Localized diffusion magnetic resonance micro-imaging of the live mouse brain.
High-resolution diffusion MRI (dMRI) is useful for resolving complex microstructures in the mouse brain, but technically challenging for in vivo studies due to the long scan time. In this study, selective excitation and a three-dimensional fast imaging sequence were used to achieve in vivo high-resolution dMRI of the mouse brain at 11.7Tesla. By reducing the field of view using spatially selective radio frequency pulses, we were able to focus on targeted brain structures and acquire high angular resolution diffusion imaging (HARDI) data at an isotropic resolution of 0.1mm and 30 diffusion encoding directions in approximately 1h. We investigated the complex tissue microstructures of the mouse hippocampus, cerebellum, and several cortical areas using this localized dMRI approach, and compared the results with histological sections stained with several axonal and dendritic markers. In the mouse visual cortex, the results showed predominately radially arranged structures in an outer layer and tangentially arranged structures in an inner layer, similar to observations from postmortem human brain specimens.
Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Dan
D
Wu
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Division of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD, USA.
Dominik
D
Reisinger
F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
Jiadi
J
Xu
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Division of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD, USA.
S Ali
SA
Fatemi
Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
Peter C M
PC
van Zijl
Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
Susumu
S
Mori
Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: jzhang3@jhmi.edu.
Jiangyang
J
Zhang
D000465:Algorithms; D000818:Animals; D001369:Axons / Q000502:physiology; D001921:Brain / Q000033:anatomy & histology*; D003712:Dendrites / Q000502:physiology; D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D005260:Female; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D059906:Neuroimaging / Q000295:instrumentation / Q000379:methods*; D012984:Software; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology