Mohammad Reza. Deevband

Shahid Beheshti University of Medical Sciences · Bioengineering and medical physics

The role and benefits of Cone-Beam CT(CBCT) in dental imaging, diagnosis and treatment planning are well known, but using the x-rays, it is not risk-free. This study aimed to provide an accurate and comprehensive data base of organs and size-specific effective doses based on body mass indexes (BMI) of patients in dental-CBCT units. In this regard,...

This study aimed to evaluate organ doses and effective doses for wide ranges of body mass indexes (BMI) of patients who underwent imaging with a dental-CBCT unit. In this regard, the Monte Carlo (MC) method used to simulate the exposure geometry for three different common protocols with GIANO. The population of the Extended Cardiac-Torso (XCAT) adu...

Purpose: With the widespread application of ionizing radiation in medical practice, concerns have been increased regarding the hazardous effects of radiation. Studies have demonstrated that some variables such as body dimensions affect the absorbed radiation dose. In this study, the association between Body Mass Index (BMI) and absorbed dose in Com...

Purpose Electronic portal images are one of the most important tools to verify the ongoing radiotherapy treatment through comparison with a reference image generated during treatment planning. In this procedure, two images are geometrically matched by means of visible bone or other landmarks of interest such as implanted fiducials. However, the int...

This study aimed to introduce a new parameter for harmonized and accurate quantitative bone quality assessment in all CBCT images considering the non-uniformity of gray values. Six CBCT units were used in our study to scan a Pro-Dent CT mk-II phantom for determining gray values of Polymethylmethacrylate (PMMA, soft tissue equivalent), Delrin (trabe...

Introduction The aim of this study is to evaluate the effective dose and cancer risk of examinations in EOS imaging system in different age and gender groups. Materials and methods In total, 555 patients who had undergone common EOS imaging examinations were entered into the study. Exposure parameters and patients’ characteristics for lower limb,...

Background: The present study was done to establish release criterion in the treated patients and to determine external radiation doses received by personnel and caregivers of patients with metastatic neuroendocrine tumors (NETs) during peptide receptor radionuclide therapy (PRRT) by means of Lutetium-177 (177Lu) DOTATATE. Materials and Methods: Fo...

Dual-energy computed tomography (DECT) has appeared as a novel approach with the aim of evaluating artery-related diseases. With the advent of DECT, concerns have been raised about the induction of diseases such as cancer due to high radiation exposure of patients. Therefore, the dose received by patients in DECT should be considered. The parameter...

The number of radioligand therapy applications for metastatic castration-resistant prostate cancer has been continuously rising in most nuclear medicine departments in Iran, but to our knowledge, no one has studied the dose to staff who perform treatment procedures. The current study aimed to determine the external radiation dose received by staff...

Aims Despite the promising results achieved by radiomics prognostic models for various clinical applications, multiple challenges still need to be addressed. The two main limitations of radiomics prognostic models include information limitation owing to single imaging modalities and the selection of optimum machine learning and feature selection me...

Objective Robust differentiation between infarcted and normal tissue is important for clinical diagnosis and precision medicine. The aim of this work is to investigate the radiomic features and to develop a machine learning algorithm for the differentiation of myocardial infarction (MI) and viable tissues in the left ventricular myocardium on non-c...

Today, the use of Cone-Beam Computed Tomography (CBCT) is increasing rapidly in medical diagnosis, therefore evaluation of patient’s dose is a very important issue in radiation protection of patients. This study aimed to evaluate the patient-specific dose using CBCT images. Since CBCT images only showed a part of the head and while, the total anato...

This study intends to evaluate the different lung CT scan protocols used for the diagnostic evaluation of COVID-19-induced lung disease in Iranian imaging centers in terms of radiation dose and image quality. After data collecting, subjective image quality, radiation dose and objective image quality such as noise, SNR and CNR were assessed. Statist...

We developed multi-modality radiomic models by integrating information extracted from 18F-FDG PET and CT images using feature- and image-level fusions, toward improved prognosis for non-small cell lung carcinoma (NSCLC) patients. Two independent cohorts of NSCLC patients from two institutions (87 and 95 patients) were cycled as training and testing...

Purpose177Lu-DKFZ-PSMA-617 is a promising treatment for patients with metastatic prostate cancer. Specific dosimetry for each patient is an important factor in planning the patient’s treatment process. This study aimed to perform an image-based absorbed dose calculation for the treatment of metastatic prostate cancer with 177Lu-DKFZ-PSMA-617.Method...

The quality of bone is a very important factor in determining the success of dental implants. Due to the original gray values in Cone Beam CT (CBCT) are unable to display actual Hounsfield Units (HUs), the quantitative analysis and bone density assessment using original gray values in CBCT are not possible carefully. This study was aimed to introdu...

