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Advancing medical imaging techniques to address the challenges in medicine
Novel imaging systems
Treatment planning of a proton therapy is currently based on x-ray CT data. However, the x-ray CT data in dose calculation do not reflect the interaction of protons with materials accurately. Therefore, proton CT is a reasonable approach to better including the interaction of proton with tissue in the treatment planning procedure. We performed a proton CT imaging in a benchtop geometry using a modulated proton beam. A modulated proton beam is designed such that the proton beam behaves like photon beam in terms of dose-depth profile. The modulated proton beam was also utilized for a feasibility study of proton radiography as a quality assurance tool of patient-specific proton range compensator. We have reported that pixel values of the EBT film-based proton radiography have close relationship with thicknesses of the proton range compensator in collaboration with the National Cancer Center (Phys. Med. Biol. 2013). Having seen its feasibility, we have extended our study to develop a sparse-view proton CT imaging (Med. Phys. 2015 - Lee, J. Instrumentation 2017).
Digital breast tomosynthesis (DBT) is gaining wide interests in clinics with evidences showing higher sensitivity and specificity compared to a mammogram alone. We are constructing a multimodality imaging system that combines the DBT with the diffuse optical tomography (DOT) in collaboration with Prof. Jong-Chul Ye in Bio-brain Engineering Department in KAIST and other institutes in Korea. On top of the DBT images, the DOT images would provide functional image information that is related to the oxygen concentration in the vessel systems associated with cancer. We are actively investigating to improve DBT image quality (Med. Phys. 2017, IEEE Tran. Med. Imag. 2019) and DOT image quality (J. Biomed. Opt. 2016). Considering the FDA requirement of taking additional mammography over the DBT, major DBT vendors provide a function of synthetic mammogram from the DBT slice images. Constructing a high-quality synthetic mammogram is also under our keen research interests.
