Background: Crocodiles are semi-aquatic animals well adapted to hear both on land and under water. Currently, there is limited information on how their amphibious hearing is accomplished. Here, we describe, for the first time, the ear anatomy in the living crocodile using photon-counting detector computed tomography (PCD-CT) and 3D rendering. We speculate on how crocodiles, despite their closed ear canals, can use tympanic hearing in water that also provides directional hearing.
Material And Methods: A Cuban crocodile ( underwent photon-counting detector computed tomography (PCD-CT), under anesthesia and spontaneous respiration. In addition two seven-month-old and a juvenile Morelet´s crocodile ( underwent micro-computed tomography (µCT) and endoscopy. One adult Cuviérs dwarf caiman ( was micro-dissected and video-recorded. Aeration, earflap, and middle ear morphology were evaluated and compared after 3D modeling.
Results And Discussion: PCD-CT and µCT with 3D rendering and segmentation demonstrated the anatomy of the external and middle ears with high resolution in both living and expired crocodiles. Based on the findings and comparative examinations, we suggest that the superior earflap, by modulating the meatal recess together with local bone conduction, may implement tympanic hearing in submerged crocodiles, including directional hearing.
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http://dx.doi.org/10.3389/fcell.2024.1471983 | DOI Listing |
Eur J Radiol
December 2024
Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre+, PO Box 5800, 6202 AZ Maastricht, the Netherlands; Mental Health and Sciences (MHeNs) Research Institute, Maastricht University, PO Box 616, 6200 MD Maastricht, the Netherlands.
Objectives: Photon-counting detector CT (PCD-CT) is expected to substantially improve and expand CT-imaging applicability due to its intrinsic spectral capabilities, increased spatial resolution, reduced electronic noise, and improved image contrast. The current study aim is to evaluate PCD-CT efficacy in characterizing bullets based on their dimensions, shape, and material composition.
Materials And Methods: This is an observational phantom study examining 11 unfired, intact bullets of various common calibers, placed in ballistic gelatin.
Invest Radiol
October 2024
From the Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich, Zurich, Switzerland (B.K., F.E., J.K., T.F., L.J.); Advanced Radiology Center, Department of Diagnostic Imaging and Oncological Radiotherapy, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Rome, Italy (C.S., A.R.L.); and Section of Radiology, Department of Radiological and Hematological Sciences, Università Cattolica del Sacro Cuore, Rome, Italy (A.R.L.).
Objectives: The aim of this study was to evaluate the feasibility and efficacy of visual scoring, low-attenuation volume (LAV), and deep learning methods for estimating emphysema extent in x-ray dose photon-counting detector computed tomography (PCD-CT), aiming to explore future dose reduction potentials.
Methods: One hundred one prospectively enrolled patients underwent noncontrast low- and chest x-ray dose CT scans in the same study using PCD-CT. Overall image quality, sharpness, and noise, as well as visual emphysema pattern (no, trace, mild, moderate, confluent, and advanced destructive emphysema; as defined by the Fleischner Society), were independently assessed by 2 experienced radiologists for low- and x-ray dose images, followed by an expert consensus read.
Tomography
November 2024
Department of Diagnostic Radiology, Tokai University School of Medicine, 143 Shimokasuya, Isehara 259-1193, Japan.
Photon-counting detector computed tomography (PCD-CT) offers energy-resolved CT data with enhanced resolution, reduced electronic noise, and improved tissue contrast. This study aimed to evaluate the visibility of intracranial perforating arteries on ultra-high-resolution (UHR) CT angiography (CTA) on PCD-CT. A retrospective analysis of intracranial UHR PCD-CTA was performed for 30 patients.
View Article and Find Full Text PDFAJR Am J Roentgenol
December 2024
Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI.
Spinning coding masks, recognized for their fast modulation rate and cost-effectiveness, are now often used in real-time single-pixel imaging (SPI). However, in the photon-counting regime, they encounter difficulties in synchronization between the coding mask patterns and the photon detector, unlike digital micromirror devices. To address this issue, we propose a scheme that assumes a constant disk rotation speed throughout each cycle and models photon detection as a non-homogeneous Poisson process (NHPP).
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