Transcranial Photoacoustic Imaging for Human Intracranial Pressure Evaluation

TL;DR

This paper introduces a multi-wavelength transcranial photoacoustic imaging system for noninvasive intracranial pressure assessment by visualizing cerebral artery oxygenation dynamics through the skull.

Contribution

It presents a novel multi-wavelength photoacoustic tomography method capable of imaging intracranial blood oxygenation and pressure changes through the human skull.

Findings

Successfully visualized oxygen saturation fluctuations in the MCA

Demonstrated system's ability to detect ICP-related vascular responses

Showed potential for noninvasive stroke and neurovascular diagnostics

Abstract

Photoacoustic imaging (PAI), by combining high optical contrast with ultrasonic resolution, offers a promising noninvasive approach for dynamic monitoring of cerebral vasculature. However, transcranial PAI still faces significant challenges due to strong attenuation of both optical and acoustic signals by the skull. In this study, we propose a multi-wavelength photoacoustic tomography system and method for intracranial pressure (ICP) assessment, enabling visualization of cross-sectional structures of the middle cerebral artery (MCA) through the human temporal bone. By utilizing multi-wavelength excitation in the near-infrared-I (NIR-I) window, quantitative maps of blood oxygen saturation ($\mathbf{sO_2}$) are reconstructed, and the relationship between oxygenation dynamics and ICP variations is established. Experimental results demonstrate that the proposed system can successfully capture dynamic $\mathbf{sO_2}$ fluctuations in the MCA despite skull attenuation, revealing its characteristic responses to ICP changes. This work provides a high-precision, noninvasive imaging tool for early stroke diagnosis, cerebral vascular function assessment, and neurointerventional guidance, highlighting the clinical translational potential of PAI in neuroscience.