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motion-compensation
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Total 23 records
Object detection based on weighted adaptive prediction in lifting scheme transform
, Article ISM 2006 - 8th IEEE International Symposium on Multimedia, San Diego, CA, 11 December 2006 through 13 December 2006 ; 2006 , Pages 652-656 ; 0769527469 (ISBN); 9780769527468 (ISBN) ; Rabiee, H. R ; Sharif University of Technology
2006
Abstract
This paper presents a new algorithm for detecting user-selected objects in a sequence of images based on a new weighted adaptive lifting scheme transform. In our algorithm, we first select a set of coefficients as object features in the wavelet transform domain and then build an adaptive transform considering the selected features. The goal of the designed adaptive transform is to "vanish" the selected features as much as possible in the transform domain. After applying both non-adaptive and adaptive transforms to a given test image, the corresponding transform domain coefficients are compared for detecting the object of interest. We have verified our claim with experimental results on 1-D...
The biomechanical response of the lower cervical spine post laminectomy: geometrically-parametric patient-specific finite element analyses
, Article Journal of Medical and Biological Engineering ; Volume 41, Issue 1 , 2021 , Pages 59-70 ; 16090985 (ISSN) ; Cheng, C. H ; Wang, J. L ; Niu, C. C ; Parnianpour, M ; Khalaf, K ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Purpose: This study aimed to investigate the biomechanical impact of laminectomy on cervical intersegmental motion and load sharing using a parametric patient-specific finite element (FE) model towards providing clinicians with a viable quantitative tool for informed decision-making and improved surgical planning. Methods: Ten subject-specific nonlinear osteo-ligamentous cervical spine (C3–C7) FE models were developed using X-ray image-based algorithms. The models were used to evaluate the effect of laminectomy on lower cervical spine biomechanics for two-level (C3–C4) and three-level (C3–C5) laminectomy procedures. Results: The average cervical spine ranges of motion (ROM) for the pre-op...
Cardiac contraction motion compensation in gated myocardial perfusion SPECT: a comparative study
, Article Physica Medica ; Volume 49 , 2018 , Pages 77-82 ; 11201797 (ISSN) ; Rahmim, A ; Fatemizadeh, E ; Akbarzadeh, A ; Farahani, M. H ; Farzanefar, S ; Ay, M. R ; Sharif University of Technology
Associazione Italiana di Fisica Medica
2018
Abstract
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...