Charité - Universitätsmedizin Berlin, Freie Universität and Humboldt-Universität zu Berlin, Department of Neurology, Epilepsy-Center Berlin-Brandenburg, Berlin, Germany.
King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, London, UK.
Hum Brain Mapp. 2023 Jun 1;44(8):3196-3209. doi: 10.1002/hbm.26274. Epub 2023 Apr 13.
The piriform cortex (PC) is located at the junction of the temporal and frontal lobes. It is involved physiologically in olfaction as well as memory and plays an important role in epilepsy. Its study at scale is held back by the absence of automatic segmentation methods on MRI. We devised a manual segmentation protocol for PC volumes, integrated those manually derived images into the Hammers Atlas Database (n = 30) and used an extensively validated method (multi-atlas propagation with enhanced registration, MAPER) for automatic PC segmentation. We applied automated PC volumetry to patients with unilateral temporal lobe epilepsy with hippocampal sclerosis (TLE; n = 174 including n = 58 controls) and to the Alzheimer's Disease Neuroimaging Initiative cohort (ADNI; n = 151, of whom with mild cognitive impairment (MCI), n = 71; Alzheimer's disease (AD), n = 33; controls, n = 47). In controls, mean PC volume was 485 mm on the right and 461 mm on the left. Automatic and manual segmentations overlapped with a Jaccard coefficient (intersection/union) of 0.5 and a mean absolute volume difference of ~22 mm in healthy controls, ~0.40/ ~28 mm in patients with TLE, and ~ 0.34/29 mm in patients with AD. In patients with TLE, PC atrophy lateralised to the side of hippocampal sclerosis (p < .001). In patients with MCI and AD, PC volumes were lower than those of controls bilaterally (p < .001). Overall, we have validated automatic PC volumetry in healthy controls and two types of pathology. The novel finding of early atrophy of PC at the stage of MCI possibly adds a novel biomarker. PC volumetry can now be applied at scale.
梨状皮层（PC）位于颞叶和额叶交界处。它在生理上参与嗅觉以及记忆，并在癫痫中起重要作用。由于缺乏 MRI 上的自动分割方法，其大规模研究受到阻碍。我们设计了一种 PC 体积的手动分割方案，将这些手动生成的图像整合到哈默斯图谱数据库（n=30）中，并使用经过广泛验证的方法（多图谱传播增强配准，MAPER）进行自动 PC 分割。我们将自动 PC 容积测量应用于单侧颞叶内侧硬化性癫痫（TLE；n=174 例，包括 n=58 例对照）患者和阿尔茨海默病神经影像学倡议队列（ADNI；n=151 例，其中轻度认知障碍（MCI）患者 n=71 例，阿尔茨海默病（AD）患者 n=33 例，对照者 n=47 例）。在对照者中，右侧 PC 平均体积为 485mm，左侧为 461mm。在健康对照者中，自动和手动分割的重叠度用 Jaccard 系数（交集/并集）表示约为 0.5，平均绝对体积差异约为 22mm；在 TLE 患者中约为 0.40/28mm，在 AD 患者中约为 0.34/29mm。在 TLE 患者中，PC 萎缩向海马硬化的一侧偏侧化（p<0.001）。在 MCI 和 AD 患者中，双侧 PC 体积均低于对照者（p<0.001）。总的来说，我们在健康对照者和两种类型的病理中验证了自动 PC 容积测量。在 MCI 阶段 PC 早期萎缩的新发现可能增加了一个新的生物标志物。现在可以大规模应用 PC 容积测量。
