$350k To Support Dr. Chen's Brain Imaging Research

ECE Prof. Jingkuang Chen has received $350,000 from NSF for developing a novel MEMS photoacoustic brain imager. The imager integrates light with sound to create a photoacoustic flashlight for 3D brain imaging.

Photoacoustic imaging is capable of anatomical, functional and molecular imaging in vivo (within a living organism) with spatial resolution approaching a single cell. Chen's project explores novel MEMS-based devices that integrate light with sound to overcome key limitations with existing photoacoustic imaging systems.

The miniature devices will facilitate real-time 3D photoacoustic imaging, Dr. Chen says, and provide new in-vivo tools for studying neural diseases such as cancer and stroke. They will also help guide interventional therapy.

New Science Magazine reported on Chen's research in this area in its November 2007 issue.

The project summary states: "Photoacoustic imaging (PAI) relies on the optical absorption of a short laser pulse followed by heating, thermoelastic expansion and generation of ultrasonic waves, which are detected to form an image. Without contrast agents, PAI provides exquisite 3D images of the neurovasculature (anatomical imaging) and also maps brain activation due to optical changes of oxygenated hemoglobin (functional imaging). With the aid of targeted optical contrast agents, PAI becomes a powerful tool for molecular imaging.

"Despite the promise of photoacoustic brain imaging, current systems typically contain bulky optical assemblies for light delivery and depend on mechanical scanning of a single element or linear array of piezoelectric ultrasound receivers for multidimensional imaging, leading to long scan times. Limitations of piezoelectric technology prevent real-time high resolution PAI."

Chen's research is exploring capacitive micromachined ultrasound transducer (CMUT) technology for integrating light delivery with ultrasound arrays to enable real-time 3D PAI and to assess key physical properties, such as sensitivity, bandwidth and light transmission, to develop optimized devices for brain imaging.

Again from the project summary: "The photoacoustic flashlight is a hand-held device composed of a thin, infrared-transparent planar array of ultrasound elements at its face and integrated light delivery through the handle. With parallel receive architecture, the complete system would provide 3D images for each laser pulse and dramatically facilitate and simplify real-time photoacoustic brain imaging based on anatomical, functional and/or molecular features. Such a powerful tool, all in a compact package, would facilitate diagnostic and image-guided therapy."

The project integrates Chen's expertise in bioengineering and CMUT technology with that of co-PI Russell Witte, assistant professor of biomedical engineering at the University of Arizona. Witte's expertise is in biomedical imaging, photoacoustics and neuroscience.

Dr. Chen can be reached at jingchenATece.unm.edu. He was the subject of an ECE Faculty Spotlight, which is here.