title: Shoulder MRI after impingement test injection.
abstract: OBJECTIVE
  To determine how long injected fluid from an impingement test remains in the bursa or adjacent soft tissues after an injection.
  
  
  METHODS
  Six patients prospectively underwent MRI of the shoulder immediately before and after an impingement test injection, and at 3 days, 2 weeks and 4 weeks later. MR images were evaluated and graded for fluid distribution within the bursa and adjacent soft tissues. The rotator cuff was evaluated for signal abnormalities related to the injection.
  
  
  CONCLUSIONS
  Three days after the injection, the soft tissue fluid had returned to pre-injection levels or less in five of the six patients. No patients showed rotator cuff signal abnormalities related to the impingement test injection. We recommend a delay of 3 days before a shoulder MR examination after an injection has been performed, to avoid misinterpretations.
authors.affiliation: Department of Radiology, Stanford University Medical Center, CA 94305-5105, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Bergman
authors.forename: M
authors.initials: M
authors.lastname: Fredericson
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D006801:Humans; D007273:Injections, Intramuscular; D008012:Lidocaine / Q000008:administration & dosage; D008279:Magnetic Resonance Imaging; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage; D008875:Middle Aged; D011446:Prospective Studies; D019534:Shoulder Impingement Syndrome / Q000175:diagnosis*; D013997:Time Factors
chemical_list: D000779:Anesthetics, Local; D000893:Anti-Inflammatory Agents; D008012:Lidocaine; D008775:Methylprednisolone