Catching Elusive Cancer Cells With Light and Sound

The Big Idea: Photoacoustic imaging, a new way to use light and sound waves to look inside the body, which could be used to improve the detection of cancer cells.

The Researcher: Lei Li, postdoctoral scholar research associate in medical engineering, member of the lab of Lihong Wang, Bren Professor of Medical Engineering and Electrical Engineering.

It provides a much clearer image, leading to a more accurate diagnosis. It will be affordable, just like an ultrasound scan. It’s painless and fast, taking only 15 seconds to scan the entire breast in 3D. And immediate results will be delivered to the patients.
— Lei Li

What Does It Mean? After his grandparents died of cancer and stroke, Li focused his expertise in optical engineering on researching the next generation of medical imaging. His work in photoacoustic imaging involved the conversion of light energy into sound energy to see into the body quickly and painlessly.

When researchers fire a laser pulse into tissue, Lei says, “the light is absorbed, raising its temperature a bit. The rise in temperature leads to a tiny fraction of volume expansion, which, in turn, generates acoustic waves.” Sensors can then process those signals to construct a 3D image more detailed than what is possible with CT scan or ultrasound. The goal is that this technology will aid in the early diagnosis of cancer and brain diseases, ultimately benefiting global health.

Read More:

  • Learn all about photoacoustic imaging at Li’s website.

  • Photoacoustic Tomography of Neural Systems, Neural Engineering, 2020. In this paper, Li and colleagues lay out the promise of photoacoustic tomography (PAT) for investigating the brain.

  • Recent Advances in Photoacoustic Tomography, BMEF, 2021. Li reviews recent progress and advances in PAT, including the development of advanced PAT systems for small-animal and human imaging, newly engineered optical probes for molecular imaging, and integration of machine learning for image reconstruction and processing.