Photoacoustic imaging is a hybrid technology to visualize optical absorption contrast using ultrasound. Optical absorption carries chemical specificity, but usually cannot be precisely located at depth because of scattering. Ultrasound, on the other hand, can see deeply into tissue but provides mostly morphological imaging. Photoacoustics provides the best of both by creating images using the pressure wave generated upon absorption of a short light pulse. Thus, it enables detailed mapping of functional information, tissue composition, and other potentially useful parameters for diagnostic and interventional applications, up to several centimeters in depth, using an echo-like imaging approach. This lecture will review the opportunities provided by photoacoustic imaging and some recent achievements. It will focus in particular on the opportunities for guidance of minimally invasive interventions, in the cardiovascular system and elsewhere. In my group, we have developed catheter-based imaging technologies for use in the heart and arteries, targeting therapy monitoring and tissue characterization in atherosclerotic plaques. I will discuss the relevant spectroscopic contrast, and preclinical data supporting the application of intravascular photoacoustic imaging in interventional treatment of coronary artery disease.
Prof. Dr. Gijs van Soest is a group leader at the Erasmus MC, University Medical Center in Rotterdam, The Netherlands. His research field lies at the intersection of imaging physics, device engineering and cardiovascular medicine. He was trained as a physicist and has been working with optical spectroscopy and light scattering since his PhD at the University of Amsterdam. A brief stint in remote sensing of atmospheric ozone steered his interests to application-oriented research. Since 2005 he has been active in the field of coronary and cardiac imaging, using invasive imaging devices. He has worked with optical coherence tomography, photoacoustics and ultrasound to characterize atherosclerosis and myocardial tissue. Broadly, his research portfolio consists of the development of new techniques and instruments for intravascular and invasive imaging, and adding value to data obtained by existing clinical imaging instruments by extracting relevant features and contrast. His work in intravascular photoacoustics led to the foundation of a spin-off company, Kaminari Medical, a start-up company that is developing this principle to a clinical reality. He is also associated with Delft University of Technology's Department of Precision Microsystems Engineering, at the Faculty of Mechanical Engineering. Here, he explores novel manufacturing and design technologies to power his medical device research. He teaches in the medicine and clinical technology bachelor programs at Erasmus MC, and lectures at a range of summer and graduate schools worldwide. He believes that biophotonics is a technology for all humans, which means the fields needs a broad range of perspectives and experiences so that its technologies work for all of us, and leave no-one behind. Professor Van Soest is now a visiting scholar at the Wellman Center for Photomedicine at Massachusetts General Hospital and Harvard Medical School until late 2023.