My Main Research Interests
- My research focus lies primarily in developing novel imaging systems, reconstruction algorithms and analysis methods. I have a broad background in medical imaging with specific expertise in X-ray based computed tomography (CT), micro-CT, tomosynthesis, and fluorescence tomography. I am convinced that CT imaging can be expanded from mostly anatomical to functional and even molecular imaging capabilities. At the time when no commercial or academic micro-CT imaging systems were capable of performing dynamic cardiac CT in the mouse, at Duke I designed and built a unique micro-CT system that was used to produce the first in vivo cine imaging of the heart in mice with isotropic resolution of 100 microns and a temporal resolution of 10 ms. Following that achievement, I have completed a second-generation dual tube/detector micro-CT system for faster dynamic imaging. With our system, the two x-ray tubes fire simultaneously, making cardiac imaging twice faster. Unlike commercial micro-CT systems, our instrument uses clinical x-ray tubes that are able to deliver very high flux with short exposures, which is ideal for both high temporal and spatial resolution. Furthermore, having two x-ray sources allows Dual Energy-CT with a single scan.
- More recently, my focus has shifted to spectral CT imaging using nanoparticle-based contrast agents for theranostics (i.e. therapy and diagnostics). One major aim of modern cancer therapy is to target, image, and treat cancer using a single nanoparticle platform. I have used my in-house-developed dual source micro-CT system to image iodinated liposomes and gold nanoparticles in various cancer and cardiac applications. Dual energy micro-CT provides separation of iodine and calcium or iodine and gold, and it was applied in imaging myocardial infarction, classification of atherosclerotic plaque composition, and the classification of tumor aggressiveness in classification of lung cancer, and classification of radiation therapy response in primary sarcoma tumors. We were the first to demonstrate dual energy micro-CT imaging using dual nanoparticles (gold and iodine) to image two important vascular biomarkers in tumors—the microvascular blood volume and vascular permeability. I have also been engaged in developing new approaches in image reconstruction suitable to address difficult undersampling cases in cardiac and spectral micro-CT using compressed sensing. We have recently introduced combined spectral and temporal 5D (3D + Time + Energy) CT imaging. See examples here.
- My talk on Multidimensional CT Imaging illustrates most of my research
Education and Training
- University of Patras (Greece), Ph.D. 2001
- Postdoctoral Studies at Duke 2001-2003
Selected Grants and Awards
- Director of Core B (Extend Micro-CT / Image Reconstruction for Functional Imaging) for P41 (EB015897) resource grant (PI Dr. G Allan Johnson).
I am also involved with teaching in Duke Medical Physics Program and I am mentoring brilliant graduate students (Darin Clark, Jeffrey Ashton, Mengheng Touch, Samuel Johnston (PhD 2012) ).
During 2007-2012, I have also served as faculty and CT imaging expert during the NCI-sponsored Cancer Research Imaging Camps
- o I am grateful to all my collaborators for being a source of inspiration and motivation. Working with these people makes my day, and gets me through all kinds of moments. It reminds me of the value of what we need to do, and helps me not forget why we ought to keep moving onwards! I am particularly grateful for collaborating with Drs. David Kirsch and Jennifer West.
- I owe a lot to CIVM colleagues and staffers including Al Johnson, Larry Hedlund, Yi Qi, James Cook, Lucy Upchurch, Sally Zimney, Tawynna Gordon. But students are the beating heart and blood of a university, and the CIVM students I have the privilege to work with are some of the best.
- Nothing I have done so far would be possible without the support of a loving and fun family.
- On CT imaging using liposomal contrast agents : Collaboration with Texas Children's
- On tumor dual energy CT using gold and iodinated nanoparticles
- "Micro-CT" Scans of Mice Zoom in on Heart Defects