10 research outputs found

    Optimization of Brain Tumor MR Image Classification Accuracy Using Optimal Threshold, PCA and Training ANFIS with Different Repetitions.

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    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 METHODS: The procedure used in this study consists of five steps: (1) T1, T2 weighted images collection, (2) tumor separation with different threshold levels, (3) feature extraction, (4) presence and absence of feature reduction applying principal component analysis (PCA) and (5) ANFIS classification with 0, 20 and 200 training repetitions. RESULTS: ANFIS accuracy was 40%, 80% and 97% for all features and 97%, 98.5% and 100% for the 6 selected features by PCA in 0, 20 and 200 training repetitions, respectively. CONCLUSION: The findings of the present study demonstrated that accuracy can be raised up to 100% by using an optimized threshold method, PCA and increasing training repetitions. KEYWORDS: ANFIS ; Brain Tumor Detection ; PCA ; Training Repetition; MR

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

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    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 method for generating a homogeneous dose distribution in the junction region between two adjacent fields in electron beam therapy. Materials and Methods: Several approaches have been proposed to solve the problem of ‘hot’ and ‘cold’ spots in the junction region between abutting electron fields. These techniques are based on beam-edge modifying devices or penumbra generators which act to broaden the electron beam penumbra, and thus facilitate field matching. But use of these devices is time consuming and design of the modifications to the applicators are generally applicator dependent. An idea which was originally proposed for matching two adjacent photon fields (with dose inhomogeneity of about 2%) is resurrected here. This method is based on the rotation of the gantry such that the adjacent fields have a common edge and the overlap region in treatment volume is eliminated. For this purpose, the effective source to surface distance (SSDeff) for the available electron beam energies (6, 9, 12 and 15 MeV) and applicators (cones) (6 × 6, 10 × 10, 15 ×15, 20 × 20 and 25 × 25 cm2) have been determined for a Varian 2100C linear accelerator. Result: Using SSDeff, in respect to beam divergence, one can use the photon beam behavior for electron beams and achieve a uniform dose distribution in adjacent electron fields. Discussion and Conclusion: Compared to beam-edge modifying devices or penumbra generators that are usually time consuming to plan and set up, rotating the gantry to eliminate the overlap region is simple and applicable in the problem of abutting electron fields

    Analytical investigation of magnetic field effects on Proton lateral deflection and penetrating depth in the water phantom: A relativistic approach

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    Background: Integrated proton therapy - MRI systems are capable of delivering high doses to the target tissues near sensitive organs and achieve better therapeutic results; however, the applied magnetic field for imaging, influences the protons path, changes the penetration depth and deflects the particles, laterally, leading to dose distribution variations. Objective: To determine the effects of a magnetic field on the range and the lateral deflection of protons, analytically. Methods: An analytical survey based on protons energy and range power law relation, without using small angle assumption was done. The penetration depth and lateral deflection of protons with therapeutic energy ranges 60- 250 MeV in the presence of uniform magnetic fields of 0-10T intensities, were calculated analytically. Calculations were done for relativistic conditions with Mathematica software version 7.0, and MATLAB 7.0 was applied to plot curves and curve fittings. Results: In the presence of a magnetic field, the depth of Bragg peak was decreased and it was shifted laterally. A second order polynomial model with power equation for its coefficients and a power model with quadratic polynomial coefficients predicted the maximum lateral deflection (ymax) and maximum penetration depth (zmax) variations with energy and magnetic field intensity, respectively. Conclusion: The applied correction for deflection angle will give more reliable results in initial energy of 250 MeV and 3T magnetic field intensity. For lower energies and magnetic field intensities the differences are negligible, clinicall

    Hypothalamic-pituitary-gonadal axis responses of the male rats to short and long time alternative magnetic fields (50 Hz) exposure

