# Accelerated Rosette Trajectories- Based 5D MR Spectroscopic Imaging AND MR Imaging of Myelin Fraction in Perinatally HIV-Infected Adults

> **NIH NIH R21** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 2024 · $415,876

## Abstract

PROJECT SUMMARY
Better understanding is needed regarding the mechanism of HIV pathogenesis to the developing brain in
individuals receiving longstanding antiretroviral therapy (ART). Despite the use of ART, brain abnormalities
occur in people living with HIV, especially among individuals with perinatally-acquired HIV (pHIV) where
abnormalities are frequently prevalent. Myelin water imaging (MWI) is generally regarded as the most rigorous
approach for noninvasive, in-vivo measurement of myelin content. Noninvasive neuroimaging tools can assess
the effectiveness of ART in preserving brain health and possibly lead to improvements in therapy. During the
past three decades, it has been demonstrated that one-dimensional (1D) MR Spectroscopy (MRS) enables the
study of only selected cerebral metabolites due to limited spectral dispersion even with 3 Tesla MRI scanners.
Recently, our group, using the home-developed two-dimensional (2D) localized correlated spectroscopy (L-
COSY) sequence combined with the prior-knowledge fitting (ProFit) algorithm showed that several cerebral
metabolites can be quantified non-invasively in the prefrontal dorsolateral white matter region of perinatally HIV-
infected youth and healthy children including novel metabolites such as glutathione (GSH), aspartate (Asp) and
scyllo-inositol (sI). However, there were limitations due to the requirement of a 27 ml voxel and longer acquisition
times. Hence, a novel five-dimensional (5D) echo-planar J-resolved spectroscopic imaging (EP-JRESI)
sequence was recently implemented by our group where two spectroscopic dimensions were combined with
three spatial dimensions to study the cerebral metabolite changes in pediatric HIV, with findings reported recently
(5R21NS086449-02). However, a total duration of approximately 25 minutes of scan time was necessary. Using
a modified rosette trajectory that densely samples both central and peripheral k-space, further
acceleration and robustness to motion can be accomplished in MRSI and MRI as compared to other non-
cartesian trajectories like radial, which will minimize patient discomfort by significantly reducing the
scan time. Hence, the proposed study will test the following hypotheses: 1) The accelerated 5D rosette
trajectories-based J-resolved Spectroscopic Imaging (ROSE-JRESI) and MWI with compressed sensing (CS)-
based reconstruction will shorten the total acquisition duration, improving its clinical applicability while the 5D
ROSE-JRESI data will also offer improved spatial resolution. 2) In the brains of pHIV young adults, decreased
axonal myelination is present even in virally suppressed individuals correlating with worse neurocognitive
performance (gross motor impairment) and altered metabolites. We propose two specific aims: 1) To optimize
5D ROSE-JRESI and 3D MWI on a 3T MRI scanner, and further optimize the CS-based reconstruction of the
5D MRSI and 3D MWI data using home developed MATLAB codes; 2a) To acquire multi-voxel 2D J-resolved...

## Key facts

- **NIH application ID:** 10924712
- **Project number:** 1R21NS134488-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **Principal Investigator:** MICHAEL Albert THOMAS
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $415,876
- **Award type:** 1
- **Project period:** 2024-08-01 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10924712

## Citation

> US National Institutes of Health, RePORTER application 10924712, Accelerated Rosette Trajectories- Based 5D MR Spectroscopic Imaging AND MR Imaging of Myelin Fraction in Perinatally HIV-Infected Adults (1R21NS134488-01A1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10924712. Licensed CC0.

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