Mohamad Javad Tahmasebi Birgani

Department of Radiation Therapy, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

[ 1 ] - Quality Control of Conventional Radiology Devices in Selected Hospitals of Khuzestan Province, Iran

Introduction Quality control techniques used to test the components of the radiological system and verify that the equipment is operating satisfactorily. In this study, quality control (QC) assessment of conventional radiology devices was performed in frequently visited radiology centers of Khuzestan province, Iran. Materials and Methods Fifteen conventional radiology devices were examined, bas...

[ 2 ] - Generating a Homogeneous Dose Distribution in the Junction Region between Two Adjacent Fields in Electron Beam Therapy

Introduction: Treatment with megavoltage electron beams is ideal for irradiating superficial tumors because of their limited range in tissues. However, for electron treatment of extended areas, such as the chest wall, two or more adjacent fields can be used. Abutment of these fields may lead to significant dose in homogeneities in the junction region. The aim of this study is to offer a new met...

[ 3 ] - تعیین PSF و SP از طریق PDD برای انرژی های مگا ولتاژ

 مقدمه: در پرتو درمانی برای محاسبه دوز جذبی بیمار، از پارا متر هایی نظیر درصد دوز عمقی (PDD)، نسبت بافت- هوا (Tissue Air Ratio)، فاکتور پراکندگی ماکزیمم (PSF) و ... استفاده می شود. در اندازه گیری TAR در انرژی های درمانی مشکلاتی وجود دارد و اندازه گیری آن به علت وجود آلودگی الکترونی همراه با فوتون دقیق نیست. هدف از انجام این مطالعه به دست آوردن فرمولی برای محاسبه TAR از طریق PDD و سپس اندازه گیر...

[ 4 ] - Determination of the attenuation coefficient for megavoltage photons in the water phantom

Background: Attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. So, its exact measurement or calculation is very important. The aim of this study was to evaluate the μ in different points in the water phantom anal...

[ 5 ] - Generating the synthetic CT (sCT) and synthetic MR (sMR: sT1w/sT2w) images of the brain using atlas based method

Introduction: Radiation therapy planning (RTP) is one of the clinical applications in which both CT scan and MRI are used. MR and CT images are applied to determine the target volume and calculation of dose distribution, respectively. In addition, using two imaging modalities increases the department workload and cost. In this study, an algorithm was presented to create synthet...

[ 6 ] - Optimization of the brain tumor MR images classification accuracy using the optimal threshold, PCA and training ANFIS with different repetitions

Introduction: One of the leading causes of death among people is brain tumors. Accurate tumor classification leads to appropriate decision-making and providing the most efficient treatment to the patients. This study aims to optimize of the brain tumor MR images classification accuracy using the optimal threshold, PCA and training Adaptive Neuro Fuzzy Inference System (ANFIS) w...

[ 7 ] - Brain metabolites Associated with Common Clinical Symptoms of multiple sclerosis patients Using MagneticResonance Imaging

Introduction: Multiple Sclerosis (MS) is an auto-immune disease that involves central nervous system (CNS). Magnetic Resonance Spectroscopy (MRS) is an analytical non- invasive method for obtaining the pathologic data of disease and it brings biochemical information about studied tissue which can be helped in studying the reasons and development process of disease and it increa...

[ 8 ] - The evaluation of change in attenuation coefficient of cerrobend block used for radiation protection of healthy tissues in megavoltage photon radiation therapy after multiple melting

Introduction: Protecting the vital organs in radiation therapy is one of the most important issues. Cerrobend alloy, the most common material used as the shield, is melted several times and used for different patients. In this study changes in attenuation coefficient of cerrobend due to melting was investigated.   Materials and Methods: In melting furnace, ...

[ 9 ] - Synthesis, in vitro evaluation of cytotoxicity and radiosensitizer activity of novel 2-(2, 4-dinitrobenzylidene) cyclohexanone derivatives against the radioresistant HT29 cell line under aerobic condition

Introduction: Bifunctional radiosensitizer agents in which nitroaromatic moieties are attached through a linker to antineoplastic moieties have demonstrated higher cytotoxicity and radiosensitizer effects than the corresponding counterparts. This study was conducted to investigate the cytotoxicity and radiosensitizer activities of 2, 4-dinitrobenzene as a radiosensitizer moiety...

[ 10 ] - Signal Intensity of High B-value Diffusion-weighted Imaging for the Detection of Prostate Cancer

Background: Diffusion-weighted imaging (DWI) is a main component of multiparametric MRI for prostate cancer detection. Recently, high b value DWI has gained more attention because of its capability for tumor characterization. Objective: To assess based on histopathological findings of transrectal ultrasound (TRUS)-guided prostate biopsy as a reference, an...

[ 11 ] - Calculating Weighting Factors for Mixing Megavoltage Photon Beams to Achieve Desirable Dose Distribution in Radiotherapy

Background: In radiotherapy, low-energy photon beams are better adapted to the treated volume, and the use of high-energy beams can reduce hot spots in the radiation therapy. Therefore, mixing low and high energies with different ratios can control the rate of hotspots, as well as the dose distribution of the target volume.Material and Methods: The percentage depth doses (PDDs) were calculated ...

[ 12 ] - Optimization of Brain Tumor MR Image Classification Accuracy Using Optimal Threshold, PCA and Training ANFIS with Different Repetitions

Background: One of the leading causes of death is brain tumors. Accurate tumor classification leads to appropriate decision making and providing the most efficient treatment to the patients. This study aims to optimize brain tumor MR images classification accuracy using optimal threshold, PCA and training Adaptive Neuro Fuzzy Inference System (ANFIS) with different repetitions.Material and Meth...

[ 13 ] - Evaluation of the Effect of Source Geometry on the Output of Miniature X-ray Tube for Electronic Brachytherapy through Simulation

Objective: The use of miniature X-ray source in electronic brachytherapy is on the rise so there is an urgent need to acquire more knowledge on X-ray spectrum production and distribution by a dose. The aim of this research was to investigate the influence of target thickness and geometry at the source of miniature X-ray tube on tube output.Method: Five sources were simulated based on problems e...