Grant: Doctoral: Vanier Canada Graduate Scholarships

Micro-bubbles (MBs) are used to increase the sensitivity of diagnostic ultrasound in detecting cancer. They can also be used as to deliver drugs and genes to tumors. However, how the micro-bubbles respond to ultrasound is poorly understood, especially at higher frequencies of ultrasound. As an example, high frequency clinical ultrasonic imaging (e.g >10 MHz) still cannot produce good ultrasound images with MBs. Understanding the how the MBs respond to ultrasound excitation, especially at higher frequencies, is the key to optimize how MBs are used for imaging but also therapy. I will investigate both theoretically and experimentally the dynamics of MBs at higher frequencies. Previously, I developed efficient experimental and theoretical methods for analyzing the behavior of single MBs. Using these methods we discovered new phenomena in the oscillations of MBs at higher frequencies that were not known before. The new oscillatory behavior of the MBs allows much better approaches to ultrasound imaging and therapy. In this research I will continue my theoretical and experimental investigations on the oscillations of MBs by extending the MB model to MBs confined within elastic walls to replicate the dynamics of MBs within small blood vessels. Our discovery of the new MB dynamics will be used in phantom experiments and in in-vivo models to investigate the improvements expected in clinical settings. We believe that our findings will have significant impact on improving the ultrasound technology used to acquire contrast enhanced images at higher resolution. This may allow early detection of cancer and monitoring of the response of the tumors to treatments. In addition, we expect these findings to improve drug delivery applications of ultrasound. The end goal will be a cost effective, portable, real-time, minimally invasive and nonionizing platform for cancer detection and therapy.