title: Utility of delayed whole-body bone scintigraphy after directed three-phase scintigraphy.
abstract: OBJECTIVE
  The purpose of this study was to determine the diagnostic yield and clinical importance of delayed whole-body bone scintigraphy in directed three-phase examinations.
  
  
  METHODS
  The records of 400 consecutively registered patients who underwent combined three-phase and delayed whole-body (99m)Tc-methylene diphosphonate bone scintigraphy for a variety of indications were reviewed. Clinical indications, findings, recommendations, and outcome were assessed.
  
  
  RESULTS
  Three-phase bone scintigraphy was performed on 156 men and boys and 244 women and girls (61%). Fifty-two patients (13%) were 17 years old or younger, and 236 patients (59%) were older than 40 years. The mean increase in study duration due to whole-body imaging was 25 minutes (range, 21-31 minutes). Excluding the three-phase area of interest, the whole-body examination had a normal tracer distribution in 131 examinations (33%), showed solely degenerative changes in 103 (26%), and showed findings unrelated to the area of interest in 166 patients (41%). In no case did the findings outside the area of interest alter the diagnosis or diagnostic certainty in the three-phase study, but those findings did generate 82 recommendations for additional diagnostic investigation. As a direct result of the recommendations, clinicians requested 18 radiographic, two CT, one MRI, and one ultrasound examinations, one additional bone scan, and two referrals to a consultant. Recommendations based on findings outside the three-phase area of interest affected treatment in one case: Temporomandibular joint uptake resulted in a referral for physical therapy.
  
  
  CONCLUSIONS
  For most indications, delayed whole-body imaging after directed three-phase bone scintigraphy does not improve diagnostic yield, does not alter patient care, and may be an unnecessary use of medical resources.
authors.affiliation: Department of Radiology, University of Michigan Health System, 1500 E Medical Center Dr., UH B1-D502, Ann Arbor, MI 48109-5030, USA. matdaven@med.umich.edu
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Davenport
authors.forename: Richard K J
authors.initials: RK
authors.lastname: Brown
authors.forename: Kirk A
authors.initials: KA
authors.lastname: Frey
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001847:Bone Diseases / Q000000981:diagnostic imaging*; D001859:Bone Neoplasms / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D033162:Incidental Findings; D007223:Infant; D008297:Male; D008875:Middle Aged; D011859:Radiography; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D013669:Technetium Tc 99m Medronate; D051598:Whole Body Imaging / Q000191:economics; D055815:Young Adult
chemical_list: D013669:Technetium Tc 99m Medronate