Label free visualization of amyloid plaques in Alzheimer's disease with polarization-sensitive photoacoustic Mueller matrix tomography

TL;DR

This paper introduces a novel label-free photoacoustic Mueller matrix tomography technique for 3D in vivo imaging of amyloid plaques in the brain, aiding early Alzheimer's disease detection.

Contribution

It develops a new PAMM imaging method that captures polarization-sensitive optical absorption to visualize amyloid plaques without labels.

Findings

Successful in vivo imaging of amyloid plaques in transgenic mice.

Provides depth-resolved, 3D detection of plaques.

Potential for early AD diagnosis and monitoring.

Abstract

The formation of amyloid plaques in the cortical and hippocampal brain regions caused by abnormal deposition of extracellular amyloid \b{eta}-protein (A\b{eta}) is a characteristic pathological hallmark of early Alzheimer's disease (AD), while label-free graphic rendering of diseased amyloid plaques in vivo is still a highly challenging task. Herein, by ingeniously extracting the polarization-sensitive optical absorption of amyloid plaques via photoacoustic (PA) technique, a novel PA Mueller matrix (PAMM) tomography that capable of providing three new conformational parameters of molecules is developed to realize depth-resolved label-free imaging of amyloid plaques. Whole brain PAMM imaging on different stages of APP/PS1 transgenic AD mice has been performed to demonstrate its ability for in situ/in vivo quantitative three-dimensional (3D) detection of amyloid plaques and its great potential for monitoring early AD pathological development without labeling.