The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.
The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.
Neuroimage Clin. 2019;21:101581. doi: 10.1016/j.nicl.2018.10.019. Epub 2018 Oct 22.
Manual quantification of the hippocampal atrophy state and rate is time consuming and prone to poor reproducibility, even when performed by neuroanatomical experts. The automation of hippocampal segmentation has been investigated in normal aging, epilepsy, and in Alzheimer's disease. Our first goal was to compare manual and automated hippocampal segmentation in ischemic stroke and to, secondly, study the impact of stroke lesion presence on hippocampal volume estimation. We used eight automated methods to segment T1-weighted MR images from 105 ischemic stroke patients and 39 age-matched controls sampled from the Cognition And Neocortical Volume After Stroke (CANVAS) study. The methods were: AdaBoost, Atlas-based Hippocampal Segmentation (ABHS) from the IDeALab, Computational Anatomy Toolbox (CAT) using 3 atlas variants (Hammers, LPBA40 and Neuromorphometics), FIRST, FreeSurfer v5.3, and FreeSurfer v6.0-Subfields. A number of these methods were employed to re-segment the T1 images for the stroke group after the stroke lesions were masked (i.e., removed). The automated methods were assessed on eight measures: process yield (i.e. segmentation success rate), correlation (Pearson's R and Shrout's ICC), concordance (Lin's RC and Kandall's W), slope 'a' of best-fit line from correlation plots, percentage of outliers from Bland-Altman plots, and significance of control-stroke difference. We eliminated the redundant measures after analysing between-measure correlations using Spearman's rank correlation. We ranked the automated methods based on the sum of the remaining non-redundant measures where each measure ranged between 0 and 1. Subfields attained an overall score of 96.3%, followed by AdaBoost (95.0%) and FIRST (94.7%). CAT using the LPBA40 atlas inflated hippocampal volumes the most, while the Hammers atlas returned the smallest volumes overall. FIRST (p = 0.014), FreeSurfer v5.3 (p = 0.007), manual tracing (p = 0.049), and CAT using the Neuromorphometics atlas (p = 0.017) all showed a significantly reduced hippocampal volume mean for the stroke group compared to control at three months. Moreover, masking of the stroke lesions prior to segmentation resulted in hippocampal volumes which agreed less with manual tracing. These findings recommend an automated segmentation without lesion masking as a more reliable procedure for the estimation of hippocampal volume in ischemic stroke.
手动量化海马体萎缩状态和速度既耗时又容易重现性差,即使由神经解剖学专家进行也是如此。海马体分割的自动化已经在正常衰老、癫痫和阿尔茨海默病中进行了研究。我们的第一个目标是比较缺血性中风患者的手动和自动海马体分割,并研究中风病灶的存在对海马体体积估计的影响。我们使用了八种自动方法来分割来自 Cognition And Neocortical Volume After Stroke (CANVAS)研究的 105 名缺血性中风患者和 39 名年龄匹配的对照者的 T1 加权磁共振图像。这些方法是:AdaBoost、来自 IDeALab 的基于图谱的海马体分割 (ABHS)、使用 3 个图谱变体 (Hammers、LPBA40 和 Neuromorphometrics) 的计算解剖工具箱 (CAT)、FIRST、FreeSurfer v5.3 和 FreeSurfer v6.0-Subfields。其中一些方法被用于在中风病灶被屏蔽(即被移除)后对中风组的 T1 图像进行重新分割。自动方法通过八种措施进行评估:过程产量(即分割成功率)、相关性(Pearson's R 和 Shrout 的 ICC)、一致性(Lin 的 RC 和 Kandall 的 W)、相关图中最佳拟合线的斜率 'a'、Bland-Altman 图中的离群值百分比,以及对照-中风差异的显著性。我们使用 Spearman 等级相关分析对各测量值之间的相关性进行分析后,消除了冗余的测量值。我们根据剩余非冗余测量值的总和对自动方法进行排名,其中每个测量值的范围在 0 到 1 之间。子领域的总得分达到 96.3%,其次是 AdaBoost(95.0%)和 FIRST(94.7%)。CAT 使用 LPBA40 图谱增加了海马体的体积,而 Hammers 图谱则总体上返回了最小的体积。FIRST(p=0.014)、FreeSurfer v5.3(p=0.007)、手动追踪(p=0.049)和使用 Neuromorphometrics 图谱的 CAT(p=0.017)都显示中风组的海马体体积平均值在三个月时明显低于对照组。此外,在分割之前屏蔽中风病灶会导致与手动追踪的结果不太一致。这些发现表明,在缺血性中风中,不进行病灶掩蔽的自动分割是一种更可靠的海马体体积估计方法。
Brain Imaging Behav. 2018-12
Brain Struct Funct. 2018-12-3
Brain Imaging Behav. 2010-3
Gigascience. 2024-1-2
Brain Commun. 2022-3-17
Alzheimers Dement (Amst). 2021-6-12