Fluid and White Matter Suppression Imaging and Voxel-Based Morphometric Analysis in Conventional Magnetic Resonance Imaging-Negative Epilepsy.

Ke Sun,Tobias Kober,Zhiwei Ren,Xueyuan Wang,Yongxiang Zhao,Yicong Lin,Jing Xiang,Guojun Zhang,Liang Qiao,Tao Yu,Dongju Yang,Duanyu Ni,Runshi Gao,Nan Chen,Xin Chen,Kun Yang

doi:10.3389/fneur.2021.651592

Abstract

Purpose: Delineation of subtle lesions in magnetic resonance imaging (MRI)-negative patients is of great importance in preoperative epilepsy evaluation. The aim of our study was to explore the diagnostic value of the novel fluid and white matter suppression (FLAWS) sequence in comparison with a voxel-based MRI postprocessing morphometric analysis program (MAP) in a consecutive cohort of non-lesional patients.Methods: Surgical candidates with a negative finding on an official neuroradiology report were enrolled. High-resolution FLAWS image and MAP maps generated based on high-resolution three-dimensional (3D) T1 image were visually inspected for each patient. The findings of FLAWS or MAP-positive (FLAWS/MAP+) regions were compared with the surgical resection cavity in correlation with surgical outcome and pathology.Results: Forty-five patients were enrolled; the pathological examination revealed focal cortical dysplasia (FCD) in 32 patients and other findings in 13 patients. The positive rate, sensitivity, and specificity were 48.9%, 0.43, and 0.87, respectively, for FLAWS and 64.4%, 0.57, and 0.8, respectively, for MAP. Concordance between surgical resection and FLAWS+ or MAP+ regions was significantly associated with a seizure-free outcome (FLAWS: p = 0.002; MAP: p = 0.0003). A positive finding in FLAWS and MAP together with abnormalities in the same gyrus (FLAWS–MAP gyral+) was detected in 31.1% of patients. FLAWS+ only and MAP+ only were found in 7 (15.5%) and 14 (31.1%) patients, respectively.Conclusions: FLAWS showed a promising value for identifying subtle epileptogenic lesions and can be used as a complement to current MAP in patients with MRI-negative epilepsy.

Highlights

Thirty percent of patients with epilepsy are pharmacoresistant [1]
fluid and white matter suppression (FLAWS) was successfully conducted in 52 patients
Four patients who did not undergo resective surgery, two patients who had poor signal on magnetic resonance imaging (MRI), and one patient lost to follow-up were excluded; a final dataset consisting of the data of 45 patients was used for analysis (Figure 1)

Summary

Introduction

Thirty percent of patients with epilepsy are pharmacoresistant [1]. Surgical resection of the epileptogenic zone has been shown to be an effective treatment option [2]. Good surgical outcome depends on accurate delineation and complete resection of the epileptogenic zone [3]. 20–40% of surgical candidates have negative results on conventional magnetic resonance imaging (MRI) [4]. The absence of a lesion on MRI may lead to insufficient evidence for forming a surgical hypothesis and is associated with poor surgical outcome [4]. In order to identify epileptic abnormalities with a higher efficiency and guide the implantation of intracranial electrodes in MRInegative epilepsy patients, novel imaging acquisition techniques and advanced imaging analysis algorithms are needed

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