Hossein Ghadiri

Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran, Iran / Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran

[ 1 ] - A novel dual energy CT-based attenuation correction method in PET/CT systems: A phantom study

  In present PET/CT scanners, PET attenuation correction is performed by relying on the information given by CT scan. In the CT-based attenuation correction methods, dual-energy technique (DECT) is the most accurate approach, which has been limited due to the increasing patient dose. In this feasibility study, we have introduced a new method that can implement dual-en...

[ 2 ] - Design and performance evaluation of spheroid geometry for brain PET scanner using Monte Carlo modeling

Introduction: There has been a curiosity about the spheroid geometry for PET scanners developments since several years ago, therefore in this study, we are aiming to evaluate the performance of this geometry and compare its performance with cylindrical geometry using Monte Carlo simulation. Methods: We simulated a spheroid geometry with a radius of 199 mm...

[ 3 ] - Fast System Matrix Calculation in CT Iterative Reconstruction

Introduction: Iterative reconstruction techniques provide better image quality and have the potential for reconstructions with lower imaging dose than classical methods in computed tomography (CT). However, the computational speed is major concern for these iterative techniques. The system matrix calculation during the forward- and back projection is one of the most time- cons...

[ 4 ] - Evaluation of the gray level in CBCT systems and its relationship with HU in CT Scanners

Introduction: Cone-beam CT (CBCT) is an imaging system which offers three-dimensional (3D), multiplanar images and has many advantages over computed tomography (CT) including shorter acquisition times for the resolution desired in dentistry, lower radiation dose to the patient, reasonable price and higher spatial resolution but CBCT scanners are unable to display actual Hounsf...

[ 5 ] - Evaluation of effect of gold nanorods and spherical gold nanoparticles of different sizes on X-ray attenuation in computed tomography

Introduction: To date, gold nanoparticles (GNPs) have been demonstrated to have great potential as contrast agent for CT imaging and therapeutics. This study was designed to evaluate any effect on X-ray attenuation that might result from using GNPs with a variety of size, surface chemistries and shapes.   Materials and Methods: Spherical GNPs and gold nanorod...

[ 6 ] - Evaluation of multifunctional targeted gold nanoparticles on X-ray attenuation in nasopharyngeal cancer cells by X- ray imaging

Introduction: Head-and-neck cancer is the sixth most common cancer worldwide with the number of cases consistently increasing in developing countries. Successful development of effective, safe and cost effective nanoprobes for head-and-neck cancer targeting imaging is a big challenge. This study is aimed to develop cysteamine-folate conjugated gold nanoparticles (F-Cys-AuNPs) a...

[ 7 ] - Transcranial Focused Ultrasound Modulates Electrical Behavior of the Neurons: Design and Implementation of a Model

Background: Recently, ultrasonic neuromodulation research has been an important and interesting issue. Ultrasonic neuromodulation is possible by the use of low-intensity transcranial focused ultrasound (tFUS) to stimulate or inhibit the neural structures. The primary capability of this method is the improvement in the treatment progress of certain neurological and psychiatric disorders noninvas...

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