Search for: diagnostic-imaging
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    Parallel nonlinear analysis of weighted brain's gray and white matter images for Alzheimer's dementia diagnosis

    , Article Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference ; 2010 , Pages 5573-5576 ; 1557170X (ISSN) Razavian, S. M ; Torabi, M ; Kim, K ; Sharif University of Technology
    In this study, we are proposing a novel nonlinear classification approach to discriminate between Alzheimer's Disease (AD) and a control group using T1-weighted and T2-weighted Magnetic Resonance Images (MRI's) of brain. Since T1-weighted images and T2-weighted images have inherent physical differences, obviously each of them has its own particular medical data and hence, we extracted some specific features from each. Then the variations of the relevant eigenvalues of the extracted features were tracked to pick up the most informative ones. The final features were assigned to two parallel systems to be nonlinearly categorized. Considering the fact that AD defects the white and gray regions... 

    Synthesis, properties and biomedical applications of carbon-based quantum dots: an updated review

    , Article Biomedicine and Pharmacotherapy ; Volume 87 , 2017 , Pages 209-222 ; 07533322 (ISSN) Namdari, P ; Negahdari, B ; Eatemadi, A ; Sharif University of Technology
    Elsevier Masson SAS  2017
    Carbon-based quantum dots (CQDs) are a newly developed class of carbon nano-materials that have attracted much interest and attention as promising competitors to already available semiconductor quantum dots owing to their un-comparable and unique properties. In addition, controllability of CQDs unique physiochemical properties is as a result of their surface passivation and functionalization. This is an update article (between 2013 and 2016) on the recent progress, characteristics and synthesis methods of CQDs and different advantages in varieties of applications. © 2017 Elsevier Masson SAS  

    Optimal sensors layout design based on reference-free damage localization with lamb wave propagation

    , Article Structural Control and Health Monitoring ; Volume 27, Issue 4 , 10 January , 2020 Keshavarz Motamed, P ; Abedian, A ; Nasiri, M ; Sharif University of Technology
    John Wiley and Sons Ltd  2020
    This study presents a new approach for designing optimal sensors layout based on accuracy of defect mapping. It is obtained from combination of the reference-free damage detection technique and the probability-based diagnostic imaging method. Considering damage indices based on continuous wavelet transform of sensors signals, the core of this study involves with development of a database of continuous wavelet transform features of a crack. In fact, the database contains the data from 594 different states in crack positions, orientations, and the considered sensing path lengths. Eventually, this database is used for localization of damage by interpolating the stored data collected from the... 

    The effect of lumbosacral orthosis on the thickness of deep trunk muscles using ultrasound imaging: a randomized controlled trial in patients with chronic low back pain

    , Article American Journal of Physical Medicine and Rehabilitation ; Volume 98, Issue 7 , 2019 , Pages 536-544 ; 08949115 (ISSN) Azadinia, F ; Takamjani, I. E ; Kamyab, M ; Kalbassi, G ; Sarrafzadeh, J ; Parnianpour, M ; Sharif University of Technology
    Lippincott Williams and Wilkins  2019
    Objective This study was conducted to evaluate the changes occurring in the thickness of deep trunk muscles, measured using ultrasound imaging, after 4 wks of lumbosacral orthosis use in conjunction with routine physical therapy. Design This parallel-group, randomized, controlled trial was conducted on 44 patients with nonspecific chronic low back pain, randomly allocated to the experimental and control groups. Both groups received eight sessions of physical therapy twice per week for 4 wks. The experimental group wore nonextensible lumbosacral orthosis, in addition to undergoing routine physical therapy. The thickness of the transversus abdominis, obliquus internus, and lumbar multifidus... 

