Supplementary Material for: Comparison of Ductoscopy, Galactography, and Imaging Modalities for the Evaluation of Intraductal Lesions: A Critical Review

<b><i>Background: </i></b>Today, in cases of nipple discharge of unclear origin, the abundance of diagnostic procedures - a ‚diagnostic dilemma' - becomes apparent, because unequivocal indications and a current, standardized examination sequence are presently not available. The diagnostic workup of patients with nipple discharge usually includes the clinical history, physical examination, mammography, ultrasonography, galactography, and nipple discharge cytology, but not ductoscopy. <b><i>Methods: </i></b>In this review we analyze and discuss the possible role of ductoscopy in evaluating intraductal pathologies and its combined use with diagnostic imaging modalities. For this purpose, we reviewed and compared the results of the radiological, pathological, and surgical studies independently. <b><i>Conclusions: </i></b>Currently, there is no solitary accurate modality to reach our definitive purpose. Being aware of the capability of each diagnostic modality may take us closer to our target. Therefore, adjunct and appropriate use of multiple imaging modalities and ductoscopy is necessary to evaluate patients with nipple discharge.

**背景：** 当前，针对不明原因乳头溢液患者，临床诊断手段繁杂，已然陷入「诊断困境」——因目前尚无明确的临床指征与统一规范的检查流程可供遵循。当前乳头溢液患者的诊断评估通常涵盖病史采集、体格检查、乳腺钼靶（mammography）、超声检查（ultrasonography）、乳腺导管造影（galactography）及乳头溢液细胞学检查，但并不包含乳腺导管镜（ductoscopy）。
**方法：** 本综述分析并探讨了乳腺导管镜在导管内病变评估中的潜在价值，及其与各类诊断成像手段的联合应用策略。为此，我们独立回顾并比对了放射学、病理学及外科学相关研究的结果。
**结论：** 目前尚无单一准确的诊断手段可达成明确诊断目标。充分了解各类诊断手段的性能特点，有助于我们更贴近诊疗目标。因此，需合理辅助联用多种成像手段与乳腺导管镜，以完成乳头溢液患者的全面评估。