title: Evaluation of macroaggregated albumin particle sizes for use in pulmonary shunt patient studies.
abstract: OBJECTIVE
  To assess commercial macroaggregated albumin (MAA) reagent kits for compliance with particle-size parameters needed for proper clinical evaluation of pulmonary shunts (right-to-left).
  
  
  METHODS
  Comparative trial.
  
  
  METHODS
  Nuclear pharmacy (laboratory setting).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Minimally, 90% of the particles contained within an MAA reagent kit should be within the 10 to 90 microns range with minimal variation in particle size distribution and as few small particles (i.e., < 10 microns) as possible. Five separate vials from five commercial brands of MAA reagent kits were obtained, and 500 to 517 particles were analyzed for each sample. An additional study was performed on one of the MAA reagent kit brands, using five vials from each of five different lot numbers to determine the variability between lots.
  
  
  METHODS
  Long axis (maximum, micron), short axis (minimum, micron), and the area (micron 2) of each MAA particle.
  
  
  RESULTS
  One MAA brand had the lowest percentage of unacceptable MAA particle sizes and maintained consistent particle sizes between vials. However, the same MAA reagent kit brand showed that only two of five lots had a low percentage of MAA particle sizes below the 10-micron limit.
  
  
  CONCLUSIONS
  Particle sizes varied among the five different brands of MAA reagent kits, as did different lots of the best-performing kit. This variability in particle sizes may affect the accuracy and reproducibility of pulmonary shunt patient studies.
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905, USA. jhung@mayo.edu
authors.forename: J C
authors.initials: JC
authors.lastname: Hung
authors.forename: M G
authors.initials: MG
authors.lastname: Redfern
authors.forename: D W
authors.initials: DW
authors.lastname: Mahoney
authors.forename: L M
authors.initials: LM
authors.lastname: Thorson
authors.forename: G A
authors.initials: GA
authors.lastname: Wiseman
mesh_terms: D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D010316:Particle Size; D011652:Pulmonary Circulation; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000737:chemistry*; D011933:Reagent Kits, Diagnostic; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013668:Technetium Tc 99m Aggregated Albumin / Q000737:chemistry*
chemical_list: D019275:Radiopharmaceuticals; D011933:Reagent Kits, Diagnostic; D013438:Sulfhydryl Compounds; D013668:Technetium Tc 99m Aggregated Albumin; C082426:technetium Tc99m-mercaptoacetyl albumin