title: Polyvinyl alcohol particle size and suspension characteristics.
abstract: OBJECTIVE
  To evaluate the size and shape of commercially available polyvinyl alcohol (PVA) particles and to determine whether they change in size when suspended in nonionic contrast and in a solution of nonionic contrast and absolute alcohol.
  
  
  METHODS
  The two-dimensional area and the long and short axis of PVA particles from several different vendors were measured using a light microscope attached to a video system and an image-processing software program. Particles were measured as packaged (dry or suspended in saline), suspended in ioversol, and suspended in ioversol containing 30% alcohol.
  
  
  RESULTS
  All brands of dry particles had similar microscopic appearances. The saline-suspended particles had fewer and finer perforations. After suspension in contrast, all sizes and brands of dry particles significantly increased in size. The particles packaged in saline did not expand. The addition of alcohol to the contrast did not consistently change particle size. Particle aggregation was similar in both contrast suspensions for all groups of particles. Particles less than 50 microns in size were rarely observed in any PVA preparation after suspension.
  
  
  CONCLUSIONS
  The three dry PVA preparations seem to be similar. All increase significantly in size when suspended in nonionic contrast or contrast-alcohol solutions. The saline-packaged PVA particles were different from the dry variety and did not enlarge in contrast or contrast-alcohol solutions. Alcohol did not change the size or suspension characteristics of PVA particles. Particles less than 50 microns in size were rarely identified.
authors.affiliation: Edward Mallinckrodt Institute of Radiology, Section of Neuroradiology, Washington University School of Medicine, St Louis, MO 63110, USA.
authors.forename: C P
authors.initials: CP
authors.lastname: Derdeyn
authors.forename: C J
authors.initials: CJ
authors.lastname: Moran
authors.forename: D T
authors.initials: DT
authors.lastname: Cross
authors.forename: H H
authors.initials: HH
authors.lastname: Dietrich
authors.forename: R G
authors.initials: RG
authors.lastname: Dacey
mesh_terms: D003287:Contrast Media; D004621:Embolization, Therapeutic; D000431:Ethanol; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018715:Microscopy, Video; D010316:Particle Size; D011142:Polyvinyl Alcohol; D013499:Surface Properties; D014283:Triiodobenzoic Acids
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D000431:Ethanol; D011142:Polyvinyl Alcohol; C054871:ioversol