Moderate Background Parenchymal Enhancement Research Articles

Ultrafast Dynamic Contrast‐Enhanced MRI of the Breast: From Theory to Practice

The development of ultrafast dynamic contrast‐enhanced (UF‐DCE) MRI has occurred in tandem with fast MRI scan techniques, particularly view‐sharing and compressed sensing. Understanding the strengths of each technique and optimizing the relevant parameters are essential to their implementation. UF‐DCE MRI has now shifted from research protocols to becoming a part of clinical scan protocols for breast cancer. UF‐DCE MRI is expected to compensate for the low specificity of abbreviated MRI by adding kinetic information from the upslope of the time‐intensity curve. Because kinetic information from UF‐DCE MRI is obtained from the shape and timing of the initial upslope, various new kinetic parameters have been proposed. These parameters may be associated with receptor status or prognostic markers for breast cancer. In addition to the diagnosis of malignant lesions, more emphasis has been placed on predicting and evaluating treatment response because hyper‐vascularity is linked to the aggressiveness of breast cancers. In clinical practice, it is important to note that breast lesion images obtained from UF‐DCE MRI are slightly different from those obtained by conventional DCE MRI in terms of morphology. A major benefit of using UF‐DCE MRI is avoidance of the marked or moderate background parenchymal enhancement (BPE) that can obscure the target enhancing lesions. BPE is less prominent in the earlier phases of UF‐DCE MRI, which offers better lesion‐to‐noise contrast. The excellent contrast of early‐enhancing vessels provides a key to understanding the detailed pathological structure of tumor‐associated vessels. UF‐DCE MRI is normally accompanied by a large volume of image data for which automated/artificial intelligence‐based processing is expected to be useful. In this review, both the theoretical and practical aspects of UF‐DCE MRI are summarized.Evidence Level5Technical EfficacyStage 2

A background parenchymal enhancement quantification framework of breast magnetic resonance imaging.

Background parenchymal enhancement (BPE) is defined as the enhanced proportion of normal fibroglandular tissue on enhanced magnetic resonance imaging. BPE shows promise as a quantitative imaging biomarker (QIB). However, the lack of consensus among radiologists in their semi-quantitative grading of BPE limits its clinical utility. The main objective of this study was to develop a BPE quantification model according to clinical expertise, with the BPE integral being used as a QIB to incorporate both the volume and intensity of the enhancement metrics. The model was applied to 2,786 cases to compare our quantitative results with radiologists' semi-quantitative BPE grading to evaluate the effectiveness of using the BPE integral as a QIB for analyzing BPE. Comparisons between multiple groups of nonnormally distributed BPE integrals were performed using the Kruskal-Wallis test. Our study found a considerable degree of concordance between our BPE quantitative integral and radiologists' semi-quantitative assessments. Specifically, our research results revealed significant variability in BPE integral attained through the BPE quantification framework among all semi-quantitative BPE grading groups labeled by experienced radiologists, including mild-moderate (P<0.001), mild-marked (P<0.001), and moderate-marked (P<0.001). Furthermore, there was an apparent correlation between BPE integral and BPE grades, with marked BPE displaying the highest BPE integral, followed by moderate BPE, with mild BPE exhibiting the lowest BPE integral value. The study developed and implemented a BPE quantification framework, which incorporated both the volume and intensity of enhancement and which could serve as a QIB for BPE.

MRI background parenchymal enhancement in patients with invasive lobular carcinoma: Endocrine hormonal treatment effect.

