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Open access

C. Iheduru, M. A. Eleruja, B. Olofinjana, O. E. Awe and A.D.A Buba

Abstract

We have explored the effectiveness of Geant4 by using it to simulate phonon conduction in Sn Host with Si Nanowire Interface. Our Monte Carlo Simulation shows that the effectiveness of the phonon conduction Geant4 simulation increases when the system attained a steady state of 100 time steps. We have simulated phonon conduction in Sn host with Si nanowire interface using a Geant4Condensed Matter Physics Monte Carlo simulation toolkit in a low cost and less powerful processing computer machine. In the simulation, phonons were displaced inside a computation domain from their initial positions with the velocities and direction vectors assigned to them. A time step was selected so that a phonon can move at most the length of one sub-cell in one time step. Our phonon conduction analysis of SiSn based alloy using Geant4 showed performance enhancement and reasonable predicted thermal values. Numerical predictions of the thermal profile simulations of the values of the temperature in each cell were all within ten percent of the average temperature of Silicon – Tin.

Open access
Open access

Pegah Moradi Khaniabadi, Daryoush Shahbazi-Gahrouei, Amin Malik Shah Abdul Majid and Bita Moradi Khaniabadi

Abstract

Non-invasive methods for breast cancer detection in early stages may help to increase the survival rate of patients. This study aimed to evaluate the application of Anti-MUC1 antibody-based iron oxide nanoparticle (SPIONs-C595) which was assessed in vivo as a molecular imaging probe for breast cancer (MCF-7) detection using MRI. Nine groups of female NRC NU/Nu mice (each group of 3), 6 to 8 weeks old were used and MCF-7 cells were injected subcutaneously into both flanks of nude mice. After two weeks the mice received an intravenous injection of different concentrations of SPIONs-C595. The uptake ability of SPIONs-C595 on three-dimension (3D) macrostructure is exploited a modified hanging drop method using Prussian blue for MCF-7 cells. The iron content was measured in liver, kidney, spleen, and tumor. The MR imaging features and biodistribution of nanoprobe was also investigated. The MR images obtained from digested tumor after nanoprobe administration in different time-period revealed that enhancement of T1 and T2 relaxation time. Moreover, the storage stability test was shown great application and no sedimentation of nanoparticles within two months storage at 4°C. Additionally, great validation of SPIONs-C595 on the 3D spheroid of MCF-7 was observed. The biodistribution analysis showed that iron content of the spleen was more than the other studied organs. These results highlighted the feasibility of an in-vivo model for detection of breast cancer MUC1 expression. Current researches are ongoing to further enhancement of relaxation times for classification of MUC1 status using clinical specimens.

Open access

K.A. Shaheer Abubacker, J. Sutha and K.A. Shahul Hameed

Abstract

This paper describes a method of retrieving stereoscopic medical images from the database that consists of feature extraction, similarity measure, and re-ranking of retrieved images. This method retrieves similar images of the query image from the database and re-ranks them according to the disparity map. The performance is evaluated using the metrics namely average retrieval precision (APR) and average retrieval rate (ARR). According to the performance outcomes, the multi-feature based image retrieval using Mahalanobis distance measure has produced better result compared to other distance measures namely Euclidean, Minkowski, the sum of absolute difference (SAD) and the sum of squared absolute difference (SSAD). Therefore, the stereo image retrieval systems presented has high potential in biomedical image storage and retrieval systems.

Open access

Amir Ghasemi Jangjoo, Hosein Ghiasi and Asghar Mesbahi

Abstract

103Pd seed is being used for prostate brachytherapy. Additionally, the dose enhancement effect of gold nanoparticles (GNP) has been reported in previous studies. The aim of this study was to characterize the dosimetric effect of gold nanoparticles in brachytherapy with a 103Pd source. Two brachytherapy seeds including 103 Pd source was simulated using MCNPX Monte Carlo code. The seeds’ models were validated by comparing the MC with reported results. Then, GNPs (10 nm in diameter) with a concentration of 7mg Au/g were simulated uniformly inside the prostate of a humanoid computational phantom. Additionally, the dose enhancement factor (DEF) of nanoparticles was calculated for both modeled brachytherapy seeds. A good agreement was found between the MC calculated and the reported dosimetric parameters. For both seeds, an average DEF of 23% was obtained in tumor volume for prostate brachytherapy. The application of GNPs in conjunction with 103Pd seed in brachytherapy can enhance the delivered dose to the tumor and consequently leads to better treatment outcome.

Open access

Daryoush Shahbazi-Gahrouei, Pegah Moradi Khaniabadi, Saghar Shahbazi-Gahrouei, Amir Khorasani and Farshid Mahmoudi

Abstract

Molecular imaging techniques using nanoparticles have significant potential to be widely used for the detection of various types of cancers. Nowadays, there has been an increased focus on developing novel nanoprobes as molecular imaging contrast enhancement agents in nanobiomedicine. The purpose of this review article is to summarize the use of a variety of nanoprobes and their current achievements in accurate cancer imaging and effective treatment. Nanoprobes are rapidly becoming potential tools for cancer diagnosis by using novel molecular imaging modalities such as Ultrasound (US) imaging, Computerized Tomography (CT), Single Photon Emission Tomography (SPECT) and Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI), and Optical Imaging. These imaging modalities may facilitate earlier and more accurate diagnosis and staging the most of cancers.

