Ahmadi Seyed-Ahmad, Bötzel Kai, Levin Johannes, Maiostre Juliana, Klein Tassilo, Wein Wolfgang, Rozanski Verena, Dietrich Olaf, Ertl-Wagner Birgit, Navab Nassir, Plate Annika
Department of Neurology, Ludwig-Maximilians University, Marchioninistraße 15, Munich 81377, Germany; German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians University, Marchioninistraße 15, Munich 81377, Germany; Chair for Computer Aided Medical Procedures (CAMP), Technical University of Munich, Boltzmannstr. 3, Garching 85748, Germany.
Department of Neurology, Ludwig-Maximilians University, Marchioninistraße 15, Munich 81377, Germany.
Neuroimage Clin. 2020;26:102185. doi: 10.1016/j.nicl.2020.102185. Epub 2020 Feb 1.
Transcranial B-mode sonography (TCS) can detect hyperechogenic speckles in the area of the substantia nigra (SN) in Parkinson's disease (PD). These speckles correlate with iron accumulation in the SN tissue, but an exact volumetric localization in and around the SN is still unknown. Areas of increased iron content in brain tissue can be detected in vivo with magnetic resonance imaging, using quantitative susceptibility mapping (QSM).
In this work, we i) acquire, co-register and transform TCS and QSM imaging from a cohort of 23 PD patients and 27 healthy control subjects into a normalized atlas template space and ii) analyze and compare the 3D spatial distributions of iron accumulation in the midbrain, as detected by a signal increase (TCS+ and QSM+) in both modalities.
We achieved sufficiently accurate intra-modal target registration errors (TRE<1 mm) for all MRI volumes and multi-modal TCS-MRI co-localization (TRE<4 mm) for 66.7% of TCS scans. In the caudal part of the midbrain, enlarged TCS+ and QSM+ areas were located within the SN pars compacta in PD patients in comparison to healthy controls. More cranially, overlapping TCS+ and QSM+ areas in PD subjects were found in the area of the ventral tegmental area (VTA).
Our findings are concordant with several QSM-based studies on iron-related alterations in the area SN pars compacta. They substantiate that TCS+ is an indicator of iron accumulation in Parkinson's disease within and in the vicinity of the SN. Furthermore, they are in favor of an involvement of the VTA and thereby the mesolimbic system in Parkinson's disease.
经颅B型超声检查（TCS）能够检测帕金森病（PD）患者黑质（SN）区域的高回声斑点。这些斑点与SN组织中的铁蓄积相关，但SN及其周围的确切体积定位仍不清楚。使用定量磁化率成像（QSM）的磁共振成像能够在体内检测脑组织中铁含量增加的区域。
在本研究中，我们：i）将23例PD患者和27例健康对照者的TCS和QSM成像采集、配准并转换到标准化图谱模板空间；ii）分析和比较两种模态中信号增强（TCS+和QSM+）所检测到的中脑铁蓄积的三维空间分布。
我们对所有MRI体积实现了足够准确的模态内目标配准误差（TRE<1毫米），对66.7%的TCS扫描实现了多模态TCS-MRI共定位（TRE<4毫米）。与健康对照相比，在中脑尾部，PD患者SN致密部内TCS+和QSM+区域扩大。在更靠头侧的位置，PD受试者中TCS+和QSM+区域在腹侧被盖区（VTA）重叠。
我们的发现与几项基于QSM的关于SN致密部铁相关改变的研究一致。它们证实TCS+是帕金森病SN内及其附近铁蓄积的一个指标。此外，它们支持VTA进而中脑边缘系统参与帕金森病。
