Lateralization of temporal lobe epileptic foci with automated chemical exchange saturation transfer measurements at 3 TeslaResearch in context
Kang Wang,
Qingqing Wen,
Dengchang Wu,
Yi-Cheng Hsu,
Hye-Young Heo,
Wenqi Wang,
Yi Sun,
Yuehui Ma,
Dan Wu,
Yi Zhang
Affiliations
Kang Wang
Epilepsy Center, Department of Neurology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310003, China
Qingqing Wen
Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, 310027, China
Dengchang Wu
Epilepsy Center, Department of Neurology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310003, China
Yi-Cheng Hsu
MR Collaboration, Siemens Healthcare Ltd., Shanghai, 201318, China
Hye-Young Heo
Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
Wenqi Wang
Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, 310027, China
Yi Sun
MR Collaboration, Siemens Healthcare Ltd., Shanghai, 201318, China
Yuehui Ma
Epilepsy Center, Department of Neurosurgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310003, China
Dan Wu
Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, 310027, China
Yi Zhang
Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, 310027, China; Corresponding author. Room 322, Zhou Yiqing Building, Yuquan Campus, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, China.
Summary: Background: Magnetic Resonance Imaging (MRI) is an indispensable tool for the diagnosis of temporal lobe epilepsy (TLE). However, about 30% of TLE patients show no lesion on structural MRI (sMRI-negative), posing a significant challenge for presurgical evaluation. This study aimed to investigate whether chemical exchange saturation transfer (CEST) MRI at 3 Tesla can lateralize the epileptic focus of TLE and study the metabolic contributors to the CEST signal measured. Methods: Forty TLE subjects (16 males and 24 females) were included in this study. An automated data analysis pipeline was established, including segmentation of the hippocampus and amygdala (HA), calculation of four CEST metrics and quantitative relaxation times (T1 and T2), and construction of prediction models by logistic regression. Furthermore, a modified two-stage Bloch–McConnell fitting method was developed to investigate the molecular imaging mechanism of 3 T CEST in identifying epileptic foci of TLE. Findings: The mean CEST ratio (CESTR) metric within 2.25–3.25 ppm in the HA was the most powerful index in predicting seizure laterality, with an area under the receiver-operating characteristic curve (AUC) of 0.84. And, the combination of T2 and CESTR further increased the AUC to 0.92. Amine and guanidinium moieties were the two leading contributors to the CEST contrast between the epileptogenic HA and the normal HA. Interpretation: CEST at 3 Tesla is a powerful modality that can predict seizure laterality with high accuracy. This study can potentially facilitate the clinical translation of CEST MRI in identifying the epileptic foci of TLE or other localization-related epilepsies. Funding: National Natural Science Foundation of China, Science Technology Department of Zhejiang Province, and Zhejiang University.