نتایج جستجو برای: mri based polymer gel dosimetry

تعداد نتایج: 3180930  

Journal: :Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics 2008
B Hill A J Venning C Baldock

Polymer gel dosimetry undertaken on a multislice CT scanner provides an alternative method to conventional dosimetry measurements. Polymer gel dosimeters were used to measure CT radiation doses and compared to TLD and ionization chamber measurements in different diameter phantoms. CTDI was investigated for each of these phantoms for a range of mAs (100-400 mAs), tube voltage (100-135 kV) and no...

M. Allahverdi, M.H. Zahmatkesh, Mahbod Sedaghat, R. Jaberi, Sh. Akhlaghpoor,

ABSTRACTBackground: Polymer gels are an emerging new class of dosimeters which are being applied to the challenges of modern radiotherapy modalities. Research on gel dosimetry involves several scientific domains, one of which is the imaging techniques with which dose data is extracted from the dosimeters. In the current work, we present our preliminary results of investigating capability of X-r...

Journal: :iranian journal of medical physics 0
hamid reza sadoughi m.sc. student of medical physics, medical physics dept., tehran university of medical sciences, tehran, iran mahmood allahverdi associate professor, medical physics dept., tehran university of medical sciences, and radiotherapy physics department of cancer institute, tehran, iran hasan nedaei assistant professor, radiotherapy physics dept., cancer institute, tehran, iran ramin jaberi radiotherapy physicist, radiotherapy physics dept., cancer institute, tehran, iran mahbod esfahani radiotherapy physicist, radiotherapy physics dept., cancer institute, tehran, iran alireza shirazi associated professor, medical physics dept., tehran university of medical sciences, tehran, iran

introduction: multiple fields and presence of heterogeneities create complex dose distributions that need three dimensional dosimetry. in this work, we investigated mr-based magic gel dosimetry as a three-dimensional dosimetry technique to measure the delivered dose to bladder and rectum in prostate radiation therapy. materials and methods: a heterogeneous slab phantom including bones was made....

Background: Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions.Objective: The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiothe...

Journal: :journal of medical signals and sensors 0
seyed salman zakariaee mikaeil molazadeh abbas takavar alireza shirazi asghar mesbahi ahad zeinali

in radiation cancer treatments, the most of the side effects could be minimized using a proper dosimeter. gel dosimeter is the only three‑dimensional dosimeter and magnetic resonance imaging (mri) is the gold standard method for gel dosimeter readout. because of hard accessibility and high cost of sample reading by mri systems, some other alternative methods were developed. the optical computed...

2007
Martin Lepage

1. Introduction Magnetic resonance imaging (MRI) can non-invasively and non-destructively probe the magnetization of hydrogen atoms on water molecules in large objects with a high spatial resolution, and in three dimensions. This unique combination of properties is exploited in polymer gel dosimetry since original gel dosimeters, in which viscosity changes were measured and related to the absor...

2008
Yves De Deene

The use of polymer gels to record radiation dose distributions in three dimensions was first proposed in 1992 as a proof-of-principle [1]. The accuracy of these early polymer gel dosimeters and scanning methods was not sufficient for most clinical applications [2]. Since then, several efforts were made to increase the accuracy and precision of both the physical gel dosimeter and the scanning te...

2008
Louis Archambault Ghyslain Leclerc Luc Beaulieu Heather M Whitney Daniel F Gochberg E. Pappas T. G. Maris S. Manolopoulos F. Zacharopoulou A. Papadakis S. Green C. Wojnecki

Small photon fields are increasingly used in modern radiotherapy and especially in IMRT and SRS/SRT treatments. Accurate beam profile measurements of such beams are crucial for a precise and effective treatment. In this work four different dosimetric methods have been used for profile measurements of three small 6 MV circular fields having diameters of 7.5, 15.0 and 30.0 mm. A small sensitive v...

Journal: :iranian journal of radiation research 0
k. adinehvand borujerd islamic azad university, borujerd, iran m.h. zahmatkesh novin radiation medicine institute, tehran, iran m.r aghamiri division of radiation medicine, shahid beheshti university, tehran, iran sh. akhlaghpour department of radiology, tehran university of medical sciences, tehran, iran s. bagheri novin radiation medicine institute, tehran, iran

background: the purpose of this study was to evaluate the dependency of magica polymer gel dosimeter response (r2) on different electron energies as well as on different mean dose rate for a standard clinically used linear accelerator. materials and methods: the sensitivity of the dosimeter was represented by the slope of calibration curve in the linear region measured for each modality. a cali...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید