Current Issue : January - March Volume : 2021 Issue Number : 1 Articles : 5 Articles
The l1-norm regularization has attracted attention for image reconstruction in computed tomography. The l0-norm of the\ngradients of an image provides a measure of the sparsity of gradients of the image. In this paper, we present a new\ncombined l1-norm and l0-norm regularization model for image reconstruction from limited projection data in computed\ntomography. We also propose an algorithm in the algebraic framework to solve the optimization effectively using the\nnonmonotone alternating direction algorithm with hard thresholding method. Numerical experiments indicate that this\nnew algorithm makes much improvement by involving l0-norm regularization....
Background: Chest CT screening as supplementary means is crucial in diagnosing\nnovel coronavirus pneumonia (COVID-19) with high sensitivity and popularity. Machine\nlearning was adept in discovering intricate structures from CT images and achieved\nexpert-level performance in medical image analysis................
To obtain some prior knowledge of breast cancer detection by microwave\nimaging, we have measured and analyzed the complex permittivity of tissues\nextracted from over 140 breast cancer surgeries. The relative permittivity and\nconductivity of tumor at 1.6 GHz were 17.5% and 16.2% higher than those of\nmammary gland tissue, respectively. In invasive ductal carcinoma of scirrhous\ntype, 8 out of 64 had higher relative permittivity and conductivity of\nmammary gland than those of tumor....
The disadvantage of visualizing tomography by slices is that an important\nattribute of the object, its volume, is not easily perceived or measured. In oncology\nthis creates a problem, which is addressed here: if early detection and\nresponse to treatment are an important prognostic element, then volume is\nimportant. The literature has proposed surrogates to volume derived from\nmeasures on slices, but geometrically they are not well founded. Actual volume\nanalysis is not complex, and the proposed method applies equally well\nto organs as to tumors....
This study investigated the ability of microwave holography to accurately reconstruct\nthe tissue structure of the human body. Numerical breast and head\nphantoms were imaged by 3D near-field holography using backscattered\nwaves obtained by a monostatic planar scan. Complex organizational structures\nhave been reconstructed accurately and quickly. In addition, breasts with relatively\nsimple histology could be reconstructed without the matching liquid....
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