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    <font face="TimesNewRoman,Bold" size="1"><font face="TimesNewRoman,Bold" size="1"><ul><li><div align="left"><strong>BACKGROUND</strong>: <font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">Electromagnetic fields are associated with production, transmission and use of electricity. In this  tudy we have investigated the effects of short and long time alternative magnetic fields' (AMF, 50 Hz) exposure on the secretion of hypothalamic-pituitary-gonadal axis in the male rats.</font></font></div></li><font face="TimesNewRoman,Bold" size="1"><font face="TimesNewRoman,Bold" size="1"><li><div align="left"><strong>METHODS</strong>: <font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">Forty eight Wistar male rats, same range of age and weight were divided into four groups and each group<li><div align="left">contained 12 rats. After one-week adaptation each  roup were exposed to AMF (0, 25, 50 and 100 <font face="+TimesNewRoman" size="2"><font face="+TimesNewRoman" size="2">4</font></font><font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">T  espectively) for 17 days, 5 hours a day. In the second protocol the time of exposure extended to 34 days. After experiments rats' blood serums were removed from their blood samples and kept frozen for usage. The results were analyzed by one way- ANOVA statistical method (p < 0.05).</font></font></div></li></font></font></div></li></font></font><font face="TimesNewRoman,Bold" size="1"><font face="TimesNewRoman,Bold" size="1"><li><div align="left"><strong>RESULTS</strong>: <font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">Chronic exposures (5h/day for 34 days) to AMFs had no effect on serum's testosterone and LH. But, AMF  t 100 </font></font><font face="+TimesNewRoman" size="2"><font face="+TimesNewRoman" size="2">4</font></font><font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">T induced an increase of serum's FSH level in  omparison with 25 μT, 50 </font></font><font face="+TimesNewRoman" size="2"><font face="+TimesNewRoman" size="2">4</font></font><font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">T and control groups. In contrast, subchronic AMFs (5 h/day for 17 days) induced a decrease of serum's testosterone in control group in  omparison with 25, 50 and 100 </font></font><font face="+TimesNewRoman" size="2"><font face="+TimesNewRoman" size="2">4</font></font><font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">T groups. But these AMFs had no effect on serum's LH and FSH levels.</font></font></div></li></font></font><font face="TimesNewRoman,Bold" size="1"><font face="TimesNewRoman,Bold" size="1"><li><div align="left"><strong>CONCLUSIONS</strong>: <font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">Increased level of FSH suggests damage to the seminiferous tubules. Our results suggest that AMFs probably causes dysfunction in gonadal axis at the hypothalamic-pituitary level in male rats in different protocols.</font></font></div></li></font></font><font face="TimesNewRoman,Bold" size="1"><font face="TimesNewRoman,Bold" size="1"><li><div align="left"><strong>KEYWORDS</strong>: <font face="TimesNewRoman" size="2"><font face="TimesNewRoman" size="2">Sex Hormones, Male Rats, Magnetic Field.</font></font></div></li></font></font></ul></font></font&gt

    An Analytical Method to Calculate Phantom Scatter Factor for Photon Beam Accelerators

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    Introduction: One of the important input factors in the commissioning of the radiotherapy treatment planning systems is the phantom scatter factor (Sp) which requires the same collimator opening for all radiation fields. In this study, we have proposed an analytical method to overcome this issue. Methods: The measurements were performed using Siemens Primus Plus with photon energy 6 MV for field sizes from 5×5cm2 to 40×40cm2 . Phantom scatter factor was measured through the division of total scatter output factors (Scp), and collimator scatter factor (Sc). Results: The mean percent difference between the measured and calculated Sp was 1.00% and -3.11% for 5×5, 40×40 cm2 field size respectively. Conclusion: This method is applicable especially for small fields used in IMRT which, measuring collimator scatter factor is not reliable due to the lateral electron disequilibriu

    Identification of A Novel Compound Heterozygous Mutation in BBS12 in An Iranian Family with Bardet-Biedl Syndrome Using Targeted Next Generation Sequencing

