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Professor Anastasio's research activities are focused generally in the areas of imaging physics and tomographic reconstruction algorithms. Below are descriptions of four projects that Professor Anastasio and his students are actively pursuing.
Megavoltage computed tomgraphy (CT) for radiation therapy tumor imaging.
In the past decade, radiation therapy has undergone a revolution. Advances in treatment delivery equipment, imaging systems, and treatment planning capabilities have resulted in treatment fields becoming smaller and more tightly conformed to the tumor. These new treatments have become much more susceptible to errors in patient positioning, caused either by set-up errors or organ motion. Thus, there is an increasing need for imaging methods to identify the tumor volume within the patient before the treatment delivery. We are developing and investigating dose-efficient tomographic imaging methods based on the local tomography paradigm that will facilitate patient positioning verification in conformal radiation therapy treatments. Professor Anastasio's research group is collaborating with clinical and basic science faculty at The University of Chicago Medical Center on this project.
Development of phase-contrast tomography
Characterizing angiogenesis and microvascular architecture in biological systems is of tremendous value in a wide range of biological fields such as tissue engineering, cancer, rehumatoid arthritis, and ischemic heart disease research. The ability to perform such characterizations efficiently and effectively is hindered, in large part, by the available imaging modalities. We are currently developing and investigating reconstruction algorithms for in-line X-ray phase-contrast microtomography, and evaluating their use for reconstructing the microvascular structure of biological tissues and tumors.
Development of imaging algorithms for thermoacoustic tomography
Thermoacoustic tomography (TAT) is an emerging imaging technique with great potential for a wide range of biomedical imaging applications. In TAT, a short electromagnetic pulse is used to irradiate a biological tissue. When the electromagnetic pulse is absorbed by the tissue, a thermoacoustic effect results in the emission of acoustic signals that are measured subsequently. The objective of TAT is to produce an image that represents a map of the spatially variant electromagnetic absorption properties of the tissue. Professor Anastasio and his research group are currently developing and evaluating tomographic reconstruction algorithms for TAT. These algorithms produce images that have greatly improved accuracy and statistical properties, which will facilitate diagnostic tasks.
Development of intensity diffraction tomography
Diffraction tomography (DT) is an imaging technique for reconstructing the complex-valued refractive index distribution of an object. An undesirable characteristic of DT is that it requires measurement of the amplitude and phase of the transmitted wavefield. Phase measurements generally present considerable difficulities in optical and X-ray applications. Recently, a new theory of intensity DT (I-DT) has been proposed that circumvents the need to make explicit wavefield phase measurements. Professor Anastatio's research group is analytically and numerically investigating the I-DT reconstruction theory and generalizing it to accommodate scanning geometries that are of practical importance. | 