Department of Medical Physics (1999 - Present)
Medical Physics
Nuclear Medicine, All India Institute of Medical Science, Delhi, India
Medical Physics
Medical Physics, Tarbiat Modares University, Tehran, Iran
Physics
Physics, Excellent school of science, Kashan, Iran
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Single photon emission tomography is widely used to detect photons emitted from the patient. Some of these emitted photons suffer from scattering and absorption because of the attenuation occurred through their path in patient's body. Therefore, the attenuation is the most important problem in single-photon emission computed tomography (SPECT) imaging. Some of the radioisotopes emit gamma rays in different energy levels, and consequently, they have different counts and attenuation coefficients. Calculation of the parameters used in the attenuation equation N out= αN in= e− μ l N in by mathematical methods is useful for the attenuation correction. Nurbs-based cardiac-torso (NCAT) phantom with an adequate attenuation coefficient and activ
Introduction: The choice of optimal radionuclides for radioimmunotherapy depends on several factors, especially the radionuclide and antibody. The dosimetric characteristics of a non-internalizing and an internalizing monoclonal antibody (MAb) labeled with beta emitting radionuclides were investigated.Methods: Using Geant4-DNA Monte Carlo simulation, we carry out dosimetric calculations for different subcellular distributions of beta-emitting radionuclides; 131 I, 177 Lu, 64 Cu, 186 Re and 153 Sm.Results: The dependency of theradialdose profiles on the energy spectra of electrons (beta particles and Auger and internal conversion electrons) and also their relative yield of emission is clear. The highest difference between the radionuclides t
Discussion & Conclusions: Distinct TEDE values must be defined for each of the aforementioned organs and confirmed before releasing patients who will be faced to the others at short distances. Otherwise, guidelines must be considered for the others who will be faced to the released patient.
Discussion & Conclusions: Distinct TEDE values must be defined for each of the aforementioned organs and confirmed before releasing patients who will be faced to the others at short distances. Otherwise, guidelines must be considered for the others who will be faced to the released patient.
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Home; Browse: Current Issue; By Issue; By Author; By Subject; Author Index; Keyword Index. Journal Info: About Journal; Aims and Scope; Editorial Board; Editorial Staff; Publication Ethics; Indexing and Abstracting; Related Links; FAQ; Peer Review Process; News. Guide for Authors; Submit Manuscript; Reviewers; Contact Us. Login; Register. Home Articles List Article Information. Save Records; |; Printable Version; |; Recommend; |; How to cite Export to RIS EndNote BibTeX APA MLA Harvard Vancouver. |; Share Share CiteULike Mendeley Facebook Google LinkedIn Twitter Telegram. Iranian Journal of Medical Physics. Articles in Press. Current Issue. Journal Archive. Volume Volume 15 (2018). Issue 4. Issue 3. Issue 2. Issue 1. Volume Volume 14 (2017)
> AbstractPurpose: GATE/GEANT is a Monte Carlo code dedicated to nuclear medicine that allows calculation of the dose to organs (bone and bone marrow) of voxel phantoms. On the other hand, Medical Internal Radiation Dose (MIRD) is a well-developed system for estimation of the dose to human organs. In this study, results obtained from GATE/GEANT using leg of Snyder phantom is compared to published MIRD data.Materials and Methods: For this, the mathematical leg of Snyder phantom was discretized and converted to a digital phantom of 100? 100? 200 voxels. The activity was considered uniformly distributed within bone and bone marrow. The GATE/GEANT Monte Carlo code was used to calculate the dose to the bone and bone marrow of the leg phantom fro
Abstract unavailable for this article.
The S-value is a standard measure in cellular dosimetry. S-values are calculated by applying analytical methods or by Monte Carlo simulation. In Monte Carlo simulation, particles are either tracked individually event-by-event or close events are condensed and processed collectively in different steps. Both of these methods have been employed for estimation of cellular S-values, but there is no consistency between the published results. In the present paper, we used the Geant4-DNA track-structure physics model as the reference to estimate the cellular S-values. We compared the results with the corresponding values obtained from the following three condensed-history physics models of Geant4: Penelope, Livermore and standard. The geometry and
Purpose: Respiration causes lesion smearing, image blurring and quality degradation, affecting lesion contrast and the ability to define correct lesion size. The spatial resolution of current multi pinhole SPECT (MPHS) scanners is sub‐millimeter. Therefore, the effect of motion is more noticeable in comparison to conventional SPECT scanner. Gated imaging aims to reduce motion artifacts. A major issue in gating is the lack of statistics and individual reconstructed frames are noisy. The increased noise in each frame, deteriorates the quantitative accuracy of the MPHS Images. The objective of this work, is to enhance the image quality in 4D‐MPHS imaging, by 4D image reconstruction. Methods: The new algorithm requires deformation vector
Nanoparticles are generally cleared by the reticuloendothelial system, taken up by Kupffer cells in liver. This principle can be used for liver imaging. Chitosan is an excellent biocompatible and biodegradable polymer. In this study, the authors synthesized 99mTc-chitosan nanoparticles and evaluated its potential for liver imaging. Chitosan nanoparticles were synthesized and radiolabeled with 99mTc. The labeling efficiency, stability, biodistribution, and imaging study in the normal mice was performed. Biodistribution and imaging studies demonstrated an efficient accumulation of the radiolabeled nanoparticles in the mice liver and indicated the 99mTc-chitosan nanoparticles may be considered as a promising radiopharmaceutical for liver imagi
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