title: Visual Pattern and Serial Quantitation of18F-Sodium Fluoride PET/CT in Asymptomatic Patients After Hip and Knee Arthroplasty.
abstract: OBJECTIVE
  We investigated the visual tracer distribution pattern and serial changes in uptake ratio in different anatomical zones during the natural postoperative course in order to establish a reference for evaluation of patients with complications.
  
  
  METHODS
  A total of 36 patients without symptoms after hip or knee arthroplasty were grouped according to the interval between surgery and the scan. The serial changes in SUVmean in each periprosthetic zone were quantified using the volume of interest isocontour method. Images were classified according to the uptake distribution pattern. The uptake ratios in the postoperative period groups were then compared using the Kruskal-Wallis test. The correlation between uptake ratio and postoperative period was then determined.
  
  
  RESULTS
  Tracer distribution patterns in hip prostheses were classified into three types and the patterns in knee prostheses into five types. In hip prostheses, intense osteoblastic activity was observed during 3-6 months and then declined in most patients, but showed a slight increase over 15-25 months in 5-10 % of patients. The correlation coefficients varied among the zones. Significant differences in uptake ratios among the period groups was found for all zones, except zone 8. Porous coated areas showed higher uptake than uncoated areas only for the period the 3-6 months. In knee prostheses, uptake ratios showed a curvilinear pattern, increasing from 3-6 to 8-15 months and declining later. The uptake ratios were different among the period groups. Every zone showed a positive correlation from 3-6 to 8-15 months, and negative correlations from 8-15 to 22-25 months.
  
  
  CONCLUSIONS
  This is the first18F-sodium fluoride PET/CT study investigating the stability of implants and sets a reference for evaluation of patients with complications.
authors.affiliation: Department of Nuclear Medicine, Dong-A University Medical Center, Dong-A University College of Medicine, 26 Daesingongwon-ro, Seo-gu, Busan, 602-812 South Korea ; Institute of Convergence Bio-Health, Dong-A University, Busan, South Korea.
authors.forename: Hye Joo
authors.initials: HJ
authors.lastname: Son
authors.affiliation: Department of Nuclear Medicine, Dong-A University Medical Center, Dong-A University College of Medicine, 26 Daesingongwon-ro, Seo-gu, Busan, 602-812 South Korea ; Institute of Convergence Bio-Health, Dong-A University, Busan, South Korea.
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Jeong
authors.affiliation: Department of Nuclear Medicine, Dong-A University Medical Center, Dong-A University College of Medicine, 26 Daesingongwon-ro, Seo-gu, Busan, 602-812 South Korea ; Institute of Convergence Bio-Health, Dong-A University, Busan, South Korea.
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Yoon
authors.affiliation: Department of Orthopedic Surgery, Dong-A University Medical Center, Dong-A University College of Medicine, Busan, South Korea.
authors.forename: Lih
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Orthopedic Surgery, Dong-A University Medical Center, Dong-A University College of Medicine, Busan, South Korea.
authors.forename: Hyeon Jun
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Institute of Convergence Bio-Health, Dong-A University, Busan, South Korea.
authors.forename: Jong-Hwan
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Nuclear Medicine, Dong-A University Medical Center, Dong-A University College of Medicine, 26 Daesingongwon-ro, Seo-gu, Busan, 602-812 South Korea ; Institute of Convergence Bio-Health, Dong-A University, Busan, South Korea.
authors.forename: Do-Young
authors.initials: DY
authors.lastname: Kang
keywords: Arthroplasty; Positron emission tomography; Postoperative; Prosthesis; Sodium fluoride