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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) ; Torabi, M ; Kim, K ; Sharif University of Technology
2010
Abstract
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...
Deep learning for caries detection: A systematic review
, Article Journal of Dentistry ; Volume 122 , 2022 ; 03005712 (ISSN) ; Motamedian, S. R ; Rohban, M. H ; Krois, J ; Uribe, S. E ; Mahmoudinia, E ; Rokhshad, R ; Nadimi, M ; Schwendicke, F ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Objectives: Detecting caries lesions is challenging for dentists, and deep learning models may help practitioners to increase accuracy and reliability. We aimed to systematically review deep learning studies on caries detection. Data: We selected diagnostic accuracy studies that used deep learning models on dental imagery (including radiographs, photographs, optical coherence tomography images, near-infrared light transillumination images). The latest version of the quality assessment tool for diagnostic accuracy studies (QUADAS-2) tool was used for risk of bias assessment. Meta-analysis was not performed due to heterogeneity in the studies methods and their performance measurements....
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) ; Negahdari, B ; Eatemadi, A ; Sharif University of Technology
Elsevier Masson SAS
2017
Abstract
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 ; Abedian, A ; Nasiri, M ; Sharif University of Technology
John Wiley and Sons Ltd
2020
Abstract
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) ; Takamjani, I. E ; Kamyab, M ; Kalbassi, G ; Sarrafzadeh, J ; Parnianpour, M ; Sharif University of Technology
Lippincott Williams and Wilkins
2019
Abstract
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) ; Hosseini, S. A ; Reza Ay, M ; Zaidi, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
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) ; Salekshahrezaee, Z ; Mohammadi Tofigh, A ; Ghanavati, R ; Arandian, B ; Chapnevis, A ; Sharif University of Technology
Hindawi Limited
2021
Abstract
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...
Numerical and experimental evaluation of ultrasound-assisted convection enhanced delivery to transfer drugs into brain tumors
, Article Scientific Reports ; Volume 12, Issue 1 , 2022 ; 20452322 (ISSN) ; Mehrarya, M ; Ghanbarzadeh Dagheyan, A ; Ahmadian, M. T ; Sharif University of Technology
Nature Research
2022
Abstract
Central Nervous System (CNS) malignant tumors are a leading cause of death worldwide with a high mortality rate. While numerous strategies have been proposed to treat CNS tumors, the treatment efficacy is still low mainly due to the existence of the Blood–Brain Barrier (BBB). BBB is a natural cellular layer between the circulatory system and brain extracellular fluid, limiting the transfer of drug particles and confining the routine treatment strategies in which drugs are released in the blood. Consequently, direct drug delivery methods have been devised to bypass the BBB. However, the efficiency of these methods is not enough to treat deep and large brain tumors. In the study at hand, the...
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) ; Ahmadi Noubari, H ; Fatemizadeh, E ; Khalili, M ; Sharif University of Technology
PWN-Polish Scientific Publishers
2016
Abstract
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) ; 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
Abstract
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) ; Fatemizadeh, E ; Soltanian Zadeh, H ; Sharif University of Technology
Abstract
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) ; Rahbarizadeh, F ; Ahmadvand, D ; Madaah Hosseini, H. R ; Sharif University of Technology
Abstract
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) ; 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
Abstract
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 ; Chashmniam, S ; Khoormizi, S. M. H ; Salehi, L ; Jamalian, S. A ; Nafar, M ; Kalantari, S ; Sharif University of Technology
Springer
2020
Abstract
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 ; Ahmadian, M. T ; Mohammadi, H ; Sharif University of Technology
Wiley-Blackwell
2020
Abstract
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) ; Chizari, M ; Mortazavi, J ; Rouhi, G ; Sharif University of Technology
BioMed Central Ltd
2021
Abstract
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...
Modeling of an ultrasound system in targeted drug delivery to abdominal aortic aneurysm: a patient-specificin silico study based on ligand-receptor binding
, Article IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control ; Volume 69, Issue 3 , 2022 , Pages 967-974 ; 08853010 (ISSN) ; Boroumand, A ; Ebrahimi, S ; Kalantarnia, F ; Maleki, S ; Moradi, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Targeted drug delivery methods have shown a significant impact on enhancing drug delivery efficiency and reducing drug side effects. While various stimuli have been used to promote the drug delivery process, applying ultrasound (US) waves to control drug particles through the human body, noninvasively, has drawn the scientist's attention. However, microcarriers delivery reaches the aneurysmal artery by US waves that exert volumetric forces on blood, and drug carriers, which can therefore affect blood flow patterns and movement pathways of drug carriers, have not yet been studied. In this study, we developed a 3-D patient-specific model of abdominal aortic aneurysm (AAA) to evaluate the...
Effect of axonal fiber architecture on mechanical heterogeneity of the white matter—a statistical micromechanical model
, Article Computer Methods in Biomechanics and Biomedical Engineering ; Volume 25, Issue 1 , 2022 , Pages 27-39 ; 10255842 (ISSN) ; Farahmand, F ; Ahmadian, M. T ; Sharif University of Technology
Taylor and Francis Ltd
2022
Abstract
A diffusion tensor imaging (DTI) -based statistical micromechanical model was developed to study the effect of axonal fiber architecture on the inter- and intra-regional mechanical heterogeneity of the white matter. Three characteristic regions within the white matter, i.e., corpus callosum, brain stem, and corona radiata, were studied considering the previous observations of locations of diffuse axonal injury. The embedded element technique was used to create a fiber-reinforced model, where the fiber was characterized by a Holzapfel hyperelastic material model with variable dispersion of axonal orientations. A relationship between the fractional anisotropy and the dispersion parameter of...
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) ; Ahmadian, M. T ; Sharif University of Technology
Abstract
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) ; Fatemizadeh, E ; Mahoor, M. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
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...