title: X-ray detection of structural orientation in human articular cartilage.
abstract: OBJECTIVE
  To determine the feasibility of detecting the structural orientation in cartilage with Diffraction Enhanced X-Ray Imaging.
  
  
  METHODS
  Human tali and femoral head specimens were Diffraction Enhanced X-Ray Imaged (DEI) at the SYRMEP beamline at Elettra at various energy levels to detect the architectural arrangement of collagen within cartilage. DEI utilizes a monochromatic and highly collimated beam, with an analyzer crystal that selectively weights out photons according to the angle they have been deviated with respect to the original direction. This provides images of very high contrast, and with the rejection of X-ray scatter.
  
  
  RESULTS
  DEI allowed the visualization of articular cartilage and a structural orientation, resembling arcades, within.
  
  
  CONCLUSIONS
  Our diffraction enhanced images represent the first radiographic detection of the structural orientation in cartilage. Our data are in line with previous studies on the structural organization of joint cartilage. They confirm the model of a vaulting system of collagen fiber bundles interrupted by proteoglycan aggregates.
authors.affiliation: Department of Anatomy and Cell Biology, Rush Medical College, IL 60612, Chicago, USA. cmuehleman@rushu.rush.edu
authors.forename: Carol
authors.initials: C
authors.lastname: Muehleman
authors.forename: Sharmila
authors.initials: S
authors.lastname: Majumdar
authors.forename: Ahi Sema
authors.initials: AS
authors.lastname: Issever
authors.forename: Fulvia
authors.initials: F
authors.lastname: Arfelli
authors.forename: Ralf Hendrik
authors.initials: RH
authors.lastname: Menk
authors.forename: Luigi
authors.initials: L
authors.lastname: Rigon
authors.forename: Gabriele
authors.initials: G
authors.lastname: Heitner
authors.forename: Bernd
authors.initials: B
authors.lastname: Reime
authors.forename: Joachim
authors.initials: J
authors.lastname: Metge
authors.forename: Andreas
authors.initials: A
authors.lastname: Wagner
authors.forename: Klaus E
authors.initials: KE
authors.lastname: Kuettner
authors.forename: Juergen
authors.initials: J
authors.lastname: Mollenhauer
mesh_terms: D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D003094:Collagen / Q000032:analysis; D004396:Coloring Agents; D005270:Femur Head / Q000000981:diagnostic imaging*; D006801:Humans; D010619:Phenazines; D011509:Proteoglycans / Q000032:analysis; D011856:Radiographic Image Enhancement / Q000379:methods; D013628:Talus / Q000000981:diagnostic imaging*; D014961:X-Ray Diffraction
chemical_list: D004396:Coloring Agents; D010619:Phenazines; D011509:Proteoglycans; D003094:Collagen; C009195:safranine T