Introduction In this study, pediatric chest digital radiography (DR) is evaluated in response to the high volume of chest DR examinations and high radiosensitivity of children and young adults. The aim of the study is to optimize irradiation parameters in chest DR to have dose as low as reasonably achievable (ALARA) and simultaneously obtain improv...

Objectives: Multi-modality radiomics-guided prognostic models proved to have a promising potential towards precision oncology. It enhances the prognostic performance through integration of information obtained from different imaging modalities into a single model. However, the selection of proper feature selection (FS) and machine learning (ML) met...

Background: Normalized glandular dose (DgN) is an important dosimetric quantity in mammography. Aim: In this study, the effect of the presence of breast cysts and their size, number and location on DgN is evaluated. Materials and methods: The effect of the presence of cysts in breast was examined using MCNPX code. This was performed by taking homog...

Tinnitus is defined as the auditory phantom perception in the absence of any objective external sound source. In this paper, we used the resting-state electroencephalography (EEG) data to reconstruct the neural sources based on the unit-noise-gain linearly constrained minimum-variance (LCMV) beamformer and applied the effective connectivity analysi...

Electromagnetic-based navigation bronchoscopy requires accurate and robust estimation of the bronchoscope position inside the bronchial tree. However, respiratory motion, coughing, patient movement, and airway deformation inflicted by bronchoscope significantly hinder the accuracy of intraoperative bronchoscopic localization. In this study, a real-...

Purpose Digital radiography has the potential to improve the practice of radiography but it also has the potential to significantly increase patient doses. Considering rapidly growing digital radiography in many centers, concerns rise about increasing the collective dose of the human population and following health effects. This study aimed to esti...

Introduction: The main purpose of this study was to determine the diagnostic reference level (DRL) for routine digital radiography examinations in Mazandaran province. Materials and methods: Thirteen digital radiographic examinations at 18 high-patient-load radiography centres were investigated. The indirect dosimetry method was performed based...

Background: Ionizing radiation has an indispensable role in diagnostic radiology and clinical treatments. Apparently, medical exposure in diagnostic radiology pertains to be the preeminent man-made source of radiation. Objective: The aim of the present scientific study is to calculate the Entrance Surface Dose (ESD) and Effective Dose (ED) in digit...

In the past decade, compressed sensing (CS) has provided an efficient framework for signal compression and recovery as the intermediate steps in signal processing. The well‐known greedy analysis algorithm, called Greedy Analysis Pursuit (GAP) has the capability of recovering the signals from a restricted number of measurements. In this article, we...

The aim of this study is the calculation of equivalent organ dose and estimation of lifetime attributable risk (LAR) of cancer incidence and mortality related to cardiac computed tomography angiography (CCTA) because the use of CT angiography as a noninvasive diagnostic method has increased. The organ dose has been calculated by ImPACT software bas...

Purpose: To identify optimal classification methods for computed tomography (CT) radiomics-based preoperative prediction of clear cell renal cell carcinoma (ccRCC) grade. Materials and methods: Seventy-one ccRCC patients (31 low grade and 40 high grade) were included in this study. Tumors were manually segmented on CT images followed by the appl...

Background: Intracytoplasmic sperm injection (ICSI) or microinjection is one of the most commonly used assisted reproductive technologies (ART) in the treatment of patients with infertility problems. At each stage of this treatment cycle, many dependent and independent variables may affect the results, according to which, estimating the accuracy o...

Purpose: To identify optimal classification methods for computed tomography (CT) radiomics-based preoperative prediction of clear cells renal cell carcinoma (ccRCC) grade. Methods and material: Seventy one ccRCC patients were included in the study. Three image preprocessing techniques (Laplacian of Gaussian, wavelet filter, and discretization of th...

Background: Electromagnetic (EM) based navigation methods without line-of-sight restrictions may improve lymph node sampling precision in Transbronchial needle aspiration (TBNA) procedure. However, EM tracking susceptibility to metallic objects severely declines its precision. Method: We proposed to track the location of a tool in a dynamic bron...

تصاویر دستگاه‌های تصویربرداری CBCT دندانی که در آن‌ها از پرتوهای مخروطی شکل استفاده شده و با فرمت DICOM ذخیره‌سازی می‌شوند، دارای کاربردهای مختلفی در حوزه دندان‌پزشکی از جمله ارزیابی چگالی استخوان برای انتخاب محل مینی ایمپلنت ارتودنسی، تشخیص از دست رفتن استخوان و سایر موارد می‌باشد. در این دستگاه‌ها تصاویر حاصل بر خلاف دستگاه‌های تصویربرداری CT دار...

