The central theme of our research is the use of nanoparticles to measure cells and proteins. We are currently focused on ultrasound. While ultrasound is well known for monitoring fetal development, it is also routine in cardiology and oncology. Ultrasound uses the inherent differences in tissue density to create contrast. While these innate density differences are perfect to image anatomy, a subset of research known as molecular imaging uses a contrast agent to image—and thus measure—function.
A special type of ultrasound is known as photoacoustic imaging. Photoacoustic imaging combines the contrast of optical imaging with the depth of penetration and high resolution of ultrasound. The signal increase that is achievable with photoacoustic imaging is several-fold higher than traditional ultrasound backscatter. In photoacoustic imaging, a short light pulse incident on the target tissue and contrast agent causes rapid heating and thermal expansion capable of acoustic detection. Photoacoustic imaging produces a tomographic image in vivo with very high spatial resolution (up to 50-500 µm) and significant depth of penetration (up to 5 cm).
On the left, we describe three projects underway in our laboratory.