRI. One incidental cancer was detected by MRI alone in a patient at high risk for breast cancer, and two cancers were detected in patients with suspicious nipple discharge and negative mammogram and US. A single false-negative MRI occurred in a patient whose evaluation for a palpable lump prompted biopsy. Problem-solving breast MRI rarely identifies otherwise occult cancer and can be falsely negative in patients with suspicious findings on mammogram and US. Until the benefits and risks of problem-solving MRI are clarified, it should be used judiciously., (© 2011 Wiley Periodicals, Inc.)

Objective: The purpose of our study is to report the outcomes at a center that routinely uses breast MRI for preoperative staging, regardless of lesion histology or patient characteristics., Materials and Methods: Five hundred ninety-two patients with recently diagnosed breast cancer who underwent staging with preoperative breast MRI between January 1, 2003, and April 30, 2007, were reviewed. Five hundred seventy patients comprised the analysis set. Patient age, breast density, index tumor histology, receptor status (ER, PR, and HER2), and lymph node status were recorded. Biopsy rates, positive predictive values (PPVs) of biopsy, and overall cancer yield were calculated and compared using the chi-square test across patient age, mammographic breast density, index tumor type, receptor status, and lymph node status., Results: Biopsy was recommended and performed for 152 of 570 (27%) patients found to have one or more suspicious lesions on MRI distinct from the index cancer. Sixty-seven of 152 women who underwent biopsy had additional cancers diagnosed, for a PPV of 44%. Overall, 12% (67/570) of women had otherwise occult cancers diagnosed by MRI, with 8% having additional sites or greater extent of ipsilateral disease and 4% having unsuspected contralateral cancer detected by MRI alone. No significant differences were found in the probability of detecting an occult cancer on the basis of patient age, breast density, index tumor characteristics, or lymph node status., Conclusion: Breast MRI detects otherwise occult cancer with an overall added cancer yield of 12% and a high PPV of 44% when applied to a diverse population of patients with newly diagnosed breast cancer.

Purpose: MRI is increasingly used for the detection of breast carcinoma. Little is known about breast MRI techniques among community practice facilities. The aim of this study was to evaluate equipment and acquisition techniques used by community facilities across the United States, including compliance with minimum standards by the ACRIN® 6667 Trial and the European Society of Breast Imaging., Methods: Breast Cancer Surveillance Consortium facilities performing breast MRI were identified and queried by survey regarding breast MRI equipment and technical parameters. Variables included scanner field strength, coil type, acquisition coverage, slice thickness, and the timing of the initial postcontrast sequence. Results were tallied and percentages of facilities meeting ACRIN® and European Society of Breast Imaging standards were calculated., Results: From 23 facilities performing breast MRI, results were obtained from 14 (61%) facilities with 16 MRI scanners reporting 18 imaging parameters. Compliance with equipment recommendations of ≥1.5-T field strength was 94% and of a dedicated breast coil was 100%. Eighty-three percent of acquisitions used bilateral postcontrast techniques, and 78% used slice thickness≤3 mm. The timing of initial postcontrast sequences ranged from 58 seconds to 8 minutes 30 seconds, with 63% meeting recommendations for completion within 4 minutes., Conclusions: Nearly all surveyed facilities met ACRIN and European Society of Breast Imaging standards for breast MRI equipment. The majority met standards for acquisition parameters, although techniques varied, in particular for the timing of initial postcontrast imaging. Further guidelines by the ACR Breast MRI Accreditation Program will be of importance in facilitating standardized and high-quality breast MRI., (Copyright © 2010 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this article is to determine the frequency, outcomes, and imaging features of high-risk lesions initially detected by breast MRI, including atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar., Materials and Methods: A retrospective review of our MRI pathology database was performed to identify all lesions initially detected with MRI (January 2003 through May 2007) that underwent imaging-guided needle biopsy yielding high-risk histopathologic abnormalities. Patient age, clinical indication, MRI BI-RADS lesion features, biopsy method, and histopathologic diagnosis were recorded. The frequencies of high-risk findings at needle biopsy and rates of upgrade to malignancy at surgical excision were compared across lesion imaging features with Fisher's exact test., Results: Four hundred eighty-two MRI-detected suspicious lesions underwent needle biopsy. High-risk histopathologic abnormalities were present in 61 (12.7%) of 482 lesions: 51 (10.6%) atypical ductal hyperplasias, six (1.2%) atypical lobular hyperplasias, three (0.6%) lobular carcinomas in situ, and one (0.2%) radial scar. Correlation between the lesion site and pathology at surgical excision was confirmed for 39 of 61 lesions. Twelve (30.8%) of those 39 lesions were upgraded to malignancy (11 atypical ductal hyperplasias and one atypical lobular hyperplasia); five (41.7%) of the 12 malignancies were invasive cancer, and seven (58.3%) were ductal carcinomas in situ. No significant lesion features predictive of subsequent upgrade to malignancy were discovered., Conclusion: There are no specific imaging features that predict upgrade for high-risk lesions when detected with MRI. Therefore, surgical excision is recommended because upgrade to invasive carcinoma or ductal carcinoma in situ can occur in up to 31% of cases, regardless of biopsy technique.

