Analysis of background parenchymal echogenicity on breast ultrasound: Correlation with mammographic breast density and background parenchymal enhancement on magnetic resonance imaging

The purpose of this study was to analyze the background parenchymal echotexture (BP echo) on breast ultrasound in detail and to evaluate the relation BP echo with menopausal status. In addition, we correlated BP echo with mammographic breast density (MGD) and background parenchymal enhancement (BPE) on magnetic resonance imaging (MRI). The institutional review board of our hospital approved this retrospective study, and the requirement of informed consent was waived. We studied 138 women (mean age 51.6 years, range from 26 to 79 years) with newly diagnosed invasive breast cancer, who had performed preoperative mammography, ultrasound, and MR from June 2013 to June 2015. BP echo was classified as homogeneous and heterogeneous according to the BI-RADS US lexicon. MGD was described into fatty, scattered, heterogeneously dense, and extremely dense. BPE was categorized as minimal, mild, moderate, and marked. The relationship between the BP echo and menopausal status was investigated. Associations between the degree of BP echo with MGD grades and BPE grades were also evaluated. Of the 138 women, 74 (54%) were premenopausal and 64 (46%) were postmenopausal. Premenopausal women were more likely to have heterogeneous BP echo (60/74, 81%) compared with postmenopausal women (10/64, 16%) (P = .000). BP echo showed significant correlation with BPE in both premenopausal and postmenopausal women (P = .000). However, MGD showed no significant correlation with BP echo or BPE, regardless of menopausal states. In the postmenopausal group, 70% women (21/30) with dense MGD showed homogeneous BP echo and 77% women (23/30) with dense MGD showed nondense BPE. In conclusion, we demonstrated that the BP echo was influenced by menopausal status. Our data support the concept that BP echo is influenced by breast hormonal changes. Because there was a significant association between BP echo and BPE in pre- and post-menopausal women, the BP echo might be a good predictor for BPE.