# SORDINO-fMRI for mouse brain applications

> **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2024 · $609,429

## Abstract

PROJECT SUMMARY
 Gradient-recalled echo (GRE)–based echo planar imaging (EPI) has been the gold standard functional
magnetic resonance imaging (fMRI) technique for nearly three decades due to its ability to rapidly acquire whole
brain volumes with MR T2* sensitivity to blood oxygenation — a well-known surrogate marker for brain activity.
This immensely utilized technique, however, suffers from high acoustic noise, ghosting and motion artifacts,
magnetic field inhomogeneity–related artifacts, low sensitivity compared to other neuroimaging modalities, and
poor spatial specificity. An fMRI sampling technique that addresses these problems has the potential to change
day-to-day fMRI practices. In particular, such a development would be of great benefit to the emerging rodent
fMRI community as anesthesia and stress confounds can be avoided. Additionally, most rodent fMRI studies are
performed under high magnetic field strengths (> 7T), wherein susceptibility artifacts in GRE-EPI are
exacerbated. Imaging sequences with “zero” acquisition delay and minimal increment of gradients are insensitive
to problems stated above and have the potential to provide superior specificity and sensitivity compared to GRE-
EPI-fMRI. The overarching goal of this project is to advance, validate, and disseminate a novel 3D brain-
wide imaging sequence: Steady-state On-the-Ramp Detection of INduction-decay signal with Oversampling
(SORDINO) for the preclinical animal fMRI community. In addition, we will investigate SORDINO contrast
mechanisms and explore a contrast-enhanced method that may further augment SORDINO sensitivity. Our
developments will be benchmarked in mice, wherein a head-fixation approach can be utilized to image mice in
an awake condition. In Aim 1, we will develop and disseminate the SORDINO sequence and reconstruction
package in a preclinical animal MRI platform. In Aim 2, we will inform the most robust imaging parameters and
benchmark them against modeled SORDINO performance and GRE-EPI-fMRI and zero echo time (ZTE)-fMRI
data. This will facilitate future SORDINO-fMRI applications and enable new capabilities to study large-scale,
functionally and behaviorally relevant brain networks in awake mice. In Aim 3, we will examine the SORDINO
contrast mechanisms using MR-compatible invasive recordings, which are crucial for data interpretation. The
contrast mechanisms, if proven to be local tissue oxygenation, cerebral blood flow, and cerebral blood volume,
will clarify SORDINO as a spatially specific approach for functional brain mapping. In Aim 4, we will leverage the
expected sensitivity gain of SORDINO at shorter baseline T1 values and use a simple manganese-enhanced
MRI (MEMRI) strategy, a method widely utilized by many preclinical MRI labs, to further augment awake mouse
SORDINO-fMRI sensitivity. Overall, we expect the knowledge and deliverables in this work to have widespread
implications and will significantly advance fMRI technologies. We also expect this w...

## Key facts

- **NIH application ID:** 10894102
- **Project number:** 5R01EB033790-02
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Yen-Yu Ian Shih
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $609,429
- **Award type:** 5
- **Project period:** 2023-08-01 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10894102

## Citation

> US National Institutes of Health, RePORTER application 10894102, SORDINO-fMRI for mouse brain applications (5R01EB033790-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10894102. Licensed CC0.

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