Aix-Marseille Univ, CNRS, CRMBM, Marseille, France; APHM, Hopital Universitaire Timone, CEMEREM, Marseille, France; Aix-Marseille Univ, Université Gustave Eiffel, LBA, Marseille, France; iLab-Spine International Associated Laboratory, Marseille-Montreal, France, Canada.
Aix-Marseille Univ, CNRS, CRMBM, Marseille, France; APHM, Hopital Universitaire Timone, CEMEREM, Marseille, France.
Magn Reson Imaging. 2021 Dec;84:18-26. doi: 10.1016/j.mri.2021.08.011. Epub 2021 Sep 10.
Magnetization Prepared 2 Rapid Acquisition Gradient Echo (MP2RAGE) is a T mapping technique that has been used broadly on brain and recently on cervical spinal cord (cSC). The growing interest for combined investigation of brain and SC in numerous pathologies of the central nervous system such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS) and traumatic injuries, now brings about the need for optimization with regards to this specific investigation. This implies large spatial coverage with high spatial resolution and short acquisition time, high CNR and low B sensitivity, as well as high reproducibility and robust post-processing tools for T quantification in different regions of brain and SC. In this work, a dedicated protocol (referred to as Pr-BSC) has been optimized for simultaneous brain and cSC T MP2RAGE acquisition at 3T. After computer simulation optimization, the protocol was applied for in vivo validation experiments and compared to previously published state of the art protocols focusing on either the brain (Pr-B) or the cSC (Pr-SC). Reproducibility and in-ROI standard deviations were assessed on healthy volunteers in the perspective of future clinical use. The mean T values, obtained by the Pr-BSC, in brain white, gray and deep gray matters were: (mean ± in-ROI SD) 792 ± 27 ms, 1339 ± 139 ms and 1136 ± 88 ms, respectively. In cSC, T values for white matter corticospinal, posterior sensory, lateral sensory and rubro/reticulospinal tracts were 902 ± 41 ms, 920 ± 35 ms, 903 ± 46 ms, 891 ± 41 ms, respectively, and 954 ± 32 ms for anterior and intermediate gray matter. The Pr-BSC protocol showed excellent agreement with previously proposed Pr-B on brain and Pr-SC on cSC, with very high inter-scan reproducibility (coefficients of variation of 0.52 ± 0.36% and 1.12 ± 0.62% on brain and cSC, respectively). This optimized protocol covering both brain and cSC with a sub-millimetric isotropic spatial resolution in one acquisition of less than 8 min, opens up great perspectives for clinical applications focusing on degenerative tissue such as encountered in MS and ALS.
磁化准备 2 快速获取梯度回波（MP2RAGE）是一种 T 映射技术，已广泛应用于脑，最近也应用于颈脊髓（cSC）。由于对中枢神经系统多种疾病（如多发性硬化症（MS）、肌萎缩侧索硬化症（ALS）和创伤性损伤）的脑和 SC 联合研究的兴趣日益浓厚，现在需要对这一特定研究进行优化。这意味着需要大的空间覆盖范围、高空间分辨率和短采集时间、高信噪比（CNR）和低 B 灵敏度，以及高重复性和用于脑和 SC 不同区域 T 定量的强大后处理工具。在这项工作中，针对 3T 下同时进行脑和 cSC T MP2RAGE 采集，优化了一种专用协议（称为 Pr-BSC）。在计算机模拟优化后，该协议用于体内验证实验，并与之前针对脑（Pr-B）或 cSC（Pr-SC）的最先进协议进行了比较。在未来的临床应用中，对健康志愿者进行了重复性和 ROI 内标准差评估。通过 Pr-BSC 获得的脑白质、灰质和深灰质的平均 T 值分别为：（平均值±ROI 内标准差）792±27ms、1339±139ms 和 1136±88ms。在 cSC 中，皮质脊髓束、后感觉束、侧感觉束和红核/网状脊髓束的白质 T 值分别为 902±41ms、920±35ms、903±46ms 和 891±41ms，前灰质和中间灰质的 T 值为 954±32ms。Pr-BSC 协议与之前提出的 Pr-B 在脑和 Pr-SC 在 cSC 上的协议非常吻合，具有非常高的扫描间可重复性（脑和 cSC 的变异系数分别为 0.52±0.36%和 1.12±0.62%）。这种优化的协议可以在不到 8 分钟的一次采集中以亚毫米各向同性空间分辨率覆盖脑和 cSC，为关注退行性组织的临床应用（如多发性硬化症和肌萎缩侧索硬化症）开辟了广阔的前景。
