Kelcz F, Santyr G
Department of Radiology, University of Wisconsin, Madison 53792, USA.
Crit Rev Diagn Imaging. 1995;36(4):287-338.
The inherent overlap in the T1 and T2 relaxation of benign and malignant breast lesions has hindered progress in the application of MRI to evaluate this organ. Indeed, lesions in a glandular breast may completely blend in with normal breast tissues, a problem unenhanced MRI shares with mammography. However, infusion of intravenous Gd-DPTA accompanied by rapid MR imaging results in successful detection of most invasive breast malignancies. Inspection of the lesion morphology and enhancement profile shows that most malignancies have an irregular border, enhance very rapidly, and display a distinct early washout phase. On the other hand, fibroadenomas have a smooth or gently lobulated border and enhance in a continuous monotonic fashion. Some pitfalls exist such as the variable enhancement associated with DCIS and premenopausal breast tissue. This publication reviews the literature with respect to Gd-enhanced breast MRI, focusing on strengths and weaknesses, and suggests appropriate indications for employing this new approach to breast imaging. Patient preparation and discussion of technical parameters and tradeoffs is also addressed. The exact place of MRI in the work-up of the breast-problem patient has yet to be settled, but already MRI can help radiologists offer a more conclusive diagnosis in mammographically perplexing situations, particularly in patients with radiographically dense breasts.
乳腺良恶性病变在T1和T2弛豫方面存在内在重叠，这阻碍了MRI在评估该器官时的应用进展。实际上，乳腺腺体内的病变可能与正常乳腺组织完全融合，这是未增强MRI与乳腺X线摄影共有的问题。然而，静脉注射钆双胺（Gd-DPTA）并结合快速MRI成像能够成功检测出大多数浸润性乳腺恶性肿瘤。对病变形态和强化特征的检查显示，大多数恶性肿瘤边界不规则，强化非常迅速，并呈现出明显的早期廓清期。另一方面，纤维腺瘤边界光滑或呈轻度分叶状，以持续单调的方式强化。也存在一些陷阱，如与导管原位癌（DCIS）和绝经前乳腺组织相关的强化变化。本出版物回顾了关于钆增强乳腺MRI的文献，重点关注其优缺点，并提出了采用这种新的乳腺成像方法的合适适应证。还讨论了患者准备以及技术参数和权衡问题。MRI在乳腺问题患者检查中的确切地位尚未确定，但MRI已经能够帮助放射科医生在乳腺X线摄影结果令人困惑的情况下，尤其是在乳腺X线表现致密的患者中，做出更具确定性的诊断。
