title: ARAS: an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes.
abstract: BACKGROUND
  Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing a safe environment for radiation workers but also to ensure accuracy of dispensed radioactivity and an efficient workflow. For this purpose, we have designed ARAS, an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes with particular focus on fluorine-18 ((18)F).
  
  
  METHODS
  The key to the system is the combination of a radiation detector measuring radioactivity concentration, in line with a peristaltic pump dispensing known volumes.
  
  
  RESULTS
  The combined system demonstrates volume variation to be within 5 % for dispensing volumes of 20 μL or greater. When considering volumes of 20 μL or greater, the delivered radioactivity is in agreement with the requested amount as measured independently with a dose calibrator to within 2 % on average.
  
  
  CONCLUSIONS
  The integration of the detector and pump in an in-line system leads to a flexible and compact approach that can accurately dispense solutions containing radioactivity concentrations ranging from the high values typical of [(18)F]fluoride directly produced from a cyclotron (~0.1-1 mCi μL(-1)) to the low values typical of batches of [(18)F]fluoride-labeled radiotracers intended for preclinical mouse scans (~1-10 μCi μL(-1)).
authors.affiliation: Crump Institute for Molecular Imaging, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. alexdooraghi@gmail.com.|Department of Molecular & Medical Pharmacology, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. alexdooraghi@gmail.com.|Present Address: Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA. alexdooraghi@gmail.com.
authors.forename: Alex A
authors.initials: AA
authors.lastname: Dooraghi
authors.affiliation: Carroll and Ramsey Associates, Berkeley, CA, 94710, USA. cra@carroll-ramsey.com.
authors.forename: Lewis
authors.initials: L
authors.lastname: Carroll
authors.affiliation: Crump Institute for Molecular Imaging, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. jeffreycollins@mednet.ucla.edu.|Department of Molecular & Medical Pharmacology, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. jeffreycollins@mednet.ucla.edu.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Collins
authors.affiliation: Crump Institute for Molecular Imaging, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. mvandam@mednet.ucla.edu.|Department of Molecular & Medical Pharmacology, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. mvandam@mednet.ucla.edu.
authors.forename: R Michael
authors.initials: RM
authors.lastname: van Dam
authors.affiliation: Crump Institute for Molecular Imaging, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. archatziioann@mednet.ucla.edu.|Department of Molecular & Medical Pharmacology, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA. archatziioann@mednet.ucla.edu.
authors.forename: Arion F
authors.initials: AF
authors.lastname: Chatziioannou
keywords: Aliquot; Automation; Beta particle; Dispense; PET; Positron; Positron emission tomography; Radiation detection