Arch Neurol：新型多光谱磁共振成像计算PD患者黒质体积

帕金森病理发展的轨迹探索的研究仍在进行中。近期，一项在美国麻省理工学院和马萨诸塞州总医院帕金森病研究中心进行的一项病例对照研究表明，帕金森病患者黑质致密部（SNc）神经变性早于基底前脑（BF），并且建立了一种新型多光谱磁共振成像技术用于追踪PD变性的生物学标志物。

该研究入选了29例PD患者（Hoehn-Yahr分期[H＆Y]1-3期）和27例相匹配的健康对照者，使用新型多光谱结构磁共振（MR）成像工具来衡量的黑质致密部（SNc）和基底前脑（BF）以验证帕金森病（PD）患者黑质致密部（SNc）发生神经变性早于胆碱能基底前脑（BF）。

研究者对每一例受试者进行多回波T1加权，多回波质子密度，T2加权，T2加权液体衰减反转恢复（FLAIR）序列等磁共振检查。对于SNc，创建了一个多重回波的平均加权值，提供高比率对比噪声的单个体积。使用T2加权FLAIR图像可视化观察BF。对于每一例受试者，手动标记这两个结构，并计算出它们的体积。

研究结果表明，与对照组相比，13例H-Y1期的PD患者SNc体积明显减小，16例H-Y2-3期患者则表现少量额外的体积减小。与此相反，BF体积的丢失则发生在疾病的后期，H-Y2-3期患者比对照者和H-Y1期患者体积丢失更明显。H-Y1期患者与对照组没有显着性差异。

因此，作者在结论中写到，我们的研究结果支持PD的神经病理学发展轨迹，并建立了新的多光谱磁共振成像方法作为追踪SNc和BF变性的生物学标志物。

doi:10.1001/jamaneurol.2013.597.
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Substantia Nigra Volume Loss Before Basal Forebrain Degeneration in Early Parkinson Disease

David A. Ziegler, PhD; Julien S. Wonderlick, MD; Paymon Ashourian, PhD; Leslie A. Hansen, BS; Jeremy C. Young, BS; Alex J. Murphy, BS; Cecily K. Koppuzha, BS; John H. Growdon, MD; Suzanne Corkin, PhD

Objective To test the hypothesis that degeneration of the substantia nigra pars compacta (SNc) precedes that of the cholinergic basal forebrain (BF) in Parkinson disease (PD) using new multispectral structural magnetic resonance (MR) imaging tools to measure the volumes of the SNc and BF. Design Matched case-control study. Setting The Athinoula A. Martinos Imaging Center at the McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), and the Massachusetts General Hospital/MIT Morris Udall Center of Excellence in Parkinson Disease Research. Patients Participants included 29 patients with PD (Hoehn and Yahr [H&Y] stages 1-3) and 27 matched healthy control subjects. Main Outcome Measures We acquired multiecho T1-weighted, multiecho proton density, T2-weighted, and T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences from each participant. For the SNc, we created a weighted mean of the multiple echoes, yielding a single volume with a high ratio of contrast to noise. We visualized the BF using T2-weighted FLAIR images. For each participant, we manually labeled the 2 structures and calculated their volumes. Results Relative to the controls, 13 patients with H&Y stage 1 PD had significantly decreased SNc volumes. Sixteen patients with H&Y stage 2 or 3 PD showed little additional volume loss. In contrast, the BF volume loss occurred later in the disease, with a significant decrease apparent in patients having H&Y stage 2 or 3 PD compared with the controls and the patients having H&Y stage 1 PD. The latter group did not differ significantly from the controls. Conclusion Our results support the proposed neuropathological trajectory in PD and establish novel multispectral methods as MR imaging biomarkers for tracking the degeneration of the SNc and BF.