Combining MRI and Magnetoencephalography

Within the UZH Global Strategy and Partnerships Funding Scheme, Patrick Freund from the University Hospital Balgrist has received funding for a joint project with colleagues from University College London (UCL), a top partner university of UZH. The project will develop a combined ultra-high-field (UHF) MRI and optically pumped MagnetoElectroencephalo-Spinography (OP-MESG) approach to measure cortico-spinal interactions during recovery of hand function following spinal cord injury.

This combined approach of M. Callaghan, G. Barnes, S. Bestmann and A. Thompson from UCL and P. Freund and K.E. Stephan from Zürich allows an in-depth description of primary and secondary neurodegenerative and compensatory processes in patients with spinal cord injury. Specifically, it will facilitate harnessing the microstructure-function relationship across the entire length of the primary motor system during normal and impaired grasping and fine finger movements at the microscale level. This will furnish biophysically-grounded models of pathology and recovery. The combination of UHF-MRI and OP-MESG measurements in the same experimental setup offers an exciting new approach beyond the established clinical and electrophysiological assessments.

UHF-MRI can achieve sub-millimeter resolution imaging with higher signal- and contrast-to-noise ratios, which are necessary for a precise delineation of motor neuron pools and single tracts across the spinal cord and brain [1, 2]. OP-MESG on the other hand allows these functional interactions between brain and cord to be measured at high spatial and temporal resolution [3, 4]. The conjoint acquisition of OP-MESG measurements from the brain and spinal cord allow, for the first time, to evaluate the functional connectivity between neural circuits across several hierarchical CNS levels [5]. To take full advantage of these technological opportunities to detect the microstructural-function interplay during recovery, both UHF-MRI and OP-MESG imaging and analysis methods will be developed at UCL and subsequently applied in a clinical setting at the University Hospital Balgrist.

References:
[1] E. Kirilina et al., “Superficial white matter imaging: Contrast mechanisms and whole-brain in vivo mapping,” Sci. Adv., vol. 6, no. 41, Oct. 2020.
[2] S. Miletić, P. L. Bazin, N. Weiskopf, W. van der Zwaag, B. U. Forstmann, and R. Trampel, “fMRI protocol optimization for simultaneously studying small subcortical and cortical areas at 7 ​T,” Neuroimage, vol. 219, Oct. 2020.
[3] C. Lin et al., “Using optically pumped magnetometers to measure magnetoencephalographic signals in the human cerebellum,” J. Physiol., vol. 597, no. 16, pp. 4309–4324, Aug. 2019.
[4] E. Boto et al., “Wearable neuroimaging: Combining and contrasting magnetoencephalography and electroencephalography,” Neuroimage, vol. 201, p. 116099, Nov. 2019.
[5] P. Freund et al., “Embodied neurology: an integrative framework for neurological disorders,” Brain, vol. 139, no. 6, pp. 1855–1861, Jun. 2016.