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PURPOSE Evaluation of the organ dose in pediatric patients up to 15 years old and Estimation of lifetime attributable risk (LAR) of cancer incidence in pediatric computed tomography procedures. MATERIALS AND METHODS Data from 532 patients below 15 years old was collected and they were categorized into four age groups of

Background: Ionizing and non-ionizing radiation are widely used in the diagnosis and treatment of diseases. Considering the potential risks of radiation, radiation safety training courses are important for medical staff. Objective: The aim of this study was to investigate the effectiveness of one-day radiation safety training program in increasing the radiation safety knowledge of physicians. Methods: In this descriptive-analytical study, subjects were 12 physicians (6 general practitioners and 6 non-radiologist specialists) participated in the training program organized by Qazvin University of Medical Sciences in 2018. A researcher-made questionnaire was used for surveying physicians before and after the training. The mean and standard deviation of the scores were first calculated. Then, the pre- and post-test scores were compared using Wilcoxon signed-rank test, and the correlation of these scores with their age, gender, expertise area, and work experience was examined by Spearmanchr('39')s correlation test. Findings: The mean total scores of the physicians before and after training were 7.00±2.56 (ranged 3-11) and 11.92± 2.31 (ranged 8-15) out of 18, respectively. The radiation safety knowledge of physicians significantly increased after training (P

The main purpose of this pilot study was to assess the regional diagnostic reference level (RDRL) of computed tomography (CT) examinations to optimise medical exposure in five pediatric medical imaging centers in Tehran, Iran where the most frequent CT examinations were investigated. For each patient, CT volume dose indexes (CTDIvol) and dose length product (DLP) in each group were recorded and their third quartile was calculated and set as RDRL. Pediatrics were divided into four age groups (

The purpose of this study is to predict chronic kidney disease (CKD) in the radiotherapy of abdominal cancers by evaluating clinical and functional assays of normal tissue complication probability (NTCP) models.Radiation renal damage was analyzed in 50 patients with abdominal cancers 12 months after radiotherapy through a clinical estimated glomerular filtration rate (eGFR). According to the common terminology criteria for the scoring system of adverse events, Grade 2 CKD (eGFR ≤30-59 ml/min/1.73 mThe confidence interval of the fitted parameters was 95%. The parameter value of DAlthough the renal medulla consists of many nephrons arranged in parallel, each nephron has a seriality architecture as renal functional subunits. Therefore, based on this principle and modeling results in this study, the whole kidney organs may have a serial-parallel combination or a secret architecture.

A new "quality-control-based (QC-based) dose survey method" has been developed for determination of diagnostic reference levels (DRL) in Computed Tomography (CT) examinations. The "QC-based dose survey method" is based on the use of retrospective data in the QC documents and reports, which are typically available from the National Regulatory Authority database. The method was applied to 70 CT scanners in Tehran, Iran, by using the available QC reports from the database. The commonly used "data collection method" was also applied by filling each questionnaire on-site to validate the new method. Using the new QC-based and data collection methods, the DRLs of four common CT examinations: head, sinus, chest, and abdomen/pelvis were determined and compared. The DRLs determined by the "QC-based method" for head, sinus, chest, and abdomen/pelvis are 59, 29, 10, and 13 mGy, respectively, for the volume computed tomography dose index (CTDIVol) and 834, 235, 233, and 522 mGy-cm for the dose length product (DLP), respectively. The difference between the DRLs obtained by the two methods is on the average 6.7 ± 5.7%, which is within the acceptance tolerance level of the IAEA for QC dosimetry tests. The "QC-based dose survey method" is believed to be an effective alternative method to the other commonly used "data collection" and "direct dose measurement method" for determination of CT examination DRLs. This new method has unique characteristics such as simplicity, time and cost effectiveness, highly reduced clinical interruptions and collaborations, and potential for large-scale surveys with capability for more frequent review of national DRL values.

In this work, chitosan/graphene oxide as a green bionanocomposite catalyst was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR) spectra, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) analysis, atomic force microscopy (AFM) and scanning electron microscopy (SEM) images. Then, it was used as a nanocatalyst for the synthesis of 3,4-dihydropyrimidin-2(1 H )-one derivatives by a one-pot three-component condensation reaction of benzaldehyde, 1,3-ketoesters and urea in excellent yields and short reaction times under solvent-free conditions. The reaction work-up was simple and the catalyst could easily be separated from the reaction mixture and reused in subsequent reactions.