The MR imaging BI-RADS atlas includes a category for probably benign findings, and many radiologists recommend short-term interval follow-up for breast MR imaging lesions. However, the characteristics of those MR imaging findings that could appropriately be considered probably benign are not well defined. This article reviews the published retrospective and prospective data regarding the use and cancer yield of the BI-RADS 3 assessment category as well as the morphology and kinetics of lesions that may be considered suitable for short-term follow-up. Consideration is also given to how the costs, clinical indication for the examination, experience of the reader, and availability of comparisons may affect the use of the BI-RADS 3 category. Based on the evidence that is available, an algorithm is offered with imaging examples as a guide for determining if lesions are appropriate for short-term follow-up. Additional research is needed to fully clarify the distinct morphologic and kinetic characteristics that allow patients to safely avoid biopsy without changing prognosis if malignancy is present., (Copyright 2010 Elsevier Inc. All rights reserved.)

Purpose: Our goal was to determine the correlations between dynamic contrast-enhanced MRI (DCE-MRI) kinetics of breast cancers and axillary nodal status (ANS) which may have prognostic value in designing radiation therapy recommendations., Methods and Materials: A retrospective review identified 167 consecutive patients treated with external beam radiotherapy for invasive breast cancer from Jan 1, 2006 to Nov 1, 2007. Patients with DCE-MRI kinetic data from our institution who underwent axillary surgical staging prior to chemotherapy were included. ANS was assessed as positive or negative by pathology record review. For each primary cancer, maximum tumor diameter and kinetic values for initial peak enhancement (PE), percent initial rapid enhancement (RE), and percent delayed washout enhancement (WE) were measured with a computer-aided evaluation program. Univariate, multivariate, and receiver operating characteristic curve analyses were performed according to the ANS., Results: Forty-six patients met study criteria, with 32 (70%) node-negative and 14 (30%) node-positive patients. Median PE was significantly greater in node-positive patients (209%) than in node-negative patients (138%, p = 0.0027). Similarly, median RE was significantly greater in node-positive patients (57%) than in node-negative patients (27%, p = 0.0436). WE was not different between groups (p = 0.9524). Median maximum tumor diameter was greater in node-positive patients (26 mm) than in node-negative patients (15 mm, p = 0.015). Multivariate analysis showed that only PE trended toward significance (p = 0.18)., Conclusions: DCE-MRI kinetics of primary breast cancers correlate with ANS. Multivariate analysis demonstrates the correlation is not due simply to underlying lesion size. If validated prospectively, DCE-MRI kinetics may aid as a tool in selecting patients or designing fields for radiation therapy.

