MP2RAGE and Susceptibility‐Weighted Imaging in Lesional Epilepsy at 7T

Pittau, Francesca; Baud, Maxime O.; Jorge, João; Xin, Lijing; Grouiller, Frédéric; Iannotti, Giannina Rita; Seeck, Margitta; Lazeyras, François; Vulliémoz, Serge; Vargas, Maria Isabel

doi:10.1111/jon.12523

Cited by 29 publications

(22 citation statements)

References 23 publications

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“…In a recent qualitative assessment in lesional epilepsy cases at 7 T, epileptogenic characteristics (cortical thickening, cortical–subcortical atrophy, and blurred GM–WM junction phenomena) were well appreciated on MP2RAGE images (6/7 cases = visual sensitivity 85.7%; Pittau et al, ). This is similar to our study, where MP2 (80%) and MP2 VBM variants showed a sensitivity between 80 and 100% in the lesional cohort ( n cases = 5).…”

Section: Discussionmentioning

confidence: 97%

“…The resultant images show enhanced contrast‐to‐noise ratio (especially GM–WM contrast), independent of T 2 *, proton density, B1 − , and reduced B1 + inhomogeneities. Thus, acquired images are, at least partially, corrected for image bias intrinsically and have been called “self‐bias corrected images.” Newer studies have shown promise of MP2RAGE in improving visualization of lesions (Beck et al, ; Pittau et al, ). Moreover, reduced intensity inhomogenities should also improve tissue segmentation, which facilitates VBM analysis for lesion detection (Ashburner & Friston, ).…”

Section: Introductionmentioning

confidence: 99%

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MP2RAGE multispectral voxel‐based morphometry in focal epilepsy

Kotikalapudi

Martin

Erb³

et al. 2019

Human Brain Mapping

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We assessed the applicability of MP2RAGE for voxel‐based morphometry. To this end, we analyzed its brain tissue segmentation characteristics in healthy subjects and the potential for detecting focal epileptogenic lesions (previously visible and nonvisible). Automated results and expert visual interpretations were compared with conventional VBM variants (i.e., T1 and T1 + FLAIR). Thirty‐one healthy controls and 21 patients with focal epilepsy were recruited. 3D T1‐, T2‐FLAIR, and MP2RAGE images (consisting of INV1, INV2, and MP2 maps) were acquired on a 3T MRI. The effects of brain tissue segmentation and lesion detection rates were analyzed among single‐ and multispectral VBM variants. MP2‐single‐contrast gave better delineation of deep, subcortical nuclei but was prone to misclassification of dura/vessels as gray matter, even more than conventional‐T1. The addition of multispectral combinations (INV1, INV2, or FLAIR) could markedly reduce such misclassifications. MP2 + INV1 yielded generally clearer gray matter segmentation allowing better differentiation of white matter and neighboring gyri. Different models detected known lesions with a sensitivity between 60 and 100%. In non lesional cases, MP2 + INV1 was found to be best with a concordant rate of 37.5%, specificity of 51.6% and concordant to discordant ratio of 0.60. In summary, we show that multispectral MP2RAGE VBM (e.g., MP2 + INV1, MP2 + INV2) can improve brain tissue segmentation and lesion detection in epilepsy.

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Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

MP2RAGE multispectral voxel‐based morphometry in focal epilepsy

Kotikalapudi

Martin

Erb³

et al. 2019

Human Brain Mapping

View full text Add to dashboard Cite

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“…Both sequences are usually performed in less than 5 minutes, and their impact would further improve with the use of higher field strengths of 3T and above. 2 The detection of a subtle lesion on SWI may also permit the performance of a timely epilepsy surgical procedure 3 in these patients, with a typically excellent outcome. Furthermore, new surgical techniques such as stereotactic laser ablation may allow for a safe and effective delivery of stereotactic therapy for epileptogenic cavernoma, especially for patients in whom open brain surgery presents a barrier to treatment.…”

Section: Susceptibility-weighted Imaging (Swi) or T2* Contrasts Shoulmentioning

confidence: 99%

Susceptibility‐weighted imaging (SWI) or T2* contrasts should remain standard in the neuroimaging of epilepsy

et al. 2019

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“…Also among these modalities is susceptibility‐weighted imaging (SWI), which combines

T_{2}^{*}

‐weighted magnitude and phase information at long echo time. While originally developed primarily for venography, taking advantage of the geometry and paramagnetic content of veins, SWI was soon found valuable for numerous other applications, including the detection of trauma, stroke, cortical dysplasia and tumors . At 7T, SWI has shown enhanced sensitivity in detecting multiple sclerosis lesions and features of polymicrogyria in epilepsy, for example.…”

Section: Introductionmentioning

confidence: 99%

Improved susceptibility‐weighted imaging for high contrast and resolution thalamic nuclei mapping at 7T

Jorge

Gretsch

Najdenovska

et al. 2020

Magnetic Resonance in Med

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Purpose:The thalamus is an important brain structure and neurosurgical target, but its constituting nuclei are challenging to image non-invasively. Recently, susceptibility-weighted imaging (SWI) at ultra-high field has shown promising capabilities for thalamic nuclei mapping. In this work, several methodological improvements were explored to enhance SWI quality and contrast, and specifically its ability for thalamic imaging. Methods: High-resolution SWI was performed at 7T in healthy participants, and the following techniques were applied: (a) monitoring and retrospective correction of head motion and B 0 perturbations using integrated MR navigators, (b) segmentation and removal of venous vessels on the SWI data using vessel enhancement filtering, and (c) contrast enhancement by tuning the parameters of the SWI phase-magnitude combination. The resulting improvements were evaluated with quantitative metrics of image quality, and by comparison to anatomo-histological thalamic atlases. Results: Even with sub-millimeter motion and natural breathing, motion and field correction produced clear improvements in both magnitude and phase data quality (76% and 41%, respectively). The improvements were stronger in cases of larger motion/field deviations, mitigating the dependence of image quality on subject performance. Optimizing the SWI phase-magnitude combination yielded substantial improvements in image contrast, particularly in the thalamus, well beyond previously reported SWI results. The atlas comparisons provided compelling evidence of anatomical correspondence between SWI features and several thalamic nuclei, for | 1219 JORGE Et al.

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MP2RAGE and Susceptibility‐Weighted Imaging in Lesional Epilepsy at 7T

Abstract: MRI at ultra-high field is very promising for the detection of inconspicuous epileptogenic lesions and may facilitate epilepsy surgery of a great number of to-date MRI-negative patients.

Cited by 29 publications

References 23 publications

MP2RAGE multispectral voxel‐based morphometry in focal epilepsy

MP2RAGE multispectral voxel‐based morphometry in focal epilepsy

Susceptibility‐weighted imaging (SWI) or T2* contrasts should remain standard in the neuroimaging of epilepsy

Improved susceptibility‐weighted imaging for high contrast and resolution thalamic nuclei mapping at 7T

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