- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Multifractal and Lacunarity Analyses of Microvascular Morphology in Eyes with Diabetic Retinopathy: A Projection Artifact Resolved Optical Coherence Tomography Angiography Study
摘要： Objective: To evaluate the degree of microvascular impairment in diabetic retinopathy using multifractal and lacunarity analyses and to compare the diagnostic ability between traditional Euclidean measures (fovea avascular zone area and vessel density) and fractal geometric features. Methods: This retrospective cross-sectional study included a total of 143 eyes of 94 patients with different stages of diabetic retinopathy. The retinal microvasculature was imaged by projection removed optical coherence tomography angiography. We examined the degree of association between fractal metrics of the retinal microvasculature and diabetic retinopathy severity. The area under the receiver operating characteristic curve was used to estimate the diagnostic performance. Results: With increasing diabetic retinopathy severity, the multifractal spectrum shifted towards the left bottom and exhibited less left skewness and asymmetry. The vessel density, multifractal features and lacunarity measured from the deep capillary plexus were strongly associated with diabetic retinopathy severity. The multifractal feature D5 showed the highest diagnostic ability. The combination of multifractal features further improved the discriminating power. Conclusions: Multifractal and lacunarity analyses can be potentially valuable tools for assessment of microvascular impairments in diabetic retinopathy. Multifractal geometric parameters exhibit a better discriminatory performance than Euclidean measures, particularly for detection of the early stages of diabetic retinopathy.
关键词： diabetic retinopathy,optical coherence tomography angiography,microvascular network,lacunarity,multifractal
更新于2025-09-04 15:30:14
-
Multiband frequency selective surfaces with a modified multifractal cantor geometry
摘要： Self-affine property of a modified multifractal Cantor geometry is exploited to design frequency selective surfaces (FSS) with multiband response. The main advantage of the proposed structure is to design multiband FSS with multiple frequency ratios between the adjacent bands and easily-built structures. In addition, the proposed structure increases the degree of freedom in design of multiband FSS response according to the number of fractal iterations. The validation of the proposed structure was initially verified through simulations in Ansoft Designer 3.5 and then a prototype was built with a validation purpose.
关键词： Multiband Response,Cantor Geometry,Multifractal,FSS
更新于2025-09-04 15:30:14