title: Spatial resolution of magnetic resonance imaging Fricke-gel dosimetry is improved with a honeycomb phantom.
abstract: The spatial accuracy of magnetic resonance imaging (MRI) Fricke-gel dosimetry is limited by diffusion of ferric ions. This paper describes a honeycomb structure to limit diffusion of Fe3+ ions in a three-dimensional phantom. Such a phantom containing the dosimeter gel was irradiated to a known dose distribution. Maps of dose distributions were produced from the MR images acquired at 2 and 24 hours after the dose was given. The dose distribution maps verified that the honeycomb structure precludes ion diffusion from one honeycomb cell to another, thus improving the usefulness of MRI Fricke-gel dosimetry.
authors.affiliation: Departamento de Física e Matemática-FFCLRP-Universidade de São Paulo, 14040-901-Ribeirão Preto, SP, Brazil.
authors.forename: Nivia Aparecida
authors.initials: NA
authors.lastname: Silva
authors.forename: Patricia
authors.initials: P
authors.lastname: Nicolucci
authors.forename: Oswaldo
authors.initials: O
authors.lastname: Baffa
mesh_terms: D003037:Cobalt Radioisotopes; D004307:Dose-Response Relationship, Radiation; D004867:Equipment Design; D005296:Ferrous Compounds / Q000528:radiation effects*; D005782:Gels / Q000528:radiation effects*; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D019047:Phantoms, Imaging; D011786:Quality Control; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012685:Sepharose / Q000528:radiation effects; D012996:Solutions / Q000528:radiation effects*
chemical_list: D003037:Cobalt Radioisotopes; D005296:Ferrous Compounds; C075364:Fricke solution; D005782:Gels; D012996:Solutions; D012685:Sepharose