We show an iterative reconstruction framework for diffraction ultrasound tomography. The use of broad-band illumination allows significant reduction of the number of projections compared to straight ray tomography. The proposed algorithm makes use of forward nonuniform fast Fourier transform (NUFFT) for iterative Fourier inversion. Incorporation of total variation regularization allows the reduction of noise and Gibbs phenomena while preserving the edges. The complexity of the NUFFT-based reconstruction is comparable to the frequency-domain interpolation (gridding) algorithm, whereas the reconstruction accuracy (in sense of the L2 and the L(infinity) norm) is better.
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http://dx.doi.org/10.1109/TMI.2002.806423 | DOI Listing |
Materials (Basel)
December 2024
Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland.
A sonochemical synthesis of SnS quantum dots using acetone as a solvent is investigated. Two different tin sources (SnCl∙2HO or SnCl∙5HO) as well as two different sulfur sources (thioacetamide or NaSO) were applied. The sonication time was also varied between 60 and 120 min.
View Article and Find Full Text PDFNature
January 2025
Department of Materials Engineering, Indian Institute of Science, Bangalore, India.
Piezoelectric materials directly convert between electrical and mechanical energies. They are used as transducers in applications such as nano-positioning and ultrasound imaging. Improving the properties of these devices requires piezoelectric materials capable of delivering a large longitudinal strain on the application of an electric field.
View Article and Find Full Text PDFUltrasound localization microscopy (ULM) enables microvascular imaging at spatial resolutions beyond the acoustic diffraction limit, offering significant clinical potentials. However, ULM performance relies heavily on microbubble (MB) signal sparsity, the number of detected MBs, and signal-to-noise ratio (SNR), all of which vary in clinical scenarios involving bolus MB injections. These sources of variations underscore the need to optimize MB dosage, data acquisition timing, and imaging settings in order to standardize and optimize ULM of microvasculature.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China. Electronic address:
This study aimed to develop ultrasonically-assisted, alcohol-free, and noncorrosive aqueous zein/turmeric essential oil (TEO)-loaded nanoemulsions (NEs) to stimulate pullulan/carboxymethyl chitosan (P/CMCS)-based edible films for mango fruit preservation. The influence of innovative sonicated zein/TEO-based NEs (ZTNEs) as nanofillers on the physico-mechanical characteristics of the resulting P/CMCS edible films was investigated. A stable and well-dispersed ZTNE was achieved using 20 % zein with 10 min of ultrasound treatment, leading to a reduced droplet size (194.
View Article and Find Full Text PDFUltrasonics
December 2024
NDT&E Laboratory, Dalian University of Technology, Dalian 116085, China. Electronic address:
Ultrasonic time-of-flight diffraction (TOFD) technique is applied to non-destructive testing in engineering, but the dead zone influences its applicable range. Alternative TOFD techniques adopt the indirect diffracted waves having long propagation times to decouple from the lateral wave and detect near-surface defects. It should be noted that the applicability of these diffracted waves varies with parameter conditions employed for detection, e.
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