An efficient protocol for the nitration of aromatic compounds in the presence of a catalytic amount of sulfuric acid-functionalized silica-based magnetic core/shell nanocomposite was reported. The designed products were obtained in high yields in relatively short reaction times at room temperature under solvent-free conditions. The nanocatalyst was simply recovered from the reaction mixture by using an external magnet and efficiently reused for several times. The characterization of particle size, morphology and elemental analysis of the nanocatalyst were provided by scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy analyses, respectively.

A sulfonated magnetic cellulose-based nanocomposite was prepared and characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. Then, it was used as a green nanocatalyst for the synthesis of α-aminonitriles by a one-pot three-component condensation reaction of aldehydes or ketones, amines and trimethylsilylcyanide in ethanol at room temperature. The reaction procedure is simple, yields are very high, reaction time is very short and the catalyst can be easily separated from the reaction mixture and reused in subsequent reactions without significant loss of catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.

Iodine-131 (I-131) therapy is one of the conventional approaches in the treatment of patients with differentiated thyroid carcinoma (DTC). The radioiodine agents also accumulate in the other organs that cause pain and damage to the patients. Radioiodine therapy is associated with various gastrointestinal (GI) toxicities. In this study, GI side effects of the radioiodine therapy were investigated. GI toxicities of the radioiodine therapy were studied in 137 patients with histologically proven DTC in Jun-Nov 2014. All the patients were treated by radioiodine agents in the research institute of Shariati Hospital, Tehran, Iran. The patients were examined 48 h after prescription (before discharge) and their GI side effects were registered. Correlation of the age, gender, administered dose, administered dose per body weight as the independent factors, and GI side effects were analyzed using the Pearson correlation test with Statistical Package for the Social Sciences (SPSS) version 20. Regression coefficients and linearity of the variable were investigated by MATLAB software. Line fitting was performed using MATLAB curve-fitting toolbox. From the subjects, 38 patients had GI complaints (30.4%). Significant factors influencing GI side effects were dose per body weight and administered doses. There was no significant correlation between age and gender as the independent parameters and GI complaints. The most prevalent GI side effect was nausea that occurs in 26.4% of the patients. From the results, it could be concluded that the GI side effects could be prevented by administering a safe radioiodine dose value less than 5,550 MBq.

A cellulose/γ-Fe2O3/Ag nanocomposite is synthesized and used as a catalyst for the synthesis of trisubstituted imidazoles and α-aminonitriles. This catalytic protocol is simple, the reaction yield is very high, and the reaction time is very short. The remarkable magnetic properties of the nanocomposite permit easy separation of the catalyst from the reaction mixture without considerable loss of catalytic activity. In addition, antibacterial properties of the nanocomposite are investigated. For this purpose, S. aureus as the representative of Gram-positive bacteria and E. coli as the representative of Gram-negative bacteria are evaluated. To study the morphology and characterization of the prepared nanocomposite, X-ray diffraction patterns (XRD), energy-dispersive X-ray spectroscopy (EDX), field-emission scanning electron microscopy (FE-SEM), vibrating sample magnetometry (VSM) and thermal gravimetric analysis/differential thermal analysis (TGA/DTA) are obtained.

The biomedical applications of gold nanoparticles (AuNPs) have experienced rapid growth in recent years, due to their expected benefits in medical imaging and therapy. In this work, we report the development of a theranostic nanocomplex constructed from alginate hydrogel co-loaded with cisplatin and AuNPs (abbreviated as ACA) for simultaneous drug delivery and computed tomography imaging. CT26 cells derived from mouse colon adenocarcinoma were exposed to various concentrations of ACA nanocomplex (for 24 h) and the cytotoxicity was measured using MTT assay. Moreover, the cells treated with ACA nanocomplex were imaged in a computed tomography scanner and the contrast enhancement due to the presence of nanocomplex was assessed. The cytotoxicity results showed that ACA nanocomplex had a more potent chemotherapy efficacy than free cisplatin, so that ACA nanocomplex at the concentration of 5 µg/ml (per cisplatin) and 20 µg/ml of free cisplatin resulted in the same cytotoxicity (survival rate: 66%). The computed tomography imaging study revealed that ACA nanocomplex increased the brightness of computed tomography images, the computed tomography number value, and contrast-to-noise ratio (CNR). ACA nanocomplex can be presented as a computed tomography-traceable nanocarrier that allows to monitor the delivery of therapeutics by assessing their localized accumulation and in vivo biodistribution.

