Suhyung Park^1,2, Sugil Kim³, Hankyeol Lee⁴, Seulgi Eun⁴, Seong-Gi Kim^4,5, and David Feinberg^6,7
1Department of Computer Engineering, Chonnam National University, Gwangju, Korea, Republic of, ²Department of ICT Convergence System Engineering, Chonnam National University, Gwangju, Korea, Republic of, ³Siemens-Healthineers, Seoul, Korea, Republic of, ⁴Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, Korea, Republic of, ⁵Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of, ⁶University of California, Berkeley, Berkeley, CA, United States, ⁷Advanced MRI Technologies, Sebastopol, CA, United States

With ultra-high fields, 3D EPI has been used by improving imaging efficiency. Nevertheless, there have been some limitations: 1) the regular sampling limits the use of temporal structure in the data and 2) parallel imaging allows up to 6-fold acceleration in 3D acquisition. Here, we developed an accelerated 3D EPI using VD-CAPI sampling with temporal random walk. Experimental studies confirm advantages in acceleration, SNR, and sensitivity of the proposed method: 1) temporal random walk allows extra spatial encoding across time, 2) temporal prior provides high SNR, and 3) the temporal incoherent sampling and high SNR result in higher BOLD activations.  

Anna K Mueller¹, Miriam Heynckes², Christopher J Wiggins³, Omer Faruk Gulban⁴, Yuhui Chai⁵, Benedikt Poser², and Renzo Huber^2
1Goethe-Universität Frankfurt am Main, Mainz, Germany, ²Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands, ³Scannexus, Maastricht, Netherlands, ⁴Brain Innovation, Maastricht, Netherlands, ⁵NIH, Bethesda, MD, United States

Laminar-specific fMRI allows neuroscientists to address research questions of directional functional connectivity within and across brain areas. While recent sequence developments allow considerable improvements in coverage, resolution, and mitigation of venous biases, it is not established how routinely useful those methods are for everyday neuroscientific application.

We present an open dataset of whole-brain CBV-sensitive layer-dependent fMRI during free movie watching. Its purpose is to:

• investigate the reproducibility of laminar connectivity results, 
• to benchmark preprocessing pipelines, 
• to provide reference atlases of laminar connectivity and venous physiology,
• and to explore new potential neuroscientific research questions that become addressable with laminar fMRI.

 

Fuyixue Wang^1,2, Zijing Dong^1,3, Lawrence L. Wald^1,2, Jonathan Polimeni^1,2, and Kawin Setsompop^4,5
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ²Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States, ³Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States, ⁴Department of Radiology, Stanford University, Stanford, CA, United States, ⁵Department of Electrical Engineering, Stanford University, Stanford, CA, United States

We introduced a novel imaging approach SE-EPTI to address the T2’-contamination in SE-EPI for higher specificity of BOLD fMRI. EPTI resolves multi-contrast distortion/blurring-free images to simultaneously obtain: a pure SE image with minimal T2’-contamination, multiple GE images with various T2’-weightings, and conventional SE-EPI images with different levels of T2’-contamination. We demonstrated at 7T that the pure SE can significantly reduce the draining-vein-effect, and by using shorter ETLs, less T2’-contamination was introduced. A new echo-train-shifting method is also proposed for SE-EPTI to offer flexibility of achieving shorter TEs, allowing us to examine the TE dependence of the signal contribution.

Nils Dennis Nothnagel¹, Alison Symon¹, Andrew Tyler Morgan^1,2, Renzo Huber³, John Riddell¹, and Jozien Goense^1
1Institute of Neuroscience & Psychology, University of Glasgow, Glasgow, United Kingdom, ²NIH, Bethesda, MD, United States, ³Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands

The most commonly used contrasts in laminar fMRI are blood-oxygen-level-dependent (BOLD) and vascular-space-occupancy (VASO). However, at laminar resolution, brain activity is often buried under noise, complicating the detection of small changes in activation.Here, we show the successful extraction of laminar brain activity of a complex-valued BOLD- and VASO-fMRI time series during a somatosensory task using NORDIC-PCA denoising. We expect this method to be a great asset for laminar sensory fMRI experiments as it reduces the need for anatomically informed smoothing or anisotropic filtering, which might be helpful for very small voxel sizes or when small activated areas are studied.

Yuhui Chai¹, Tina Liu¹, Sean Marrett¹, Linqing Li¹, Arman Khojandi¹, Daniel Handwerker¹, Arjen Alink², Lars Muckli³, and Peter Bandettini^1
1NIMH, Bethesda, MD, United States, ²University Medical Centre Hamburg-Eppendorf, Hamburg, Germany, ³University of Glasgow, Glasgow, United Kingdom

Multisensory interplay can occur in areas that are commonly considered unisensory, such as planum temporale (PT). The roles of different afferents to PT in multisensory processing are not well understood. Using sub-millimeter fMRI at 7T, we compared laminar activity patterns across topographical subfields of PT under unimodal and multisensory stimuli. We found (1) anterior PT was activated more by auditory inputs and received feedback in superficial layers, likely coming from higher-order multimodal areas; (2) posterior PT was preferentially activated by visual inputs and received visual feedback in both superficial and deep layers, likely projected directly from the early visual cortex.