Rationale and Objectives: To evaluate the associations of patient age and clinical indication with the risk of malignancy for suspicious lesions initially detected on breast magnetic resonance imaging (MRI)., Methods and Materials: After institutional review board approval, a retrospective review of our breast MRI database was performed to identify all nonpalpable, mammographically occult, MRI-detected suspicious lesions between January 1, 2003, and November 30, 2006, that underwent needle or excisional biopsy. Clinical indication and patient age were recorded and their associations with risk of malignancy were assessed using univariate and multivariate generalized estimating equations., Results: The likelihood of malignancy was significantly higher (P = .0004) for suspicious lesions found on MRI examinations performed for a patient history of known cancer/evaluate extent of disease (130/309, 42%) compared to lesions identified on examinations conducted for high-risk screening (21/96, 22%). Suspicious lesions found in patients > or = 50 years of age were also more likely to be malignant (92/209, 44%) compared to those found in patients <50 years of age (59/196, 30%) (P = .004). In a multivariable model, both clinical indication of known cancer (OR 2.39, 95% CI 1.33-4.30) and age of 50 years or older (OR 1.66, 95% CI 1.03-2.68) were independently associated with greater risk of malignancy., Conclusion: The clinical indication of known cancer/evaluate extent of disease and patient age of 50 years or older significantly increase the risk of malignancy in suspicious MRI-detected lesions.

Objective: The purpose of our study was to evaluate the predictive features of BI-RADS lesion characteristics and the risk of malignancy for mammographically and clinically occult lesions detected initially on breast MRI., Materials and Methods: We reviewed 1,523 consecutive breast MRI examinations performed from January 1, 2003, to June 30, 2005, to identify all lesions initially detected on MRI and assessed as BI-RADS 4 or 5 for which the patient underwent subsequent imaging-guided needle or excisional biopsy. BI-RADS lesion features were recorded for each case, and the risk of malignancy was assessed using generalized estimating equations. Separate multivariate models were constructed for lesions classified as masses., Results: Included in the analysis were 258 suspicious lesions in 196 women. Among all lesions, those of 1 cm or greater were significantly more often malignant (50/147, 34%) than lesions of less than 1 cm (22/111, 20%; odds ratio, 2.09; 95% CI, 1.13-3.83). For masses, size, BI-RADS margin, and enhancement pattern predicted malignancy. In multivariate analysis of combinations of features, masses of 1 cm or greater with heterogeneous enhancement and irregular margins had a 68% probability of malignancy. Masses of 1 cm or greater with smooth margins and homogeneous enhancement had the lowest predicted probability of malignancy of 3%. BI-RADS descriptors and size were not significant predictors of malignancy for nonmasslike enhancement (NMLE)., Conclusion: Combinations of BI-RADS lesion descriptors can predict the probability of malignancy for breast MRI masses but not for NMLE. If our model is validated, masses with a low probability of malignancy may be eligible for short-interval follow-up rather than biopsy. Further research focused on predictive features of NMLE is needed.

Objective: The purpose of our study was to describe the characteristics of probably benign breast MRI lesions and determine how these characteristics could be used to define the MRI BI-RADS 3 category., Materials and Methods: We prospectively collected morphology and kinetic data on lesions assessed as BI-RADS 3 in 2,569 consecutive breast MRI examinations from January 2003 through November 2006. The clinical indications for MRI, follow-up assessments, and pathology findings through May 2008 were collected from clinical records. Data were linked to the regional tumor registry to identify cases of malignancy in patients who did not follow-up at our institution. Frequency of BI-RADS 3 and cancer yield were calculated. Characteristics of probably benign lesions were analyzed for predictors of malignancy., Results: Three hundred sixty-two lesions were assessed as BI-RADS 3 in 260 (10.1%) of 2,569 examinations in 236 patients. The 362 lesions included 168 (46%) foci, 132 (36%) nonmasslike enhancements, and 62 (17%) masses. Delayed kinetic information was available in 275 lesions. The most suspicious delayed kinetic enhancement was persistent in 164 (60%) of 275, plateau in 47 (17%) of 275, and washout in 64 (23%) of 275. The cancer yield in patients with a BI-RADS 3 assessment was two (0.85%) of 236; both were ductal carcinoma in situ lesions. There were no malignancies in the 69 foci with 100% persistent enhancement., Conclusion: The characteristics of BI-RADS 3 lesions were highly variable in our population, and the risk of malignancy was low (0.85%). Assigning foci with 100% persistent enhancement to the BI-RADS 2 category can decrease the frequency of BI-RADS 3 assessment and maintain a likelihood of malignancy in less than 2% of cases.

