Marked Background Parenchymal Enhancement Research Articles

Background parenchymal enhancement in breast magnetic resonance imaging: A review of current evidences and future trends.

Background parenchymal enhancement (BPE) on breast magnetic resonance imaging (MRI) is a dynamic process, which varies among women and within the same woman over time due to different factors. BPE has profound implications for women with or at risk of breast cancer. Breast radiologist should be aware of factors that could potentially influence BPE and have to be familiar with its typical appearance. Marked BPE could indeed affect the diagnostic accuracy of breast MRI, but this shortcoming can be minimized through evaluation by dedicated radiologists, in order to correctly interpret and properly manage the additional findings. BPE shows promise as an imaging biomarker but many issues need to be addressed before it can be used either to determine screening strategy or the value of risk-reducing interventions. This review analyzes the clinical influence of BPE on breast MRI interpretation, breast cancer staging and surgical outcome and discusses current available evidences about BPE as an imaging biomarker.

Is Background Parenchymal Enhancement in Breast Magnetic Resonance Imaging Associated with Breast Cancer?

Background: Background parenchymal enhancement (BPE) in breast magnetic resonance imaging (MRI) potentially correlates with breast cancer (BC). Thus, BPE may be used for BC risk stratification and for monitoring chemo-prevention. Objectives: We aimed to investigate the BPE patterns in benign and malignant breast lesions and in pre-menopausal and post-menopausal women. Methods: In 2017, 128 consecutive pre-menopausal or post-menopausal patients underwent breast MRI with different indications were examined. Subjects with the history of breast surgery, radiotherapy, or chemotherapy were excluded. A 1.5 Tesla device was used with the same protocol, and a blinded radiologist visually assessed and categorized breast BPE as minimal, mild, moderate, and marked. We used frequency distribution, mean, and standard deviation to report the findings. Comparing age or BPE in categorical variables, we appropriately used ANOVA, or Chi-square and Fisher’s exact tests. Results: The mean (± standard deviation) age was 42.43 (± 10.82) years, and 89 (69.5%) patients were hormonally active. Eighteen (14.1%), 55 (43.0%), 41 (32.0%), and 14 (10.9%) patients were classified as having minimal, mild, moderate, and marked BPE, respectively. Age did not change among BPE levels (P = 0.197). Prevalence of moderate and marked BPE was higher in pre-menopausal women. BPE was not associated with breast lesion histopathology (P value = 0.857) in pre-menopausal or post-menopausal women (P = 0.790, and 0.840, respectively). Conclusions: BPE is a measure of breast tissue hormonal activity, and it is not correlated with histopathological diagnosis of breast lesion in both pre-menopausal and post-menopausal women. The data of this study do not support the use of BPE for BC risk estimation.

Quantitative analysis of background parenchymal enhancement in whole breast on MRI: Influence of menstrual cycle and comparison with a qualitative analysis

ObjectiveWe quantitatively analyzed background parenchymal enhancement (BPE) in whole breast according to menstrual cycle and compared it with a qualitative analysis method. Materials and methodsA data set of breast magnetic resonance imaging (MRI) from 273 breast cancer patients was used. For quantitative analysis, we used semiautomated in-house software with MATLAB. From each voxel of whole breast, the software calculated BPE using following equation: [(signal intensity [SI] at 1 min 30 s after contrast injection – baseline SI)/baseline SI] × 100%. ResultsIn total, 53 patients had minimal, 108 mild, 87 moderate, and 25 marked BPE. On quantitative analysis, mean BPE values were 33.1% in the minimal, 42.1% in the mild, 59.1% in the moderate, and 81.9% in the marked BPE group showing significant difference (p = .009 for minimal vs. mild, p < 0.001 for other comparisons). Spearman’s correlation test showed that there was strong significant correlation between qualitative and quantitative BPE (r = 0.63, p < 0.001).The mean BPE value was 48.7% for patients in the first week of the menstrual cycle, 43.5% in the second week, 49% in the third week, and 49.4% for those in the fourth week. The difference between the second and fourth weeks was significant (p = .005). Median, 90th percentile, and 10th percentile values were also significantly different between the second and fourth weeks but not different in other comparisons (first vs. second, first vs. third, first vs. fourth, second vs. third, or third vs. fourth). ConclusionQuantitative analysis of BPE correlated well with the qualitative BPE grade. Quantitative BPE values were lowest in the second week and highest in the fourth week.

