Real-time optoacoustic tracking of single moving micro-objects in deep tissue-mimicking phantoms

TL;DR

This paper demonstrates real-time tracking of single micro-objects beneath tissue-mimicking phantoms using multispectral optoacoustic tomography, enhanced by gold nanorod coatings for improved contrast and specificity.

Contribution

First demonstration of real-time optoacoustic tracking of moving micro-objects in deep tissue-mimicking phantoms with spectral discrimination capabilities.

Findings

Successful tracking of micro-objects below 1 cm tissue phantoms

Enhanced contrast using gold nanorods on micro-objects

Potential for in vivo applications in targeted diagnostics

Abstract

Medical imaging plays an important role in diagnosis and treatment of multiple diseases. It is a field under continuous development which seeks for improved sensitivity and spatiotemporal resolution to allow the dynamic monitoring of diverse biological processes that occur at the micro- and nanoscale. Emerging technologies for targeted diagnosis and therapy such as nanotherapeutics, micro-implants, catheters and small medical tools also need to be precisely located and monitored while performing their function inside the human body. In this work, we show for the first time the real-time tracking of moving single micro-objects below centimeter thick tissue-mimicking phantoms, using multispectral optoacoustic tomography (MSOT). This technique combines the advantages of ultrasound imaging regarding depth and resolution with the molecular specificity of optical methods, thereby facilitating the discrimination between the spectral signatures of the micro-objects from those of intrinsic tissue molecules. The resulting MSOT signal is further improved in terms of contrast and specificity by coating the micro-objects surface with gold nanorods, possessing a unique absorption spectrum, which will allow their discrimination from surrounding biological tissues when translated to in vivo settings.