Automatic quality control of the numerical accuracy of EEG lead fields
Precise individualized EEG source localization is predicated on having accurate subject-specific Lead Fields (LFs) obtained from their Magnetic Resonance Images (MRI). LF calculation is a complex process involving several error-prone steps that start with obtaining a realistic head model from the MR...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-06-01
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| Series: | NeuroImage |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1053811923002379 |
| _version_ | 1827957522688901120 |
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| author | Usama Riaz Fuleah A Razzaq Ariosky Areces-Gonzalez Maria Carla Piastra Maria L. Bringas Vega Deirel Paz-Linares Pedro A. Valdés-Sosa |
| author_facet | Usama Riaz Fuleah A Razzaq Ariosky Areces-Gonzalez Maria Carla Piastra Maria L. Bringas Vega Deirel Paz-Linares Pedro A. Valdés-Sosa |
| author_sort | Usama Riaz |
| collection | DOAJ |
| description | Precise individualized EEG source localization is predicated on having accurate subject-specific Lead Fields (LFs) obtained from their Magnetic Resonance Images (MRI). LF calculation is a complex process involving several error-prone steps that start with obtaining a realistic head model from the MRI and finalizing with computationally expensive solvers such as the Boundary Element Method (BEM) or Finite Element Method (FEM). Current Big-Data applications require the calculation of batches of hundreds or thousands of LFs. LF. Quality Control is conventionally checked subjectively by experts, a procedure not feasible in practice for larger batches. To facilitate this step, we introduce the Lead Field Automatic-Quality Control Index (LF-AQI) that flags LF with potential errors. We base our LF-AQI on the assumption that LFs obtained from simpler head models, i.e., the homogeneous head model LF (HHM-LF) or spherical head model LF (SHM-LF), deviate only moderately from a ''good'' realistic test LF. Since these simpler LFs are easier to compute and check for errors, they may serve as ''reference LF'' to detect anomalous realistic test LF. We investigated this assumption by comparing correlation-based channel ρmin(ref,test)and source τmin(ref,test) similarity indices (SI) between ''gold standards,'' i.e., very accurate FEM and BEM LFs, and the proposed references (HHM-LF and SHM-LF). Surprisingly we found that the most uncomplicated possible reference, HHM-LF had high SI values with the gold standards—leading us to explore further use of the channel ρmin(HHM−LF,test)and source τmin(HHM−LF,test) SI as a basis for our LF-AQI. Indeed, these SI successfully detected five simulated scenarios of LFs artifacts. This result encouraged us to evaluate the SI on a large dataset and thus define our LF-AQI. We thus computed the SI of 1251 LFs obtained from the Child Mind Institute (CMI) MRI dataset. When ρmin(HHM−LF,test)and source τmin(HHM−LF,test) were plotted for all test subjects on a 2D space, most were tightly clustered around the median of a high similarity centroid (HSC), except for a smaller proportion of outliers. We define the LF-AQI for a given LF as the log Euclidean distance between its SI and the HSC median. To automatically detect outliers, the threshold is at the 90th percentile of the CMI LF-AQIs (-0.9755). LF-AQI greater than this threshold flag individual LF to be checked. The robustness of this LF-AQI screening was checked by repeated out-of-sample validation. Strikingly, minor corrections in re-processing the flagged cases eliminated their status as outliers. Furthermore, the ''doubtful'' labels assigned by LF-AQI were validated by neuroscience students using a Likert scale questionnaire designed to manually check the LF's quality. Item Response Theory (IRT) analysis was applied to the questionnaire results to compute an optimized model and a latent variable θ for that model. A linear mixed model (LMM) between the θ and LF-AQI resulted in an effect with a Cohen's d value of 1.3 and a p-value <0.001, thus validating the correspondence of LF-AQI with the visual quality control. We provide an open-source pipeline to implement both LF calculation and its quality control to allow further evaluation of our index. |
| first_indexed | 2024-04-09T15:20:21Z |
| format | Article |
| id | doaj.art-5e3863cfc8e4494e9b30e3e2681ca091 |
| institution | Directory Open Access Journal |
| issn | 1095-9572 |
| language | English |
| last_indexed | 2024-04-09T15:20:21Z |
| publishDate | 2023-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | NeuroImage |