    MCNP-FBSM: Development of MCNP/MCNPX Source Model for Simulation of Multi-Slice Fan-Beam X-Ray CT Scanners

    , Article 2019 IEEE International Symposium on Medical Measurements and Applications, MeMeA 2019, 26 June 2019 through 28 June 2019 ; 2019 ; 9781538684276 (ISBN) Khodajou Chokami, H ; Hosseini, S. A ; Reza Ay, M ; Zaidi, H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Computed tomography (CT) is one of the most valuable diagnostic imaging tools in the clinic and is widely used worldwide. One of the main motivations driving research and development in CT is to achieve better image quality while keeping the radiation dose to the patient as low as possible. In this regard, computer simulations play a key role in the optimization of CT design. In this work, a fan-beam source model (FBSM) for the simulation of multi-slice fan-beam CT scanners using the MCNP Monte Carlo code, has been developed and implemented. The use of this model removes the need for using the collimator in the system configuration and thus to overcome the perennial problem of particle... 

    COVID-19 diagnosis using capsule network and fuzzy c -means and mayfly optimization algorithm

    , Article BioMed Research International ; Volume 2021 , 2021 ; 23146133 (ISSN) Farki, A ; Salekshahrezaee, Z ; Mohammadi Tofigh, A ; Ghanavati, R ; Arandian, B ; Chapnevis, A ; Sharif University of Technology
    Hindawi Limited  2021
    The COVID-19 epidemic is spreading day by day. Early diagnosis of this disease is essential to provide effective preventive and therapeutic measures. This process can be used by a computer-aided methodology to improve accuracy. In this study, a new and optimal method has been utilized for the diagnosis of COVID-19. Here, a method based on fuzzy C-ordered means (FCOM) along with an improved version of the enhanced capsule network (ECN) has been proposed for this purpose. The proposed ECN method is improved based on mayfly optimization (MFO) algorithm. The suggested technique is then implemented on the chest X-ray COVID-19 images from publicly available datasets. Simulation results are... 

    Classification of abnormalities in mammograms by new asymmetric fractal features

    , Article Biocybernetics and Biomedical Engineering ; Volume 36, Issue 1 , 2016 , Pages 56-65 ; 02085216 (ISSN) Beheshti, S. M. A ; Ahmadi Noubari, H ; Fatemizadeh, E ; Khalili, M ; Sharif University of Technology
    PWN-Polish Scientific Publishers  2016
    In this paper we use fractal method for detection and diagnosis of abnormalities in mammograms. We have used 168 images that were carefully selected by a radiologist and their abnormalities were also confirmed by biopsy. These images included asymmetric lesions, architectural distortion, normal tissue and mass lesion where in case of mass lesion they included circumscribed benign, ill-defined and spiculated malignant masses. At first, by using wavelet transform and piecewise linear coefficient mapping, image enhancement were done. Secondly detection of lesions was done by fractal method as a ROI. Since in investigation of breast cancer, it is important that fibroglandular tissues in both... 

    Nanotechnology in diagnosis and treatment of coronary artery disease

    , Article Nanomedicine ; Volume 11, Issue 5 , 2016 , Pages 513-530 ; 17435889 (ISSN) Karimi, M ; Zare, H ; Bakhshian Nik, A ; Yazdani, N ; Hamrang, M ; Mohamed, E ; Sahandi Zangabad, P ; Moosavi Basri, S. M ; Bakhtiari, L ; Hamblin, M. R ; Sharif University of Technology
    Future Medicine Ltd 
    Nanotechnology could provide a new complementary approach to treat coronary artery disease (CAD) which is now one of the biggest killers in the Western world. The course of events, which leads to atherosclerosis and CAD, involves many biological factors and cellular disease processes which may be mitigated by therapeutic methods enhanced by nanotechnology. Nanoparticles can provide a variety of delivery systems for cargoes such as drugs and genes that can address many problems within the arteries. In order to improve the performance of current stents, nanotechnology provides different nanomaterial coatings, in addition to controlled-release nanocarriers, to prevent in-stent restenosis.... 