In the present work, a green, rapid, convenient and eco-friendly method for the synthesis of 2,4,5-trisubstituted imidazoles is described. In this method, we used 1,2-diketone or α-hydroxy ketone, an aldehyde and ammonium acetate in the presence of graphene oxide–chitosan bionanocomposite, which acted as an efficient nanocatalyst. This protocol has many advantages such as short reaction time, high yield, easy separation of the catalyst and solvent-free condition. We used differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM) to confirm that the nanocomposite was formed, and FT-IR, 1H and 13C NMR analyses were performed for the confirmation of the synthesized products.

The purpose of this study was to evaluate the effects of the gantry angulation on dose profiles along the z-axis, the CTDIW value and the CTDIW efficiency in the head examinations. A Monte Carlo simulation model of a GE LightSpeed 16-slice CT scanner was developed by a GATE toolkit. The CTDI100 in air at the isocenter and in a head dosimetry phantom were measured using a pencil ion chamber. Dose profiles were studied in the central and peripheral holes of the head phantom using thermoluminescence LiF disc dosemeters for gantry angulations of 0°, 10° and 20°. Results show a small shift for only the peripheral dose profiles with increasing the gantry angulation (maximum shift of 24 mm at 20°). The peak amplitude of the dose profiles was reduced for both of the central and peripheral holes by ~5%, while the CTDIW values and the CTDIW efficiencies did not change significantly.

Background and Aim: To reduce surgical site infections and its complications, hand antiseptic is performed on the basis of product type either by rubbing or washing method. Silver Nanocolloid is a wide range disinfectant entered in world and also Iran markets as a surgical hand antiseptic, but any study about this subject hasn’t yet conducted. The aim of this study is comparing of Betadine, Sterillium and Silver Nanocolloid immediate effect on surgical hand antiseptic. Materials and Methods: This study design was randomized cross-over trial. Betadine, Sterillium, and Silver Nanocolloid with specific volume, duration (according to manufacturers’ instructions), and intervals (at least 24 hours) is conducted on 30 volunteer's hands. They occupy in operating room of hospital. Immediately after hands antisepsis, the samples were taken from the subject’s hands, transported to the blood agar plate, and plates were taken to the laboratory. In laboratory was incubated in 36 ± 1 degrees centigrade for 24 hours. For any growth medium, positive or negative of colony forming is surveyed and statistical analyses were conducted by SPSS software. Results: There’s not a statistically significant difference between negative cultures of Betadine and Sterillium, but negative culture of Betadine 20 (66.7%) and Sterillium 18 (60%), each of them separately, is significantly greater than Silver Nanocolloid 30 (10%) (P < 0.0001). 1 and 4 subjects experience much allergic reaction on their hands, respectively by using Sterillium and Silver Nanocolloid.Conclusions: The immediate antiseptic effects of Betadine and Sterillium are the same that conform to other studies and more than Silver Nanocolloid.

Cone beam computed tomography, CBCT, is a kind of CT scanner producing conical diverging X-rays, in which a large area of a two-dimensional detector is irradiated in each rotation. Different investigations have been performed on dosimetry of dental CBCT. As there is no special protocol for dental CBCT, CT scan protocols are used for dosimetry. The purpose of this study is measurement of dose to head and neck organs in two CBCT systems, i.e. Planmeca 3D Mid (PM) and NewTom VGi (NT), using thermoluminescence dosimetry and Rando phantom. The thermoluminescent dosimetry (TLD)-100 chips were put at the position of different organs of the head and neck. Two TLD-100 chips were inserted at each position, the dose values were measured for several different field sizes, i.e. 8 × 8, 12 × 8 and 15 × 15 cm2 for NewTom, and 10 × 10 and 20 × 17 cm2 for Planmeca systems. According to the results, the average effective dose in PM is much more than the NT system in the same field size, because of the greater mAs values. For routine imaging protocols used for NT, the effective dose values are 70, 73 and 121 µSv for 8 × 8, 12 × 8 and 15 × 15 cm2 field sizes, respectively. In PM, the effective dose in 10 × 10 cm2 and 17 × 20 cm2 is 259 and 341 µSv, respectively.

