A sub-pixel image shifter is presented, for use in enhancing the spatial resolution of digital image sensors by combining multiple displaced sub-images using a super-resolution (SR) algorithm. The device uses the walk-off phenomenon in birefringent crystals to separate images with opposite polarizations by a sub-pixel displacement. A liquid crystal (LC) waveplate plus a polarizer can then select the specific image to be exposed, with fast, non-mechanical control. This cascaded device, comprising two sapphire crystals, two LCs, and a single polarizer, is capable of 2-dimensional image shift with displacements of 0.5 pixels. The experimental results show that the image registration stability can be precisely controlled within 0.05 pixels and the contrast transfer function ratio of the SR image is enhanced by up to 1.36 times compared to the original captured image. Moreover, based on the fast transition time of LCs, the displaced sub-images can be recorded in video form with a frame rate of 40 fps.
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http://dx.doi.org/10.1364/OE.17.022992 | DOI Listing |
Comput Med Imaging Graph
January 2025
CAS Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China; National Key Laboratory of Kidney Diseases, Beijing 100853, China. Electronic address:
In clinical optical molecular imaging, the need for real-time high frame rates and low excitation doses to ensure patient safety inherently increases susceptibility to detection noise. Faced with the challenge of image degradation caused by severe noise, image denoising is essential for mitigating the trade-off between acquisition cost and image quality. However, prevailing deep learning methods exhibit uncontrollable and suboptimal performance with limited interpretability, primarily due to neglecting underlying physical model and frequency information.
View Article and Find Full Text PDFEur J Radiol
January 2025
Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, USA. Electronic address:
Purpose: To evaluate the feasibility of aortoiliac CT-Angiography (CTA) using dual-source photon-counting detector (PCD)-CT with minimal iodine dose.
Methods: This IRB-approved, single-center prospective study enrolled patients with indications for aortoiliac CTA from December 2022 to March 2023. All scans were performed using a first-generation dual-source PCD-CT.
Am Fam Physician
January 2025
University of Florida College of Medicine, Gainesville.
Jaundice is an indication of hyperbilirubinemia and is caused by derangements in bilirubin metabolism. It is typically apparent when serum bilirubin levels exceed 3 mg/dL and can indicate serious underlying disease of the liver or biliary tract. A comprehensive medical history, review of systems, and physical examination are essential for differentiating potential causes such as alcoholic liver disease, biliary strictures, choledocholithiasis, drug-induced liver injury, hemolysis, or hepatitis.
View Article and Find Full Text PDFJ Neurosurg
January 2025
2Department of Radiology, Service of Interventional Neuroradiology, Centre hospitalier de l'Université de Montréal (CHUM), Montréal.
Objective: Many patients with ruptured intracranial aneurysms (RIAs) underrepresented or excluded from previous randomized controlled trials (RCTs) comparing surgery with endovascular treatment (EVT) are still considered for surgical clipping, but the best management of these patients remains unknown.
Methods: The International Subarachnoid Aneurysm Trial-2 was a randomized trial comparing surgical versus EVT of RIAs considered for surgical clipping, despite the results of previous RCTs, and also eligible for EVT. The primary endpoint was death or dependency according to the modified Rankin Scale score (mRS score > 2) at 1 year.
J Neurosurg Pediatr
January 2025
1Department of Neurosurgery, Queensland Children's Hospital, Brisbane; and.
Objective: Ventricular shunt insertion is a common procedure in pediatric neurosurgical practice. In many areas of medicine there is a push toward rationalization of healthcare resources and a reduction in low-value tests or procedures. The intraoperative sampling of CSF at the time of shunt insertion is one traditional aspect of care that has not been rigorously evaluated.
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