Purpose: Arm-artifact, a type of streak artifact frequently observed in computed tomography (CT) images obtained at arms-down positioning in polytrauma patients, is known to degrade image quality. This study aimed to develop a novel arm-artifact reduction algorithm (AAR) applied to projection data.
Methods: A phantom resembling an adult abdomen with two arms was scanned using a 16-row CT scanner. The projection data were processed by AAR, and CT images were reconstructed. The artifact reduction for the same phantom was compared with that achieved by two latest iterative reconstruction (IR) techniques (IR1 and IR2) using a normalized artifact index (nAI) at two locations (ventral and dorsal side). Image blurring as a processing side effect was compared with IR2 of the model-based IR using a plastic needle phantom. Additionally, the projection data of two clinical cases were processed using AAR, and the image noise was evaluated.
Results: AAR and IR2 significantly reduced nAI by 87.5% and 74.0%, respectively at the ventral side and 84.2% and 69.6%, respectively, at the dorsal side compared with each filtered back projection (P < 0.01), whereas IR1 did not. The proposed algorithm mostly maintained the original spatial resolution, compared with IR2, which yielded apparent image blurring. The image noise in the clinical cases was also reduced significantly (P < 0.01).
Conclusions: AAR was more effective and superior than the latest IR techniques and is expected to improve the image quality of polytrauma CT imaging with arms-down positioning.
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http://dx.doi.org/10.1016/j.ejmp.2019.11.019 | DOI Listing |
Biomed Opt Express
January 2025
Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
In fiber-based confocal microscopy, using two separate fibers for illumination and collection enables the use of a few-mode fiber to achieve an effect similar to opening the pinhole in a conventional confocal microscope. In some Fourier-domain applications, however, or when a spectral measurement is involved, the coherent light detection would lead to noticeable spectral modulation artifacts that result from differential mode delay, an effect caused by the multimode propagation in the collection fiber. After eliminating these artifacts by using mode-dependent polarization control, we demonstrate effective spectrally encoded imaging with improved signal efficiency and lower speckle noise, and only a minor, negligible reduction in lateral and axial resolutions.
View Article and Find Full Text PDFComput Methods Programs Biomed
January 2025
Key Laboratory of Computer Network and Information Integration (Southeast University), Ministry of Education, Nanjing, China; School of Computer Science and Engineering, Southeast University, Nanjing, China.
Purpose: Dual-energy computed tomography (DECT) enables the differentiation of different materials. Additionally, DECT images consist of multiple scans of the same sample, revealing information similarity within the energy domain. To leverage this information similarity and address safety concerns related to excessive radiation exposure in DECT imaging, sparse view DECT imaging is proposed as a solution.
View Article and Find Full Text PDFInvest Radiol
January 2025
From the Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Bonn, Germany (N.M., A.I., A.L., L.B., T.D., D. Kravchenko, D. Kuetting, C.C.P., J.A.L.); Quantitative Imaging Lab Bonn (QILaB), Bonn, Germany (N.M., A.I., L.B., D. Kravchenko, D. Kuetting, J.A.L.); Philips Healthcare, Hamburg, Germany (C.K.); Philips Medical Systems, Eindhoven, the Netherlands (A.H.-M.); and Department of Diagnostic and Interventional Radiology, University Hospital Aachen, Aachen, Germany (C.Y.).
Objectives: Impaired image quality and long scan times frequently occur in respiratory-triggered sequences in liver magnetic resonance imaging (MRI). We evaluated the impact of an in-bore active breathing guidance (BG) application on image quality and scan time of respiratory-triggered T2-weighted (T2) and diffusion-weighted imaging (DWI) by comparing sequences with standard triggering (T2S and DWIS) and with BG (T2BG and DWIBG).
Materials And Methods: In this prospective study, random patients with clinical indications for liver MRI underwent 3 T MRI with standard and BG acquisitions.
J Orthop Case Rep
January 2025
Department of Trauma and Orthopaedic Surgeon, Cork University Hospital, Ireland.
Introduction: In this article, we report a unique case of head-stem dissociation in a metal-on-metal total hip replacement which utilized an Exeter stem. Although metallosis and pseudotumor formation are well recognized complications of metal-on-metal hip replacements, head-stem dissociations are rare with few being reported in literature. To the best of our knowledge, this case report is the first to report this occurrence in an Exeter stem.
View Article and Find Full Text PDFGlobal Spine J
January 2025
Department of Orthopedics, IRCCS Galeazzi Orthopaedic Institute, Milan, Italy.
Study Design: Narrative Review.
Objective: The management of spinal tumors requires a multi-disciplinary approach including surgery, radiation, and systemic therapy. Surgical approaches typically require posterior segmental instrumentation to maintain long-term spinal stability.
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