High background parenchymal enhancement (BPE) levels and asymmetric distribution could cause diagnostic uncertainty due to morphological similarity to breast cancer, especially invasive lobular carcinoma (ILC). We investigated BPE in ILC patients, its association with the tumor hormonal profile, and the effect of endocrine treatment (ET). The analysis included all MRI examinations performed at our institution between 2010 and 2019 for ILC-diagnosed patients. Baseline study and the first follow-up study were reviewed. Digital medical records were reviewed to retrieve demographics/pathology results/treatment information. BPE and fibroglandular tissue were assessed qualitatively on the contralateral breast according to the criteria of the Breast Imaging Reporting and Data System (BI-RADS). The study included 129 patients. Most (91%) had pure ILC. All received ET; 12% also received chemotherapy; 90% had surgery first; 70% by breast conservation. On the baseline MRI, 70% had mild or moderate BPE; whereas, on the follow-up study, the majority (59%) had minimal BPE. Most BPE reductions were by 2 degrees. In the baseline study, additional biopsies were required in 59% of cases, and in 17%, a short-term follow-up was recommended. In the follow-up study, biopsies were recommended in 10%, and a short-term follow-up was requested in 16%. A correlation between progesterone receptor intensity index and baseline BPE level was observed (r =0.3, p =0.004). ILC patients usually exhibit high BPE. ET decreases BPE, and therefore may decrease false-positive interpretations. Additional research is needed to explore whether study can be performed on ET without compromising sensitivity. ∙ High background parenchymal enhancement levels reduces breast MRI sensitivity, yielding high false positive rates especially when reporting cases of invasive lobular carcinoma [ILC].∙Treatment of ILC with endocrine therapy reduces background parenchymal enhancement and thus could decrease these false-positive interpretations.

Breast cancer and background parenchymal enhancement at breast magnetic resonance imaging: a meta-analysis

BackgroundThe background parenchymal enhancement at breast magnetic resonance imaging use to predict breast cancer attracts many searchers to draw a possible relationship. However, the results of their relationships were conflicting. This meta-analysis was performed to assess breast cancer frequency associations with background parenchymal enhancement.MethodsA systematic literature search up to January 2020 was performed to detect studies recording associations between breast cancer frequency and background parenchymal enhancement. We found thirteen studies including 13,788 women at the start with 4046 breast cancer. We calculated the odds ratio (OR) and the 95% confidence intervals (CIs) between breast cancer frequency and background parenchymal enhancement by the dichotomous technique with a random or fixed-effect model.ResultsWomen with minimal or mild background parenchymal enhancement at breast magnetic resonance imaging did not have any risk of breast cancer compared to control women (OR, 1.20; 95% CI 0.54–2.67). However, high background parenchymal enhancement at breast magnetic resonance imaging (OR, 2.66; 95% CI 1.36–5.19) and moderate (OR, 2.51; 95% CI 1.49–4.21) was associated with a significantly higher rate of breast cancer frequency compared to control women.ConclusionsOur meta-analysis showed that the women with high and moderate background parenchymal enhancement at breast magnetic resonance imaging have higher risks, up to 2.66 fold, of breast cancer. We suggest that women with high or moderate background parenchymal enhancement at breast magnetic resonance imaging to be scheduled for more frequent follow-up and screening for breast cancer to avoid any complications.

Metabolic changes in breast cancer on dual-time-point 18F-FDG PET/CT imaging according to primary tumor uptake and background parenchymal enhancement.

This study was aimed at investigating metabolic changes in breast cancer on dual-time-point 18F-FDG PET/CT imaging (DTPI) according to primary tumor uptake and determining whether this technique is affected by background parenchymal enhancement (BPE). A total of 189 patients with newly diagnosed breast cancer who underwent DTPI examination were retrospectively evaluated. DTPI was performed using a standard FDG/PET protocol followed by delayed image acquisition at 120min after injection. Patients were divided into two groups according to primary tumor uptake as breast cancer with low maximum standard uptake value (SUVmax) (< 2.5) and high SUVmax (≥ 2.5). The maximal SUV of the primary breast tumor (T-SUVmax), contralateral breast parenchyma uptake (B-SUVmax) according to different BPE grades, tumor to background ratio (T/B-SUVmax), and their percentage changes between early and delayed images (retention index, RI) were calculated. For primary tumor uptake, tumors with high SUV had a significant increase in mean T-SUVmax between early and delayed images (8.17 vs. 9.16, P < 0.001), and %RI T-SUVmax was 10.52%. Conversely, mean T-SUVmax did not change between early and delayed images for tumors with low SUV (1.96 vs. 1.94, P = 0.610), and %RI T-SUVmax was -1.41%. The mean %RI B-SUVmax was -12.43% for minimal BPE, -14.19% for mild BPE, -19.49% for moderate BPE, and -21.25% for marked BPE grade, indicating that higher BPE grades undergo better washouts on delayed imaging (β = -3.220, P < 0.001 for trend). The %RI T/B-SUVmax of both breast cancer groups with low SUV and high SUV was 18.86% and 32.47%, respectively. Breast cancer with low SUV undergoes no significant change in SUV on DTPI; however, washing of background parenchymal activity was evident over time, resulting in significantly increased tumor contrast in delayed images, which leads to increased sensitivity. Breast parenchymal washout was more significant with increased BPE level. Therefore, DTPI is expected to be more useful for evaluating breast lesions in regions with marked BPE on MRI.

