Development of the Human Dynamic Neurochemical Connectome Scanner

Project Summary
We seek support to develop and build the next generation 7-Tesla magnetic resonance (MR)-compatible
positron emission tomography (PET) brain scanner with dramatically improved spatiotemporal resolution
(HSTR-BrainPET). 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. However, there is no equivalent dedicated head device
on the market to address the needs of the researchers and clinicians focusing on the brain and the
performance of whole-body devices is rather limited for this purpose. More importantly, although current PET
technology achieves high molecular sensitivity with a broad set of probes for neurochemical targets, PET still
lacks the capability to track dynamic changes in a time scale comparable to functional processes. Our main
goal is to build an MR-compatible PET camera with very high sensitivity to enable truly dynamic PET imaging
of brain neurotransmission. One of the first MR-compatible brain PET prototypes was installed at the Martinos
Center in 2008 when human PET/MR imaging was in its infancy. Following a close collaboration with Siemens
to address the remaining technical challenges, proof-of-principle PET/MR studies demonstrating the
advantages and potential of this novel imaging modality were performed. A decade later, a new type of photon
detector technology has reached a level of maturity that would allow us to build the next generation integrated
system with dramatically improved spatiotemporal resolution. We propose to address the hardware and
software challenges in building 7-T MR-compatible PET technology purpose-built to extend the temporal
window of PET down to just a few seconds. Additionally, the substantial improvement in spatial resolution will
also allow for imaging of cortical substructures and nuclei that cannot be resolved with current state-of-the-art
devices. Specifically, we propose to: (1) Build the hardware components of the HSTR-BrainPET insert,
integrate it with the 7-T MR scanner and characterize the combined device; (2) Implement the software for PET
data acquisition, processing and image reconstruction adapted to the non-conventional geometry we are
proposing; (3) Apply the integrated scanner to dynamic assessment of neurochemical events and brain
activation in healthy human subjects.
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Grant Number: 5U01EB029826-05
NIH Institute/Center: NIH
Principal Investigator: Ciprian Catana