Search Results

You are looking at 1 - 10 of 78 items :

  • "Artifacts Reduction" x
Clear All

tm 11/2010 Beiträge Synchronous Artefact Reduction in Industrial Computed Tomography Einsatzsynchrone Artefakt-Reduktion in der industriellen Computertomografie Matthias Franz, Stefan Kasperl, Fraunhofer-Institut für Integrierte Schaltungen, Fürth, Marc Stamminger, Friedrich-Alexander-Universität Erlangen-Nürnberg Summary Computed tomography (CT) can be used for di- mensional measurement. Reliable results require an effective artefact correction. In two earlier papers a Synchronous Arte- fact Correction (German: Einsatzsynchrone Artefakt-Reduktion EAR) was

Abstract

Tagged Magnetic Resonance Imaging (MRI) is a noninvasive technique for examining myocardial function and deformation. Tagged MRI can also be used in quasistatic MR elastography to acquire strain maps of other biological soft tissues. Harmonic phase (HARP) provides automatic and rapid analysis of tagged MR images for the quantification and visualization of myocardial strain. We propose a new artifact reduction method in strain maps. Image intensity of the DC component is estimated and subtracted from spatial modulation of magnetization (SPAMM) tagged MR images. DC peak interference in harmonic phase extraction is greatly reduced after DC component subtraction. The proposed method is validated using both simulated and MR acquired tagged images. Strain maps are obtained with better accuracy and smoothness after DC component subtraction.

. Monochromatic images synthesized from spectral imaging CT, metal artifact reduction algorithm, and iterative reconstruction are the three mostly applied approaches to reduce metal artifacts [ 2 , 3 , 4 , 5 , 6 ]. However, these techniques are highly dependent on the composition of the metal materials and may not be fully effective for implants with high attenuation coefficients such as dental fillings and hip implants. In this study, CT images were reconstructed using 40% ASiR and SMAR algorithms, and the image quality and the effectiveness of metal artifact reduction were

Artifact Reduction in Multichannel ECG Recordings Acquired with Textile Electrodes D. Zelle, P. Fiedler, J. Haueisen Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany patrique.fiedler@tu-ilmenau.de Abstract Textile electrodes integrated into clothes are an innovative approach for mobile ECG monitoring. However, the lack of electrode fixation on the skin causes high susceptibility to artifacts due to movements and changing electrochemical characteristics of the textile electrodes. In this paper we

interpolation approach. Most importantly, please note that small anatomical details are preserved and are not suppressed by the regularization term. Figure 4 Progression of the reconstruction. In each iteration a new non-local prior image is calculated. In the last raw a comparison of the proposed algorithm and the linear interpolation approach is shown. 4 Conclusion A metal artifact reduction algorithm is proposed, which integrates information based on a prior image. A transformation between intermediate results of the reconstruction and the prior image is found. The result

}\text{HU} . Choosing this interval allows to differentiate between the high-density metals and its surroundings [ 16 ]. However, metals may cause artifacts on CT images at both HU ranges which complicates a proper geometric delineation of the metallic objects and the structures nearby. A Siemens Somatom Definition Flash Dual Source CT scanner providing the above mentioned HU ranges was used. Maximum tube energy of 100 kV and 140 kV was available. The CT scanner provided metal artifact reduction (MAR) algorithms developed to improve image quality and RT treatment planning [ 17

to suppress artifacts as much as possible is the essential and meaningful work. Figure 1 The exterior circular CBCT scanning geometry configuration. When the cone angle is small and the projection data are complete, the FDK (Feldkamp–Davis–Kress) algorithm [ 6 ] and its modifications are the most popular methods in CBCT. However, in the ECCBCT, the FDK algorithm has a poor performance in artifact reduction. Many researchers deeply analyzed the reasons for the appearance of artifacts and proposed some algorithms to reduce artifacts [ 10 , 14 , 15 , 7 , 16

-295. 8. Komatsu, T., K. Aizawa, T. Igarashi. Signal-Processing Based Method for Acquiring Very High Resolution Image with Multiple Cameras and Its Theoretical Analysis. - Proc. Inst. Elec. Eng, Vol. 140, 1993, No 1, 19-25. 9. Patti, A. J., Y. Altunbasak. Artifact Reduction for Set Theoretic Super Resolution Image Reconstruction with Edge Adaptive Constraints and Higher-Order Interpolants. - IEEE Transactions on Image Processing, Vol. 10, 2001, No 1, 179-186. 10. Elad, M., A. Feuer. Restoration of a Single Super-Resolution Image from Several Blurred, Noisy and

vorgestellten Fusionsverfahren im Hinblick auf eine bestmögliche Artefaktreduktion weiter zu erhöhen. Danksagung Vielen Dank außerdem an die Firma Edscha für die Unterstützung und die zur Verfügungstellung des interessanten Untersuchungsobjekts. References 1. Gjesteby, L., De Man, B., Jin, Y., Paganetti, H., Verburg, J., Giantsoudi, D., & Wang, G. (2016). Metal artifact reduction in CT: where are we after four decades? IEEE Access, 4, 5826–5849. 10.1109/ACCESS.2016.2608621 Gjesteby L. De Man B. Jin Y. Paganetti H. Verburg J. Giantsoudi D. Wang G. 2016 Metal artifact reduction

reason the image quality parameters are measured for the focal depth (CBFF) and 2cm away from the focal depth (CBFUF). The simulation results (Table 1) show superior contrast for the CBF method but there is a major decrease in image quality outside of the focal zone. Biomed Tech 2013; 58 (Suppl. 1) © 2013 by Walter de Gruyter · Berlin · Boston. DOI 10.1515/bmt-2013-4264 Table 1: Simulation results for different variations of the beamforming methods Method Frame Rate Lateral Resolution Artefact Reduction Image Contrast CBFF 60 Hz 0.7 mm -32 dB 76 dB