Ramsar, in the north of Iran by the Caspian Sea, has been known for the highest natural radiation background on Earth due to the local geology and hydrogeology. The residents and visitors use the hot springs that distribute the natural radionuclides especially 226Ra and its decay products in the areas. Many studies have been undertaken to measure t...

Introduction: In order to reduce patient setup error in treatment field, portal images with treatment beam (megavoltage x-ray) are widely used. These images are acquired by electronic portal imaging devices (EPID). However, portal images suffer from insufficient anatomical information, contrast, and spatial resolution, because of the fact that Comp...

چکیده تصاویر سیستم های تصویر برداری CBCTدندانی که در آنها از پرتوهای مخروطی شکل استفاده شده و با فرمت DICOMذخیره سازی می شوند، دارای کاربردهای مختلفی در حوزه دندانپزشکی از جمله ارزیابی چگالی استخوان برای انتخاب محل مینی ایمپلنت ارتودنسی، تشخیص از دست رفتن استخوان و سایر موارد می باشد. در این سیستم ها تصاویر حاصل بر خلاف سیستم های تصویر برداری CTدار...

Background: Tinnitus known as a central nervous system disorder is correlated with specific oscillatory activities within auditory and non-auditory brain areas. Several studies in the past few years have revealed that in the most tinnitus cases, the response pattern of neurons in auditory system is changed due to auditory deafferentation, which le...

Acute lymphoblastic leukemia (ALL) is the most popular form of white blood cells cancer in children. It is classified into three forms of L1, L2 and L3. Typically, it is identified through screening of blood smearsvia pathologists. Since this is laborious and tedious, automatic systems are desired for suitable detection; but the high similarity bet...

Background: Positron Emission Tomography-Computed Tomography (PET-CT) is a useful hybrid imaging modality in the diagnosis of various malignancies. This modality imposes almost 20 mSv radiation dose to the patient. The purpose of the present study was to evaluate the uncertainties in calculated CT effective dose in TUBE CURRENT MODULATION-activated...

Image segmentation is one of the major preprocessing steps of magnetic resonance imaging (MRI) analysis in many medical and research applications. Accurate differentiation between three major soft tissues of the brain - grey matter, white matter and cerebrospinal fluid - is a key step in structural and functional brain analysis, visualization of th...

Background: Electrocardiogram (ECG) is defined as an electrical signal, which represents cardiac activity. Heart rate variability (HRV) as the variation of interval between two consecutive heartbeats represents the balance between the sympathetic and parasympathetic branches of the autonomic nervous system. Objective: In this study, we aimed to...

Introduction: Automatic and accurate arterial input function (AIF) selection has an essential role for quantification of cerebral perfusion hemodynamic parameters using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI). The purpose of this study is to develop an optimal automatic method for arterial input function determination i...

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 un...

Introduction: Dental Cone beam CT (CBCT) is an imaging modality which has emerged as a 3D imaging modality of choice for osseous structures in the maxillofacial region. With increased usage of CBCT imaging for diagnosis and treatment planning, it is imperative that stringent dose assessments must be performed for dose estimation to safeguard both t...

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 un...

Background Ramsar, a city of Iran located on the coast of the Caspian Sea, has been considered to be enormously important due to its high natural radioactivity levels. People living in High Level Natural Radiation Areas (HLNRAs) have been exposed by several sources, one of which could be foodstuff. However, many studies have been carried out to mea...

Neutron energy spectrum unfolding has been the subject of research for several years. The Bayesian theory, Monte Carlo simulation, and iterative methods are some of the methods that have been used for neutron spectrum unfolding. In this study, the radial basis function (RBF), multilayer perceptron, and artificial neural networks (ANNs) were used fo...

Among High Level Natural Radiation Areas (HLNRAs) all over the world, the northern coastal city of Ramsar has been considered enormously important. Many studies have measured environmental radioactivity in Ramsar, however, no survey has been undertaken to measure concentrations in the diets of residents. This study determined the 226Ra activity con...

PET and SPECT are common and useful imaging modalities in diagnosis and follow-up of lots of diseases. Hybrid imaging in nuclear medicine can improve the diagnostic value of images by providing anatomical registration and attenuation correction (AC). Computed tomography (CT) by providing high spatial resolution, noiseless, high quality and fast att...

Introduction: Nowadays Heart failure is one of the most common diseases; nuclear medicine (N.M) and Gated Single Photon Emission Tomography (SPECT) serves as a specific and sensitive imaging modality in the diagnosis of ischemia and infarction in heart parenchyma. International commission on radiation protection (ICRP) didn’t establish any limit fo...

