From the Department of Radiology, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115.
Radiographics. 2014 Jan-Feb;34(1):234-47. doi: 10.1148/rg.341135034.
At magnetic resonance (MR) imaging, both normal and abnormal breast tissue enhances after contrast material administration. The morphology and temporal degree of enhancement of pathologic breast tissue relative to normal breast tissue form the basis of MR imaging's diagnostic accuracy in the detection and diagnosis of breast disease. Normal parenchymal enhancement at breast MR imaging is termed background parenchymal enhancement (BPE). BPE may vary in degree and distribution in different patients as well as in the same patient over time. Typically BPE is minimal or mild in overall degree, with a bilateral, symmetric, diffuse distribution and slow early and persistent delayed kinetic features. However, BPE may sometimes be moderate or marked in degree, with an asymmetric or nondiffuse distribution and rapid early and plateau or washout delayed kinetic features. These patterns cause diagnostic difficulty because these features can be seen with malignancy. This article reviews typical and atypical patterns of BPE seen at breast MR imaging. The anatomic and physiologic influences on BPE in women undergoing diagnostic and screening breast MR imaging are reviewed. The potential for false-positive and false-negative interpretations due to BPE are discussed. Radiologists can improve their interpretive accuracy by increasing their understanding of various BPE patterns, influences on BPE, and the potential effects of BPE on MR imaging interpretation.
在磁共振（MR）成像中，正常和异常的乳腺组织在对比剂给药后都会增强。病理性乳腺组织相对于正常乳腺组织的形态和时间增强程度是 MR 成像在乳腺疾病的检测和诊断中诊断准确性的基础。乳腺 MR 成像中的正常实质增强称为背景实质增强（BPE）。BPE 在不同患者以及同一患者随时间的变化在程度和分布上可能有所不同。通常，BPE 在整体程度上是轻微或轻度的，具有双侧、对称、弥漫性分布和早期缓慢持续延迟动力学特征。然而，BPE 在程度上有时可能是中度或重度的，具有不对称或非弥漫性分布和早期快速平台或洗脱延迟动力学特征。这些模式会导致诊断困难，因为这些特征也可能与恶性肿瘤有关。本文回顾了乳腺 MR 成像中所见的典型和非典型 BPE 模式。回顾了在接受诊断性和筛查性乳腺 MR 成像的女性中 BPE 的解剖和生理影响。讨论了由于 BPE 导致的假阳性和假阴性解读的可能性。放射科医生可以通过增加对各种 BPE 模式、BPE 影响以及 BPE 对 MR 成像解读的潜在影响的理解，提高其解读准确性。
