Neuroimaging Technologies Across Scales

Abstract/Project Summary Blood oxygenation level dependent (BOLD) fMRI is widely used in neuroscience studies. Technical advancement in the recently years has enabled BOLD signals to be acquired at sub-second temporal resolution, opening a new window for examining functional dynamics of the human brain, e.g. resting- state fMRI. The BOLD signal originates from the mismatch between cerebral blood flow (CBF) and metabolism changes, and is complex; it serves as an indirect measure of neural activities.

Abstract The overall goal of this research is to develop next generation positron emission tomography (PET) detector technology to support non-invasive, quantitative brain imaging at spatial and temporal resolutions currently not achievable with human neuro-PET systems. The developed PET detector technology will also be compatible with operation in an MRI system.

PROJECT SUMMARY/ABSTRACT An innovative head-only 7T MRI system that delivers spatial resolution that is difficult to achieve with today's whole-body 7T systems, and has the footprint and weight of a whole-body 3T scanner is proposed. This new im- aging system combines a high-performance asymmetrical head gradient that delivers 130 mT/m and 900 T/m/s performance in an actively shielded, low-cryogen, lightweight head-only 7T magnet.

Project Summary: High SNR Functional Brain Imaging using Oscillating Steady State MRI Functional brain imaging using MRI (functional MRI or fMRI) has grown rapidly over the past 25 years and is widely used for basic cognitive neuroscience research and for presurgical planning. It is increasingly being used for developing biomarkers for neurological and psychiatric disorders and for population based studies of, for example, normal and abnormal development and aging.

PROJECT SUMMARY    Understanding how neural circuits operate and interconnect at mesoscopic (sub-­millimeter) scale, and how  neuroenergetic  metabolism  and  neurotransmitters  support  brain  function  at  resting  and  working  state  is  essential to brain research and 

PROJECT SUMMARY The goal of this research project is to determine if it is possible to develop a PET radiotracer capable of imaging GPCR heterodimers and not their corresponding homodimeric complexes. GPCR heterodimers represent the functional state of these receptors, yet there is currently no method for imaging these receptors in vivo with PET. Our initial strategy will focus on the development of probes for imaging the dopamine D2- adenosine A2A (i.e, D2/A2A) heterodimer.

Project Summary Molecular imaging provides the means to quantitatively study many types of processes in the human brain in a minimally invasive manner. However, the complexity of the brain results in many instances in which it is desirable to be able to study more than one property simultaneously, such as measuring neuroreceptor binding at the same time as transporters or cerebral perfusion together with receptor occupancy. While one option for doing so in some cases may be to use multiple modalities (e.g.

Project Summary We seek support to develop and build the positron emission tomography (PET) detector module for the next generation 7-Tesla magnetic resonance (MR)-compatible PET brain scanner with dramatically improved spatio-temporal resolution. PET and MRI are two of the most powerful imaging modalities currently in use for studying the human brain. Recently, scanners capable of simultaneous PET and MR whole-body data acquisition in human subjects have become commercially available.

SUMMARY We present Connectome 2.0, the next-generation human MRI scanner for imaging structural anatomy and connectivity spanning the microscopic, mesoscopic and macroscopic scales. This work builds upon our expertise in engineering the first human Connectome MRI scanner with 300 mT/m maximum gradient strength (Gmax), the highest ever achieved for a human system, for the Human Connectome Project (HCP). The goal of the HCP was to map the macroscopic structural connections of the in vivo healthy adult human brain using diffusion tractography.

Project Summary/Abstract A more thorough understanding of human brain function has profound implications for advancing neuroscience research and combatting neurological disease. Despite tremendous progress towards this goal through contemporary neuroimaging techniques, a number of challenges remain unaddressed, such as a lack of safe and non-invasive imaging modalities for continuous brain function assessments, limited spatiotemporal resolution in in vivo imaging of human brain dynamics, and suboptimal accuracy due to improper consideration of complex 3D brain anatomy.