This article investigates the restoration of ultrasonic pulse-echo C-scan images by means of deconvolution with a point spread function (PSF). The deconvolution concept from linear system theory (LST) is linked to the wave equation formulation of the imaging process, and an analytic formula for the PSF of planar transducers is derived. For this analytic expression, different numerical and analytic approximation schemes for evaluating the PSF are presented. By comparing simulated images with measured C-scan images, we demonstrate that the assumptions of LST in combination with our formula for the PSF are a good model for the pulse-echo imaging process. To reconstruct the object from a C-scan image, we compare different deconvolution schemes: the Wiener filter, the ForWaRD algorithm, and the Richardson-Lucy algorithm. The best results are obtained with the Richardson-Lucy algorithm with total variation regularization. For distances greater or equal twice the near field distance, our experiments show that the numerically computed PSF can be replaced with a simple closed analytic term based on a far field approximation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1109/TUFFC.2014.006717 | DOI Listing |
Mol Ecol
January 2025
Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, Guangdong, China.
Rhinolophus bats have been identified as natural reservoirs for viruses with global health implications, including severe acute respiratory syndrome-related coronaviruses (SARSr-CoV) and swine acute diarrhoea syndrome-related coronavirus (SADSr-CoV). In this study, we characterised the individual viromes of 603 bats to systematically investigate the diversity, abundance and geographic distribution of viral communities within R. affinis, R.
View Article and Find Full Text PDFBiosens Bioelectron
January 2025
Jinling Clinical Medical College, Nanjing University of Chinese Medicine, 210002, Nanjing, Jiangsu Province, China; Department of Orthopedics, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, 210002, Nanjing, Jiangsu Province, China; Division of Trauma and Acute Care Surgery, Department of Surgery, Jinling Hospital, Jinling Clinical Medical College, Nanjing University of Chinese Medicine, 210002, Nanjing, Jiangsu Province, China. Electronic address:
The rapid and reliable diagnosis of methicillin-resistant Staphylococcus aureus (MRSA) is essential for preventing the spread of MRSA infections and guiding therapeutic strategies. However, there is still a huge challenge in further simplifying MRSA detection procedures and improving detection selectivity to reduce false-positive results. In this study, we developed a derivative CRISPR-associated protein 9/CRISPR-derived RNA Linked Immunological Assay (dCLISA) for the sensitive and specific detection of MRSA.
View Article and Find Full Text PDFUltramicroscopy
January 2025
Nanopatterning-Nanoanalysis-Photonic Materials Group, Department of Physics, Paderborn University, Warburgerstr. 100, Paderborn, 33098, Germany. Electronic address:
Electron energy-loss spectroscopy (EELS) performed in a scanning transmission electron microscope (STEM) is susceptible to noise, just like every other measurement. EELS measurements are also affected by signal blurring, related to the energy distribution of the electron beam and the detector point spread function (PSF). Moreover, the signal blurring caused by the detector introduces correlation effects, which smooth the noise.
View Article and Find Full Text PDFNat Commun
January 2025
Research Laboratory of Electronics, MIT, Cambridge, MA, USA.
Three-dimensional subcellular imaging is essential for biomedical research, but the diffraction limit of optical microscopy compromises axial resolution, hindering accurate three-dimensional structural analysis. This challenge is particularly pronounced in label-free imaging of thick, heterogeneous tissues, where assumptions about data distribution (e.g.
View Article and Find Full Text PDFJ Craniofac Surg
November 2024
Department of Physical Functions, Division of Oral and Maxillofacial Surgery, Kyushu Dental University.
In cases where oral cancer spreads toward the maxillary tubercle, surgery may extend to the pterygopalatine fossa. There are 2 main extraoral approaches: anterior and lateral. Previously, we introduced a modified lateral approach with a mouth corner incision from the lower lip, that preserves the mental and marginal mandibular nerves.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!