Design and Demonstration of a Configurable Imaging Platform for Combined Laser, Ultrasound, and Elasticity Imaging

Abstract

This paper introduces a configurable combined laser, ultrasound, and elasticity (CLUE) imaging platform. The CLUE platform enables imaging sequences capable of simultaneously providing quantitative acoustic, optical, and mechanical contrast for comprehensive diagnosis and monitoring of complex diseases, such as cancer. The CLUE imaging platform was developed on a Verasonics ultrasound scanner integrated with a pulsed laser, and it was designed to be modular and scalable to allow researchers to create their own specific imaging sequences efficiently. The CLUE imaging platform and sequence were demonstrated in a tissue-mimicking phantom containing a stiff inclusion labeled with optically-activated nanodroplets and in an ex vivo mouse spleen. We have shown that CLUE imaging can simultaneously capture multi-functional imaging signals providing quantitative information on tissue.

Fig. 1.

Block diagram of an overall imaging set-up with integrated ultrasound and laser systems.

Fig. 2.

Design and execution process of an imaging sequence using the CLUE imaging platform. All imaging modules here are uniquely color-coded for better visualization of them for the rest of the paper.

Fig. 3.

A diagram showing the role of the CLUE imaging platform in interfacing users and Verasonics software and hardware.

Fig. 4.

A proposed CLUE imaging sequence including 5 sets of pre-laser US, PA, and post-laser US imaging sequences (blue rectangle) as a function of optical fluence and three sets of SWEI sequences (red rectangle). Two pre-laser US, one PA, and 20 post-laser US images were repeatedly and serially acquired with increasing optical fluence.

Fig. 5.

Processed pre-laser US, PA, post-laser US, and US images as a function of optical fluence obtained from the tissue-mimicking gelatin phantom.

Fig. 6.

Means and SDs of PA signals obtained inside and outside of the inclusion as a function of optical fluence.

Fig. 7.

Means and SDs of US signals obtained inside and outside of the inclusion as a function of optical fluence.

Fig. 8.

Estimated axial velocity sequences visualizing the propagation of the shear waves generated at three lateral locations in the gelatin phantom and three corresponding SWV maps.

Fig. 9.

Processed pre-laser US, PA, post-laser US, and ΔUS images as a function of optical fluence. The images were obtained from the ex vivo mouse spleen embedded in gelatin phantom.

Fig. 10.

Estimated axial velocity sequences visualizing the propagation of the shear waves generated at three lateral locations in the phantom embedding the ex vivo mouse spleen and three corresponding SWV maps.