title: Radiographic texture analysis in the characterization of trabecular patterns in periprosthetic osteolysis.
abstract: OBJECTIVE
  Periprosthetic osteolysis is a disease attributed to the body's reaction to fine polyethylene wear debris shed from total hip replacements. The purpose of this preliminary study was to investigate the ability of radiographic texture analysis (RTA) to characterize the trabecular texture patterns on pelvic images for osteolysis and normal total hip arthroplasty (THA) cases.
  
  
  METHODS
  Fourier-based and fractal-based texture features were calculated for a database of digitized radiographs from 202 THA cases, 70 of which developed osteolysis. The features were calculated from regions of interest selected at two time points: less than 1 month after surgery, and at the first clinical indication of osteolysis (or randomly selected follow-up time for normal cases). Receiver operating characteristic (ROC) analysis was used to compare feature performance at baseline and follow-up for osteolysis and normal cases.
  
  
  RESULTS
  Separation between the RTA features for osteolysis and normal cases was negligible at baseline and increased substantially for the follow-up images. The directional Fourier-based feature provided the best separation with an A(z) value from ROC analysis of 0.75 for the follow-up images, in the task of distinguishing between normal and osteolytic cases.
  
  
  CONCLUSIONS
  The results from this preliminary analysis indicate that qualitative changes in trabecular patterns from immediately after surgery to the eventual detection of osteolysis correspond to quantitative changes in RTA features. It therefore appears that RTA provides information that could potentially be useful to aid in the detection of this disease.
authors.affiliation: Department of Radiology, The University of Chicago Medical Center, MC 2026, 5841 S. Maryland Avenue, Chicago, IL 60637, USA.
authors.forename: Joel R
authors.initials: JR
authors.lastname: Wilkie
authors.forename: Maryellen L
authors.initials: ML
authors.lastname: Giger
authors.forename: Charles A
authors.initials: CA
authors.lastname: Engh
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hopper
authors.forename: John M
authors.initials: JM
authors.lastname: Martell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D005260:Female; D005583:Fourier Analysis; D017709:Fractals; D006801:Humans; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000000981:diagnostic imaging* / Q000209:etiology*; D012372:ROC Curve; D011859:Radiography