Purpose: To evaluate the reduction of artifacts caused by total hip replacements (THR) in dual-layer DECT (DLCT) provided by the combination of virtual monoenergetic images (VMI) and orthopedic metal artifact reduction (MAR).
Materials And Methods: A total of 24 consecutive patients carrying THR, who received DLCT, were included. Four different images were reconstructed from the same CT dataset: a) conventional images (CI), b) conventional images with orthopedic metal artifact reduction (CI) c) VMI and d) VMI combined with orthopedic metal artifact reduction (VMI). VMI and VMI were reconstructed at 140 keV, 160 keV, 180 keV and 200 keV. Attenuation (HU) and noise (SD) were measured in order to evaluate reduction of hypodense and hyperdense artifacts, evaluate reduction of image noise as well as to calculate contrast-to-noise ratios (CNR). Image quality was additionally rated with regard to: a) extent of artifact reduction and assessment of b) pelvic organs, c) bone and d) muscle adjacent to the metal implants. Statistical analysis was performed using Wilcoxon test.
Results: VMI at high keV, 140, 160, 180 and 200 keV, led to the greatest reduction of hypodense artifacts in comparison to plain VMI or CI (p < 0.01), while in comparison to CI hyperdense artifacts were significantly reduced in all reconstructions (p < 0.05). Accordingly, subjective analysis found VMI to be superior in reducing hypodense artifacts in comparison to VMI and CI (p < 0.05), while hyperdense artifacts were equally reduced in all reconstructions compared to CI (p < 0.0001). Additionally, assessment of the pelvic organs and adjacent bone was significantly improved in VMI in comparison to VMI and CI (p < 0.05). In contrast, muscles adjacent to the metal implants were significantly better assessable in all reconstructions compared to CI (p < 0.01).
Conclusion: The combination of VMI and MAR yields strongest reduction of hypo- and hyperdense artifacts caused by total hip replacements in staging DLCT in comparison to each technique by itself.
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http://dx.doi.org/10.1016/j.ejrad.2018.12.008 | DOI Listing |
Phys Med Biol
January 2025
Electrical and Computer Engineering, University of Massachusetts Lowell, Ball Hall, 1 University Ave, Lowell, Massachusetts, 01854, UNITED STATES.
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View Article and Find Full Text PDFPLoS One
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Trinity Centre for Biomedical Engineering, Trinity College Dublin, Dublin, Ireland.
Electroencephalographic signals are obtained by amplifying and recording the brain's spontaneous biological potential using electrodes positioned on the scalp. While proven to help find changes in brain activity with a high temporal resolution, such signals are contaminated by non-stationary and frequent artefacts. A plethora of noise reduction techniques have been developed, achieving remarkable performance.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
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University of Toronto, Chemistry, 1265 Military Trail, M1C1A4, Toronto, CANADA.
The 2024 Zurich perfluorinated compounds (PFCs) summit reiterated the urgent need for non-selective analytical approaches for PFC detection. 19F NMR holds great potential, however, sensitivity limitations lead to long analysis times and/or the possibility of not detecting low concentration species. Steady State Free Precession (SSFP) NMR collects the signal in a steady state regime, allowing 100's of acquisitions in the timespan of a single traditional NMR scan.
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View Article and Find Full Text PDFNMR Biomed
March 2025
Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland, Australia.
In this work, we introduce spatial and chemical saturation options for artefact reduction in magnetic resonance fingerprinting (MRF) and assess their impact on T and T mapping accuracy. An existing radial MRF pulse sequence was modified to enable spatial and chemical saturation. Phantom experiments were performed to demonstrate flow artefact reduction and evaluate the accuracy of the T and T maps.
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