Objective: Computer-aided evaluation (CAE) programs for breast MRI provide automated lesion kinetic information. The CAE kinetic parameters that best predict malignancy have not been established. We compared three CAE kinetic features of suspicious breast MRI lesions to determine associations with benign or malignant outcomes., Materials and Methods: From 1,532 MRI examinations, all suspicious breast lesions initially detected with MRI and having CAE kinetics and subsequent biopsy were identified. Three CAE variables were compared for benign and malignant lesions: initial phase peak enhancement (greatest percentage signal intensity increase on first contrast-enhanced sequence), delayed phase enhancement categorized by a single type of kinetics comprising the largest percentage of enhancement (washout, plateau, or persistent), and delayed phase enhancement categorized by single most suspicious type of kinetics (any washout > any plateau > any persistent)., Results: One hundred twenty-five lesions (42 malignant, 83 benign) comprised the analysis set. There were no significant differences in initial peak enhancement (p = 0.28) or delayed kinetics categorized by largest percentage enhancement types (p = 0.39) between benign and malignant lesions. There was a significant difference in delayed kinetics categorized by the most suspicious enhancement types (p = 0.005). Of lesions with washout as most suspicious (any washout), 45.7% were malignant compared with 20.0% with plateau and 13.3% with entirely persistent enhancement., Conclusion: Of CAE kinetics analyzed, only delayed enhancement categorized by most suspicious type was significantly different between benign and malignant lesions. This supports the American College of Radiology BI-RADS Breast MRI Lexicon recommendation to report the "worst looking" kinetic curve.

To identify the Breast Imaging Reporting and Data System magnetic resonance imaging (MRI) enhancement characteristics of ductal carcinoma in situ (DCIS). A retrospective review of consecutive patients who underwent breast MRI for newly diagnosed breast carcinoma prior to surgery was conducted. This yielded 381 lesions in 361 patients with pathologic confirmation of either DCIS alone, invasive carcinoma alone, or mixed invasive and in-situ disease. Presence or absence of a MRI lesion at the site of the documented carcinoma was recorded, and for all identified MRI lesions the Breast Imaging Reporting and Data System morphology patterns were recorded. MRI features of the different malignancy types were compared utilizing Fisher's exact tests; 64/381 (16.8%) lesions had DCIS, 101/381 (26.5%) had invasive carcinoma, and 216/381 (56.7%) had mixed invasive/in situ carcinoma. A MRI lesion corresponding to the known cancer was identified in 55/64 (85.9%) cases of DCIS, 98/101 (97.0%) cases of invasive carcinoma, and 212/216 (98.1%) cases of mixed invasive and in-situ carcinoma. For pure DCIS lesions, 38/64 (59.4%) exhibited nonmass-like enhancement (NMLE), 9/64 (14.1%) were masses, and 8/64 (12.5%) were a focus. For pure invasive carcinomas 79/101(78.2%) were masses, 16/101 (15.8%) were NMLE, and 3/101 (3.0%) were a focus. For mixed lesions 163/216 (75.5%) were masses, 44/216 (20.4%) demonstrated NMLE, and 5/216 (2.3%) were a focus. The most common NMLE patterns of pure DCIS were segmental distribution and clumped internal enhancement. Although there is overlap in the MRI morphology and enhancement pattern of in situ and invasive breast carcinoma, DCIS more frequently manifests as NMLE than does invasive carcinoma.

