Ischemic perfusion radiomics: assessing neurological impairment in acute ischemic stroke.

Introduction: Accurate neurological impairment assessment is crucial for the clinical treatment and prognosis of patients with acute ischemic stroke (AIS). However, the original perfusion parameters lack the deep information for characterizing neurological impairment, leading to difficulty in accurate assessment. Given the advantages of radiomics technology in feature representation, this technology should provide more information for characterizing neurological impairment. Therefore, with its rigorous methodology, this study offers practical implications for clinical diagnosis by exploring the role of ischemic perfusion radiomics features in assessing the degree of neurological impairment. Methods: This study employs a meticulous methodology, starting with generating perfusion parameter maps through Dynamic Susceptibility Contrast-Perfusion Weighted Imaging (DSC-PWI) and determining ischemic regions based on these maps and a set threshold. Radiomics features are then extracted from the ischemic regions, and the t-test and least absolute shrinkage and selection operator (Lasso) algorithms are used to select the relevant features. Finally, the selected radiomics features and machine learning techniques are used to assess the degree of neurological impairment in AIS patients. Results: The results show that the proposed method outperforms the original perfusion parameters, radiomics features of the infarct and hypoxic regions, and their combinations, achieving an accuracy of 0.926, sensitivity of 0.923, specificity of 0.929, PPV of 0.923, NPV of 0.929, and AUC of 0.923, respectively. Conclusion: The proposed method effectively assesses the degree of neurological impairment in AIS patients, providing an objective auxiliary assessment tool for clinical diagnosis.

Fabrication of moiré on curved surfaces.

Moiré is an appealing visual effect observable when two or more repetitive patterns are superposed. Fabrication of moiré effects has already proven to be useful in a range of applications, from art to engineering. Here, we introduce a method for designing and fabricating level-line moirés on curved surfaces. These moiré shapes are obtained by superposing a partly absorbing layer and a layer formed by an array of cylindrical lenses or by two layers of cylindrical lenses. We formulate the problem of placing an array of cylindrical lenses on a curved surface as a design problem with a small number of dimensions. The range of possible solutions can therefore be explored by a human observer. We demonstrate the quality of our method by rendered simulations and by fabrication. The resulting static displays can be manufactured using different fabrication techniques, from multi-material 3D printing to molding.