Relationship between Background Parenchymal Enhancement on High-risk Screening MRI and Future Breast Cancer Risk

To determine if background parenchymal enhancement (BPE) on screening breast magnetic resonance imaging (MRI) in high-risk women correlates with future cancer. All screening breast MRIs (n = 1039) in high-risk women at our institution from August 1, 2004, to July 30, 2013, were identified. Sixty-one patients who subsequently developed breast cancer were matched 1:2 by age and high-risk indication with patients who did not develop breast cancer (n = 122). Five fellowship-trained breast radiologists independently recorded the BPE. The median reader BPE for each case was calculated and compared between the cancer and control cohorts. Cancer cohort patients were high-risk because of a history of radiation therapy (10%, 6 of 61), high-risk lesion (18%, 11 of 61), or breast cancer (30%, 18 of 61); BRCA mutation (18%, 11 of 61); or family history (25%, 15 of 61). Subsequent malignancies were invasive ductal carcinoma (64%, 39 of 61), ductal carcinoma in situ (30%, 18 of 61) and invasive lobular carcinoma (7%, 4of 61). BPE was significantly higher in the cancer cohort than in the control cohort (P = 0.01). Women with mild, moderate, or marked BPE were 2.5 times more likely to develop breast cancer than women with minimal BPE (odds ratio = 2.5, 95% confidence interval: 1.3-4.8, P = .005). There was fair interreader agreement (κ = 0.39). High-risk women with greater than minimal BPE at screening MRI have increased risk of future breast cancer.

Abstract P4-02-13: Can background parenchymal enhancement (BPE) predict the chance of multicentric/ bilateral breast cancer on staging breast MRI?

Abstract Purpose: Can background parenchymal enhancement (BPE) predict the chance of multicentric/ bilateral breast cancer on staging Breast MRI? Materials and Methods: Retrospective review of women diagnosed with breast cancer who underwent a breast MRI for staging of disease was performed at a single institution from October 2012 to September 2015. Results: Breast MRI for staging was done for 435 patients diagnosed with breast cancer. Ages ranging from 24 to 86 years old (median, 52 years); sizes ranging from 0.5 to 13.5 cm (mean, 3.5 cm). 29 patients (7 %) had biopsy-proven second tumors in the same breast but different quadrant as the primary tumor or in the contralateral breast. From the 435 patients, 304 had minimal/ mild BPE and 103 had moderate/marked BPE (28 missing). Of the patients with an invasive primary cancer and a second tumor in the same breast but different quadrant as the primary tumor or in the contralateral breast, 12 of 29 patients had discordance in subtypes between the primary and secondary tumors (41%) and 17 of 29 had concordance in the subtypes between the primary and secondary tumors (59%). 6.3% (19 out 304) of patients with minimal/ mild BPE had multicentric /bilateral disease and 9.7% (10 out 103) of patients with moderate/ marked BPE had multicentric/ bilateral breast cancer. Conclusion: 435 patients with recent diagnosis of breast cancer who underwent staging breast MRI for diagnosis of additional sites of disease, 7% was diagnosed with an additional site of cancer. From these group of patients, approximately 6% had other site of disease among patients who had minimal/ mild BPE in the breast MRI versus 10% of patients with moderate/marked BPE. BPE may play a role in the setting of multicentric/ bilateral breast cancer. Citation Format: Benveniste APA, Ebuoma LO, Jonna A, Sam K, Severs Jr. FJ, Roark A, Sepulveda KA, Tamara O-P, Sedgwick EE. Can background parenchymal enhancement (BPE) predict the chance of multicentric/ bilateral breast cancer on staging breast MRI? [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-13.

Abstract P4-02-09: Breast cancer and magnetic resonance imaging (MRI): Background parenchymal enhancement (BPE) predicting response to neoadjuvant chemotherapy (NAC)

