ABSTRACT
Objective To evaluate the influence of menopause status on breast fibrograndular tissue (FGT),background parenchymal enhancement volume ratio (BPEv) and intensity ratio (BPEI) by breast MR image automatic quantitative analysis.Methods From 14 033 consecutive patients who underwent breast MR in our center from 2009 to 2012,we randomly selected 101 normal cases (47cases of premenopausal and 54 cases of postmenopausal).Premenopausal status was subclassified into four groups (8 cases in the 1st week and 13 cases in the 2nd,3rd and 4th week,respectively) based on the menstrual cycle.We evaluated FGT,BPEv and BPEI at early (2 minutes),medium (4 minutes) and late (6 minutes) enhanced time phases of breast MRI for quantitative assessment.The FGT,BPEv and BPEI in premenopausal and postmenopausal women were compared using the Mann-Whitney U test.Comparison of each menstrual cycle was made using the Kruskal-Wallis test.Results The FGT,BPEv and middle-late BPEI of postmenopausal women were significantly lower than that of premenopausal women (P＜0.05).The maximum BPEI was in the 1st week,the minimum in the 2nd week in premenopausal women (P＜0.05).The FGT and BPEv in the 1st week were the highest among the 4 weeks,but there was no significant difference.Conclusions The FGT,BPEv and BPEI were significantly decreased after menopause.The optimal time of breast MR examination is in the 2nd week of menstrual cycle.
ABSTRACT
Objective To retrospectively investigate the characteristics of background parenchymal enhancement(BPE)in the contralateral breast following neoadjuvant chemotherapy(NAC)and whether BPE could help predict tumor response in early stage of advanced breast cancer. Methods Data from 161 patients who were diagnosed with unilateral breast cancer and then underwent NAC before surgery were analyzed retrospectively from August 2014 to December 2016.All the patients underwent both bilateral breast MRI scan with contrast enhancement. Two experienced radiologists independently categorized the patients' levels of BPE into four categories (1=minimal, 2=mild, 3=moderate, 4=marked) at baseline and after the 2nd cycle of NAC. All the patients were divided in to pathologic complete response (pCR) group and non-pCR group according to the histopathologic tumour response.The status of estrogen receptor(ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) were recorded before underwent NAC.The t test and Pearson chi-squared test were used to compare the baseline characteristics of the pCR and Non-pCR groups.The kappa test was used to test the inter-observer agreement.The Wilcoxon test was used to test for changes of BPE categories after NAC.The Mann-Whitney U test was used to test the difference of BPE between pre-and post-menopausal status. Associations were evaluated using Binary logistic regression models. Results Fifty nine patients achieved pCR, and 102 patients had residual disease (non-pCR). Age, tumor size, distribution of size, menopausal status and lymph node showed no significance between pCR and non-pCR groups(all P>0.05),while only ER/PR status and HER2 status had a significant difference (P>0.05 in both). Inter-observer agreement regarding BPE categorization was moderate and substantial before and after NAC(Kappa value 0.644 and 0.708).The level of BPE was higher in premenopausal than post-menopausal women both at baseline and after the 2nd cycle of NAC(P<0.01). Decreased BPE was observed in 106 cases(premenopausal 60 cases and postmenopausal 46 cases),and no change in BPE were observed in 55 cases (premenopausal 27 cases and postmenopausal 28 cases). A significant reduction in BPE was observed after the 2nd NAC cycle in the overall cases, pre-and post-menopausal cases (all P<0.01). Logistic model showed that hormonal receptor (HR) negative and HER-2 receptor at baseline and the change of BPE after NAC were the independent factors for predicting pCR. Conclusions Regardless of the menopausal status, BPE showed a reduction after NAC, and it can serve as an additional imaging biomarker of tumour response at an early stage of NAC.
ABSTRACT
Breast background parenchymal enhancement (BPE) is a special form of breast dynamic contrast enhanced MRI.The diagnosis and research of breast diseases which shows BPE is becoming more and more important.The relationship between BPE and the risk factors of breast cancer is one of the focuses in breast MRI.In this review,the definition and typical manifestations of BPE,the relationship between BPE and fibroglandular tissue,and the influence factors of BPE in the breast MRI were reviewed.