With the development of the compressive sensing theory, the image reconstruction from the projections viewed in limited angles is one of the hot problems in the research of computed tomography technology. This paper d...With the development of the compressive sensing theory, the image reconstruction from the projections viewed in limited angles is one of the hot problems in the research of computed tomography technology. This paper develops an iterative algorithm for image reconstruction, which can fit the most cases. This method gives an image reconstruction flow with the difference image vector, which is based on the concept that the difference image vector between the reconstructed and the reference image is sparse enough. Then the l1-norm minimization method is used to reconstruct the difference vector to recover the image for flat subjects in limited angles. The algorithm has been tested with a thin planar phantom and a real object in limited-view projection data. Moreover, all the studies showed the satisfactory results in accuracy at a rather high reconstruction speed.展开更多
The present work describes the use of noninvasive diffuse optical tomography(DOT)technology to measure hemodynamic changes,providing relevant information which helps to understand the basis of neurophysiology in the h...The present work describes the use of noninvasive diffuse optical tomography(DOT)technology to measure hemodynamic changes,providing relevant information which helps to understand the basis of neurophysiology in the human brain.Advantages such as portability,direct measurements of hemoglobin state,temporal resolution,non-restricted movements as occurs in magnetic resonance imaging(MRI)devices mean that DOT technology can be used in research and clinical fields.In this review we covered the neurophysiology,physical principles underlying optical imaging during tissue-light interactions,and technology commonly used during the construction of a DOT device including the source-detector requirements to improve the image quality.DOT provides 3 D cerebral activation images due to complex mathematical models which describe the light propagation inside the tissue head.Moreover,we describe briefly the use of Bayesian methods for raw DOT data filtering as an alternative to linear filters widely used in signal processing,avoiding common problems such as the filter selection or a false interpretation of the results which is sometimes due to the interference of background physiological noise with neural activity.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2006CB7057005)the National High Technology Research and Development Program of China(Grant No.2009AA012200)the National Natural Science Foundation of China (Grant No.60672104)
文摘With the development of the compressive sensing theory, the image reconstruction from the projections viewed in limited angles is one of the hot problems in the research of computed tomography technology. This paper develops an iterative algorithm for image reconstruction, which can fit the most cases. This method gives an image reconstruction flow with the difference image vector, which is based on the concept that the difference image vector between the reconstructed and the reference image is sparse enough. Then the l1-norm minimization method is used to reconstruct the difference vector to recover the image for flat subjects in limited angles. The algorithm has been tested with a thin planar phantom and a real object in limited-view projection data. Moreover, all the studies showed the satisfactory results in accuracy at a rather high reconstruction speed.
文摘The present work describes the use of noninvasive diffuse optical tomography(DOT)technology to measure hemodynamic changes,providing relevant information which helps to understand the basis of neurophysiology in the human brain.Advantages such as portability,direct measurements of hemoglobin state,temporal resolution,non-restricted movements as occurs in magnetic resonance imaging(MRI)devices mean that DOT technology can be used in research and clinical fields.In this review we covered the neurophysiology,physical principles underlying optical imaging during tissue-light interactions,and technology commonly used during the construction of a DOT device including the source-detector requirements to improve the image quality.DOT provides 3 D cerebral activation images due to complex mathematical models which describe the light propagation inside the tissue head.Moreover,we describe briefly the use of Bayesian methods for raw DOT data filtering as an alternative to linear filters widely used in signal processing,avoiding common problems such as the filter selection or a false interpretation of the results which is sometimes due to the interference of background physiological noise with neural activity.