Possible Breast Cancer Risk Related to Background Parenchymal Enhancement at Breast MRI: A Meta-Analysis Study

Background The higher level of background parenchymal enhancement (BPE) at breast magnetic resonance imaging (MRI) has drawn considerable attention in the early detection and prediction of breast cancer. It has been reported that there is a possible relationship between the level of BPE at breast MRI and the presence of breast cancer. This meta-analysis was performed to evaluate this relationship. Methods Through a systematic literature search up to December 2019, 12 studies with 9541 females, 3870 of them were breast cancer. They were identified reporting relationships between breast cancer and BPE at breast MRI with its different categories (10 related to minimal or mild BPE, eight related to moderate BPE and nine related to high BPE). Odd ratio(OR) with 95% confidence intervals (CIs) was calculated comparing breast cancer prevalence and BPE at breast MRI using dichotomous method with a random or fixed effect model. Results Females with high (OR, 2.93; 95% CI, 1.24–6.88) and moderate (OR, 2.89; 95% CI, 1.51–5.52) BPE at breast MRI was related with high odds to breast cancer compared to control females. However, females with minimal or mild BPE at breast MRI (OR, 1.33; 95% CI, 0.56–3.17) did not have such risk on breast cancer. The impact of BPE on breast cancer may have a great influence as a tool for improving early detection and prevention of breast cancer. Conclusions Based on this meta-analysis, females with high or moderate BPE at breast MRI may have an independent relationship with the risk of breast cancer. This relationship forces us to recommend follow up with those with high or moderate BPE at breast MRI to avoid any complication.

The Association of Background Parenchymal Enhancement at Breast MRI with Breast Cancer: A Systematic Review and Meta-Analysis

BackgroundThe higher level of background parenchymal enhancement (BPE) at breast MRI has the potential for early detection and prediction of the risk of breast cancer. However, conflicting findings have been reported about the association between the level of BPE at breast MRI and the presence of breast cancer.PurposeTo evaluate the association between qualitative and quantitative BPE at dynamic contrast material-enhanced MRI and breast cancer among populations with average risk and high risk separately.Materials and MethodsA retrospective meta-analysis of observational studies comparing either qualitative or quantitative assessments of BPE in women with and women without breast cancer was performed for studies published through July 2018. Pooled odds ratios (ORs) or standardized mean differences and 95% confidence intervals (CIs) were estimated by using DerSimonian-Laird random-effects models. The heterogeneity across the studies was measured by using the statistic I 2. Sensitivity analyses were conducted to test this association according to different study characteristics. P values less than or equal to 5% were considered to indicate statistically significant results.ResultsEighteen studies comprising 1910 women with breast cancer and 2541 control participants were included in the analysis. Among women with high risk, at least moderate BPE (OR, 1.6; 95% CI: 1.0, 2.6; P = .04) or at least mild BPE (OR, 2.1; 95% CI: 1.5, 3.0; P < .001) was associated with higher odds of breast cancer. Furthermore, women with breast cancer showed a higher average BPE percentage compared with control participants with high risk (standardized mean difference, 0.5; 95% CI: 0.2, 0.9; P = .001). No association was observed between at least mild BPE level (P = .15) or at least moderate BPE level (P = .38) and the presence of breast cancer among the population with average risk.ConclusionA higher level of background parenchymal enhancement measured at breast MRI is associated with the presence of breast cancer in women with high risk, but not in women with average risk.© RSNA, 2019Online supplemental material is available for this article.See also the editorial by Mann and Pinker in this issue.

