School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom.
School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom.
J Neurosci Methods. 2022 Dec 1;382:109708. doi: 10.1016/j.jneumeth.2022.109708. Epub 2022 Sep 8.
Clinical estimates of brain iron concentration are achievable with quantitative transverse relaxation rate R, via time-consuming multiple spin-echo (SE) sequences. The objective of this study was to investigate whether quantitative iron-sensitive information may be derived from 3.0 T dual-contrast fast-spin-echo (FSE) sequences (typically employed in anatomical non-quantitative evaluations), as a routinely-collected alternative to evaluate iron levels in healthy (HC) and Parkinson's disease (PD) brains.
MRI 3.0 T FSE data from the Parkinson's Progression Markers Initiative (PPMI) (12 PD, 12 age- and gender-matched HC subjects) were cross-sectionally and longitudinally evaluated. A new measure, 'effective R', was calculated for bilateral subcortical grey matter (caudate nucleus, putamen, globus pallidus, red nucleus, substantia nigra). Linear regression analysis was performed to correlate 'effective R' with models of age-dependent brain iron concentration and striatal dopamine transporter (DaT) receptor binding ratio.
Effective R was strongly correlated with estimated brain iron concentration. In PD, putaminal effective R difference was observed between the hemispheres contra-/ipsi-lateral to the predominantly symptomatic side at onset. This hemispheric difference was correlated with the putaminal DaT binding ratios in PD.
COMPARISON WITH EXISTING METHOD(S): Effective R, derived from rapid dual-contrast FSE sequences, showed viability as an alternative to R from SE sequences. Linear correlation of effective R with estimated iron concentration was comparable to documented iron-dependent R. The effective R correlation coefficient was consistent with theoretical R iron-dependence at 3.0 T.
Effective R has clinical potential as a fast quantitative method, as an alternative to R, to aid evaluation of brain iron levels and DaT function.
通过耗时的多回波自旋回波（SE）序列，临床可以实现基于横向弛豫率 R 的脑铁浓度估计。本研究旨在探究 3.0T 双对比快速自旋回波（FSE）序列（常用于解剖学非定量评估）是否可以提供定量铁敏感信息，作为评估健康（HC）和帕金森病（PD）脑内铁水平的常规采集替代方法。
对帕金森进展标志物倡议（PPMI）的 3.0T MRI FSE 数据（12 名 PD 患者和 12 名年龄和性别匹配的 HC 受试者）进行了横断面和纵向评估。为双侧皮质下灰质（尾状核、壳核、苍白球、红核、黑质）计算了新的测量值“有效 R”。进行线性回归分析，以关联“有效 R”与年龄依赖性脑铁浓度模型和纹状体多巴胺转运体（DaT）受体结合率。
有效 R 与估计的脑铁浓度密切相关。在 PD 中，在疾病起始时优势症状侧的对侧/同侧半脑壳核、苍白球、尾状核、红核和黑质的有效 R 差异明显。这种半球差异与 PD 患者的纹状体 DaT 结合率相关。
来自快速双对比 FSE 序列的有效 R 显示出作为 SE 序列 R 的替代方法的可行性。有效 R 与估计的铁浓度的线性相关性与文献中记录的铁依赖性 R 相当。有效 R 的相关系数与 3.0T 时的理论 R 铁依赖性一致。
有效 R 具有作为快速定量方法的临床潜力，可作为 R 的替代方法，辅助评估脑内铁水平和 DaT 功能。
