Tri-modality ultrasound imaging system: Design and phantom experiment results

Most pathological processes due to disease, transplantation, or implantation of engineered tissue constructs result in complex changes to tissue. These changes can lead to morphological, compositional, mechanical, and functional differences which can be used for diagnosis, treatment strategies, and progress monitoring. Technological advances in ultrasound imaging including photoacoustic imaging, shear wave elasticity imaging, and ultrasound thermal strain imaging allow the assessment of these changes. In a manner similar to co-registration of positron emission tomography and computed tomography images, co-registration of these disparate images might help to more accurately localize and identify pathological changes to tissue structure and function. This study presents and evaluates the first non-invasive hybrid ultrasound imaging system that incorporates photoacoustic imaging, shear wave elasticity imaging, and ultrasound thermal strain imaging. In co-registered images using a single probe, the tri-modality system successfully detected an indocyanine green dyed gelatin inclusion, a stiff gelatin inclusion, and a rubber inclusion (mimicking lipid-based tissue).