Purpose: To evaluate the cancer yield, frequency of use, and follow-up compliance of breast MR examinations assessed as "probably benign.", Materials and Methods: We retrospectively reviewed our MR database of 809 consecutive examinations between January 2003 and June 2004. We identified all examinations that ultimately received an MR breast imaging reporting and data system (BI-RADS) 3 assessment and recommendation for a short-interval follow-up MR with or without an antecedent targeted ultrasound. The clinical indication for breast MR, date of the follow-up examination, follow-up assessment, and any pathology findings through June 2005 were collected from clinical records and radiology and pathology reports. Frequency of BI-RADS 3 use, follow-up compliance, and cancer yield were calculated., Results: A total of 160 out of 809 (20%) examinations comprise the study population. A total of 100 out of 160 (63%) women returned for the recommended follow-up MR, in which three out of 100 (3%) were upgraded to BI-RADS 4 with biopsy recommended. One patient underwent biopsy and the result was benign. A total of seven out of 160 (4%) underwent mastectomy in lieu of MR for known cancer elsewhere in the breast. One out of seven mastectomy specimens contained malignancy that corresponded to the probably benign finding, resulting in a cancer yield of one out of 160 (0.6%)., Conclusion: Our data suggest that follow-up MR is a valid alternative to biopsy for MR BI-RADS 3 lesions., ((c) 2007 Wiley-Liss, Inc.)

Purpose: To retrospectively determine the sensitivity of kinetic features measured with computer-aided evaluation at breast magnetic resonance (MR) imaging in discriminating benign from malignant lesions, with histopathologic findings used as the reference standard., Materials and Methods: Institutional review board approval was obtained for this HIPAA-compliant study. Informed consent was waived. Suspicious breast lesions visible only at MR imaging and in which biopsy had been performed with MR imaging guidance were retrospectively evaluated with a computer-aided evaluation program. Computer-generated kinetic features for each lesion were recorded, and those of benign and malignant lesions were compared. Features analyzed included the presence or absence of computer-aided evaluation "threshold enhancement" at 50% and 100% minimum thresholds; degree of initial peak enhancement; and enhancement profiles composed of lesion percentages of washout, plateau, and persistent enhancement. The Fisher exact test and Student t test were used to assess differences in these analyses., Results: One hundred fifty-four consecutive lesions (41 malignant, 113 benign) in 125 women (age range, 27-86 years; mean age, 52 years) were evaluated. The presence of threshold enhancement at computer-aided evaluation was sensitive for malignancy, with 38 of 41 (93%) malignant lesions demonstrating enhancement at both the 50% and 100% thresholds. Absence of threshold enhancement at computer-aided evaluation helped improve the discrimination between benign and malignant lesions when compared with that at initial interpretation by the radiologists. False-positive rates were reduced by 8.8% at the 50% enhancement threshold (not significant) and by 23.0% at the 100% enhancement threshold (P=.02) when compared with that at initial interpretation. Analyses of initial peak enhancement values and enhancement profiles did not demonstrate further improvements in lesion discrimination., Conclusion: The use of computer-aided evaluation for breast MR imaging significantly helped improve the discrimination of benign from malignant lesions when compared with that at initial interpretations by radiologists., ((c) RSNA, 2007.)

Objective: We sought to compare the accuracy of breast MRI interpretations with and without a new software application (CADstream) that provides automated evaluations of breast MR examinations., Materials and Methods: Thirty-three consecutive lesions seen only on MRI (nine malignant, 24 benign) were evaluated with and without the automated software system. Automated analyses of kinetic enhancement for each lesion were recorded at 50%, 80%, and 100% enhancement thresholds. Computer-assisted analyses included presence or absence of "significant" enhancement and classification of enhancement patterns into percent volumes of washout, plateau, and persistent enhancement. Fisher's exact tests were performed to compare the likelihood of malignancy based on the presence of software-defined significant enhancement at the three thresholds. Enhancement profiles of malignant versus benign lesions were compared using the Student's t test., Results: All malignant lesions showed significant enhancement at all thresholds. Compared with the unassisted interpretations, the computer-assisted analyses yielded false-positive rates that were reduced by 25% at a 50% threshold (not significant [NS]), 33% at an 80% threshold (p = 0.05), and 50% at a 100% threshold for enhancement (p < 0.01). There were no significant differences between enhancement profiles of benign and malignant lesions, with all lesions showing a wide range of washout, plateau, and persistent patterns of enhancement., Conclusion: New automated software applied to interpret breast MR examinations accurately showed significant enhancement in all the malignant lesions while depicting 12 of 24 benign lesions as showing insignificant enhancement. If these results are validated by a larger study, the number of unnecessary biopsies of MR lesions could be reduced without a concomitant decrease in cancer detection.