    Sparse registration of diffusion weighted images

    , Article Computer Methods and Programs in Biomedicine ; Volume 151 , 2017 , Pages 33-43 ; 01692607 (ISSN) Afzali, M ; Fatemizadeh, E ; Soltanian Zadeh, H ; Sharif University of Technology
    Background and objective Registration is a critical step in group analysis of diffusion weighted images (DWI). Image registration is also necessary for construction of white matter atlases that can be used to identify white matter changes. A challenge in the registration of DWI is that the orientation of the fiber bundles should be considered in the process, making their registration more challenging than that of the scalar images. Most of the current registration methods use a model of diffusion profile, limiting the method to the used model. Methods We propose a model-independent method for DWI registration. The proposed method uses a multi-level free-form deformation (FFD), a sparse... 

    Anti-HER2 VHH targeted magnetoliposome for intelligent magnetic resonance imaging of breast cancer cells

    , Article Cellular and Molecular Bioengineering ; Volume 10, Issue 3 , 2017 , Pages 263-272 ; 18655025 (ISSN) Khaleghi, S ; Rahbarizadeh, F ; Ahmadvand, D ; Madaah Hosseini, H. R ; Sharif University of Technology
    The combination of liposomes with magnetic nanoparticles, because of their strong effect on T2 relaxation can open new ways in the innovative cancer therapy and diagnosis. In order to design an intelligent contrast agent in MRI, we chose anti-HER2 nanobody the smallest fully functional antigen-binding fragments evolved from the variable domain, the VHH, of a camel heavy chain-only antibody. These targeted magnetoliposomes bind to the HER2 antigen which is highly expressed on breast and ovarian cancer cells so reducing the side effects as well as increasing image contrast and effectiveness. Cellular iron uptake analysis and in vitro MRI of HER2 positive cells incubated with targeted... 

    Optical radiomic signatures derived from optical coherence tomography images improve identification of melanoma

    , Article Cancer Research ; Volume 79, Issue 8 , 2019 , Pages 2021-2030 ; 00085472 (ISSN) Turani, Z ; Fatemizadeh, E ; Blumetti, T ; Daveluy, S ; Moraes, A. F ; Chen, W ; Mehregan, D ; Andersen, P. E ; Nasiriavanaki, M ; Sharif University of Technology
    American Association for Cancer Research Inc  2019
    The current gold standard for clinical diagnosis of melanoma is excisional biopsy and histopathologic analysis. Approximately 15–30 benign lesions are biopsied to diagnose each melanoma. In addition, biopsies are invasive and result in pain, anxiety, scarring, and disfigurement of patients, which can add additional burden to the health care system. Among several imaging techniques developed to enhance melanoma diagnosis, optical coherence tomography (OCT), with its high-resolution and intermediate penetration depth, can potentially provide required diagnostic information noninvasively. Here, we present an image analysis algorithm, "optical properties extraction (OPE)," which improves the... 

    Urine and serum NMR-based metabolomics in pre-procedural prediction of contrast-induced nephropathy

    , Article Internal and Emergency Medicine ; Volume 15, Issue 1 , 2020 , Pages 95-103 Dalili, N ; Chashmniam, S ; Khoormizi, S. M. H ; Salehi, L ; Jamalian, S. A ; Nafar, M ; Kalantari, S ; Sharif University of Technology
    Springer  2020
    Contrast induced nephropathy (CIN) has been reported to be the third foremost cause of acute renal failure. Metabolomics is a robust technique that has been used to identify potential biomarkers for the prediction of renal damage. We aim to analyze the serum and urine metabolites changes, before and after using contrast for coronary angiography, to determine if metabolomics can predict early development of CIN. 66 patients undergoing elective coronary angiography were eligible for enrollment. Urine and serum samples were collected prior to administration of CM and 72 h post procedure and analyzed by nuclear magnetic resonance. The significant differential metabolites between patients who... 