Abstract Objective: To assess the association of MRI BPE and pathological response in women diagnosed with stage II/III breast cancer submitted to NAC. Methods: This observational and cross-sectional retrospective study was performed in consecutive women who underwent NAC and had MRI exams before and after chemotherapy. The MRI was done before and after 2 weeks of completing NAC. BPE was classified according to ACR-BIRADS 5th edition. The type of BPE before NAC, its changes and the relationship to total pathologic complete response (TpCR) were evaluated. Data were paired with patient age, size on MRI before and after NAC, features of clinical response according to the RECIST criteria, tumor grade and immunohistochemical (IHC) subtypes. MRI assessment included amount of fibroglandular tissue, symmetry of BPE and measurement of tumor at the longest diameter. All images were blinded reviewed by a radiologist. We used for the changes of the BPE the Bowker symmetry test or the McNemar test and to analyze the factors related to the clinical and pathologic responses, logistic regression analysis. The level of significance adopted was 5% (p&amp;lt;0.05). Results: We studied 71 women between 2009 and 2016. The medium age was 37 years old. BPE was symmetrical in 68 women (95.8%). Moderate and marked BPE was present in 28 (39.4%) of the affected breasts and in 25 (34.2%) of the contralateral breasts. After NAC all BPE were symmetrical and just 3% of them were moderate or marked. Regarding the IHC subtype, 40 women (56.3%) were triple negative or HER2 positive, and these women had a higher frequency of TpCR (55% for each, compared to 12.9% in patients with luminal subtypes). We found to be independently associated with pCR: the reduction of BPE (in the affected or contralateral breast) and the molecular subtypes triple negative and HER2 positive Table 1. Multivariate Analysis related to TpCR (n=71).VariableCategoryP-ValueO.R.*CI 95% O.R.*Tumor Size on MR pre-MAC (cm) 0.1710,8590.691-1.068Luminal subtypeLuminal B (ref.)---1.00--- Luminal A0.3120.450.10-2.11 HER2pos/ Luminal B HER20.0055.781.71-19.58 Triple negative0.0493.271.01-10.64Age (years) 0.3870.9820.942-1.023Nottingham grade1 (ref.)---1.00--- 20.0817.830.78-79.16 30.0967.100.71-71.31BPE pre-NAC (S or A)Asymmetric (ref.)---1.00--- Symmetric0.3273.030.33-27.76BPE pre-NAC affected breastMinimal (ref.)---1.00--- Mild0.8120.860.24-3.09 Moderate0.3711.890.47-7.64 Marked0.5911.570.30-8.17BPE pre-NAC contralateral breastMinimal (ref.)---1.00--- Mild0.7130.790.22-2.81 Moderate0.2502.330.55-9.77 Marked0.4701.880.34-10.43BPE ChangeSame/increased (ref.)---1.00--- Reduction0.0263.011.14-7.96* OR (Odds Ratio) = Risk ratio to pCR; (n=26 pCR, n=7 DpCR, n=31 PR e n=7 ED, where Total pCR is pathological complete response (without invasive and DCIS in the breast and axilla) DpCR is pathological response with just DCIS, PR is partial response and ED is stable disease – we haven't progression disease). CI 95% OR = Confidence interval of 95% to risk ratio. Ref.: reference level. Proportional risk models. Conclusion: BPE reduction was significantly associated with TpCR. Nevertheless, patterns of BPE pre-NAC have no association with pathological response. Citation Format: Teixeira SRC, Camargo HSAd, Ramalho S, Natal R, Machado HdC, Camargo MMAd, Azevedo J, Arruda MdS, Negrão EMS, Almeida NR, Teixeira AL, Cabello V, Cabello C. Breast cancer and magnetic resonance imaging (MRI): Background parenchymal enhancement (BPE) predicting response to neoadjuvant chemotherapy (NAC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-09.

Background parenchymal enhancement: is it just an innocent effect of estrogen on the breast?

We aimed to retrospectively analyze whether background parenchymal enhancement (BPE) on breast magnetic resonance imaging (MRI) correlates with menarche, menopause, reproductive period, menstrual cycle, gravidity-parity, family history of breast cancer, and the Breast Imaging-Reporting and Data System (BI-RADS) category of the patient. The study included 126 pre- and 78 postmenopausal women who underwent breast MRI in our institute between 2011 and 2016. Patients had filled a questionnaire form before the MRI. Two radiologists blinded to patient history graded the BPEs and the results were compared and analyzed. The BPE was correlated with patient age and the day of menstrual cycle (P < 0.01 for both). No correlation was found with menarche age, menopause age, total number of reproductive years, and family history of breast cancer. In the moderate BPE group, only 1 out of 35 patients and in the marked BPE group only 1 out of 13 patients were postmenopausal and had BI-RADS scores of 4 and 5, respectively. Increased symmetrical BPE is mainly due to current hormonal status in the premenopausal women. High-grade BPE, whether symmetrical or not, is rarely seen in postmenopausal women; hence, these patients should be further investigated or closely followed up.

Effect of Background Parenchymal Enhancement on Breast MR Imaging Interpretive Performance in Community-based Practices.

