Tissue engineering is an interdisciplinary field that combines various aspects of engineering and life sciences and aims to develop biological substitutes to restore, repair or maintain tissue function. Currently, the ability to have quantitative functional assays of engineered tissues is limited to existing invasive methods like biopsy. Hence, an imaging tool for non-invasive and simultaneous evaluation of the anatomical and functional properties of the engineered tissue is needed. In this paper we present an advanced in-vivo imaging technology - ultrasound biomicroscopy combined with complementary photoacoustic and elasticity imaging techniques, capable of accurate visualization of both structural and functional changes in engineered tissues, sequential monitoring of tissue adaptation and/or regeneration, and possible assistance of drug delivery and treatment planning. The combined imaging at microscopic resolution was evaluated on tissue mimicking phantoms imaged with 25 MHz single element focused transducer. The results of our study demonstrate that the ultrasonic, photoacoustic and elasticity images synergistically complement each other in detecting features otherwise imperceptible using the individual techniques. Finally, we illustrate the feasibility of the combined ultrasound, photoacoustic and elasticity imaging techniques in accurately assessing the morphological and functional changes occurring in engineered tissue.
A hybrid imaging system is proposed for cancer detection, diagnosis and therapy monitoring by integrating three complementary imaging techniques - ultrasound, photoacoustic and elasticity imaging. Indeed, simultaneous imaging of the anatomy (ultrasound imaging), cancer-induced angiogenesis (photoacoustic imaging) and changes in biomechanical properties (elasticity imaging) of tissue is based on many synergistic features of these modalities and may result in a unique and important imaging tool. To facilitate the design and development of a real-time imaging system for clinical applications, we have investigated the core components of the imaging system using numerical simulations. Differences and similarities between each imaging technique were considered and contrasted. The results of our study suggest that the integration of ultrasound, photoacoustic and elasticity imaging is possible using a custom designed imaging system.