如何准确诊断多发性硬化（multiple sclerosis，MS）是富有挑战性的临床问题。尽管已有诸多指南和共识定义了MS的典型影像学特征，然而在临床实践中，由于非典型临床表现和同病异像的干扰，许多其他的神经科疾病往往被误诊为MS。脑小血管病（cerebral small vessel disease，CSVD）的临床症状和影像学表现与MS相似，因此容易被误诊为MS。通过检索既往文献报道的误诊病例，发现遗传性CSVD和获得性CSVD的不典型影像学表现可以模拟MS，并且满足MS的影像学诊断标准而被误诊。然而，从病理机制角度进行深入探讨，发现MS和CSVD均有相应的特征性表现，同时引起误诊的白质高信号病灶在形态学和分布等特征上存在可辨识的差异。影像学特征的差异反映了2类疾病发病机制的差异。本文对既往文献报道的误诊为MS的CSVD病例进行复习，从影像学特征和病理机制角度探讨2者的异同，旨在帮助临床医师更好地鉴别MS与CSVD，避免误诊。

How to make an accurate diagnose of multiple sclerosis (MS) is a challenging clinical problem. Although many guidelines and consensus have clearly defined the typical imaging characteristics of MS, other neurological diseases are often misdiagnosed as MS due to the interference of untypical manifestations and radiological mimickers in clinical practice. Cerebral small vessel disease (CSVD) is likely to be misdiagnosed as MS due to its similarity in clinical manifestations and radiological pattern. By reviewing the misdiagnosed cases reported in the previous literature, it is found that the atypical imaging manifestations of hereditary CSVD and acquired CSVD can mimic MS and lead to misdiagnosis in satisfying the diagnostic criteria for MS. However, through research in the pathologic mechanism, it reveals that MS and CSVD have corresponding characteristics and there are distinct differences in morphology and distribution of the white matter hyperintensity between MS and CSVD. Such differences in imaging manifestations reflect the discrepancy in the pathogenesis of two kinds of diseases. This paper reviews the cases of CSVD misdiagnosed as MS reported in the previous literature, and discusses the similarities and differences between them from the perspective of imaging features and pathological mechanism, so as to help clinicians better distinguish MS from CSVD and avoid misdiagnosis.