Introduction: PET-CT is a useful imaging modality in diagnosis of cancers, cardiac and brain disorders. In spite of lower resolution than CT and MRI as a functional imaging tool, indications of PET-CT imaging has increased recently. It is critical to know the exact attenuation coefficients of surrounding tissue at energy of 511Kev to have an accura...

Introduction: The use of PET-CT imaging in the diagnosis and treatment follow-up is increasing. The radiation dose up to 27mSv was reported for this modality, which is worrying. Computed Tomography (CT) is responsible for large portion of this radiation dose. There is increasing concerns about hazardous effects of CT radiation dose on public. Accor...

Aims: The dose levels for Computed Tomography (CT) localization and attenuation correction of Single Photon Emission Computed Tomography (SPECT) are limited and reported as Volume Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP). This work presents CT dose estimation from Cardiac SPECT/CT based on new American Association of...

Glioma, as a primary tumor of central nervous system, is the main cause of death in patients with brain cancer. Therefore, development of an efficient strategy for treatment of glioma is worthy. The aim of the current study was to develop a SRL peptide-coated dendrimer as a novel dual gene delivery system for targeting the LRP receptor, an up-regul...

In recent years, with the introduction of 64-slice CT and dual-source CT technology, coronary CT angiography (CCTA) has emerged as a useful diagnostic imaging modality as a non-invasive assessment of coronary heart disease. CT produces a larger radiation dose than other imaging tests and cardiac CT involves higher radiation dose with the advances i...

Background: Computed Tomography (CT) is main contributor of population dose from diagnostic X-ray examinations. Children are more radiosensitive than adults, thus optimization of CT examination in these patients is essential. The purpose of this study was to evaluate dose delivered to pediatric patients’ undergoing CT examination of the common exam...

Background: The most efficient application of ionizing radiation is serving medical purposes and using this radiation has caused people to learn that artificial sources of radiation exposure among these resources can be of highest exposure rate. Obiective: The present study is aimed at initially establishing a baseline for local-reference dose l...

Radon, a naturally occurring radioactive gas in the decay series of Uranium238 is ubiquitous in indoor environment. The main sources of 222Rn to the air are soil and rock. It is a major natural radiation source of human exposure to ionizing radiation (half of it). At present radon is considered the second most probable cause of lung cancer after sm...

Purpose of the study: This study conducted a review on nuclear medicine (NM) services in Mazandaran Province with a view to establish adult diagnostic reference levels (DRLs) and provide updated data on population radiation exposure resulting from diagnostic NM procedures. Materials and methods: The data were collected from all centers in all ci...

Background: Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT) are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. Objective: This study is ai...

In order to establish diagnostic reference levels (DRLs) for multi-detector computed tomography (MDCT), four routine CT examinations were identified and a computer program was developed to collect data from 19 MDCT scanners in Iran. Mean values of Volume computed tomography dose index (CTDIvol) and dose-length product (DLP) in each site were calcul...

Using computed tomography (CT) scans in clinical diagnosis has been dramatically increased during recent years. This technique is associated with high levels of radiation dose to patients compared to other imaging methods. Therefore, using accurate and precise methods of estimating the absorbed dose in CT scans is of prime importance. The present s...

Background: Radiation therapy uses high-energy radiation to kill cancer cells. Photoneutron contamination and induced radioactivity of high energy therapeutic photon beams are considered as the main source of occupational exposure to radiation therapists who works with linear accelerators operating above 10 MV. Materials and Methods: The gamma dose...

Blood-brain barrier inhibits most of drugs and genetic materials from reaching the brain. So, developing high efficiency carriers for gene and drug delivery to the brain, is the challenging area in pharmaceutical sciences. This investigation aimed to target DNA to brain using Serine-Arginine-Leucine (SRL) functionalized PAMAM dendrimers as a novel...

Autism Spectrum Disorders (ADS), with unknown etiology, is one of the most understudy fields of research worldwide that requires complicated and delicate analytical study methods. The purpose of this study was to compare active regions of Brain Default Mode Network (DMN) using Group Independent Component Analysis (6ICA) among resting state patients...

Background: The radiation doses resulting from diagnostic X-ray examinations are routinely measured in terms of entrance surface dose (ESD) and effective dose (ED). In this study, for the purpose of radiation protection, the radiation doses received from Digital chest X-ray examination were evaluated in terms of ESD and ED. Material and Methods: Th...

Background: The Poly-Allyl Diglycol Carbonate (PADC) detector is of particular interest for development of a fast neutron dosimeter. Fast neutrons interact with the constituents of the CR-39 detector and produce H, C and O recoils, as well as (n, α) reaction. These neutron- induced charged particles contribute towards the response of CR-39 detector...