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.

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.

Updated breast MRI lexicon

The American College of Radiology (ACR) BI-RADS Breast Imaging Lexicon was developed over a 5 year period, initially organized in 1999 by a Breast MRI “Lesion Diagnosis Working Group” and later by the ACR. This work resulted in a lexicon (dictionary) of terms to describe breast lesions on contrast-enhanced breast magnetic resonance imaging studies. The first publication was developed when breast MRI was first being used and referencing the little data available to produce the lexicon of terms in describing lesions seen on breast MRI. Even though the ACR Lexicon has proved robust for the most part, since its publication there have been technical advances in breast MRI hardware, coils and pulse sequences, resulting in new information on breast cancer morphology and kinetic behavior. Publication on MRI studies using the new hardware and software resulted in increases in cancer sensitivity and specificity in published literature. As a result, information is now available on technical parameters required to obtain both high spatial and temporal resolution on breast MRI scans that resulted in high sensitivity and specificity. These advances and scientific data were used in developing and updating the new Lexicon. The new breast MRI Lexicon is chaired by Elizabeth A Morris, M.D and is expected to be published in the fall of 2012. The new ACR Lexicon includes a web-based format (hardcopy is also available), recommends mammography/US/MRI correlation, and has evidence based information with hyperlinks to references. The Lexicon also includes sections on Quality Assessment with technical parameters and kinetic/functional considerations that influence MRI images. There is a new section on audit recommendations. The ACR also lists a separate ACR Breast MRI Accreditation Program that accredits breast MRI facilities in the United States with technical, outcome and personnel credentialing criteria. Breast MRI Lexicon recommendations include adding T2weighted non-contrast sequences, and combined reporting of MRI with mammographic and ultrasound findings. Finally, simultaneous bilateral MRI scans are recommended and are considered standard of care. There is a new section on breast implants, with a lexicon describing the implant type, location, and findings commonly seen in intact and ruptured implants. In silicone breast implant studies, imaging terms include normal radial folds, subcapsular line, linguine and keyhole/teardrop. Importantly, there is a new section describing background parenchymal enhancement (BPE) that describes how much of the normal breast parenchyma enhances, which in turn can influence the sensitivity of breast MRI to detect cancer. The BPE can be described as none, minimal, mild, moderate or marked. Terms that previously were used to describe findings seen on breast MRI such as “diffuse stippled enhancement” may actually represent moderate BPE, which is a normal finding. As before, both morphology and kinetic information is considered important. There are no changes to the kinetic terminology. Morphology terms in the lexicon have been added or deleted, adding terms that were commonly used, and deleting those that were not used in the scientific literature. Deleted terms include central and septal enhancement, and enhancing septations. Morphology additions include clustered ring enhancement in contrast-enhanced studies. Morphology terms that have been revised include “non-masslike” to “non-mass” enhancement, and “irregular” mass margins to “uneven” mass margins in masses that have an irregular shape. Last, the Lexicon recommends a final BIRADS assessment including BIRADS codes 0 – Incomplete, Need Additional Imaging Evaluation, 1 – Negative, 2 – Benign, 3 – Probably Benign, 4 – Suspicious, 5 – Highly Suggestive of Malignancy, and 6 – Known Biopsy Proven Malignancy. The ACR Breast MRI Lexicon publication also includes an atlas that illustrates the key findings described in the lexicon. Because the contributors to the atlas were based both in the USA and around the world, there are a wide variety of techniques and pulse sequences that were used to generate the images. Variability in the examples include axial, sagittal, multi-planar reconstructions, fatsuppressed and non-fat-suppressed images chosen as state-of-theart, providing the reader with the rare chance to view MRI studies of specific findings using high-quality, varying techniques.