Assistant Professor of Electrical and Computer Engineering at University of Oklahoma
Stephenson Cancer Center at University of Oklahoma Health Sciences Center
X-ray-induced Acoustic Computed Tomography (XACT)
Abstract
X-ray computed tomography (CT) has proved tremendously useful for noninvasive medical imaging ever since its inception nearly 50 years ago. However, there remain two major limitations: radiation harm and inaccessibility to patient.
In 2013, for the first time, we reported a novel x-ray imaging modality, x-ray induced acoustic computed tomography (XACT), to overcome these limitations of conventional x-ray CT imaging. In XACT, pulsed x-ray excitation of a sample results in localized heating, and subsequent thermoelastic expansion, for sufficiently short-lasting pulses, this results in the emission of a detectable acoustic wave in the ultrasound regime, with amplitude proportional to x-ray absorption. This unique hybrid imaging modality combines high x-ray absorption contrast with the 3D propagation advantages provided by high resolution encoding ultrasound waves. XACT imaging shows potential to produce a 3D volumetric image from a single X-ray projection. Thus, XACT can dramatically reduce radiation dose and improve imaging speed as compared to conventional x-ray CT with hundreds of projections. Moreover, XACT imaging also requires only single-side access to the patient versus traditional X-ray imaging’s requirement for access to two opposing sides of the patient. We expect our work may profoundly advance X-ray imaging technology.
My main research interest is in developing XACT imaging and enable its clinical translation. I will present a wide range of applications of XACT ranging from radiation oncology (in vivo dosimetry for external radiotherapy on breast cancer and prostate cancer), to radiological imaging (breast microcalcification, bone tumor, and osteoporosis).
Biography
Dr. Liangzhong Xiang is an Assistant Professor in the Department of of Electric and Computer Engineering, and Stephenson Cancer Center at University of Oklahoma (OU). Dr. Xiang received his Ph.D. degree from South China Normal University on photoacoustic molecular imaging. He was a postdoctoral fellow trained in medical physics at Stanford Medical School, and he awarded the U.S. Department of Defense (DoD) Prostate Cancer Postdoctoral Training Program at Stanford University (2012-2015).
In research, Dr. Xiang and his laboratory was the first to report x-ray-induced acoustic computed tomography (XACT). His work on XACT imaging was the cover article for Medical Physics in 2013. His talk entitled “X-ray acoustic computed tomography: concept and design” has been identified as a “Hot Topic” presentation for the 2013 AAPM Annual Meeting. And he received the Slvia Sorkin Greenfield Award for the best paper of the Medical Physics at AAPM 50th Annual Meeting. His research has led to over 60+ peer-reviewed publications, 12 patents, 30+ presentations. Sponsored by NIH, DoD and Oklahoma state funding agencies with over $ 3 million dollars active grant support. In education, he received Nancy L. Mergler Faculty Mentor Award for Undergraduate Research (the only recipient at OU in 2017). He strategically guides lab students to become extraordinary and independent scientists. His students have been awarded SPIE Education Scholarship (2019, 2018), SPIE Travel Scholarship (2016). His postdoctoral research fellows were awarded the Trainee Research Prize from the Radiological Society of North America (RSNA, 2015). In service, Dr. Xiang has served as conference chairs in AAPM annual meeting (2019) and International Conference on Information Optics and Photonics (CIOP 2018), SPIE Student Chapter advisor, associate editor of Medical Physics journal, and grant reviewer for U S Department of Energy, Russian Science Foundation (RSF), and Helmholtz Association of German Research Centre.
For more information or to schedule a meeting with the speaker, please contact Hanna Kim.
