Based on the Wallerian degeneration in the spinal cord pathways,the changes in synaptic connections,and the spinal cord-related cellular responses that alter the cellular structure of the brain,we presumed that brain ...Based on the Wallerian degeneration in the spinal cord pathways,the changes in synaptic connections,and the spinal cord-related cellular responses that alter the cellular structure of the brain,we presumed that brain diffusion tensor imaging(DTI)parameters may change after spinal cord injury.However,the dynamic changes in DTI parameters remain unclear.We established a Beagle dog model of T10 spinal cord contusion and performed DTI of the injured spinal cord.We found dynamic changes in DTI parameters in the cerebral peduncle,posterior limb of the internal capsule,pre-and postcentral gyri of the brain within 12 weeks after spinal cord injury.We then performed immunohistochemistry to detect the expression of neurofilament heavy polypeptide(axonal marker),glial fibrillary acidic protein(glial cell marker),and NeuN(neuronal marker).We found that these pathological changes were consistent with DTI parameter changes.These findings suggest that DTI can display brain structure changes after spinal cord injury.展开更多
Due to the lossy transmission in the JPEG2000 image compression standard,the loss of wavelet coefficients heavily af-fects the quality of the received image.In this paper,we propose a novel wavelet inpainting model ba...Due to the lossy transmission in the JPEG2000 image compression standard,the loss of wavelet coefficients heavily af-fects the quality of the received image.In this paper,we propose a novel wavelet inpainting model based on tensor diffusion(TDWI)to restore the missing or damaged wavelet coefficients.A hybrid model is built by combining structure-adaptive anisotropic regu-larization with wavelet representation.Its associated Euler-Lagrange equation is also given for analyzing its regularity performance.Owing to the matrix representation of the structure tensor in the regularization term,the shape of diffusion kernel changes adaptivelyaccording to the image features,including sharp edges,corners and homogeneous regions.Compared with existing wavelet inpaint-ing models,the proposed one can control more adaptively and accurately the geometric regularity in the image and exhibits betterrobustness to noise.In addition,an effective and proper numerical scheme is adopted to improve the computation.Experimentalresults on a variety of loss scenarios are given to demonstrate the advantages of our proposed model.展开更多
基金supported by the National Natural Science Foundation of China, No. 82102676 (to CBL)a grant from Beijing Municipal Science & Technology Commission, No. Z171100001017076 (to JJL)+1 种基金National Key Research and Development Program, No. 2018YFF0301104 (to JJL)Research on Medical Protection Technology and Application of Induced Neural Stem Cells in the Treatment of Military Spinal Cord Injury, No. Z181100004118004 (to JL)
文摘Based on the Wallerian degeneration in the spinal cord pathways,the changes in synaptic connections,and the spinal cord-related cellular responses that alter the cellular structure of the brain,we presumed that brain diffusion tensor imaging(DTI)parameters may change after spinal cord injury.However,the dynamic changes in DTI parameters remain unclear.We established a Beagle dog model of T10 spinal cord contusion and performed DTI of the injured spinal cord.We found dynamic changes in DTI parameters in the cerebral peduncle,posterior limb of the internal capsule,pre-and postcentral gyri of the brain within 12 weeks after spinal cord injury.We then performed immunohistochemistry to detect the expression of neurofilament heavy polypeptide(axonal marker),glial fibrillary acidic protein(glial cell marker),and NeuN(neuronal marker).We found that these pathological changes were consistent with DTI parameter changes.These findings suggest that DTI can display brain structure changes after spinal cord injury.
基金Supported by National Natural Science Foundation of China(61003196,61105066)the Fundamental Research Funds for the Central Universities(K50510040007)
文摘Due to the lossy transmission in the JPEG2000 image compression standard,the loss of wavelet coefficients heavily af-fects the quality of the received image.In this paper,we propose a novel wavelet inpainting model based on tensor diffusion(TDWI)to restore the missing or damaged wavelet coefficients.A hybrid model is built by combining structure-adaptive anisotropic regu-larization with wavelet representation.Its associated Euler-Lagrange equation is also given for analyzing its regularity performance.Owing to the matrix representation of the structure tensor in the regularization term,the shape of diffusion kernel changes adaptivelyaccording to the image features,including sharp edges,corners and homogeneous regions.Compared with existing wavelet inpaint-ing models,the proposed one can control more adaptively and accurately the geometric regularity in the image and exhibits betterrobustness to noise.In addition,an effective and proper numerical scheme is adopted to improve the computation.Experimentalresults on a variety of loss scenarios are given to demonstrate the advantages of our proposed model.
