Abbass Mohamad, Taha Alaa, Gilmore Greydon, Santyr Brendan, Chalil Alan, Jog Mandar, MacDougall Keith, Parrent Andrew G, Peters Terry M, Lau Jonathan C
Department of Clinical Neurological Sciences, Division of Neurosurgery, Western University, London, Canada.
Imaging Research Laboratories, Robarts Research Institute, Western University, London, Canada.
Imaging Neurosci (Camb). 2025 May 16;3. doi: 10.1162/imag_a_00579. eCollection 2025.
Effects of deep brain stimulation (DBS) depend on millimetric accuracy and are commonly studied across populations by registering patient scans to a stereotactic space. Multiple factors contribute to estimates of electrode position, but the millimetric contributions of these factors remain poorly quantified. We previously validated 32 anatomical fiducials (AFIDs) to measure AFID registration error (AFRE), which can capture focal misregistration not observed using volume-based methods. To this end, we used the AFIDs framework to examine the effects of misregistration on electrode position in stereotactic space, leveraging a retrospective series of patients who underwent subthalamic nucleus (STN) DBS. Raters independently localized DBS electrodes and AFIDs on patient scans, which were non-linearly registered to a common stereotactic (MNI) space. AFIDs provided intuitive measures of registration accuracy, with AFREs ranging from 1.49 mm to 6.85 mm across brain regions. Subcortical AFIDs in proximity to the DBS target (STN) had AFREs that spatially covaried, suggesting consistent spatial patterns of misregistration to stereotactic space. These identified spatial patterns account for 28% of the variance in electrode position along the axis of maximum variance, corresponding to a median of 0.64 mm (range of 0.05 to 2.05 mm). The AFIDs framework provides millimetric estimates of registration accuracy in DBS, while allowing the uncoupling of registration-related factors from other sources of variance in electrode position. Furthermore, they can be employed for estimating registration-related variance in population studies, for quality control, and to provide a basis for comparison as well as optimization of registration parameters and software.
深部脑刺激（DBS）的效果取决于毫米级的精度，并且通常通过将患者扫描图像配准到立体定向空间来对不同人群进行研究。多种因素会影响电极位置的估计，但这些因素在毫米级上的影响仍未得到很好的量化。我们之前验证了32个解剖基准点（AFIDs）来测量AFID配准误差（AFRE），它可以捕捉到基于体积的方法未观察到的局部配准错误。为此，我们利用AFIDs框架，通过回顾性研究一系列接受丘脑底核（STN）DBS治疗的患者，来研究配准错误对立体定向空间中电极位置的影响。评估人员在患者扫描图像上独立定位DBS电极和AFIDs，这些图像被非线性配准到一个共同的立体定向（MNI）空间。AFIDs提供了直观的配准精度测量方法，不同脑区的AFRE范围为1.49毫米至6.85毫米。靠近DBS靶点（STN）的皮质下AFIDs的AFRE在空间上存在协变，表明与立体定向空间的配准错误存在一致的空间模式。这些确定的空间模式占电极位置沿最大方差轴方差的28%，对应中位数为0.64毫米（范围为0.05至2.05毫米）。AFIDs框架提供了DBS中配准精度的毫米级估计，同时允许将与配准相关的因素与电极位置的其他方差来源解耦。此外，它们可用于估计人群研究中与配准相关的方差，用于质量控制，并为比较以及优化配准参数和软件提供基础。
