# Highly parallel long wavelength heterodyne diffuse correlation spectroscopy for brain functional imaging

> **NIH NIH R01** · MASSACHUSETTS GENERAL HOSPITAL · 2022 · $857,735

## Abstract

PROJECT SUMMARY
Non-invasive imaging of human brain function plays an important role in advancing neuroscience research and
understanding neurological diseases. This need has been met primarily by functional magnetic resonance
imaging (fMRI). fMRI, though powerful, is an expensive technique that is not suitable for subjects who cannot
tolerate small spaces or cannot stay still (e.g. children, psychiatric disorders), and cannot be used for tasks that
require subjects to interact with a natural environment, or for tasks that conflict with the scanner noise, e.g.
auditory studies. In this context, functional near-infrared spectroscopy (fNIRS) has emerged as an alternative
neuroimaging modality with the same physiological basis as fMRI (dynamic changes in hemoglobin
concentration as a result of neural activation). A more recently developed technique, diffuse correlation
spectroscopy (DCS), shares many of the advantages of fNIRS, while also providing a fundamentally different
functional imaging approach through its ability to directly measure blood flow. DCS is substantially more
sensitive than NIRS to cerebral blood flow due to the 6x brain vs. scalp perfusion ratio. we propose to develop
a multi-channel, compact, inexpensive and scalable functional DCS (fDCS) system with dramatically improved
performance vs. fNIRS systems. To this end we will leverage recent advances in long-wavelength (1064 nm)
DCS (proposed by our group and demonstrated to bring a 10x SNR improvement vs. DCS at typical NIR
wavelengths) in combination with a camera based, interferometric multi-speckle detection approach that offers
another 1-2 order of magnitude increase in signal to noise performance without the need for photon counting
detectors. We term this approach long-wavelength multi-speckle functional interferometric DCS (LW-mifDCS).

## Key facts

- **NIH application ID:** 10479451
- **Project number:** 1R01EB033202-01
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **Principal Investigator:** Stefan Alexandru Carp
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $857,735
- **Award type:** 1
- **Project period:** 2022-09-19 → 2026-03-18

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10479451

## Citation

> US National Institutes of Health, RePORTER application 10479451, Highly parallel long wavelength heterodyne diffuse correlation spectroscopy for brain functional imaging (1R01EB033202-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10479451. Licensed CC0.

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