# Transcranial Photoacoustic Imaging Using a Virtual Array

> **NIH NIH R21** · PENNSYLVANIA STATE UNIVERSITY, THE · 2020 · $455,226

## Abstract

Abstract
Human brain mapping has become one of the most exciting contemporary research areas, with major
breakthroughs expected in the following decades. Modern brain imaging techniques have allowed
neuroscientists to gather a wealth of anatomic and functional information about the brain. Among these
techniques, by virtue of its rich optical absorption contrast, high spatial and temporal resolutions, and relatively
deep penetration, photoacoustic tomography (PAT) has attracted substantial attention, and is playing an
increasingly important role in brain studies. In particular, PAT complements other brain imaging modalities by
providing high-resolution functional and metabolic imaging. More importantly, PAT’s unique scalability enables
scrutinizing the brain at both microscopic and macroscopic scales, using the same imaging contrast.
However, to bring PAT to studying human subjects or non-human primates, one critical issue must be addressed.
That is, the human or non-human primate skulls severely distort the photoacoustic (PA) signals, giving rise to
substandard images. Time-reversal based reconstruction is considered one of the most accurate and
sophisticated reconstruction algorithms for transcranial PAT. Time-reversal based methods are capable of
correcting for both the phase and amplitude distortions due to the skull when imaging the brain. However, this
method is slow, which presents a significant hurdle to the application of real-time functional imaging. Here, we
propose to develop an innovative virtual array approach for achieving accurate and real-time transcranial PAT
to image the brain cortex of non-human primates and humans. Instead of using the actual PA signals for image
reconstruction, we propose to use virtual signals received by a virtual array situated inside the skull, which is
considerably less affected by the skull. This can be implemented in real-time as a propagator (also known as the
propagation operator) can be pre-computed. The specific tasks to be completed during this grant period are:
First, develop and validate the virtual array algorithm for transcranial PAT using synthetic data, second, verify
our new method experimentally on a full-ring-array based PAT system, using head-mimicking phantoms coupled
with an ex vivo monkey skull.
At the end of this project we would have confirmed the effectiveness of the proposed virtual array approach. The
results from this project will provide a route for probing brain cortex functions in a highly efficient and accurate
manner and pave the way for future applications of this novel PAT technique.

## Key facts

- **NIH application ID:** 9984718
- **Project number:** 1R21EB027981-01A1
- **Recipient organization:** PENNSYLVANIA STATE UNIVERSITY, THE
- **Principal Investigator:** Yun Jing
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $455,226
- **Award type:** 1
- **Project period:** 2020-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9984718

## Citation

> US National Institutes of Health, RePORTER application 9984718, Transcranial Photoacoustic Imaging Using a Virtual Array (1R21EB027981-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9984718. Licensed CC0.

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