title: A new polymer gel for magnetic resonance imaging (MRI) radiation dosimetry.
abstract: New composition polymer gels, the N-vinylpyrrolidone argon (VIPAR) gels, were developed and investigated as MRI dosimeters. VIPAR gels were irradiated in the dose range of 0-12 Gy by a 6 MV x-ray linear accelerator and MR-scanned in a 1.5 T magnetic resonance imager. A linear relationship was found between absorbed dose and spin spin relaxation rate R2. The dose sensitivity was found to be approximately 0.1 s(-1) Gy(-1) for a gel composition of 4% w/w in N-vinylpyrrolidone, 4% w/w in N,N'-methylene-bisacrylamide, 5% w/w in gelatine type A and 87% w/w in water. This dose sensitivity was stable with time and did not deteriorate even when a boost radiation dose of 2.5 Gy was applied 15 days after the first irradiation. Good reproducibility of these results was observed when a new batch of gels was produced and used for corresponding measurements and analysis.
authors.affiliation: Physics Department, University of Athens, Panepistimioupolis, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Pappas
authors.forename: T
authors.initials: T
authors.lastname: Maris
authors.forename: A
authors.initials: A
authors.lastname: Angelopoulos
authors.forename: M
authors.initials: M
authors.lastname: Paparigopoulou
authors.forename: L
authors.initials: L
authors.lastname: Sakelliou
authors.forename: P
authors.initials: P
authors.lastname: Sandilos
authors.forename: S
authors.initials: S
authors.lastname: Voyiatzi
authors.forename: L
authors.initials: L
authors.lastname: Vlachos
mesh_terms: D005782:Gels; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010315:Particle Accelerators; D011205:Povidone / Q000031:analogs & derivatives; D011829:Radiation Dosage; D011834:Radiation Monitoring; D014965:X-Rays
chemical_list: D005782:Gels; D011205:Povidone