| spelling | doaj.art-5e3863cfc8e4494e9b30e3e2681ca0912023-04-29T14:47:18ZengElsevierNeuroImage1095-95722023-06-01273120091Automatic quality control of the numerical accuracy of EEG lead fieldsUsama Riaz0Fuleah A Razzaq1Ariosky Areces-Gonzalez2Maria Carla Piastra3Maria L. Bringas Vega4Deirel Paz-Linares5Pedro A. Valdés-Sosa6The Clinical Hospital of Chengdu Brain Sciences, University of Electronic Science and Technology of China, Chengdu, China; Corresponding authors.The Clinical Hospital of Chengdu Brain Sciences, University of Electronic Science and Technology of China, Chengdu, ChinaThe Clinical Hospital of Chengdu Brain Sciences, University of Electronic Science and Technology of China, Chengdu, China; Department of Informatics, University of Pinar del Rio Hermanos Saiz Montes de Oca, CubaClinical Neurophysiology group, University of Twente, NetherlandsThe Clinical Hospital of Chengdu Brain Sciences, University of Electronic Science and Technology of China, Chengdu, China; Cuban Neuroscience Center, Havana, CubaThe Clinical Hospital of Chengdu Brain Sciences, University of Electronic Science and Technology of China, Chengdu, China; Corresponding authors.The Clinical Hospital of Chengdu Brain Sciences, University of Electronic Science and Technology of China, Chengdu, China; Cuban Neuroscience Center, Havana, Cuba; Corresponding authors.Precise individualized EEG source localization is predicated on having accurate subject-specific Lead Fields (LFs) obtained from their Magnetic Resonance Images (MRI). LF calculation is a complex process involving several error-prone steps that start with obtaining a realistic head model from the MRI and finalizing with computationally expensive solvers such as the Boundary Element Method (BEM) or Finite Element Method (FEM). Current Big-Data applications require the calculation of batches of hundreds or thousands of LFs. LF. Quality Control is conventionally checked subjectively by experts, a procedure not feasible in practice for larger batches. To facilitate this step, we introduce the Lead Field Automatic-Quality Control Index (LF-AQI) that flags LF with potential errors. We base our LF-AQI on the assumption that LFs obtained from simpler head models, i.e., the homogeneous head model LF (HHM-LF) or spherical head model LF (SHM-LF), deviate only moderately from a ''good'' realistic test LF. Since these simpler LFs are easier to compute and check for errors, they may serve as ''reference LF'' to detect anomalous realistic test LF. We investigated this assumption by comparing correlation-based channel ρmin(ref,test)and source τmin(ref,test) similarity indices (SI) between ''gold standards,'' i.e., very accurate FEM and BEM LFs, and the proposed references (HHM-LF and SHM-LF). Surprisingly we found that the most uncomplicated possible reference, HHM-LF had high SI values with the gold standards—leading us to explore further use of the channel ρmin(HHM−LF,test)and source τmin(HHM−LF,test) SI as a basis for our LF-AQI. Indeed, these SI successfully detected five simulated scenarios of LFs artifacts. This result encouraged us to evaluate the SI on a large dataset and thus define our LF-AQI. We thus computed the SI of 1251 LFs obtained from the Child Mind Institute (CMI) MRI dataset. When ρmin(HHM−LF,test)and source τmin(HHM−LF,test) were plotted for all test subjects on a 2D space, most were tightly clustered around the median of a high similarity centroid (HSC), except for a smaller proportion of outliers. We define the LF-AQI for a given LF as the log Euclidean distance between its SI and the HSC median. To automatically detect outliers, the threshold is at the 90th percentile of the CMI LF-AQIs (-0.9755). LF-AQI greater than this threshold flag individual LF to be checked. The robustness of this LF-AQI screening was checked by repeated out-of-sample validation. Strikingly, minor corrections in re-processing the flagged cases eliminated their status as outliers. Furthermore, the ''doubtful'' labels assigned by LF-AQI were validated by neuroscience students using a Likert scale questionnaire designed to manually check the LF's quality. Item Response Theory (IRT) analysis was applied to the questionnaire results to compute an optimized model and a latent variable θ for that model. A linear mixed model (LMM) between the θ and LF-AQI resulted in an effect with a Cohen's d value of 1.3 and a p-value <0.001, thus validating the correspondence of LF-AQI with the visual quality control. We provide an open-source pipeline to implement both LF calculation and its quality control to allow further evaluation of our index.http://www.sciencedirect.com/science/article/pii/S1053811923002379EEGBEMFEMLead fieldAutomated quality controlItem response theory |
| spellingShingle | Usama Riaz Fuleah A Razzaq Ariosky Areces-Gonzalez Maria Carla Piastra Maria L. Bringas Vega Deirel Paz-Linares Pedro A. Valdés-Sosa Automatic quality control of the numerical accuracy of EEG lead fields NeuroImage EEG BEM FEM Lead field Automated quality control Item response theory |
| title | Automatic quality control of the numerical accuracy of EEG lead fields |
| title_full | Automatic quality control of the numerical accuracy of EEG lead fields |
| title_fullStr | Automatic quality control of the numerical accuracy of EEG lead fields |
| title_full_unstemmed | Automatic quality control of the numerical accuracy of EEG lead fields |
| title_short | Automatic quality control of the numerical accuracy of EEG lead fields |
| title_sort | automatic quality control of the numerical accuracy of eeg lead fields |
| topic | EEG BEM FEM Lead field Automated quality control Item response theory |
| url | http://www.sciencedirect.com/science/article/pii/S1053811923002379 |
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