Improving visibility in photoacoustic imaging using dynamic speckle illumination

TL;DR

This paper demonstrates that dynamic speckle illumination enhances visibility of otherwise invisible structures in high-frequency photoacoustic imaging, enabling detection of complex shapes and small features.

Contribution

The study introduces a novel approach using dynamic speckle illumination to reveal hidden photoacoustic features, improving imaging of large or limited-view structures.

Findings

Successfully imaged a 5 mm absorbing cylinder

Detected a 30 micrometer black thread

Enhanced visibility of complex shapes

Abstract

In high-frequency photoacoustic imaging with uniform illumination, homogeneous photo-absorbing structures may be invisible because of their large size or limited-view issues. Here we show that, by exploiting dynamic speckle illumination, it is possible to reveal features which are normally invisible with a photoacoustic system comprised of a 20MHz linear ultrasound array. We demonstrate imaging of a 5 mm diameter absorbing cylinder and a 30 micrometer black thread arranged in a complex shape. The hidden structures are directly retrieved from photoacoustic images recorded for different random speckle illuminations of the phantoms by assessing the variation in the value of each pixel over the illumination patterns.