title: Susceptibility weighted imaging of cartilage canals in porcine epiphyseal growth cartilage ex vivo and in vivo.
abstract: OBJECTIVE
  High-resolution visualization of cartilage canals has been restricted to histological methods and contrast-enhanced imaging. In this study, the feasibility of non-contrast-enhanced susceptibility weighted imaging (SWI) for visualization of the cartilage canals was investigated ex vivo at 9.4 T, further explored at 7 and 3 T and demonstrated in vivo at 7 T, using a porcine animal model.
  
  
  METHODS
  SWI scans of specimens of distal femur and humerus from 1 to 8 week-old piglets were conducted at 9.4 T using 3D-GRE sequence and SWI post-processing. The stifle joints of a 2-week old piglet were scanned ex vivo at 7 and 3 T. Finally, the same sites of a 3-week-old piglet were scanned, in vivo, at 7 T under general anesthesia using the vendor-provided sequences.
  
  
  RESULTS
  High-contrast visualization of the cartilage canals was obtained ex vivo, especially at higher field strengths; the results were confirmed histologically. In vivo feasibility was demonstrated at 7 T and comparison of ex vivo scans at 3 and 7 T indicated feasibility of using SWI at 3 T.
  
  
  CONCLUSIONS
  High-resolution 3D visualization of cartilage canals was demonstrated using SWI. This demonstration of fully noninvasive visualization opens new avenues to explore skeletal maturation and the role of vascular supply for diseases such as osteochondrosis.
authors.affiliation: Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA; Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Nissi
authors.forename: Ferenc
authors.initials: F
authors.lastname: Toth
authors.forename: Jinjin
authors.initials: J
authors.lastname: Zhang
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schmitter
authors.forename: Michael
authors.initials: M
authors.lastname: Benson
authors.forename: Cathy S
authors.initials: CS
authors.lastname: Carlson
authors.forename: Jutta M
authors.initials: JM
authors.lastname: Ellermann
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D005269:Femur / Q000033:anatomy & histology*; D006132:Growth Plate / Q000033:anatomy & histology*; D006811:Humerus / Q000033:anatomy & histology*; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D013552:Swine; D055114:X-Ray Microtomography
keywords: cartilage canals; epiphyseal cartilage; imaging; susceptibility weighted imaging