Shruti Mishra^1,2, Bin Deng^2,3,4, W. Scott Hoge^1,2,3, Yanmei Tie^2,5, Giacomo Annio⁶, Ralph Sinkus⁶, and Samuel Patz^1,2
1Radiology, Brigham & Women's Hospital, Boston, MA, United States, ²Harvard Medical School, Boston, MA, United States, ³Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ⁴Radiology, Massachusetts General Hospital, Boston, MA, United States, ⁵Neurosurgery, Brigham & Women's Hospital, Boston, MA, United States, ⁶Laboratory for Vascular Translational Science (LVTS), Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France

A stimulus-interleaved magnetic resonance elastography (MRE) sequence was utilized to demonstrate fast functionally mediated localized changes in shear wavelength during a motor task. Four healthy adult subjects underwent a visual-cue mediated right-hand finger-tapping task, switching between tapping and no-tapping blocks every 2 seconds. Areas of greatest significance between the stimulus states were localized to the left primary motor cortex. A decreased stiffness of ~30% was observed during task performance compared to rest. Compared to traditional BOLD fMRI with a 20-second block, functional MRE areas of greatest statistical difference demonstrated greater percentage change and greater spatial localization.

Nikos Priovoulos¹, Mads Andersen^2,3, Vincent Oltman Boer⁴, and Wietske van der Zwaag^1
1Spinoza Center for Neuroimaging, Amsterdam, Netherlands, ²Philips Healthcare, Copenhagen, Denmark, ³Lund University Bioimaging Center, Lund University, Lund, Sweden, ⁴Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark

The cerebellum is an important but challenging to image part of the human brain, due to its thin and highly-folded cortex. Here we demonstrate that using motion-corrected high-resolution 7T-MRI data, we can derive segmentations and surfaces of the cerebellar cortex with unprecedented accuracy in vivo. We expect this technique to greatly facilitate cognitive and clinical neuroscience research in the cerebellum.

Dana Yacobi¹, Amir Seginer², and Rita Schmidt^1
1Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel, ²Siemens Healthcare Ltd, Rosh Ha’ayin, Israel

Quantitative T₂ mapping is an important tool towards standardization of MRI in clinics and research, whose implementation in 7T MRI will gain SNR and resolution. In this work, we demonstrate a phase-based method with fast 3D spoiled GRE acquisition to estimate T₂ and B₁ maps in 7T brain imaging. We introduce a new approach employing a dual steady-state with interleaving flip angles - denoted as TWISTARE. This approach is suited to address the RF field inhomogeneity in 7T and can shorten the total scan duration. The new approach was examined using a 3D head-shaped phantom and in human imaging.

Rüdiger Stirnberg¹, Andreas Deistung², and Tony Stöcker^1,3
1German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany, ²University Clinic and Outpatient Clinic for Radiology, University Hospital Halle (Saale), Halle, Germany, ³Department of Physics and Astronomy, University of Bonn, Bonn, Germany

We propose a dual-polarity readout technique to eliminate residual segmentation artifacts in interleaved multi-shot EPI despite established echo time shifting. The method only requires retrospective averaging of two or more complex-valued images acquired with alternating EPI readout polarity across measurements. The approach has been integrated into a custom skipped-CAIPI 3D-EPI sequence, combining highly segmented EPI with CAIPIRINHA parallel imaging. We present dual-polarity skipped-CAIPI 3D-EPI for ultrahigh-resolution, rapid, motion-robust whole-brain T₂*-weighted imaging and quantitative susceptibility mapping at 7 Tesla. We demonstrate its capability to acquire exquisite imaging contrast at 0.7mm and 0.4mm isotropic resolution in only 1:15 and 6:14 [min:s], respectively.

Eleonora Patitucci¹, Michael Germuska¹, Valentina Tomassini^2,3,4,5,6, and Richard G Wise^1,2,3
1School of Psychology, CUBRIC, Cardiff University, Cardiff, United Kingdom, ²Department of Neuroscience, Imaging and Clinical Sciences, University “G. d'Annunzio” of Chieti-Pescara, Chieti, Italy, ³Institute for Advanced Biomedical Technologies, University “G. d'Annunzio” of Chieti-Pescara, Chieti, Italy, ⁴MS Centre, Neurology Unit, “SS. Annunziata” University Hospital, Chieti, Italy, ⁵Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, United Kingdom, ⁶Helen Durham Centre for Neuroinflammation, University Hospital of Wales, Cardiff, United Kingdom

The role of cortical myelin for cortical function is still under debate. Here we investigate the relationship between cortical myelination (represented by R1) and functional activation (represented by BOLD-fMRI and arterial spin labelling CBF signals) during the execution of a motor task. We demonstrate associations between cortical myelination and functional activity in a subset of task-responding regions. We observe a decrease of the significance of these relationships in the deeper cortical layers.

Subin Lee¹, Hyeong-Geol Shin¹, and Jongho Lee^1
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of

The in-vivo imaging of iron and myelin concentrations along cortical laminae in the brain has significance in advancing knowledge about the roles of iron and myelin in brain function and in disease. In this study, we apply χ-separation, a recently developed advanced susceptibility imaging method, to explore changes in iron and myelin content throughout the cortex and into the white matter. Our findings show that iron and myelin peak at different laminar surfaces and that there is regional differences in the intensity profiles. The results suggest regional and laminar variation of iron and myelin throughout the brain.

Jordi P.D. Kleinloog^1,2, Stefano Mandija^1,2, Federico D'Agata³, Oscar van der Heide^1,2, Beyza Koktas¹, Sarah M. Jacobs⁴, Cornelis A.T. van den Berg^1,2, Jeroen Hendrikse², Anja G. van der Kolk², and Alessandro Sbrizzi^1,2
1Computational Imaging Group for MR diagnostic and therapy, Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands, ²Department of Radiotherapy, University Medical Centre Utrecht, Utrecht, Netherlands, ³Department of Neurosciences, University of Turin, Turin, Italy, ⁴Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, Utrecht, Netherlands

Magnetic Resonance Spin TomogrAphy in Time-domain (MR-STAT) reconstructs multiple quantitative MR parameters from a single fast scan. This quantitative information can be leveraged for several purposes, including the synthetization of clinically desired image contrasts. Preliminary results of the first clinical trial using MR-STAT in patients with neurological diseases show that the synthetically generated contrast images (i.e., T1w, T2w, PDw and FLAIR) were acceptable for diagnostic use (5-point Likert scale ≥ 3), although the score was lower compared to conventional contrasts. This highlights the potential of MR-STAT to provide synthetic contrasts on top of quantitative maps, while reducing scan time.