From cosmos to clinic: using Star Wars seismics for diagnosis and therapy

Ultrasonic imaging is becoming the most popular medical imaging modality, owing to the low price per examination and its safety. However, blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies. For perfusion imaging, markers have been designed to enhance the contrast in B-mode imaging. These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells. In his inaugural lecture presentation at the University of the Witwatersrand, Johannesburg, Professor Michiel Postema explained the physical principles of ultrasound contrast agent microbubble behaviour and their adjustment for drug delivery including sonoporation are described. It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition, and how these phenomena may be utilised in ultrasound-assisted therapy. Aided by high-speed photography and other futuristic toys, our improved understanding of encapsulated microbubble behaviour leads to more sophisticated detection and delivery techniques. As a consequence, pancreatic cancer is now being treated with a combination of microbubbles and sound. At the University of the Witwatersrand, several projects have been started on the manipulation of blood. Furthermore, so-called antibubbles have been tested for imaging and delivery. Curiously, several of the sonic drug delivery techniques presented are remarkably similar to some of the weapons in the Star Wars saga.