title: Experimental procedure for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry.
abstract: A simple methodology for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry is presented to enable individuals to undertake such work in a routine clinical environment. Samples of PAG were irradiated using a linear accelerator and imaged using a 0.5 T (22 MHz) Philips Gyroscan MRI scanner. The mean spin-lattice relaxation rate was measured using a 'turbo-mixed' sequence, consisting of a series of 90 degrees pulses, each followed by acquisition of a train of spin echoes. The mean sensitivity for five different batches of PAG in the range up to 10 Gy was calculated to be 0.0285 s-1 Gy-1 for the mean spin-lattice relaxation rate with a percentage standard deviation of 1.25%. The overall reproducibility between batches was calculated to be 2.69%. This methodology, which introduces the novel use of pre-filled nitrogen vials for calibration, has been used to develop techniques for filling anatomically shaped anthropomorphic phantoms.
authors.affiliation: Centre for Medical and Health Physics, Queensland University of Technology, Brisbane, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Baldock
authors.forename: R P
authors.initials: RP
authors.lastname: Burford
authors.forename: N
authors.initials: N
authors.lastname: Billingham
authors.forename: G S
authors.initials: GS
authors.lastname: Wagner
authors.forename: S
authors.initials: S
authors.lastname: Patval
authors.forename: R D
authors.initials: RD
authors.lastname: Badawi
authors.forename: S F
authors.initials: SF
authors.lastname: Keevil
mesh_terms: D000180:Acrylic Resins / Q000138:chemical synthesis* / Q000528:radiation effects / Q000592:standards*; D055592:Biophysical Phenomena; D001703:Biophysics; D005782:Gels; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D010315:Particle Accelerators; D019047:Phantoms, Imaging; D011786:Quality Control; D011874:Radiometry / Q000379:methods* / Q000592:standards; D012015:Reference Standards
chemical_list: D000180:Acrylic Resins; D005782:Gels; C016680:polyacrylamide gels