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    Bardet-Biedl syndrome (BBS) is a pleiotropic and multisystemic disorder characterized by rod-cone dystrophy, polydactyly, learning difficulties, renal abnormalities, obesity and hypogonadism. This disorder is genetically heterogeneous. Until now, a total of nineteen genes have been identified for BBS whose mutations explain more than 80% of diagnosed cases. Recently, the development of next generation sequencing (NGS) technology has accelerated mutation screening of target genes, resulting in lower cost and less time consumption. Here, we screened the most common BBS genes (BBS1-BBS13) using NGS in an Iranian family of a proposita displaying symptoms of BBS. Among the 18 mutations identified in the proposita, one (BBS12 c.56T>G and BBS12 c.1156C>T) was novel. This compound heterozygosity was confirmed by Sanger sequencing in the proposita and her parents. Although our data were presented as a case report, however, we suggest a new probable genetic mechanism other than the conventional autosomal recessive inheritance of BBS. Additionally, given that in some Iranian provinces, like Khuzestan, consanguineous marriages are common, designing mutational panels for genetic diseases is strongly recommended, especially for those with an autosomal recessive inheritance pattern

    Evaluate the Effect of Dendrosomal Curcumin on Expression Level of HOTAIR Long Noncoding RNA in MCF-7 Breast Cancer Cell Line

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    Introduction: Breast cancer is one of the most common malignancies in women. Treatment with herbal drugs has been considered by researchers due to the lower side effects. Curcumin is a polyphenol extracted from turmeric with confirmed anti-cancer properties. Curcumin is water-insoluble with rapid metabolism. Drug delivery using nano-carriers is suggested to overcome such limitations. The aim of this study was based on evaluating the effect of Dendrosomes curcumin on expression level of HOTAIR long noncoding RNA in MCF-7 breast cancer cell line. Methods: This study was an applied basic research. Firstly, curcumin was loaded in dendrosomes and the entry of dendrosomal curcumin into cells was studied using fluorescent microscopy.  Cell death was investigated using MTT assay and apoptosis detection kit. The expression of HOTAIR gene was measured using real-time PCR. Increased expression of this gene was reported in a wide range of tumors. The data were analyzed using GraphPad Prism V9.5 statistical software, using NOVA one-way statistical analysis and Student t-test; the results were reported as mean ± standard deviation. Results: Dendrosomes increased the solubility of curcumin. The effective inhibitory doses of dendrosomal curcumin after 24 and 48h treatment were 25 and 20 micromolar, respectively. The percent of cells undergoing early apoptosis were 22.97±0.03 and 56.22±0.05, respectively, which was statistically significant in comparison with non-treated control cells. Following 24 and 48h treatment with 20 micromolar of dendrosomal curcumin, the HOTAIR gene expression was significantly decreased (P=0.001). Conclusion: These findings suggest that dendrosomal curcumin may promote breast tumor cells toward programmed cell death by reducing HOTAIR gene expression

    Quality Control of Conventional Radiology Devices in Selected Hospitals of Khuzestan Province, Iran

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    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, based on the protocol proposed in Report No. 77 by the Institute of Physics and Engineering in Medicine (IPEM). Ten standard QC tests, including voltage accuracy and reproducibility, exposure time accuracy and reproducibility, tube output linearity (time and milliampere), filtration (half-value layer), tube output (70 kV at FSD =100 cm), tube output reproducibility and beam alignment were performed and assessed. All measurements were performed, using Barracuda multi-purpose detector. Results The reproducibility of voltage, exposure time and dose output, as well as output linearity, met the standard criteria in all devices. However, in 60% of the units, the results of the beam alignment test were poor. We also found that 66.7% of the studied units offer services to more than 18,000 patients annually or 50 patients per day. Conclusion Despite the fact that radiological devices in Khuzestan province are relatively old with high workload, the obtained results showed that these devices met the standard criteria. This may be mainly related to proper after-sale services, provided by the companies. Although these services may be expensive for radiology centers, the costs may be significantly reduced if QC is defined as a routine procedure performed by qualified medical physicists or radiation safety officers
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