SoHyun Han^1,2, HyungJoon Cho³, Kâmil Uludaǧ^1,2, and Seong-Gi Kim^1,2
1Center for Neuroscience Imaging Research, Suwon, Korea, Republic of, ²Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of, ³Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Korea, Republic of

Spatial-specificity is important for high spatial-resolution-fMRI to determine neuronal activity laminar-profiles. GE-BOLD-signals have low specificity because the highest signals originate from draining-veins at the surface of the cortex, not from capillaries nearby active neurons. However, SE-BOLD-signal has been proposed to be a better indicator of the location of neural activity. In this study, double SE-EPI-sequence was developed to achieve increased sensitivity in SE-BOLD-fMRI and demonstrated its feasibility for fMRI with 0.8-mm in-plane resolution. The results confirm that dSE-BOLD has higher specificity than GE-BOLD and better sensitivity than conventional-SE-BOLD and its potential to probe the function of cortical-circuits with high specificity.

Sebastian Dresbach¹, Renzo Huber¹, Rainer Goebel¹, and Amanda Kaas^1
1Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands

While inter-digit interactions are crucial for manual abilities like tool use or object manipulation, individual digits seem to be distinctly represented in the primary somatosensory cortex. Here, we used cortical depth-resolved high-resolution CBV-measurements to investigate these representations in the putative S1-subregion “BA3b” and depth-dependent temporal correlation during rest, as a potential index for layer-specific integration between digit representations. We found that we can

1. identify individual digit-representations in human subjects during stimulation using VASO
2.  show more specific depth profiles for VASO than BOLD
3.  see intrinsic interactions between digits at rest, which might be driven by deep-to-deep layer connections

Chencan Qian^1,2, Chengwen Liu³, Jinyou Zou⁴, Yan Zhuo^1,2, Sheng He^1,2,5, and Peng Zhang^1,2
1State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, ²University of Chinese Academy of Sciences, Beijing, China, ³Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China, ⁴Max-Planck-Institute for Biological Cybernetics, Tübingen, Germany, ⁵Department of Psychology, University of Minnesota, Minneapolis, MN, United States

Binocular rivalry is a unique window to study the neural correlates of consciousness. Where and how does binocular rivalry arise in the human brain remains an open question. Using laminar fMRI at 7T, we found that eye-specific modulation of BOLD signal peaked in the middle layer of primary visual cortex (V1) during simulated replay, but stronger in the superficial layer during rivalry. Furthermore, eye-specific modulation of lateral geniculate nucleus (LGN) activity was robust in the replay but minimal in the rivalry condition. These findings support that binocular rivalry mainly arises from interocular interaction in the superficial layer of V1.

Nikos Priovoulos¹, Icaro Agenor Ferreira de Oliveira¹, Benedikt Poser², David G Norris^3,4, and Wietske van der Zwaag^1
1Spinoza Center, Amsterdam, Netherlands, ²Maastricht University, Maastricht, Netherlands, ³Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands, ⁴Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany

BOLD-fMRI has transformed human neuroscience, but is limited in its spatial specificity compared to cerebral blood-volume approaches. Arterial-Blood-Contrast was recently suggested as a cerebral-blood-volume method based on Magnetization transfer. Here, we apply Arterial-Blood-Contrast in the SAR-constrained 7T environment and examine its submillimeter usage. The results suggest good localization compared to BOLD and high-sensitivity.

Hsin-Ju Lee^1,2, Pu-Yeh Wu¹, Hankyeol Lee³, Kamil Uludag^3,4, Hsiang-Yu Yu^5,6,7, Cheng-Chia Lee^6,7,8, Chien-Chen Chou^5,6, Chien Chen^5,6, Wen-Jui Kuo^7,9, and Fa-Hsuan Lin^1,2,10
1Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada, ²Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, ³Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Korea, Republic of, ⁴Techna Institute & Koerner Scientist in MR Imaging,, Joint Department of Medical Imaging and Krembil Brain Institute, University Health Network, Toronto, ON, Canada, ⁵Department of Epilepsy, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ⁶School of Medicine, National Yang-Ming University, Taipei, Taiwan, ⁷Brain Research Center, National Yang-Ming University, Taipei, Taiwan, ⁸Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ⁹Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan, ¹⁰Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland

We explored the correlation between cortical depth-dependent fMRI signal and oscillatory neural activity during music listening using high-resolution fMRI (7T with 0.8 mm and 3T with 1.5 mm isotropic resolution, respectively) and invasive electrode recording on epilepsy patients. The hemodynamic responses in the auditory cortex were found positively and negatively correlated with neural oscillations in the gamma and alpha/beta band at right and both hemispheres, respectively. These correlations were highest at the intermediate cortical depth. Core and non-core areas of the auditory cortex had different correlations.