Purpose A new quality-control-based (QC-based) method is introduced to obtain correction factors to be applied to displayed patient dose indices (CTDI Vol and DLP) on CT scanner consoles to verify improvement of dose surveys for diagnostic reference levels (DRLs) determination. Method An available data-base of QC documents and reports of 57 CT scanners in Tehran, Iran was used to estimate CTDI Vol , DLP and relevant correction factors for three CT examination types including head, chest and abdomen/pelvis. The correction factor is the ratio of QC-based estimated dose to displayed dose. A dose survey was performed by applying on-site “data collection method” and correction factors obtained in order to select CT scanners in three modes for determination of CT DRLs by inclusion of: (a) all CT scanners before displayed dose indices were corrected (57), (b) only CT scanners calibrated by QC experts (41) and (c) all CT scanners after displayed dose indices were corrected (57). Results For the 41 CT scanners, correction factors of three examination types obtained in this study are within the acceptance tolerance of IAEA HHS-19. The correction factors range from 0.45 to 1.7 (average of 3 examinations) which is due to the change in the calibrated value of CTDI Vol over extended time. The DRL differences in three modes are within ±1.0% for CTDI Vol and ±12.4% for DLP. Conclusions The “QC-based correction method” applied to mode (c) has improved the DRLs obtained by other two modes. This method is a strong alternative to “direct dose measurement” with simplicity and cost effectiveness.

A sulfonated magnetic cellulose-based nanocomposite was prepared and characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. Then, it was used as a green nanocatalyst for the synthesis of α-aminonitriles by a one-pot three-component condensation reaction of aldehydes or ketones, amines and trimethylsilylcyanide in ethanol at room temperature. The reaction procedure is simple, yields are very high, reaction time is very short and the catalyst can be easily separated from the reaction mixture and reused in subsequent reactions without significant loss of catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.

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 in the spatial and temporal resolution. The aims of this study are patient dose assessment and establishment of national diagnostic reference level for CCTA in Iran. A questionnaire was sent to CCTA centers. Data for patient and CT protocols were obtained. The volumetric CT dose index (CTDIvol), dose length product (DLP) and total DLP were considered in the 32 cm standard body phantom. Calculation of estimated effective dose (ED) was obtained by multiplying the DLP by a conversion factor [k = 0.014 mSv (mGy·cm)-1]. Mean value of CTDIvol and DLP for CCTA was 50 mGy and 825 mGy·cm. The third quartile (75th) of the distribution of mean CTDIvol (66.54 mGy) and DLP (1073 mGy·cm) values was expressed as the diagnostic reference level (DRL) for CCTA in Iran. The median of ED was 10.26 mSv and interquartile range of ED was 7.08-15.03 mSv. A large variety in CTDIvol and DLP among CT scanner and different sites due to variability in CT parameter is noted. It seems that training could help to reduce patient's dose.

An efficient method for the synthesis of GO-chitosan bionanocomposite is demonstrated. Also, GO-chitosan is used as a green nanocatalyst in the synthesis of tetra-substituted imidazoles. This protocol has many advantages such as short reaction time, high yield, easy isolation of the catalyst and solvent-free conditions. We put upon Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) analyzes for the confirmation of the nanocomposite production.

In the present work, cellulose-based silver nanocomposite is synthesized by a new method and used as a catalyst for the synthesis of heterocyclic compounds. To study the morphology and characterization of the nanocomposite, scanning electron microscopy (SEM) and X-ray diffraction (XRD) were obtained.

Imidazoles (III) are rapidly, conveniently, and eco-friendly obtained by reaction of benzil (I) or benzoin with various aromatic aldehydes and ammonium acetate.

High diagnostic sensitivity and specificity while maintaining the least dose to the patient is the ideal mammography. The objective of this work was to evaluate patient dose and image quality of mammograms to propose corrective actions. The image quality for 1242 patient in 7 mammography facilities in Tehran city was evaluated based on selected image quality criteria using a three-point scale. Clinical image quality, the entrance surface air kerma, the average glandular dose and optical density of films for standard PMMA phantom of 4.5 cm thickness were evaluated. The results showed that up to 72 % of mammograms were in good condition to be diagnosed, and only about 3.4 % of the images were unacceptable or with suboptimal quality. The entrance surface air kerma values were in the range of 3.8-10.5 mGy, average glandular dose 0.5-1.8 mGy and optical density of films 0.74-2.03. The image quality evaluation after correction actions, periodic image quality evaluation and using the correct equipment certainly will improve patient dose.