    Rigid-bar loading on pregnant uterus and development of pregnant abdominal response corridor based on finite element biomechanical model

    , Article International Journal for Numerical Methods in Biomedical Engineering ; Volume 36, Issue 1 , January , 2020 Irannejad Parizi, M ; Ahmadian, M. T ; Mohammadi, H ; Sharif University of Technology
    Wiley-Blackwell  2020
    During pregnancy, traumas can threaten maternal and fetal health. Various trauma effects on a pregnant uterus are little investigated. In the present study, a finite element model of a uterus along with a fetus, placenta, amniotic fluid, and two most effective ligament sets is developed. This model allows numerical evaluation of various loading on a pregnant uterus. The model geometry is developed based on CT-scan data and validated using anthropometric data. Applying Ogden hyper-elastic theory, material properties of uterine wall and placenta are developed. After simulating the “rigid-bar” abdominal loading, the impact force and abdominal penetration are investigated. Findings are compared... 

    Can the body slope of interference screw affect initial stability of reconstructed anterior cruciate ligament?: An in-vitro investigation

    , Article BMC Musculoskeletal Disorders ; Volume 22, Issue 1 , 2021 ; 14712474 (ISSN) Daneshvarhashjin, N ; Chizari, M ; Mortazavi, J ; Rouhi, G ; Sharif University of Technology
    BioMed Central Ltd  2021
    Background: Superior biomechanical performance of tapered interference screws, compared with non-tapered screws, with reference to the anterior cruciate ligament (ACL) reconstruction process, has been reported in the literature. However, the effect of tapered interference screw’s body slope on the initial stability of ACL is poorly understood. Thus, the main goal of this study was to investigate the effect of the interference screw’s body slope on the initial stability of the reconstructed ACL. Methods: Based on the best screw-bone tunnel diameter ratios in non-tapered screws, two different tapered interference screws were designed and fabricated. The diameters of both screws were equal to... 

    Investigation of the effect of high +Gz accelerations on human cardiac function

    , Article Journal of the Mechanical Behavior of Biomedical Materials ; Volume 27 , 2013 , Pages 54-63 ; 17516161 (ISSN) Jamshidi, M ; Ahmadian, M. T ; Sharif University of Technology
    This study investigates the effect of body acceleration on human cardiac function. Finite element analysis is conducted to simulate geometrical and mechanical properties of human heart. Heart geometrical modeling in three-dimension is performed by segmentation of cardiac MRI images. The nonlinear mechanical behavior of myocardium is modeled by Mooney-Rivlin, Polynomial, Ogden and Yeoh hyperelastic material models. Stress-strain curves of myocardial tissue are obtained from experimental compression tests on bovine heart samples. The experimental results are employed for the evaluation of material coefficients by the nonlinear least squares method. Among hyperelastic models, the Yeoh model... 

    Intensity estimation of spontaneous facial action units based on their sparsity properties

    , Article IEEE Transactions on Cybernetics ; Volume 46, Issue 3 , 2016 , Pages 817-826 ; 21682267 (ISSN) Mohammadi, M. R ; Fatemizadeh, E ; Mahoor, M. H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Automatic measurement of spontaneous facial action units (AUs) defined by the facial action coding system (FACS) is a challenging problem. The recent FACS user manual defines 33 AUs to describe different facial activities and expressions. In spontaneous facial expressions, a subset of AUs are often occurred or activated at a time. Given this fact that AUs occurred sparsely over time, we propose a novel method to detect the absence and presence of AUs and estimate their intensity levels via sparse representation (SR). We use the robust principal component analysis to decompose expression from facial identity and then estimate the intensity of multiple AUs jointly using a regression model... 

    Review on different experimental techniques developed for recording force-deformation behaviour of soft tissues; with a view to surgery simulation applications

    , Article Journal of Medical Engineering and Technology ; Volume 41, Issue 4 , 2017 , Pages 257-274 ; 03091902 (ISSN) Afshari, E ; Rostami, M ; Farahmand, F ; Sharif University of Technology
    Different experimental techniques which have been developed to obtain data related to force-deformation behaviour of soft tissues play an important role in realistically simulating surgery processes as well as medical diagnoses and minimally invasive procedures. Indeed, an adequate quantitative description of soft-tissue-mechanical-behaviour requires high-quality experimental data to be obtained and analysed. In this review article we will first scan the motivations and basic technical issues on surgery simulation. Then, we will concentrate on different experimental techniques developed for recording force-deformation (stress-strain) behaviour of soft tissues with focussing on the in-vivo... 