Purpose To evaluate the effect of background parenchymal enhancement (BPE) on breast magnetic resonance (MR) imaging interpretive performance in a large multi-institutional cohort with independent analysis of screening and diagnostic MR studies. Materials and Methods Analysis of 3770 breast MR studies was conducted. Examinations were performed in 2958 women at six participating facilities in the San Francisco Bay Area from January 2010 to October 2012. Findings were recorded prospectively in the San Francisco Mammography Registry. Performance measures were compared between studies with low BPE (mild or minimal) and those with high BPE (moderate or marked) by using binomial tests of proportions. Results Of 1726 MR imaging studies in the screening group, 1301 were classified as having low BPE and 425 were classified as having high BPE (75% vs 25%, respectively; P < .001). Of 2044 MR imaging studies in the diagnostic group, 1443 were classified as having low BPE and 601 were classified as having high BPE (71% vs 29%, respectively; P < .001). For low versus high BPE groups at screening, abnormal interpretation rate was 157 of 1301 versus 111 of 424 (12% vs 26%, P < .001); biopsy recommendation rate was 85 of 1301 versus 54 of 424 (7% vs 13%, P < .001); and specificity was 89% (95% confidence interval [CI]: 87, 91) versus 75% (95% CI: 71, 80) (P = .01). For the low versus high BPE groups at diagnostic MR imaging, biopsy recommendation rate was 325 of 1443 versus 195 of 601 (23% vs 32%, P < .001); and specificity was 86% (95% CI: 84, 88) versus 75% (95% CI: 74, 82) (P < .001). There were no significant differences between studies with low versus high BPE in sensitivity for screening (76% [95% CI: 55, 91] vs 83% [95% CI: 52, 98]; P = .94) or diagnostic (93% [95% CI: 87, 97] vs 96% [95% CI: 87, 99]; P = .69) MR imaging, nor were there significant differences in cancer detection rate per 1000 patients between the low BPE versus high BPE groups for screening (15 per 1000 vs 24 per 1000, P = .30) or diagnostic (78 per 1000 vs 85 per 1000, P = .64) MR imaging. Conclusion Relative to MR studies with minimal or mild BPE, those with moderate or marked BPE were associated with higher abnormal interpretation and biopsy rates and lower specificity, with no difference in cancer detection rate. © RSNA, 2017 Online supplemental material is available for this article.

Diagnostic Performance of and Breast Tissue Changes at Early Breast MR Imaging Surveillance in Women after Breast Conservation Therapy.

Purpose To investigate the diagnostic performance and tissue changes in early (1 year or less) breast magnetic resonance (MR) imaging surveillance in women who underwent breast conservation therapy for breast cancer. Materials and Methods This prospective study was approved by the institutional review board, and written informed consent was obtained. Between April 2014 and June 2016, 414 women (mean age, 51.5 years; range, 21-81 years) who underwent 422 early surveillance breast MR imaging examinations (median, 6.0 months; range, 2-12 months) after breast conservation therapy were studied. The cancer detection rate, positive predictive value of biopsy, sensitivity, specificity, accuracy, and area under the curve of surveillance MR imaging, mammography, and ultrasonography (US) were assessed. Follow-up was also obtained in 95 women by using positron emission tomography (PET)/computed tomography (CT). Background parenchymal enhancement (BPE) changes in the contralateral breast were assessed according to adjuvant therapy by using the McNemar test. Results Of 11 detected cancers, six were seen at MR imaging only, one was seen at MR imaging and mammography, two were seen at MR imaging and US, one was seen at mammography only, and one was seen at PET/CT only. Three MR imaging-depicted cancers were observed at the original tumor bed, and two MR imaging-depicted cancers were observed adjacent to the original tumor. Among two false-negative MR imaging diagnoses (two cases of ductal carcinoma in situ), one cancer had manifested as calcifications at mammography without differentiated enhancement at MR imaging, and the other cancer was detected at PET/CT, but MR imaging results were negative because of marked BPE, which resulted in focal lesion masking. The positive predictive value of biopsy and the sensitivity, specificity, accuracy, and area under the curve for MR imaging were 32.1% (nine of 28), 81.8% (nine of 11), 95.1% (391 of 411), 94.7% (400 of 422), and 0.88, respectively. The sensitivity of surveillance MR imaging (81.8%; 95% confidence interval [CI]: 48.2%, 97.7%) was higher than that of mammography (18.2%; 95% CI: 2.3%, 51.8%) and US (18.2%; 95% CI: 2.3%, 51.8%), with an overlap in CIs. The BPE showed a significant decrease in the group of patients who received adjuvant chemotherapy (43 BPE decreases and four BPE increases) and the group of patients who received hormone therapy (55 BPE decreases and two BPE increases) (P < .0001 for both). Conclusion Early MR imaging surveillance after breast conservation therapy can be useful in patients who have breast cancer, with superior sensitivity compared with that of mammography and US. The BPE tends to be decreased at short-term follow-up MR imaging in patients who receive adjuvant therapy. © RSNA, 2017.

Is Background Parenchymal Enhancement on Magnetic Resonance Imaging Helpful in Risk Assessment of Breast Cancer?

