Fatemeh Shahedi

Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.

[ 1 ] - Evaluation of the Portal Imaging System Performance for an Elekta Precise Linac in Radiotherapy

Introduction: Electronic portal imaging devices (EPIDs) provide two- and three-dimensional planar and volumetric cone beam images to improve the accuracy of radiation treatment delivery. Periodic quality assurance (QA) of EPIDs is essential for dosimetric verification in radiotherapy. In this study, a QA program was implemented to evaluate the function of the EPID to be confident in applying co...

[ 2 ] - Quality assessment of conventional X-ray diagnostic equipment by measuring X-ray exposure and tube output parameters in Great Khorasan Province, Iran

Introduction: Regular implementation of quality control (QC) program in diagnostic X-ray facilities may affect both image quality and patient radiation dose due to the changes in exposure parameters. Therefore, this study aimed to investigate the status of randomly selected conventional radiographic X-ray devices installed in radiology centers of Great Khorasan Province, Iran, to produce the da...

[ 3 ] - A feasibility study on the use of MV-CBCT images for urgent palliative treatment planning

Introduction: The application of 3D volumetric imaging modalities in treatment planning of radiation therapy can provide more precisely define tumor localization, and computed tomography (CT) is the most common accepted method for treatment planning. Given the lack of a CT scanner stationed in all radiotherapy departments and equipping most of the medical linear accelerators wi...

[ 4 ] - Mega Voltage Cone Beam Computed Tomography (MV- CBCT) using a Standard Medical Linear Accelerator and EPID: A feasibility study.

Introduction: The success of radiotherapy cancer treatment delivery depends on the accuracy of patient positioning for each treatment session. A number of kilovoltage x-ray volumetric imaging modalities with an additional source and detector have been developed to allow patient set-up verification based on the internal anatomy, but a significant portion of medical linacs are on...

[ 5 ] - An Empirical Transmitted EPID Dosimetry Method using a Back-Projection Algorithm

Background: The present study aimed to introduce a rapid transmission dosimetry through an electronic portal-imaging device (EPID) to achieve two-dimensional (2D) dose distribution for homogenous environments. Material and Methods: In this Phantom study, first, the EPID calibration curve and correction coefficients for field size were obtained from EPID and ionization chamber. Second, the...

[ 6 ] - Applications of gold nanoparticles for medical imaging

Background & Aim: Molecular imaging enables us to non-invasively visualize tissue microstructures and lesion characterization, allowing accurate diagnosis of diseases at early stages. A successful molecular imaging requires a nontoxic contrast agent with high sensitivity. Nowadays, a wide range of nanoparticles have been developed as contrast agents for medical imaging modalities. Here, we revi...

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