多发性硬化脑内病灶MRI典型及不典型表现:附82例MRI分析

An analysis of typical and atypical MRI findings of brain lesions in multiple sclerosis:a 82 cases report

目的分析我国多发性硬化病例典型及不典型影像学改变。方法回顾经McDonald诊断标准明确诊断的82例多发性硬化患者的头部MRI检查结果,分析病灶部位、大小、数目、形状、信号强度及强化方式等。结果我国多发性硬化的典型影像学表现:(1)病灶部位以脑室旁(62例,75.61%)及幕上深部白质(55例,67.07%)多见。(2)病灶数目多在10个以上(62例,75.61%)。(3)病灶直径以≤1 cm为主(62例,75.61%),>5 cm次之(23例,28.05%)。(4)信号强度及强化特征为T_1WI平扫呈等或略低信号,T_1WI高信号,PDwI高于脑脊液中水信号;T_1WI增强图像黑洞从微小至大片状均可见,形状多呈类圆形或条片状;<1 cm病灶显示结节状强化,1～5 cm病灶一般呈环状强化,>5 cm病灶以边缘强化或内部呈不规则环状强化为主,皮质病灶多见弓状强化。我国多发性硬化的不典型影像学表现为:病灶较大,最大直径>5 cm(23例,28.05%);强化显著且强化持续时间较长;脑干病灶多见(61例,74.39%)。结论侧脑室旁或深部白质内多发小病灶是多发性硬化的典型MRI表现;侧脑室旁病灶致侧脑室变形、大脑凸面的微小黑洞及侧脑室边缘的条片状黑洞,以及近皮质或围绕侧脑室颞角的弓状强化具有重要诊断价值。病灶大、强化显著及脑干病灶多见,是我国多发性硬化不同于欧美地区的主要表现。

Objective To analyse the typical and atypical magnetic resonance imaging （MRI） findings of brain multiple sclerosis （MS） lesions in Chinese MS patients. Methods MRI findings of 82 Chinese MS patients who fulfilled McDonald criteria were reviewed retrospectively. The analysis items included the distribution, size, number, shape, intensity and enhancement of all lesions on head MRI. Results The typical MRI findings of these patients were as follow： 1） most lesions were located at periventricle area （62 cases, 75.61%） and the deep part of supratentorial white matter （55 cases, 67.07%）; 2） there were over 10 lesions in 62 cases （75.61%）; 3） the lesions were predominantly ~〈 1 cm （62 cases, 75.61%）, and the next were 〉 5 cm （23 cases, 28,05%）; 4） intensity and enhancement features presented T^WI iso- or hypo- intensity, T2WI hyperintensity, and proton density weighted image （PDWI） lesions intensity higher than water in the ventricle; the black hole appeared in various size and mostly with round or patchy shape; nodular enhancement was more often seen in lesions smaller than 1 cm and ring-like in middle size lesions; peripheral or irregular enhancement was popular for big lesions and arc-like for subcortical lesions. In the atypical MRI findings： 1） lesions were large [maximum diameter 〉 5 cm （23 cases, 28.05%）]; 2） lesion enhancement was remarkable and last longer; 3） brain stem lesions were more common （61 cases, 74.39%）. Conclusion Multiple and small lesions at periventricle area or deep white matter are the typical MRI findings for MS. Deformation due to MS lesions, microblack hole at convex or line-shape black hole at periventricle, arc- like enhancement for juxtacortical lesions or enhancement beside the temporal horn are improtant in the diagnosis of MS. Big lesions with remarkable enhancement and prevalent in brain stem are the findings in Chinese MS patients which are different from American or European MS cases.