Objectives: Background parenchymal enhancement (BPE) on contrast-enhanced magnetic resonance imaging (CE-MRI) corresponds to hormonally active breast fibroglandular tissue. Several studi.es have reported increased odds of breast cancer in patients with marked BPE. The purpose of the present study was to evaluate BPE in contralateral breast of biopsy proven breast cancer patients and comparison of the results with control group. Methods: In a case-control study, CE-MRI of the contralateral breasts of 40 biopsy-proven breast cancer patients and 40 patients with biopsy- proven benign breast lesions, were retrospectively reviewed by an experienced radiologist and degree of BPE, and pattern of enhancement were determined, finally, BPE was compared between case and control groups using chi square test. Pearson correlation test was used to determine association between FGT amount and BPE. P value < 0.05 was considered significant. Results: In the case group, 4, 17, 14, and 5 patients had minimal, mild, moderate, and marked BPE, respectively. In the control group, 12, 24, .and 4 participants had minimal, mild, and moderate BPE, respectively. BPE was significantly higher in the case group in comparison with the control group (P value < 0.05). Patients with invasive carcinoma had significantly higher BPE in comparison with the patients with carcinoma in situ. (P value < 0.05) There was a moderate correlation (r = 0.4, P value < 0.05) between FGT amount and degree of BPE. In the case group, 3, 26, and 11 patients had mass-non mass, mass, and non mass pattern of enhancement, respectively. In the control group, 25, antl15 participants had mass, and non mass pattern of enhancement, respectively. Pattern of enhancement was not significantly different between the two groups. Conclusions: Our study revealed that patients with the diagnosis of breast cancer have greater BPE in comparison with control group. The results may be indicative for higher probability of developing breast cancer in patients with higher BPE. Therefore, CE-MRI could be a useful tool for breast cancer risk assessment.

Abstract P5-16-16: Role of tumor microenvironment, as assessed by breast MRI background parenchymal enhancement (BPE), in modulating response to neoadjuvant chemotherapy in young women with localized breast cancer

Abstract Background: Neoadjuvant chemotherapy (NACT) is generally established as a therapeutic option for selected high-risk patients with localized breast cancer, including triple negative breast cancer (TNBC). On a patient level, achievement of pathologic complete response (pCR) at the time of surgery is associated with improved long-term outcomes and is considered to be a surrogate marker. Response to NACT is a complex phenomenon dependent on both host and tumor characteristics. While tumor characteristics, such as receptors and tumor grade, have been well studied as predictors of pCR, host characteristics to predict pCR have been less well studied. Background parenchymal enhancement (BPE) is an imaging characteristic that reflects the normal enhancement of the fibroglandular tissue on breast MRI, and could potentially modulate response to NACT by influencing the tumor microenvironment and vasculature. The aim of this study was to explore the ability of baseline BPE to predict pCR in a cohort of young women with localized breast cancer. Methods: A retrospective chart review was conducted of women ages 40 and under with stage II-III breast cancer treated with NACT at our institution from 2004 – 2014. Demographic, clinical, and pathological variables were extracted from the medical records. The primary outcome was achievement of pCR, defined as ypT0/is ypN0, after NACT. BPE pattern in the contralateral breast was obtained from pre-treatment breast MRI reports if available and otherwise was retrospectively determined by a breast radiologist blinded to patient outcomes. BPE was dichotomized as low (minimum and mild) vs. high (moderate and marked). Logistic regression was used for statistical analysis. Results: A total of 69 patients ages 40 and under received NACT for localized breast cancer during the study period and had available pre-treatment breast MRI images. Median age at diagnosis was 36 (range 27-40). The majority of patients had grade 3 (65.2%), ER+/HER2- (60.9%) tumors while 24.6% had TNBC. Among pre-treatment breast MRIs, 42 (60.9%) patients had minimum or mild BPE and 27 (39.1%) patients had moderate or marked BPE. The overall pCR rate was 39%. After controlling for tumor grade, ER status, HER2 status, clinical stage, and type of NACT, high baseline BPE was associated with a trend towards higher odds of achieving pCR compared to low BPE (OR = 1.49, 95% CI 0.47–4.71), though statistical significance was not reached (p = 0.50). When stratified by ER status, the relationship was stronger among the ER+ subset (OR 1.8, p = 0.49) compared to the ER- subset (OR 1.3, p = 0.78). Conclusions: A statistically significant association between high baseline BPE and achievement of pCR was not found in this limited sample size, but a trend towards higher pCR rates, particularly with ER+ tumors, was seen. While tumor factors have traditionally been used to predict pCR, BPE is a readily available MRI imaging characteristic that reflects the tumor microenvironment and may be useful in building a model that incorporates tumor factors along with host factors to develop personalized NACT regimens for young women with breast cancer. Citation Format: Spring L, Rutledge G, Yala A, Haddad S, Specht M, Moy B, Barzilay R, Lehman C, Bardia A. Role of tumor microenvironment, as assessed by breast MRI background parenchymal enhancement (BPE), in modulating response to neoadjuvant chemotherapy in young women with localized breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-16.

