Canna Antonietta, Mangia Silvia, Michaeli Shalom, Ponticorvo Sara, Russillo Maria Claudia, Andreozzi Valentina, Manara Renzo, Di Salle Francesco, Picillo Marina, Barone Paolo, Esposito Fabrizio, Pellecchia Maria Teresa
Montreal Neurological Institute and Hospital, the Neuro, McGill University, Montreal, QC, Canada.
Center for Magnetic Resonance Research (CMRR), Department of Radiology, University of Minnesota, Minneapolis (MN), USA.
Sci Rep. 2025 Jul 24;15(1):26954. doi: 10.1038/s41598-025-10812-6.
Rotating frame relaxation (RFR) techniques provide robust and sensitive quantitative MRI (qMRI) metrics able to detect subtle alterations of brain tissue integrity in multiple neurological disorders. We performed a cross-sectional qMRI study in 16 patients with Multiple System Atrophy (MSA) and 14 age- and sex-matched healthy controls. The MRI protocol included the acquisition of RFR metrics, namely adiabatic T1ρ and T2ρ relaxation time constants, along with the acquisition of conventional relaxation metrics, namely R1 and R2*, and a semi-quantitative metric describing magnetization transfer (MT). Between-group comparisons of voxel-based and region-based outcomes were obtained both with and without accounting for the effect of atrophy. Significant brain atrophy was observed in the MSA patients in the white matter and grey matter of the cerebellum, and frontal white matter. On the other hand, group differences of virtually all relaxation metrics were observed for both voxel-wise and ROI analyses in many brain areas. These differences were reduced in spatial extent and/or effect size when the atrophy effect was accounted for. However, T1ρ values remained significantly longer in patients' ROIs encompassing both cerebellar grey matter and white matter, while MT, and R1 values were smaller. Cerebellar gray matter ROIs of patients also exhibited longer T2ρ and smaller R2*. Other voxel-wise group differences were still present after atrophy correction in several clusters, including among others, longer T1ρ in patients' putamen, and longer T1ρ and T2ρ and smaller MT in the patients' pons. Altogether, our findings suggest multiple processes of tissue integrity loss during the course of neurodegeneration that go beyond macrostructural alterations. We conclude that adiabatic T1ρ and T2ρ are valuable MRI metrics that expand the set of multi-parametric qMRI available to characterize the brain of MSA, providing additional and specific information on the brain tissue alterations occurring in this disease.
旋转框架弛豫（RFR）技术提供了强大且灵敏的定量磁共振成像（qMRI）指标，能够检测多种神经系统疾病中脑组织完整性的细微变化。我们对16例多系统萎缩（MSA）患者和14名年龄及性别匹配的健康对照者进行了一项横断面qMRI研究。MRI方案包括获取RFR指标，即绝热T1ρ和T2ρ弛豫时间常数，以及获取传统弛豫指标，即R1和R2*，还有一个描述磁化传递（MT）的半定量指标。在考虑和不考虑萎缩效应的情况下，分别对基于体素和基于区域的结果进行组间比较。在MSA患者中，观察到小脑白质和灰质以及额叶白质有明显的脑萎缩。另一方面，在许多脑区的体素分析和感兴趣区（ROI）分析中，几乎所有弛豫指标都存在组间差异。当考虑萎缩效应时，这些差异在空间范围和/或效应大小上有所减小。然而，在包含小脑灰质和白质的患者ROI中，T1ρ值仍然显著更长，而MT和R1值更小。患者的小脑灰质ROI也表现出更长的T2ρ和更小的R2*。在几个簇中，萎缩校正后仍存在其他体素水平的组间差异，包括患者壳核中更长的T1ρ，以及患者脑桥中更长的T1ρ和T2ρ以及更小的MT。总之，我们的研究结果表明，在神经退行性变过程中，存在多种超出宏观结构改变的组织完整性丧失过程。我们得出结论，绝热T1ρ和T2ρ是有价值的MRI指标，扩展了可用于表征MSA患者大脑的多参数qMRI集合，为该疾病中发生的脑组织改变提供了额外的特定信息。
