Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Istituto di Ricovero e di Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, Milan, Italy.
Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy.
JAMA Neurol. 2021 Mar 1;78(3):351-364. doi: 10.1001/jamaneurol.2020.4689.
Although magnetic resonance imaging (MRI) is useful for monitoring disease dissemination in space and over time and excluding multiple sclerosis (MS) mimics, there has been less application of MRI to progressive MS, including diagnosing primary progressive (PP) MS and identifying patients with relapsing-remitting (RR) MS who are at risk of developing secondary progressive (SP) MS. This review addresses clinical application of MRI for both diagnosis and prognosis of progressive MS.
Although nonspecific, some spinal cord imaging features (diffuse abnormalities and lesions involving gray matter [GM] and ≥2 white matter columns) are typical of PPMS. In patients with PPMS and those with relapse-onset MS, location of lesions in critical central nervous system regions (spinal cord, infratentorial regions, and GM) and MRI-detected high inflammatory activity in the first years after diagnosis are risk factors for long-term disability and future progressive disease course. These measures are evaluable in clinical practice. In patients with established MS, GM involvement and neurodegeneration are associated with accelerated clinical worsening. Subpial demyelination and slowly expanding lesions are novel indicators of progressive MS.
Diagnosis of PPMS is more challenging than diagnosis of RRMS. No qualitative clinical, immunological, histopathological, or neuroimaging features differentiate PPMS and SPMS; both are characterized by imaging findings reflecting neurodegeneration and are also impacted by aging and comorbidities. Unmet diagnostic needs include identification of MRI markers capable of distinguishing PPMS from RRMS and predicting the evolution of RRMS to SPMS. Integration of multiple parameters will likely be essential to achieve these aims.
尽管磁共振成像（MRI）可用于监测疾病在空间和时间上的扩散，并排除多发性硬化症（MS）的类似物，但在进展性 MS 中应用 MRI 的情况较少，包括诊断原发性进展型（PP）MS 并识别出有发展为继发性进展型（SP）MS 风险的缓解复发型（RR）MS 患者。本综述介绍了 MRI 在进展性 MS 的诊断和预后中的临床应用。
尽管非特异性，但一些脊髓成像特征（弥漫性异常和累及灰质[GM]和≥2 个白质柱的病变）是 PPMS 的典型特征。在 PPMS 患者和发病后复发的 MS 患者中，病变位于关键中枢神经系统区域（脊髓、颅后窝区域和 GM）以及诊断后最初几年 MRI 检测到的高炎症活性是长期残疾和未来进行性疾病过程的风险因素。这些措施可在临床实践中评估。在已确诊的 MS 患者中，GM 受累和神经退行性变与加速临床恶化有关。软脑膜下脱髓鞘和缓慢扩展的病变是进展性 MS 的新指标。
PPMS 的诊断比 RRMS 的诊断更具挑战性。没有定性的临床、免疫学、组织病理学或神经影像学特征可以区分 PPMS 和 SPMS；两者均以反映神经退行性变的影像学表现为特征，并且还受到衰老和合并症的影响。未满足的诊断需求包括识别能够将 PPMS 与 RRMS 区分开的 MRI 标志物，并预测 RRMS 向 SPMS 的演变。整合多个参数可能对于实现这些目标至关重要。