Effect of Background Parenchymal Enhancement on Pre-Operative Breast Magnetic Resonance Imaging: How It Affects Interpretation and the Role of Second-Look Ultrasound in Patient Management

Background parenchymal enhancement (BPE) on breast magnetic resonance imaging (MRI) may either obscure or mimic malignancy. We evaluated the impact of BPE on the diagnostic performance of pre-operative MRI in breast cancer patients, and how second-look ultrasound (US) can help in guiding patient management. Two hundred fifty-three breast cancer patients with pre-operative MRI were included. In moderate or marked BPE, abnormal interpretation rate (38.9% vs. 12.2%) and biopsy rate (27.8% vs. 8.3%) were higher, and specificity (64.7% vs. 89.8%) was lower, compared with minimal or mild BPE (all p < 0.001). Visibility of MRI-detected additional suspicious lesions on second-look US did not differ between the two groups (86.7% in minimal or mild BPE vs. 77.1% in moderate or marked BPE, p = 0.296). Increased BPE was related to increased abnormal interpretation rate, additional biopsy rate and decreased specificity. Second-look US was useful in visualization of MRI-detected additional suspicious lesions, regardless of BPE.

Ultrafast Bilateral DCE-MRI of the Breast with Conventional Fourier Sampling: Preliminary Evaluation of Semi-quantitative Analysis

The study aimed to evaluate the feasibility and advantages of a combined high temporal and high spatial resolution protocol for dynamic contrast-enhanced magnetic resonance imaging of the breast. Twenty-three patients with enhancing lesions were imaged at 3T. The acquisition protocol consisted of a series of bilateral, fat-suppressed "ultrafast" acquisitions, with 6.9- to 9.9-second temporal resolution for the first minute following contrast injection, followed by four high spatial resolution acquisitions with 60- to 79.5-second temporal resolution. All images were acquired with standard uniform Fourier sampling. A filtering method was developed to reduce noise and detect significant enhancement in the high temporal resolution images. Time of arrival (TOA) was defined as the time at which each voxel first satisfied all the filter conditions, relative to the time of initial arterial enhancement. Ultrafast images improved visualization of the vasculature feeding and draining lesions. A small percentage of the entire field of view (<6%) enhanced significantly in the 30 seconds following contrast injection. Lesion conspicuity was highest in early ultrafast images, especially in cases with marked parenchymal enhancement. Although the sample size was relatively small, the average TOA for malignant lesions was significantly shorter than the TOA for benign lesions. Significant differences were also measured in other parameters descriptive of early contrast media uptake kinetics (P < 0.05). Ultrafast imaging in the first minute of dynamic contrast-enhanced magnetic resonance imaging of the breast has the potential to add valuable information on early contrast dynamics. Ultrafast imaging could allow radiologists to confidently identify lesions in the presence of marked background parenchymal enhancement.

Foci on breast magnetic resonance imaging in high-risk women: cancer or not?

PurposeTo assess how frequently foci are identified on MRI in high-risk patients, and their association with malignancy, breast density, and background parenchymal enhancement (BPE).Materials and methodsIn this multicentric study, two readers, in consensus, retrospectively reviewed screening breast MRI of 245 high-risk women, performed between 2009 and 2014. Eligible patients had at least two consecutive screening MRI, and a follow-up of at least 1 year after a lesion was first detected; histology was available for all suspicious findings. Breast density, BPE (both using BI-RADS lexicon), presence, and changes at follow-up for foci were evaluated. Clinical history of the patients was reviewed. Chi-square test was used to define significant correlations.Results166 women (mean age 43 years), who underwent a median of 4 MRI (range 2–6) during the study period, were included. 68 foci were found in 58 women [34.9 %, 95 % confidence interval (CI) 28.1–42.5 %]. Foci were more frequent in dense breasts (P = 0.079) and with moderate or marked BPE (P < 0.001). During follow-up, two foci increased in size (2.9 %, 95 % CI 0.8–10.1 %) and at biopsy, a cancer was found (1 high-grade ductal carcinoma in situ, 1 tubular carcinoma). Breast cancer was diagnosed in the other three cases, not initially appearing as foci, and it was more frequent in women with dense breasts (P = 0.04); no correlation between cancer and BPE was found (P = 0.145).ConclusionsFoci are relatively frequent in screening MRI, and they are usually benign. An increase in size is the most reliable criteria to suspect malignancy.

Characteristics, Malignancy Rate, and Follow-up of BI-RADS Category 3 Lesions Identified at Breast MR Imaging: Implications for MR Image Interpretation and Management.

