MEGIN Masterclass
Accurate yet MRI-free magnetic source imaging with the pseudo-MRI engine
Presented by Amit Jaiswal, PhD and Lauri Parkkonen, PhD.
Abstract: Structural head MRIs are a crucial ingredient in MEG/EEG source imaging; they are used to define a realistically shaped volume conductor model, constrain the source space, and visualize the source estimates. However, individual MRIs are not always available, or they may be of insufficient quality for segmentation, leading to the use of a generic template MRI, matched MRI, or the application of a spherical conductor model. Unfortunately, such approaches often lead to a model geometry that deviates from the true head structure and limits the accuracy of the forward solution.
A potential solution to such issues is our pseudo-MRI engine that generates individualized synthetic MRIs based on the external head shape alone. This software refines the head-shape digitization acquired during an MEG/EEG measurement and warps a given MRI template to fit the subject’s head. The software was systematically validated for healthy adults by 1) geometrically comparing their real individual MRIs and pseudo-MRIs, and 2) performing source estimation with both types of MRIs. The validation demonstrated that the pseudo-MRI enables comparable source localization accuracy to the one obtained with the subject’s real MRI. More details are available in our article: https://doi.org/10.1002/hbm.70148
In addition to the published study, the approach was also investigated and demonstrated for pediatric subjects and adults with early dementia. The findings showed that a pseudo-MRI can replace an individual MRI in MEG/EEG source imaging in many applications that do not require subcentimeter spatial accuracy.
Bios:
Lauri Parkkonen (PhD) – Professor, Department of Neuroscience & Biomedical Engineering at Aalto University, and Senior Technology Advisor, MEGIN
Prof. Lauri Parkkonen is a professor and vice head of the Department of Neuroscience & Biomedical Engineering, School of Science, Aalto University, Espoo, Finland. Prof. Parkkonen has been working in the MEG field and other brain-imaging technologies for more than three decades. His areas of expertise include neuroscience, neurotechnology, human brain imaging, medical technology, and MEG sensor technology.
Amit Jaiswal (PhD) – MEG Application Scientist, MEGIN
Dr. Amit Jaiswal works as an MEG application scientist at MEGIN. He has been working with MEG/EEG for over a decade and holds a PhD in biomedical engineering from Aalto University, Finland. His work focuses on improving the MEG/EEG methods and developing clinical applications. He has also been working with several open-source analysis software and implementing tools for MEG/EEG analysis and multimodal integration.
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