Characterization of polymer networks using the dipolar correlation effect on the stimulated echo and field-cycling nuclear-magnetic resonance relaxometry

1998 ◽  
Vol 109 (2) ◽  
pp. 846-854 ◽  
Author(s):  
Elmar Fischer ◽  
Farida Grinberg ◽  
Rainer Kimmich ◽  
Siegfried Hafner
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Polymer Networks ◽  
Correlation Effect ◽  
Stimulated Echo ◽  
Nuclear Magnetic Resonance Relaxometry ◽  
Field Cycling ◽  
Nuclear Magnetic

scholarly journals Preliminary magnetic resonance relaxometric analysis of Fricke gel dosimeters produced with polyvinyl alcohol and glutaraldehyde

2017 ◽  
Vol 32 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Salvatore Gallo ◽  
Giorgio Collura ◽  
Giuseppina Iacoviello ◽  
Anna Longo ◽  
Luigi Tranchina ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Polyvinyl Alcohol ◽  
Dose Range ◽  
Relaxation Times ◽  
Ion Concentration ◽  
Nuclear Magnetic Resonance Relaxometry ◽  
New Formulation ◽  
Nuclear Magnetic

This work describes the preliminary analysis of Fricke gels dosimeters characterized by a new formulation making use of a matrix of polyvinyl alcohol cross-linked by adding glutaraldehyde and analyzed by means of nuclear magnetic resonance relaxometry. In previous optical studies, these gels have shown promising dosimetric features in terms of photon sensitivity and low diffusion of ferric ions produced after irradiation. In this work, we used a portable nuclear magnetic resonance relaxometer to measure the relaxation times (which are important for dosimetric applications) of these gel materials. For this purpose, we performed a study for optimizing the acquisition parameters with a nuclear magnetic resonance relaxometer. Gel samples were exposed to clinical 6 MV photons in the dose range between 0 and 20 Gy. Nuclear magnetic resonance relaxometry measurements were per- formed and the sensitivity to photon beams was measured for various values of the Fe2+ ion concentration. The analyses pointed out that the MR signal increases as the Fe2+ content in- creases and the increase is about 75 % when the concentration of Fe2+ ions is increased from 0.5 mM to 2.5 mM. Furthermore, the sensitivity improvement achieved with increasing the Fe2+ concentration is about 60 %. This paper shows that the portable nuclear magnetic resonance relaxometer used for analysis of porous materials can be used for characterization of these dosimetric gels and this study can be considered as the first step for the characterization of these dosimeters which in future could be used for 3-D dose mapping in clinical applications.

Field-cycling nuclear magnetic resonance relaxometry of thermoreversible polybutadiene networks

1997 ◽  
Vol 107 (15) ◽  
pp. 5973-5978 ◽  
Author(s):  
R. Kimmich ◽  
K. Gille ◽  
N. Fatkullin ◽  
R. Seitter ◽  
S. Hafner ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nuclear Magnetic Resonance Relaxometry ◽  
Field Cycling ◽  
Nuclear Magnetic
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