Multimodal Fingerprints of Resting State Networks as assessed by Simultaneous Trimodal MR-PET-EEG Imaging

Abstract

Simultaneous MR-PET-EEG (magnetic resonance imaging - positron emission tomography – electroencephalography), a new tool for the investigation of neuronal networks in the human brain, is presented here for the first time. It enables the assessment of molecular metabolic information with high spatial and temporal resolution in a given brain simultaneously. Here, we characterize the brain’s default mode network (DMN) in healthy male subjects using multimodal fingerprinting by quantifying energy metabolism via 2- [18F]fluoro-2-desoxy-D-glucose PET (FDG-PET), the inhibition – excitation balance of neuronal activation via magnetic resonance spectroscopy (MRS), its functional connectivity via fMRI and its electrophysiological signature via EEG. The trimodal approach reveals a complementary fingerprint. Neuronal activation within the DMN as assessed with fMRI is positively correlated with the mean standard uptake value of FDG. Electrical source localization of EEG signals shows a significant difference between the dorsal DMN and sensorimotor network in the frequency range of δ, θ, α and β–1, but not with β–2 and β–3. In addition to basic neuroscience questions addressing neurovascular-metabolic coupling, this new methodology lays the foundation for individual physiological and pathological fingerprints for a wide research field addressing healthy aging, gender effects, plasticity and different psychiatric and neurological diseases.

Excitatory-Inhibitory Balance within EEG Microstates and Resting-state fMRI Networks: Assessed via Simultaneous PET-MR-EEG Imaging

“…In our study, we replicate a significantly higher FDG uptake (corresponding to a higher glucose metabolism) in the core RSNs -DMN and the SN-compared to the SMN and the whole-brain GM regions in the resting state, as already previously shown in other studies (Tomasi, Wang and Volkow, 2013;N.J. Shah et al, 2017).…”

Simultaneous task-based BOLD-fMRI and [18-F] FDG functional PET for measurement of neuronal metabolism in the human visual cortex

“…(39)) which can be very informative but do not allow quantitative inferences to be made. Most existing BOLD-fMRI/FDG-PET studies use a data integration approach, where data from each modality is analysed separately and compared at the second-level using correlation (e.g., (16,21,45,46,48)) or similarity metrics (e.g., (40)). A data integration approach is useful for examining broad relationships between data types, but does not fully capitalise on the shared information between the modalities.…”

From simultaneous to synergistic MR‐PET brain imaging: A review of hybrid MR‐PET imaging methodologies

“…Using the TRIMAGE trimodal system, Shah et al (2017) examined the relationship between BOLD-fMRI activity in the default mode network to FDG-PET uptake in the network and resting-state EEG. Biomarker discovery projects have been largely focused towards schizophrenia, since putative schizophrenia biomarkers have been developed using each technology independently, without showing sufficient specificity to be diagnostic.…”

“…Biomarker discovery projects have been largely focused towards schizophrenia, since putative schizophrenia biomarkers have been developed using each technology independently, without showing sufficient specificity to be diagnostic. Using the TRIMAGE trimodal system, Shah et al (2017) examined the relationship between BOLD-fMRI activity in the default mode network to FDG-PET uptake in the network and resting-state EEG. BOLD-fMRI activity in the default mode network was positively related to FDG uptake in the network, but neither BOLD nor FDG was related to EEG connectivity across frequency bands (δ, θ, α, β1 -4).…”