Purpose To (a) evaluate the frequency of Breast Imaging Reporting and Data System (BI-RADS) category 3 assessment in screening and diagnostic breast magnetic resonance (MR) imaging, (b) review findings considered indicative of BI-RADS category 3, and (c) determine outcomes of BI-RADS category 3 lesions, including upgrades, downgrades, and malignancy rates. Materials and Methods This retrospective study was approved by the institutional review board and compliant with HIPAA. The authors retrospectively reviewed the breast MR imaging database (2009-2011) to identify breast MR images classified as showing BI-RADS category 3 lesions. There were 9216 BI-RADS assessments in 5778 examinations (3360 women). Of the 9216 assessments, 567 (6%) in 483 women (average age, 47.2 years; median age, 47.0 years) were assigned BI-RADS category 3. In women with more than one BI-RADS category 3 lesion, the first lesion reported in the impression was used for data analysis. Outcomes data were available for 435 of the 483 women (90.1%). These women comprised the study cohort. Medical records from January 1, 2009, to May 31, 2015, were reviewed to obtain demographic characteristics and outcomes. χ(2) statistics and 95% exact confidence intervals (CIs) were constructed. Results MR imaging was performed for high-risk screening in 240 of the 435 patients (55.2%) and for diagnostic purposes in 195 (44.8%). Findings included mass (n = 125, 28.7%), focus (n = 111, 25.5%), nonmass enhancement (n = 80, 18.3%), moderate or marked background parenchymal enhancement (BPE) (n = 91, 20.9%), posttreatment changes (n = 16, 3.8%), and other findings (n = 12, 2.8%). Outcomes were as follows: 339 of the 435 patients (78%) did not have evidence of malignancy at more than 24 months, 28 (6.4%) underwent mastectomy (all benign), and 68 (15.6%) had lesion upgrades, with 11 cancers (2.5%). All 11 cancers were diagnosed in women with a genetic mutation or a personal history of breast cancer. No cancer was detected in cases of moderate or marked BPE. Conclusion Six percent of all breast MR imaging assessments were categorized as BI-RADS category 3, with a cancer rate of 2.5% (95% CI: 1.3%, 4.5%). All cancers were in women with a genetic mutation or personal history of breast cancer. Marked BPE does not necessitate a BI-RADS 3 assessment. (©) RSNA, 2016.

Effect of background parenchymal enhancement on breast cancer detection with magnetic resonance imaging.

To investigate whether background parenchymal enhancement (BPE) may influence the sensitivity of dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging in breast cancer detection. A total of 180 consecutive women with 194 breast cancers underwent MR imaging examination. Women were assigned to two different groups depending on the degree of BPE. Group 1 consisted of women with minimal or mild BPE and group 2 of women with moderate or marked BPE. The distributions of histotypes of tumors within the two groups were compared using the χ(2) test. Difference in sensitivities of DCE-MR imaging for tumor detection between the two groups was searched for using the Student t-test. No differences in terms of distributions of histotypes of tumors between the two groups of women were found (P=0.5). The 11% difference in sensitivity of DCE-MR imaging for tumor detection between group 1 (91/92; 99%; 95% CI: 94-100%) and group 2 (90/102; 88%; 95% CI: 80-94%) was statistically significant (P=0.0058). The sensitivity of DCE-MR imaging is significantly lower in women with moderate and marked BPE as compared with women with minimal and mild BPE regardless of cancer histotype. BPE could represent a limitation for breast MR imaging interpretation and should be indicated in MR imaging reports.

Breast MRI background parenchymal enhancement (BPE) correlates with the risk of breast cancer

ObjectivesTo investigate whether background parenchymal enhancement (BPE) and breast cancer would correlate searching for any significant difference of BPE pattern distribution in case of benign or malignant lesions. Methods386 patients, including 180 pre-menopausal (group 1) and 206 post-menopausal (group 2), underwent MR examination. Two radiologists evaluated MR images classifying normal BPE as minimal, mild, moderate or marked. The two groups of patients were subdivided into 3 categories based on MRI findings (negative, benign and malignant lesions). The distribution of BPE patterns within the two groups and within the three MR categories was calculated. The χ2 test was used to evaluate BPE type distribution in the three patient categories and any statistically significant correlation of BPE with lesion type was calculated. The Student t test was applied to search for any statistically significant difference between BPE type rates in group 1 and 2. ResultsThe χ2 test demonstrated a statistically significant difference in the distribution of BPE types in negative patients and benign lesions as compared with malignant ones (p<0.05). A significantly higher prevalence of moderate and marked BPE was found among malignant lesions (group 1: 32% and 42%, respectively; group 2: 31% and 46%, respectively) while a predominance of minimal and mild BPE among negative patients (group 1: 60% and 36%, respectively; group 2: 68% and 32%, respectively) and benign lesions (group 1: 54% and 38%, respectively; group 2: 75% and 17%, respectively) was found. The Student t test did not show a statistically significant difference between BPE type rates in group 1 and 2 (p>0.05). ConclusionNormal BPE could correlate with the risk of breast cancer being such BPE patterns as moderate and marked associated with patients with malignant lesions in both pre and post-menopausal women.

Prediction of background parenchymal enhancement on breast MRI using mammography, ultrasonography, and diffusion-weighted imaging.

