title: Long-term results 8 years after autologous osteochondral transplantation: 7 T gagCEST and sodium magnetic resonance imaging with morphological and clinical correlation.
abstract: OBJECTIVE
  To correlate long-term clinical outcome and the results of morphological as well as advanced biochemical magnetic resonance imaging (MRI) techniques [T2-mapping, glycosaminoglycan chemical exchange saturation transfer (gagCEST), sodium-23-imaging] in patients after autologous osteochondral transplantation (AOT) in knee joints.
  
  
  METHODS
  Nine AOT patients (two female and seven male; median age, 49) had clinical [International Knee Documentation Committee (IKDC), modified Lysholm, visual analog scale (VAS)] and radiological long-term follow-up examinations at a median of 7.9 years (inter-quartile range, 7.7-8.2). Standard morphological MRI and T2-mapping of cartilage were performed on a 3 T MR unit. Biochemical imaging further included sodium-23-imaging and chemical exchange saturation transfer (CEST) imaging at 7 T. The Magnetic resonance Observation of CArtilage Repair Tissue (MOCART) score was used for quantitative assessment of morphological MRI.
  
  
  RESULTS
  Clinical outcome was good with a median modified Lysholm score of 90. Median VAS revealed 1.0 and median MOCART score 75 points. The difference between native and repair cartilage was statistically significant for all three biochemical imaging techniques. The strongest correlation was found between the results of the advanced biochemical imaging methods sodium-23 and CEST [ρ = 0.952, 95% confidence interval (CI): (0.753; 0.992)]. Comparing the results from morphological and biochemical imaging, a correlation was found between MOCART score and CEST ratio [ρ = -0.749, 95% CI: (-0.944; -0.169)]. Comparing the results from clinical scores with MRI, a correlation between modified Lysholm and T2-mapping [ρ = -0.667, 95% CI: (-0.992; -0.005)] was observed.
  
  
  CONCLUSIONS
  Long-term clinical outcome in patients 7.9 years after AOT was good, but did not correlate with morphological and biochemical imaging results except for T2-mapping.
authors.affiliation: Department of Trauma Surgery, Medical University of Vienna, Austria.
authors.forename: I
authors.initials: I
authors.lastname: Krusche-Mandl
authors.affiliation: MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Austria.
authors.forename: B
authors.initials: B
authors.lastname: Schmitt
authors.affiliation: Department of Trauma Surgery, Medical University of Vienna, Austria.
authors.forename: L
authors.initials: L
authors.lastname: Zak
authors.affiliation: MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Apprich
authors.affiliation: Department of Trauma Surgery, Medical University of Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Aldrian
authors.affiliation: MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Austria; Department of Imaging Methods, Institute of Measurement Science, Slovac Academy of Sciences, Bratislava, Slovakia.
authors.forename: V
authors.initials: V
authors.lastname: Juras
authors.affiliation: Division of Neuroradiology and Musculoskeletal Radiology, Department of Radiology, Medical University of Vienna, Austria.
authors.forename: K M
authors.initials: KM
authors.lastname: Friedrich
authors.affiliation: Department of Trauma Surgery, Medical University of Vienna, Austria. Electronic address: smarlovits@alain-hospital.ae.
authors.forename: S
authors.initials: S
authors.lastname: Marlovits
authors.affiliation: Department of Radiology, Medical University of Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Weber
authors.affiliation: MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Trattnig
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000293:injuries* / Q000378:metabolism / Q000473:pathology; D019902:Chondrocytes / Q000637:transplantation*; D005260:Female; D005500:Follow-Up Studies; D050724:Fractures, Cartilage / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007718:Knee Injuries / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D012964:Sodium / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D006025:Glycosaminoglycans; D012964:Sodium