Background

Blood-brain barrier (BBB) permeability change is a possible pathologic mechanism of autoimmune encephalitis.

Purpose

To evaluate the change in BBB permeability in patients with autoimmune encephalitis as compared with healthy controls by using dynamic contrast-enhanced (DCE) MRI and to explore its predictive value for treatment response in patients.

Materials and Methods

This single-center retrospective study included consecutive patients with probable or possible autoimmune encephalitis and healthy controls who underwent DCE MRI between April 2020 and May 2021. Automatic volumetric segmentation was performed on three-dimensional T1-weighted images, and volume transfer constant (K^trans) values were calculated at encephalitis-associated brain regions. K^trans values were compared between the patients and controls, with adjustment for age and sex with use of a nonparametric approach. The Wilcoxon rank sum test was performed to compare K^trans values of the good (improvement in modified Rankin Scale [mRS] score of at least two points or achievement of an mRS score of ≤2) and poor (improvement in mRS score of less than two points and achievement of an mRS score >2) treatment response groups among the patients.

Results

Thirty-eight patients with autoimmune encephalitis (median age, 38 years [IQR, 29–59 years]; 20 [53%] female) and 17 controls (median age, 71 years [IQR, 63–77 years]; 12 [71%] female) were included. All brain regions showed higher K^trans values in patients as compared with controls (P < .001). The median difference in K^trans between the patients and controls was largest in the right parahippocampal gyrus (25.1 × 10⁻⁴ min⁻¹ [95% CI: 17.6, 43.4]). Among patients, the poor treatment response group had higher baseline K^trans values in both cerebellar cortices (P = .03), the left cerebellar cortex (P = .02), right cerebellar cortex (P = .045), left cerebral cortex (P = .045), and left postcentral gyrus (P = .03) than the good treatment response group.

Conclusion

DCE MRI demonstrated that BBB permeability was increased in all brain regions in patients with autoimmune encephalitis as compared with controls, and baseline K^trans values were higher in patients with poor treatment response in the cerebellar cortex, left cerebral cortex, and left postcentral gyrus as compared with the good response group.

© RSNA, 2024

Supplemental material is available for this article.

See also the editorial by Filippi and Rocca in this issue.

中文翻译：

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自身免疫性脑炎血管通透性改变的动态对比增强 MRI 定量

背景

血脑屏障（BBB）通透性改变是自身免疫性脑炎的可能病理机制。

目的

利用动态对比增强（DCE）MRI评估自身免疫性脑炎患者与健康对照者相比血脑屏障通透性的变化，并探讨其对患者治疗反应的预测价值。

材料和方法

这项单中心回顾性研究包括在 2020 年 4 月至 2021 年 5 月期间接受 DCE MRI 的连续患有可能或疑似自身免疫性脑炎的患者和健康对照。对三维 T1 加权图像进行自动体积分割，并计算体积转移常数 ( K ^trans）值是在脑炎相关的大脑区域计算的。比较患者和对照组之间的K ^trans值，并使用非参数方法调整年龄和性别。进行 Wilcoxon 秩和检验以比较良好（改良Rankin量表 [mRS] 得分至少提高两分或 mRS 得分≤2）和较差（mRS 得分改善小于 2 分）的K^反式值。患者中治疗反应组获得两分并达到 mRS 评分 >2)。

结果

38 名自身免疫性脑炎患者（中位年龄，38 岁 [IQR，29-59 岁]；20 名 [53%] 女性）和 17 名对照者（中位年龄，71 岁 [IQR，63-77 岁]；12 名 [71 岁] %]女性）也被包括在内。与对照组相比，患者的所有大脑区域都显示出更高的K^{反式值 (} P < .001)。患者和对照组之间K ^trans的中值差异在右侧海马旁回最大（25.1 × 10 ^-4 min ^-1 [95% CI：17.6，43.4]）。在患者中，治疗反应差组的^两个小脑皮质 ( P = .03)、左侧小脑皮质 ( P = .02)、右侧小脑皮质 ( P = .045)、左侧大脑皮质 ( P = .045) 和左中央后回 ( P = .03) 比治疗反应良好的组。

结论

DCE MRI显示，与对照组相比，自身免疫性脑炎患者所有脑区的BBB通透性均增加，且治疗反应不佳的患者小脑皮质、左大脑皮层和左中央后回的基线K ^trans值较高。与良好的反应组。

© 北美放射学会，2024

本文提供了补充材料。

另请参阅本期 Filippi 和 Rocca 的社论。