Feasibility Study of Capillary Blood Viscosity Estimation using MRI

, M.Sc. Thesis Sharif University of Technology Rafiei, Alireza (Author) ; Samadfam, Mohammad (Supervisor) ; Ashoor, Mansoor (Co-Advisor)

Abstract

Magnetic resonance imaging is one of non-invasive methods to measure the hemodynamic and morphologic parameters of tissues, especially brain tissues. Hemodynamic parameters monitoring in brain tissue is of significant importance in many majors such as detection of tumor occurrence, brain abnormalities, and track of treatment procedures. Blood is a suspension, comprised of plasma, red blood cells, white blood cells, platelet, etc. Plasma is a Newtonian fluid which is composed of proteins and has a constant viscosity in body temperature. Rheological properties of blood are highly dependent on mechanical and rheological properties of its cells and this dependence is multiplied in narrow vessels...

Estimation of mean radius, length and density of microvasculature using diffusion and perfusion MRI

, Article Scientia Iranica ; Volume 13, Issue 4 , 2006 , Pages 348-354 ; 10263098 (ISSN) Ashoor, M ; Jahed, M ; Chopp, M ; Mireshghi, A ; Sharif University of Technology

Sharif University of Technology 2006

Abstract

In theory, diffusion and perfusion information in MRI maps can be combined to yield morphological information, such as capillary density, volume and possibly capillary plasma velocity. This paper suggests a new method for determination of mean radius, length and capillary density in normal regions using diffusion and perfusion MRI. Mean Transit Time (MTT), Cerebral Blood Volume (CBV), Apparent Diffusion Coefficient (ADC), pseudo-diffusion coefficient (D*) and ΔR2 and ΔR2* values were utilized to calculate mean radius, length and capillary density. To verify the proposed theory, a special protocol was designed and tested on normal regions of a male Wistar rat using obtained functions. Mean...

Introducing a new definition towards clinical detection of microvascular changes using diffusion and perfusion MRI

, Article Scientia Iranica ; Volume 12, Issue 1 , 2005 , Pages 109-115 ; 10263098 (ISSN) Ashoor, M ; Jiang, Q ; Chopp, M ; Jahed, M ; Sharif University of Technology

Sharif University of Technology 2005

Abstract

Based on MRI diffusion and perfusion, a new criterion for detection and the healing progress of damaged tissue is suggested. The study is based on the ratio of capillary radii in symmetrical damaged and normal tissue neighboring spaces. The Apparent Diffusion Coefficient (ADC) and Cerebral Blood Flow (CBF) were measured in the brain tissues of six male Wistar rats utilizing suggested MRI measurement techniques. The ADC values of damaged and normal regions were (392 ± 34.1) × 10-6 mm2s-1 and (659 ± 40.7) × 10-6 mm2s-1, respectively. The CBF values of damaged and normal regions were 14.5 ± 10.13 ml/min/ 100 g and 125 ± 41.03 ml/min/100 g, respectively. The geometrical parameters of the...

Human Facial Activity Recognition using RGBD Videos

, M.Sc. Thesis Sharif University of Technology Ghanbarpour Jooybari, Mohsen (Author) ; Jamzad, Mansoor (Supervisor)

Abstract

Human facial activity recognition is one of the endeavors to improve human-computer interaction. Recognition of excitements and emotions on human face by machine and makinga corresponding reaction is essential for man machine intraction.The purpose of this project is recognizingactivities such as speaking, eating, laughing, agree and disagree which have more complexity than usualemotions such as fear and happinesscontained in common datasets.So, adataset in accordance with the above mentioned 5 activities was collected and the appropriate feature vector for analyzing these face activities were implemented.Distance between the interest points located on the face were used as parameters in...

Using genetic algorithm to identify soft-error derating blocks of an application program

, Article Proceedings - 15th Euromicro Conference on Digital System Design, DSD 2012, 5 September 2012 through 8 September 2012 ; September , 2012 , Pages 359-367 ; 9780769547985 (ISBN) Arasteh, B ; Rahmani, A. M ; Mansoor, A ; Miremadi, S. G ; Sharif University of Technology

2012

Abstract

Soft-errors are increasingly considered as a major cause for computer system failures. Software techniques are used as cost-effective and flexible techniques to tolerate soft-errors but the introduced overhead is not acceptable in some safety-critical real-time systems. The identification of the program blocks and protecting only vulnerable blocks against soft-errors reduces the performance overhead. In this paper, we present a genetic algorithm to identify the vulnerable program blocks as well as the derating program blocks against soft-errors. Then, only vulnerable blocks are protected by some software-based soft-error tolerance techniques to achieve a lower performance and space overhead....

High Speed Digital Receiver, Design and Implementation

, M.Sc. Thesis Sharif University of Technology Aarabi, Masoud (Author) ; Sanaei, Esmaeel (Supervisor) ; Pezeshk, Amir Mansoor (Supervisor)

Abstract

Nowadays, increasingly improvements in the digital technology and the advantages of using digital signal processing methods lead engineers to use digital signal processing instead of analog processing in variant domains. However, speed limitations in analog to digital converters (ADCs) and data transfer ports prevent its penetration to high frequency signals region. In this thesis, an Instantaneous Frequency Measurement (IFM) system that can measure frequency in the range of 2-18 GHz is implemented fully digital (DIFM) on FPGA. To do so, monobit sampling technique with the sampling rate of 10 GHz is selected, and GTX high speed serial port is configured to transfer digital data into FPGA....

The effect of a two steps searching mechanism Using Feature Vectors Related to Image Class in Improving the Performance of CBIR System

, M.Sc. Thesis Sharif University of Technology Sherafati, Shima (Author) ; Jamzad, Mansoor (Supervisor) ; Manzuri Shalmani, Mohammad Taghi (Co-Advisor)

Abstract

Nowadays, retrieval is an inseparable part of user activities and due to growing usage of Content-Based Image Retrieval (CBIR), it has become a hot and challenging research topic specially in the past decade. The most important challenge that retrieval systems (including CBIR systems) are facing is the semantic gap between abstractions in the user’s mind and what is searched. One of the ways of dealing with this challenge is getting more information from the user about what he needs and so decreasing the distance between user’s will and what he gives to search engine as the description of his need. In this research, the class of query image is supposed to be given. For using this...