title: Nonuniformity intrinsic flood artifact caused by point-source syringe needle.
abstract: The purpose of this study was to investigate the cause of a nonuniformity artifact seen on an intrinsic flood.
  
  
  METHODS
  Intrinsic floods were acquired on three different cameras using a point source in a 1-cc syringe, with and without a needle attached. Floods were obtained with the syringe placed perpendicular and parallel to the camera face.
  
  
  RESULTS
  A nonuniformity artifact was evident if a syringe with a needle was placed perpendicular to the crystal face.
  
  
  CONCLUSIONS
  If a syringe is used as a point source during the acquisition of an intrinsic quality control flood, the needle should not be placed perpendicular to the camera face.
authors.affiliation: Nuclear Medicine Service, Department of Veterans Affairs Medical Centers, Lexington, Kentucky 40511-1093, USA.
authors.forename: M T
authors.initials: MT
authors.lastname: Hackett
authors.forename: S L
authors.initials: SL
authors.lastname: Magoun
authors.forename: R B
authors.initials: RB
authors.lastname: Thompson
mesh_terms: D016477:Artifacts; D004867:Equipment Design; D015902:Gamma Cameras; D006801:Humans; D009339:Needles; D011786:Quality Control; D019275:Radiopharmaceuticals; D013499:Surface Properties; D013594:Syringes; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation
chemical_list: D019275:Radiopharmaceuticals; D013667:Technetium