Open access

S.Z. Islami Rad, R. Gholipour Peyvandi and M.K. Sadeghi

Abstract

Monte Carlo simulation is widely used in emission tomography, in order to assess image reconstruction algorithms and correction techniques, for system optimization, and study the parameters affecting the system performance. In the current study, the performance of the IRI-microPET system was simulated using the GATE Monte Carlo code and a number of performance parameters, including spatial resolution, scatter fraction, sensitivity, RMS contrast, and signal-to-noise ratio, evaluated and compared to the corresponding measured values. The results showed an excellent agreement between simulated and measured data: The experimental and simulated spatial resolutions (radial) for 18F in the center of the AFOV were 1.81 mm and 1.65 mm, respectively. The difference between the experimental and simulated sensitivities of the system was <7%. Simulated and experimental scatter fractions differed less than 9% for the mouse phantom in different timing windows. The validation study of the image quality indicated a good agreement in RMS contrast and signal-to-noise ratio. Also, system performance was compared with the two available commercial scanners which were simulated using GATE code. In conclusion, the assessment of the Monte Carlo modeling of the IRI-microPET system reveals that the GATE code is a flexible and accurate tool for describing the response of an animal PET system.

Open access

Sam Deva Kumar Johnjothi, Arulpandiyan Ranganathan, Vasanth Christopher Jayapaul, Rithesh Santosham, Dhanabalan Rajasekaran, Vivekanandan Nagarajan and Selvaluxmy Ganesharaja

Abstract

Aim: To check the feasibility of simultaneous integrated boost (SIB) using a forward planned field in field (FIF) conformal technique for the treatment of carcinoma of the cervix IIIB and compare it dosimetrically with other advanced inverse planning techniques.

Methods: In our study 33 patients of carcinoma of the cervix IIIB were planned for SIB using conformal FIF technique and they were compared with retrospectively planned IMRT and VMAT techniques. SIB using conformal FIF was planned by two different methods.

Results: The results of our study indicate that forward planned Conformal SIB techniques are comparable with inverse planned techniques dosimetrically, in terms of conformity Index, Homogeneity Index, Maximum dose, etc. The ability of FIF SIB plans to produce dose contrast in differential dose accumulation was compared and analyzed and the results were encouraging. To treat an advanced/bulky disease like Carcinoma of the Cervix IIIB in centers with large patient load, utilizing advanced techniques such as IMRT and VMAT is both technically and practically difficult. Despite VMAT’s shorter delivery time, the procedures involved are time-consuming.

Conclusion: Hence forward planned SIB techniques may be used to achieve similar dosimetric effects of IMRT and VMAT techniques without much compromise in plan quality and patient throughput for treating bulky carcinoma of the cervix IIIB cases. However, the clinical results need to be carefully compared and evaluated and reported.

Open access

Sathya D Janaki and K Geetha

Abstract

Diabetic Retinopathy (DR) is one of the leading causes of visual impairment. Diabetic Retinopathy is the most recent technique of identifying the intensity of acid secretion in the eye for diabetic patients. The identification of DR is performed by visual analysis of retinal images for exudates (fat deposits) and the main patterns are traced by ophthalmologists. This paper proposes a fully automated Computer Assisted Evaluation (CAE) system which comprises of a set of algorithms for exudates detection and to classify the different stages of Diabetics Retinopathy, which are identified as either normal or mild or moderate or severe. Experimental validation is performed on a real fundus retinal image database. The segmentation of exudates is achieved using fuzzy C-means clustering and entropy filtering. An optimal set obtained from the statistical textural features (GLCM and GLHM) is extracted from the segmented exudates for classifying the different stages of Diabetics Retinopathy. The different stages of Diabetic Retinopathy are classified using three classifiers such as Back Propagation Neural Network (BPN), Probabilistic Neural Network (PNN) and Support Vector Machine (SVM). The experimental results show that the SVM classifiers outperformed other classifiers for the examined fundus retinal image dataset. The results obtained confirm that with new a set of texture features, the proposed methodology provides better performance when compared to the other methods available in the literature. These results suggest that our proposed method in this paper can be useful as a diagnostic aid system for Diabetic Retinopathy.

Open access

Itumeleng Setilo, Oluwaseyi Michael Oderinde and Freek Cp du Plessis

Abstract

Introduction: Small fields photon dosimetry is associated with many problems. Using the right detector for measurement plays a fundamental role. This study investigated the measurement of relative output for small photon fields with different detectors. It was investigated for three-photon beam energies at SSDs of 90, 95, 100 and 110 cm. As a benchmark, the Monte Carlo simulation was done to calculate the relative output of these small photon beams for the dose in water.

Materials and Methods: 6, 10 and 15 MV beams were delivered from a Synergy LINAC equipped with an Agility 160 multileaf collimator (MLC). A CC01 ion chamber, EFD-3G diode, PTW60019 microdiamond, EBT2 radiochromic film, and EDR2 radiographic film were used to measure the relative output of the linac. Measurements were taken in water for the CC01 ion chamber, EFD-3G diode, and the PTW60019. Films were measured in water equivalent RW3 phantom slabs. Measurements were made for 1 × 1, 2 × 2, 3 × 3, 4 × 4, 5 × 5 and a reference field of 10 × 10 cm2. Field sizes were defined at 100cm SSD. Relative output factors were also compared with Monte Carlo (MC) simulation of the LINAC and a water phantom model. The influence of voxel size was also investigated for relative output measurement. Results and Discussion: The relative output factor (ROF) increased with energy for all fields large enough to have lateral electronic equilibrium (LEE). This relation broke down as the field sizes decreased due to the onset of lateral electronic disequilibrium (LED). The high-density detector, PTW60019 gave the highest ROF for the different energies, with the less dense CC01 giving the lowest ROFs.

Conclusion: These are results compared to MC simulation, higher density detectors give higher ROF values. Relative to water, the ROF measured with the air-chamber remained virtually unchanged. The ROFs, as measured in this study showed little variation due to increased SSDs. The effect of voxel size for the Monte Carlo calculations in water does not lead to significant ROF variation over the small fields studied.