Improved Visualization of Focal Cortical Dysplasia With Surface-Based Multiparametric Quantitative MRI.

Michelle Maiworm,Helmuth Steinmetz,Ulrike Nöth,Ralf Deichmann,René-Maxime Gracien,Marlies Wagner,Susanne Knake,Elke Hattingen,Felix Rosenow

doi:10.3389/fnins.2020.00622

Michelle Maiworm, Helmuth Steinmetz + Show 7 more

Open Access

https://doi.org/10.3389/fnins.2020.00622

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Abstract

PurposeIn the clinical routine, detection of focal cortical dysplasia (FCD) by visual inspection is challenging. Still, information about the presence and location of FCD is highly relevant for prognostication and treatment decisions. Therefore, this study aimed to develop, describe and test a method for the calculation of synthetic anatomies using multiparametric quantitative MRI (qMRI) data and surface-based analysis, which allows for an improved visualization of FCD.Materials and MethodsQuantitative T1-, T2- and PD-maps and conventional clinical datasets of patients with FCD and epilepsy were acquired. Tissue segmentation and delineation of the border between white matter and cortex was performed. In order to detect blurring at this border, a surface-based calculation of the standard deviation of each quantitative parameter (T1, T2, and PD) was performed across the cortex and the neighboring white matter for each cortical vertex. The resulting standard deviations combined with measures of the cortical thickness were used to enhance the signal of conventional FLAIR-datasets. The resulting synthetically enhanced FLAIR-anatomies were compared with conventional MRI-data utilizing regions of interest based analysis techniques.ResultsThe synthetically enhanced FLAIR-anatomies showed higher signal levels than conventional FLAIR-data at the FCD sites (p = 0.005). In addition, the enhanced FLAIR-anatomies exhibited higher signal levels at the FCD sites than in the corresponding contralateral regions (p = 0.005). However, false positive findings occurred, so careful comparison with conventional datasets is mandatory.ConclusionSynthetically enhanced FLAIR-anatomies resulting from surface-based multiparametric qMRI-analyses have the potential to improve the visualization of FCD and, accordingly, the treatment of the respective patients.

Highlights

Focal cortical dysplasia (FCD) is a developmental cortical malformation with a high epileptogenic potential, often causing drug-refractory epilepsy (Gaitanis and Donahue, 2013)
Synthetically enhanced fluid-attenuated inversion recovery (FLAIR)-anatomies resulting from surface-based multiparametric quantitative MRI (qMRI)-analyses have the potential to improve the visualization of FCD and, the treatment of the respective patients
To visualize the effect of FCD on quantitative parameter values at the white matter (WM)/cortex-junction, Figure 2 shows, for a representative patient, the result of the tissue segmentation superimposed on the T2-map

Summary

Introduction

Focal cortical dysplasia (FCD) is a developmental cortical malformation with a high epileptogenic potential, often causing drug-refractory epilepsy (Gaitanis and Donahue, 2013). Diagnostics and pre-surgical evaluation include MRI to identify the FCD and estimate its extent and localization This information is crucial as the complete resection of the lesion is an important factor for postsurgical outcome (Fauser et al, 2004; Lerner et al, 2009; Kabat and Król, 2012). MR-changes are often subtle and detection and evaluation of the location and extent of the lesions can be challenging with conventional MRI-techniques (Colombo et al, 2003; Kabat and Król, 2012; Hong et al, 2016) Still, clinicians need this information for treatment decisions

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