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Voxel‐based magnetic resonance image postprocessing in epilepsy

OBJECTIVE: Although the general utility of voxel‐based processing of structural magnetic resonance imaging (MRI) data for detecting occult lesions in focal epilepsy is established, many differences exist among studies, and it is unclear which processing method is preferable. The aim of this study wa...

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Autores principales: Martin, Pascal, Winston, Gavin P., Bartlett, Philippa, de Tisi, Jane, Duncan, John S., Focke, Niels K.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5601223/
https://www.ncbi.nlm.nih.gov/pubmed/28745400
http://dx.doi.org/10.1111/epi.13851
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author Martin, Pascal
Winston, Gavin P.
Bartlett, Philippa
de Tisi, Jane
Duncan, John S.
Focke, Niels K.
author_facet Martin, Pascal
Winston, Gavin P.
Bartlett, Philippa
de Tisi, Jane
Duncan, John S.
Focke, Niels K.
author_sort Martin, Pascal
collection PubMed
description OBJECTIVE: Although the general utility of voxel‐based processing of structural magnetic resonance imaging (MRI) data for detecting occult lesions in focal epilepsy is established, many differences exist among studies, and it is unclear which processing method is preferable. The aim of this study was to compare the ability of commonly used methods to detect epileptogenic lesions in magnetic resonance MRI‐positive and MRI‐negative patients, and to estimate their diagnostic yield. METHODS: We identified 144 presurgical focal epilepsy patients, 15 of whom had a histopathologically proven and MRI‐visible focal cortical dysplasia; 129 patients were MRI negative with a clinical hypothesis of seizure origin, 27 of whom had resections. We applied four types of voxel‐based morphometry (VBM), three based on T1 images (gray matter volume, gray matter concentration, junction map [JM]) and one based on normalized fluid‐attenuated inversion recovery (nFSI). Specificity was derived from analysis of 50 healthy controls. RESULTS: The four maps had different sensitivity and specificity profiles. All maps showed detection rates for focal cortical dysplasia patients (MRI positive and negative) of >30% at a strict threshold of p < 0.05 (family‐wise error) and >60% with a liberal threshold of p < 0.0001 (uncorrected), except for gray matter volume (14% and 27% detection rate). All maps except nFSI showed poor specificity, with high rates of false‐positive findings in controls. In the MRI‐negative patients, absolute detection rates were lower. A concordant nFSI finding had a significant positive odds ratio of 7.33 for a favorable postsurgical outcome in the MRI‐negative group. Spatial colocalization of JM and nFSI was rare, yet showed good specificity throughout the thresholds. SIGNIFICANCE: All VBM variants had specific diagnostic properties that need to be considered for an adequate interpretation of the results. Overall, structural postprocessing can be a useful tool in presurgical diagnostics, but the low specificity of some maps has to be taken into consideration.
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spelling pubmed-56012232017-10-03 Voxel‐based magnetic resonance image postprocessing in epilepsy Martin, Pascal Winston, Gavin P. Bartlett, Philippa de Tisi, Jane Duncan, John S. Focke, Niels K. Epilepsia Full‐length Original Research OBJECTIVE: Although the general utility of voxel‐based processing of structural magnetic resonance imaging (MRI) data for detecting occult lesions in focal epilepsy is established, many differences exist among studies, and it is unclear which processing method is preferable. The aim of this study was to compare the ability of commonly used methods to detect epileptogenic lesions in magnetic resonance MRI‐positive and MRI‐negative patients, and to estimate their diagnostic yield. METHODS: We identified 144 presurgical focal epilepsy patients, 15 of whom had a histopathologically proven and MRI‐visible focal cortical dysplasia; 129 patients were MRI negative with a clinical hypothesis of seizure origin, 27 of whom had resections. We applied four types of voxel‐based morphometry (VBM), three based on T1 images (gray matter volume, gray matter concentration, junction map [JM]) and one based on normalized fluid‐attenuated inversion recovery (nFSI). Specificity was derived from analysis of 50 healthy controls. RESULTS: The four maps had different sensitivity and specificity profiles. All maps showed detection rates for focal cortical dysplasia patients (MRI positive and negative) of >30% at a strict threshold of p < 0.05 (family‐wise error) and >60% with a liberal threshold of p < 0.0001 (uncorrected), except for gray matter volume (14% and 27% detection rate). All maps except nFSI showed poor specificity, with high rates of false‐positive findings in controls. In the MRI‐negative patients, absolute detection rates were lower. A concordant nFSI finding had a significant positive odds ratio of 7.33 for a favorable postsurgical outcome in the MRI‐negative group. Spatial colocalization of JM and nFSI was rare, yet showed good specificity throughout the thresholds. SIGNIFICANCE: All VBM variants had specific diagnostic properties that need to be considered for an adequate interpretation of the results. Overall, structural postprocessing can be a useful tool in presurgical diagnostics, but the low specificity of some maps has to be taken into consideration. John Wiley and Sons Inc. 2017-07-26 2017-09 /pmc/articles/PMC5601223/ /pubmed/28745400 http://dx.doi.org/10.1111/epi.13851 Text en © 2017 The Authors. Epilepsia published by Wiley Periodicals, Inc. on behalf of International League Against Epilepsy. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Full‐length Original Research
Martin, Pascal
Winston, Gavin P.
Bartlett, Philippa
de Tisi, Jane
Duncan, John S.
Focke, Niels K.
Voxel‐based magnetic resonance image postprocessing in epilepsy
title Voxel‐based magnetic resonance image postprocessing in epilepsy
title_full Voxel‐based magnetic resonance image postprocessing in epilepsy
title_fullStr Voxel‐based magnetic resonance image postprocessing in epilepsy
title_full_unstemmed Voxel‐based magnetic resonance image postprocessing in epilepsy
title_short Voxel‐based magnetic resonance image postprocessing in epilepsy
title_sort voxel‐based magnetic resonance image postprocessing in epilepsy
topic Full‐length Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5601223/
https://www.ncbi.nlm.nih.gov/pubmed/28745400
http://dx.doi.org/10.1111/epi.13851
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