Effect of Mega Voltage Energy on Dose Enhancement in Phantom Study by Using Gold Nanoparticle Polymer Gel Dosimeter
Gholamreza Atae,
Seyed Rabee Mahdavi,
Akram Mohammadi Nokhandani,
Syede Mahsa Taheri Otaghsara,
Mahboubeh Khadem Abolfazli
Issue:
Volume 3, Issue 1, February 2015
Pages:
1-4
Received:
29 November 2014
Accepted:
16 December 2014
Published:
20 January 2015
Abstract: Background: Polymer gels beam sensitive are valuable and confident for measurement of 3D dose distributions. One of the special features of this type of dosimeters is their tissue equivalence, which makes them appropriate for the investigation of dose enhancement with contrast agents with high atomic number. Objective: The purpose of this study is an investigating of dose enhancement dependent in energy within the gel medium with used of conformal distribution gold nanoparticle as contrast agents by high atomic number material. Methods: In this work, gold nanoparticles (GNPs) of 50nm diameter with 0.1m concentration embedded in gel and irradiated by different megavoltage energy of 18MVand 6MV photon beam. Then GN- MAGICA and MAGICA dose response curves compare and achieved dose enhancement. Results: Experimental results have shown dose enhancement factor of 6MV and 18MV in 0.1mM, concentration is 1.74 and 1.04 respectively. Conclusion: The results showed that by adding of gold nanoparticles to the MAGICA polymer gel absorbed dose is increased. The levels of polymerization of irradiated gels with and without AuNPs in energy 6MV is more than energy 18MV. It seems that because of the dominance of photoelectric effect at low energies and pair production effect at high energies.
Abstract: Background: Polymer gels beam sensitive are valuable and confident for measurement of 3D dose distributions. One of the special features of this type of dosimeters is their tissue equivalence, which makes them appropriate for the investigation of dose enhancement with contrast agents with high atomic number. Objective: The purpose of this study is ...
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Teaching College Students Principle of Endoscopes Through an Educational Method of Image Processing
Issue:
Volume 3, Issue 1, February 2015
Pages:
5-10
Received:
3 March 2015
Accepted:
19 March 2015
Published:
24 March 2015
Abstract: We gave a lecture regarding the principles of endoscopes to students studying medical engineering. The following was the lecture. The light from the light source passed through the rotating RGB filter, and changed to a red, a green, and a blue light, respectively, and these three colored lights illuminated an object. Each light reflected from the object passed through a lens and was received by the CCD. The light signals were changed into electric signals by the CCD, and the memory recorded the red, green, and blue electric signals. The video processor processed these color signals. And, the image of the object was displayed on the monitor. Next, we gave a lecture about RGB colors to the students. The RGB color model was an additive color model of red, green, and blue light. The model could reproduce a broad array of colors using various ways. To allow the students to experience these principles, we gave the students an experimental subject. We prepared a CCD camera, RGB filters, a power supply code, and a video cable. The CCD camera was a Super Color Camera NA-C2660. The RGB filters were the additive types of Dichroic Color Filters that were manufactured by Edmund Optics, Co. These filters were three of colors: red, green, and blue. The video capture board was an Analog Video Capture Board GV-VCP3R/PCI that was manufactured by I-O DATA Device, Inc. Students were divided into 36 groups with 5-6 students in each group. The students combined the three images photographed with the RGB filters, and performed the image processing. The students compared the RGB values of the combined images with the RGB values of the normal image. They brought the RGB value of the combined image as close as possible to the RGB value of the normal image using the Paint Shop Pro 8 software. Next, the differences in the RGB values between the normal image and the modified image were calculated; the maximum of those values was extracted. According to the results, the number of the groups whose difference of the RGB value were greater than 5 and less than or equal to 10 showed the maximum. Moreover, the group which showed the 2nd value was the group whose difference of the RGB value were less than or equal to 5. In the end, the students could experience the principles of endoscopes and image processing.
Abstract: We gave a lecture regarding the principles of endoscopes to students studying medical engineering. The following was the lecture. The light from the light source passed through the rotating RGB filter, and changed to a red, a green, and a blue light, respectively, and these three colored lights illuminated an object. Each light reflected from the o...
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