Introduction: Cardiac contraction significantly degrades quality and quantitative accuracy of gated myocardial perfusion SPECT (MPS) images. In this study, we aimed to explore different techniques in motion-compensated temporal processing of MPS images and their impact on image quality and quantitative accuracy.
Material And Method: 50 patients without known heart condition underwent gated MPS. 3D motion compensation methods using Motion Freezing by Cedars Sinai (MF), Log-domain Diffeomorphic Demons (LDD) and Free-Form Deformation (FFD) were applied to warp all image phases to fit the end-diastolic (ED) phase. Afterwards, myocardial wall thickness, myocardial to blood pool contrast, and image contrast-to noise ratio (CNR) were measured in summed images with no motion compensation (NoMC) and compensated images (MF, LDD and FFD). Total Perfusion Defect (TPD) was derived from Cedars-Sinai software, on the basis of sex-specific normal limits.
Result: Left ventricle (LV) lateral wall thickness was reduced after applying motion compensation (p < 0.05). Myocardial to blood pool contrast and CNR in compensated images were greater than NoMC (p < 0.05). TPD_LDD was in good agreement with the corresponding TPD_MF (p = 0.13).
Conclusion: All methods have improved image quality and quantitative performance relative to NoMC. LDD and FFD are fully automatic and do not require any manual intervention, while MF is dependent on contour definition. In terms of diagnostic parameters LDD is in good agreement with MF which is a clinically accepted method. Further investigation along with diagnostic reference standards, in order to specify diagnostic value of each technique is recommended.
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http://dx.doi.org/10.1016/j.ejmp.2018.05.004 | DOI Listing |
MAGMA
December 2024
IADI U1254, Inserm, Université de Lorraine, 54000, Nancy, France.
Objective: Computing the trajectories of mandibular condyles directly from MRI could provide a comprehensive examination, providing both anatomical and kinematic details. This study aimed to investigate the feasibility of extracting 3D condylar trajectories from 2D real-time MRI.
Materials And Methods: Twenty healthy subjects underwent real-time MRI while performing jaw opening and closing movements.
Biomimetics (Basel)
December 2024
Devol Advanced Automation, Inc., Shenzhen 518101, China.
Direct-drive servo systems are extensively applied in biomimetic robotics and other bionic applications, but their performance is susceptible to uncertainties and disturbances. This paper proposes an adaptive disturbance rejection Zeta-backstepping control scheme with adjustable damping ratios to enhance system robustness and precision. An iron-core permanent magnet linear synchronous motor (PMLSM) was employed as the experimental platform for the development of a dynamic model that incorporates compensation for friction and cogging forces.
View Article and Find Full Text PDFBackground: Failure after rotator cuff repair is typically due to a loss of integrity of the bone-tendon interface. The BioWick anchor (Zimmer-Biomet) is an interpositional scaffold-anchor that was developed to improve tendon-bone healing. The purpose of this study was to determine the clinical efficacy of this novel anchor compared with a standard anchor with respect to retear rates and patient outcomes.
View Article and Find Full Text PDFNano Lett
December 2024
Tianjin Key Laboratory for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering, Nankai University, 300350 Tianjin, China.
Architectures based on a magnetic domain wall (DW) can store and process information at a high speed in a nonvolatile manner with ultra-low power consumption. Recently, transition-metal rare earth metal alloy-based ferrimagnets have attracted a considerable amount of attention for the ultrafast current-driven DW motion. However, the high-speed DW motion is subject to film inhomogeneity and device edge defects, causing challenges in controlling the DW motion and hindering practical application.
View Article and Find Full Text PDFClin Biomech (Bristol)
December 2024
Scottish Rite for Children, Dallas, TX, USA.
Background: Adolescent hip dysplasia is a condition that often affects hip mechanics, leading to loss of function, pain, and early onset osteoarthritis. Objective literature investigating functional activities remains sparse within this population. A traditional body weight deep squat has translation to everyday tasks, is a clinical screening tool, and is also a common pre/rehabilitation exercise.
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