Research Group Of Hamedan Mehdieh Charitable

Hamadān, Iran

Research Group Of Hamedan Mehdieh Charitable

Hamadān, Iran
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Masoudi S.,Azad University | Jalilian A.R.,Nuclear Medicine Research Group Agricultural | Tavakol A.,Research Group of Hamedan Mehdieh Charitable | Zandi H.,Research Group of Hamedan Mehdieh Charitable | Tayarzadeh Z.,Islamic Azad University
World Academy of Science, Engineering and Technology | Year: 2011

This paper presents a study on the Noise reduction and tumor detection in SPECT system images by Wavelet for animal study. Wavelet transforms and other multi-scale analysis functions have been used for compact signal and image representations in denoising, compression and feature detection processing problems for about twenty years[1]. The wavelet transform itself offers great design flexibility. Basis selection, spatial-frequency tiling, and various wavelet threshold strategies can be optimized for best adaptation to a processing application, data characteristics and feature of interest. Denoising is performed via thresholding estimators in the transform domain.


Fayaz V.,Islamic Azad University | Zandi H.,Research Group Of Hamedan Mehdieh Charitable | Tavakol A.,Research Group Of Hamedan Mehdieh Charitable
World Academy of Science, Engineering and Technology | Year: 2011

Estimation of surface dose is very important for patients undergoing radiation therapy. Several instruments have been used to measure absorbed radiation dose under non-electronic equilibrium conditions, such as in the build-up region or near the interface between two different media, including the surface. Many of these detectors are discussed in this paper. A common method of measuring the absorbed dose distribution and electron contamination in the build-up region of high-energy beams for radiation therapy is by means of parallel-plate ionisation chambers. Thermoluminescent dosimeters (TLDs), diodes and radiographic film have also been used to obtain surface dose measurements. The diamond detector was used recently by the author in an investigation on the effects of beam-modifying devices on skin dose and it is also described in this report.


Fayaz V.,Islamic Azad University | Zandi H.,Research Group Of Hamedan Mehdieh Charitable
World Academy of Science, Engineering and Technology | Year: 2011

The penumbra for electron beams is defined either in terms of the distance between two isodose values on a beam profile at the depth of maximum dose (or at the standard measurement depth), or indirectly in terms of distances between specified isodoses and the geometric field edge under stated conditions as above. If the former, then generally the 20%-80% width is expected to be 10 mm to12 mm for electron beams below 10 MeV, and 8 mm to10 mm for electron beams between 10 MeV and 20 MeV. These values apply for applicators with the final collimation stage at 5 cm or less from the skin, but for greater seperation between the applicator and the skin the penumbra will increase.


Fayaz V.,Islamic Azad University | Tavakol A.,Research Group of Hamedan Mehdieh Charitable
World Academy of Science, Engineering and Technology | Year: 2011

To investigate the applicability of the EDR-2 film for clinical radiation dosimetry, percentage depth-doses, profiles and distributions in open and dynamically wedged fields were measured using film and compared with data from a Treatment Planning system.The validity of the EDR2 film to measure dose in a plane parallel to the beam was tested by irradiating 10 cm×10 cm and 4 cm×4 cm fields from a Siemens, primus linac with a 6MV beam and a source-to-surface distance of 100 cm. The film was placed Horizontally between solid water phantom blocks and marked with pin holes at a depth of 10 cm from the incident beam surface. The film measurement results, in absolute dose, were compared with ion chamber measurements using a Welhoffer scanning water tank system and Treatment Planning system. Our results indicate a maximum underestimate of calculated dose of 8 % with Treatment Planning system.

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