Rationale and Objectives: MRI has shown promise in assessing breast cancer patients undergoing neoadjuvant chemotherapy. Computer-aided detection (CAD) for MRI can automatically display tumor enhancement parameters. This study was performed to determine the utility of CAD applied to breast MRI in this patient population., Materials and Methods: Fifteen patients with 16 newly diagnosed locally advanced breast cancers were evaluated with MRI before and after neoadjuvant chemotherapy. CAD assessments, including presence or absence of significant enhancement, enhancement profiles, and maximum sizes, were recorded. Pre-chemotherapy and post-chemotherapy enhancement profiles were compared. Sizes were compared to those measured by the radiologist and at final pathology., Results: Prior to chemotherapy, all tumors demonstrated CAD-assessed significant enhancement. Following chemotherapy, 7/16 tumors showed no residual significant enhancement, but all had residual disease at pathology. In those patients with residual enhancement, comparison of the post-chemotherapy to pre-chemotherapy CAD enhancement profiles showed a significant decrease in percentage of washout enhancement (P = 0.0147) in patients with less than 5 mm of residual microscopic disease. Radiologist-measured tumor sizes demonstrated better correlation with sizes at pathology (r = 0.60) than did CAD-generated tumor sizes (r = 0.32)., Conclusion: CAD may be helpful in assessing changes in MRI enhancement profiles of tumors following chemotherapy. However, CAD-assessed significant enhancement following chemotherapy can be falsely negative for residual malignancy, and CAD tumor sizes are less accurate than those measured by the radiologist in predicting size of residual malignancy. CAD may complement but should not replace the radiologist's assessment of tumors in this patient population.

Objective: The objective of our study was to evaluate a new commercially available method of MRI-guided vacuum-assisted breast biopsy using an open coil and a closed 1.5-T scanner., Materials and Methods: Consecutive MRI-guided vacuum-assisted breast biopsies of 38 lesions in 28 women performed between May and September 2003 at two practice sites in the United States were retrospectively reviewed. Lesion characteristics including size, morphology, and enhancement were recorded. Times to perform each procedure, defined as the time from the start of the first localizing scan to the final scan after biopsy, were recorded. Histologic results for all lesions were obtained, and surgical, imaging, or clinical follow-up was performed., Results: Enhancing masses and foci ranged from 2.5 to 19 mm. Nonmasslike enhancements ranged from 6 to 70 mm. All 38 biopsies (100%) were technically successful, and no complications were associated with any of the biopsy procedures. The average time to perform the 19 single-site MRI-guided procedures was 38 min (range, 23-57 min). The 11 multiple-site biopsies performed in a single breast averaged 59 min (range, 51-68 min), and eight bilateral biopsies averaged 64 min (range, 46-80 min). Histologic results from vacuum-assisted breast biopsy revealed malignancy in 14 lesions (37%), atypical ductal hyperplasia in two lesions (5%), and benign findings in 22 lesions (58%). One of two lesions with atypical ductal hyperplasia was upgraded to ductal carcinoma in situ after surgery, for an overall cancer yield of 40% (15/38)., Conclusion: This new method of MRI-guided vacuum-assisted breast biopsy is a safe, effective, and time-efficient means of MRI-guided tissue sampling.