    Findings of DTI-p maps in comparison with T 2 /T 2 -FLAIR to assess postoperative hyper-signal abnormal regions in patients with glioblastoma 08 Information and Computing Sciences 0801 Artificial Intelligence and Image Processing

    , Article Cancer Imaging ; Volume 18, Issue 1 , 2018 ; 14707330 (ISSN) Beigi, M ; Safari, M ; Ameri, A ; Shojaee Moghadam, M ; Arbabi, A ; Tabatabaeefar, M ; Salighehrad, H ; Sharif University of Technology
    BioMed Central Ltd  2018
    Purpose: The aim of this study was to compare diffusion tensor imaging (DTI) isotropic map (p-map) with current radiographically (T 2/T 2 -FLAIR) methods based on abnormal hyper-signal size and location of glioblastoma tumor using a semi-automatic approach. Materials and methods: Twenty-five patients with biopsy-proved diagnosis of glioblastoma participated in this study. T 2, T 2 -FLAIR images and diffusion tensor imaging (DTI) were acquired 1 week before radiotherapy. Hyper-signal regions on T 2, T 2 -FLAIR and DTI p-map were segmented by means of semi-automated segmentation. Manual segmentation was used as ground truth. Dice Scores (DS) were calculated for validation of semiautomatic... 

    An improved synthesis and preliminary biodistribution study of a technetium-99m-labeled2-amino-2-deoxy(thioacetyl)-D-glucose complex ([ 99mTc]-TA-DG) as a tumor imaging agent

    , Article Iranian Journal of Nuclear Medicine ; Volume 15, Issue 28 , 2007 , Pages 43-48 ; 16812824 (ISSN) Johari Daha, F ; Sadeghzadeh, M ; Charkhlooie, G ; Haghir Ebrahimabadi, K ; Saeedi, M. R ; Sharif University of Technology
    Introduction: This report describes the synthesis of 2-Amino-2-deoxy(S- benzoylthioacetyl)-D-glucose (S-Bz-TA-DG), radiolabeled with [ 99mTc(CO)3(OH2)3]+ complex with a procedure including deprotection of the benzoyl group, characterization by HPLC using a C18 reverse phase column and preliminary biodistribution study in normal mice. Methods: [99mTc(CO) 3(H2O)3]+ complex was used to label TA-DG with 99mTc. This complex was prepared using up to 46 mCi of Na99mTcO4 in 1mL saline. The radiochemical purity (>95%) was determined by TLC in normal saline solution as the mobile phase. Radio-HPLC analysis of [99mTc]-(TA-DG) at pH=9.5-10, revealed that labeling with 99mTc resulted in the formation of... 

    Spatiotemporal registration and fusion of transthoracic echocardiography and volumetric coronary artery tree

    , Article International Journal of Computer Assisted Radiology and Surgery ; Volume 16, Issue 9 , 2021 , Pages 1493-1505 ; 18616410 (ISSN) Ghodsizad, T ; Behnam, H ; Fatemizadeh, E ; Faghihi Langroudi, T ; Bayat, F ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Purpose: Cardiac multimodal image fusion can offer an image with various types of information in a single image. Many coronary stenosis, which are anatomically clear, are not functionally significant. The treatment of such kind of stenosis can cause irreversible effects on the patient. Thus, choosing the best treatment planning depend on anatomical and functional information is very beneficial. Methods: An algorithm for the fusion of coronary computed tomography angiography (CCTA) as an anatomical and transthoracic echocardiography (TTE) as a functional modality is presented. CCTA and TTE are temporally registered using manifold learning. A pattern search optimization algorithm, using...