Optical tomography (OT) is an emerging biomedical imaging modality that employs visible and near-infrared light to probe biological tissues. Unlike many other medical imaging modalities, such as X-ray imaging or positron emission tomography, OT does not relay on potentially harmful radiation. Furthermore, the high contrast of many optical markers promises disease detection on the molecular level. However, this technology still has to overcome some major hurdles before true clinical utility can be achieved. For example, it is well established that he most accurate image reconstruction schemes are based on the equation of radiative transfer (ERT). But the accuracy comes at the cost of long computation times. Besides a general overview on how to implement ERT-based reconstruction algorithms, this talk focuses on various method that accelerated the image reconstruction process. PDE-constrained algorithms, SPN methods and parametric reconstruction techniques will be discussed. Furthermore, instrumentation that incorporates digital-signal-processing (DSP) chip technology has significantly increased the signal-to-noise ratios, and ever-smaller signals can be detected in shorter times. This opens the doors to novel applications in dynamic optical tomography. Practical examples encountered in clinical and preclinical imaging will be presented, including monitoring of tumor growth and regression, effects of anti-angiogenic drugs in pediatric cancer treatment, breast cancer screening, and detection of arthritis. An overview of our most recent advances in machine learning approaches to computer-aided diagnostic (CAD) for OT image classification concludes the talk.

Andreas H. Hielscher received his PhD degree in Electrical and Computer Engineering from Rice University, Houston, Texas, in 1995.  After spending 2 years as Postdoctoral Fellow at the Los Alamos National Laboratory in New Mexico, he joined the faculty at the State University of New York Downstate Medical Center in Brooklyn, New York. In September 2001 he moved to Columbia University in New York City, where he is now the Director of the Biophotonics and Optical Radiology Laboratory and the Shared Small Animal Imaging Resources at the Herbert Irving Comprehensive Cancer Center. He holds appointments as Associate Professor in the Departments of Biomedical Engineering and Radiology.

Dr. Hielscher’s work focuses on the development of state-of-the-art imaging software and hardware for optical tomography. Among his many pioneering contributions to this field are the introduction of transport-theory-based reconstruction algorithms both for absorption and fluorescence imaging, the development of the first fully digital-signal-processor (DSP) based optical tomographic imaging system, and the first three-dimensional optical tomographic reconstruction of a complete rat brain and the human frontal lobe. Currently his team applies this emerging technology to imaging of cancer and joint diseases and uses it in support of drug development. He has published over 120 articles in peer-reviewed scientific journals and conference proceedings, which have been cited over 2500 times. Dr. Hielscher’s work has been funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), the National Heart, Lung, and Blood Institute (NHLB), the National Institute for Biomedical Imaging and Bioengineering (NIBIB), the Whitaker Foundation for Biomedical Engineering, and the New York State Office of Science, Technology and Academic Research.

Dr. Hielscher currently serves as Associate Editor of the IEEE Transactions of Medical Imaging and has reviewed papers for over 30 scientific journals, including the Journal of Biomedical Optics, Optics Letters, IEEE Transactions on Biomedical Engineering, Medical Physics, Physics Review Letters, and Review of Scientific Instrumentation.  He has been active in organizing conferences and meetings that promote the field of Biomedical Optics on more than 30 occasions.  Among others, he was Chair of the Biomedical Optical Spectroscopy Group at the Optical Society of America (OSA) from October 2001 – 2003, and chaired symposia and sessions on optical imaging at the IEEE –EMBS conferences in 1997, 1998, 1999, and 2005. In 2006 he was the publication chair for the annual IEEE-EMBS conference in New York City. His is also a member of the SPIE Medical Imaging Conference Program Committee on "Physiology, Function, and Structure from Medical Images,” and the OSA Conference Program Committee for “Advances in Optical Imaging and Photon Migration.” In addition he frequently serves on review panels for the National Institutes of Health (NIH) and National Science Foundation (NSF) as well as several international funding agencies, such as the British Welcome Trust or Dutch Organization for Scientific Research. He is listed in Marquis Who’s is Who in America since 2005.