This retrospective study assessed the effects of menopausal status and menstrual cycle on background parenchymal enhancement (BPE) of breast magnetic resonance imaging (MRI), and investigated whether the degree of BPE can be predicted by findings of mammography, ultrasonography (US), and diffusion-weighted MR imaging (DWI). There were 160 study patients (80 premenopausal, 80 postmenopausal). Degree of BPE was classified into minimal, mild, moderate, or marked. Mammographic density was classified into fatty, scattered, heterogeneously dense, and extremely dense. BP echotexture on US and BP intensity on DWI were visually classified as homogeneous or heterogeneous. Apparent diffusion coefficient (ADC) values of normal breast tissue were measured. Associations of the degree of BPE with menopausal status, menstrual cycle, or imaging features were evaluated by univariate and multivariate analyses. No significant correlation was found between mammographic density and BPE (p=0.085), whereas menopausal status (p=0.000), BP echotexture (p=0.000), and BP intensity on DWI (p= 0.000), and ADC values (p=0.000) showed significant correlations with BPE. Multivariate analysis showed that postmenopausal status was an independent predictor of minimal BPE (p=0.002, OR=3.743). In premenopausal women, there was no significant correlation between menstrual cycle and BPE, whereas BP echotexture was an independent predictor of whether BPE was less than mild or greater than moderate (p=0.001, OR=26.575). BPE on breast MRI is associated with menopausal status and the findings of US and DWI. Because premenopausal women with heterogeneous BP echotexture may be predicted to show moderate or marked BPE, scheduling of breast MRI should preferentially be adjusted to the menstrual cycle.

Are Qualitative Assessments of Background Parenchymal Enhancement, Amount of Fibroglandular Tissue on MR Images, and Mammographic Density Associated with Breast Cancer Risk?

To investigate whether qualitative magnetic resonance (MR) imaging assessments of background parenchymal enhancement (BPE), amount of fibroglandular tissue (FGT), and mammographic density are associated with risk of developing breast cancer in women who are at high risk. In this institutional review board-approved HIPAA-compliant retrospective study, all screening breast MR images obtained from January 2006 to December 2011 in women aged 18 years or older and at high risk for but without a history of breast cancer were identified. Women in whom breast cancer was diagnosed after index MR imaging comprised the cancer cohort, and one-to-one matching (age and BRCA status) of each woman with breast cancer to a control subject was performed by using MR images obtained in women who did not develop breast cancer with follow-up time maximized. Amount of BPE, BPE pattern (peripheral vs central), amount of FGT at MR imaging, and mammographic density were assessed on index images. Imaging features were compared between cancer and control cohorts by using conditional logistic regression. Twenty-three women at high risk (mean age, 47 years ± 10 [standard deviation]; six women had BRCA mutations) with no history of breast cancer underwent screening breast MR imaging; in these women, a diagnosis of breast cancer (invasive, n = 12; in situ, n = 11) was made during the follow-up interval. Women with mild, moderate, or marked BPE were nine times more likely to receive a diagnosis of breast cancer during the follow-up interval than were those with minimal BPE (P = .007; odds ratio = 9.0; 95% confidence interval: 1.1, 71.0). BPE pattern, MR imaging amount of FGT, and mammographic density were not significantly different between the cohorts (P = .5, P = .5, and P = .4, respectively). Greater BPE was associated with a higher probability of developing breast cancer in women at high risk for cancer and warrants further study.

Background parenchymal enhancement on breast MRI and mammographic breast density: correlation with tumour characteristics

To investigate the relationship between mammographic breast density (MGD) and background parenchymal enhancement (BPE) at breast MRI and histopathological features of invasive breast cancers. A total of 178 women with unilateral invasive breast cancer who preoperatively underwent mammography and breast MRI were included in the study. Two radiologists rated MGD and BPE according to BI-RADS criteria in consensus. The relationship between MGD and BPE was investigated, and compared with histopathological features of invasive breast cancers according to the level of MGD and BPE. At MRI, there is no significant difference in the distribution of MGD and BPE of the contralateral breast in women with invasive breast cancer according to menopausal status (p=0.226, 0.384). Women with high MGD (>50% glandular) were more likely to have oestrogen-receptor (ER)-positive breast cancer (p=0.045) and progesterone receptor (PR)-positive breast cancer (p=0.020). With regard to BPE, PR positivity correlated with moderate or marked BPE with borderline significance (p=0.054). Multivariate logistic regression analyses revealed that women with high MGD were less likely to have triple-negative (i.e., a cancer that is ER negative, PR negative, and human epidermal growth factor receptor type 2 [HER2] negative) breast cancer compared with ER (+)/HER2 (-) cancer (OR=0.231, 95% CI: 0.070, 0.760; p=0.016). No association between the histological tumour characteristics and BPE was observed. In women with invasive breast cancer, high MGD is associated with ER positivity of the invasive breast cancer. However, at MRI, BPE of the contralateral breast seems to be independent of tumour characteristics.