title: Quantitative assessment of the equine hoof using digital radiography and magnetic resonance imaging.
abstract: BACKGROUND
  Evaluation of laminitis cases relies on radiographic measurements of the equine foot. Reference values have not been established for all layers of the foot.
  
  
  OBJECTIVE
  To establish normal hoof wall and sole measurements using digital radiography (DR) and magnetic resonance imaging (MRI) and to document tissue components present in the dorsal hoof wall and solar layers seen on DR.
  
  
  METHODS
  Prospective observational case-control study.
  
  
  METHODS
  Digital radiography and MRI were performed on 50 cadaver front feet from 25 horses subjected to euthanasia for nonlameness-related reasons. Four observers measured hoof wall (dorsal, lateral and medial) and sole thickness (sagittal, lateral and medial) using DR and magnetic resonance images. One observer repeated the measurements 3 times. Inter- and intraobserver correlation was assessed.
  
  
  RESULTS
  Digital radiography and MRI measurements for the normal hoof wall and sole were established. Inter- and intraobserver pairwise Pearson's correlation for DR (r>0.98) and MRI measurements (r>0.99) was excellent. Based on MRI, the less radiopaque layer on DR is comprised of the stratum lamellatum and stratum reticulare.
  
  
  CONCLUSIONS
  Normal DR and MRI measurements for the hoof wall and sole were established. On DR images, the less radiopaque layer of the foot observed corresponds to the critical tissues injured in laminitis, the strata lamellatum and reticulare. These reference measurements may be used by the clinician to detect soft-tissue changes in the laminitic equine foot and provide a foundation for future research determining changes in these measurements in horses with laminitis.
authors.affiliation: Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, USA.
authors.forename: I N M
authors.initials: IN
authors.lastname: Grundmann
authors.affiliation: Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, USA.
authors.forename: W T
authors.initials: WT
authors.lastname: Drost
authors.affiliation: Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, USA.
authors.forename: L J
authors.initials: LJ
authors.lastname: Zekas
authors.affiliation: Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Belknap
authors.affiliation: Department of Preventive Veterinary Medicine, The Ohio State University, Columbus, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Garabed
authors.affiliation: Department of Veterinary Biosciences, The Ohio State University, Columbus, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Weisbrode
authors.affiliation: The Department of Large Animal Medicine, The University of Georgia, Athens, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Parks
authors.affiliation: Wright Center of Innovation in Biomedical Imaging, The Ohio State University, Columbus, USA.
authors.forename: M V
authors.initials: MV
authors.lastname: Knopp
authors.affiliation: Department of Anatomy, Histology and Embryology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Maierl
mesh_terms: D000818:Animals; D002102:Cadaver; D006724:Hoof and Claw / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006736:Horses / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary*; D011856:Radiographic Image Enhancement / Q000379:methods*
keywords: diagnostic imaging; horse; laminitis; magnetic resonance imaging