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Full-Text Articles in Biomedical Engineering and Bioengineering
Three-Dimensional Image Reconstruction In Transcranial Photoacoustic Computed Tomography, Joemini Poudel
Three-Dimensional Image Reconstruction In Transcranial Photoacoustic Computed Tomography, Joemini Poudel
McKelvey School of Engineering Theses & Dissertations
Photoacoustic computed tomography (PACT) is an emerging imaging modality that exploitsoptical contrast and ultrasonic detection principles to form images of the photoacousticallyinduced initial pressure distribution within tissue. The PACT reconstruction problemcorresponds to an inverse source problem in which the initial pressure distribution is recoveredfrom measurements of the radiated pressure wavefield. A major challenge in transcranialPACT brain imaging is compensation for aberrations in the measured data due to the presenceof the skull. Ultrasonic waves undergo absorption, scattering and longitudinal-to-shear wavemode conversion as they propagate through the skull. To properly account for these effects, awave-equation-based inversion method should be employed that can …
Joint Reconstruction For Single-Shot Edge Illumination Phase-Contrast Tomography (Eixpct), Yujia Chen
Joint Reconstruction For Single-Shot Edge Illumination Phase-Contrast Tomography (Eixpct), Yujia Chen
McKelvey School of Engineering Theses & Dissertations
Edge illumination X-ray phase-contrast tomography (EIXPCT) is an emerging X-ray phasecontrast tomography technique for estimating the complex-valued X-ray refractive index distribution of an object with laboratory-based X-ray sources. Conventional image reconstruction approaches for EIXPCT require multiple images to be acquired at each tomographic view angle. This contributes to prolonged data-acquisition times and elevated radiation doses, which can hinder in vivo applications. In this dissertation, a new “single-shot” method without restrictive assumptions related to the object, imaging geometry or hardware is proposed for joint reconstruction (JR) of the real and imaginary-valued components of the refractive index distribution from a tomographic data …
Image Reconstruction Of The Speed Of Sound And Initial Pressure Distributions In Ultrasound Computed Tomography And Photoacoustic Computed Tomography, Thomas Paul Matthews
Image Reconstruction Of The Speed Of Sound And Initial Pressure Distributions In Ultrasound Computed Tomography And Photoacoustic Computed Tomography, Thomas Paul Matthews
McKelvey School of Engineering Theses & Dissertations
Ultrasound computed tomography (USCT) and photoacoustic computed tomography (PACT) are two emerging imaging modalities that have a wide range of potential applications from pre-clinical small animal imaging to cancer screening in human subjects. USCT is typically employed to measure acoustic contrasts, including the speed of sound (SOS) distribution, while PACT typically measures optical contrasts or some related quantity such as the initial pressure distribution. Their complementary contrasts and similar implementations make USCT and PACT a natural fit for a hybrid imaging system. Still, much work remains to realize this promise. First, USCT image reconstruction methods based on the acoustic wave …