title: Delayed gadolinium-enhanced MRI of cartilage in the ankle at 3 T: feasibility and preliminary results after matrix-associated autologous chondrocyte implantation.
abstract: OBJECTIVE
  To demonstrate the feasibility of delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) in the ankle at 3 T and to obtain preliminary data on matrix associated autologous chondrocyte (MACI) repair tissue.
  
  
  METHODS
  A 3D dual flip angle sequence was used with an eight-channel multipurpose coil at 3 T to obtain T1 maps both pre- and postintravenous contrast agent (Magnevist, 0.2 mM/kg). Postcontrast T1 over time was evaluated in three volunteers; a modified dGEMRIC protocol was then used to assess 10 cases after MACI in the ankle.
  
  
  RESULTS
  Forty-five minutes were found sufficient for maximum T1 decrease. MACI cases had a precontrast mean T1 of 1050 +/- 148.4 msec in reference cartilage (RC) and 1080 +/- 165.6 msec in repair tissue (RT). Postcontrast T1 decreased to 590 +/- 134.0 msec in RC and 554 +/- 133.0 msec in RT. There was no significant difference between the delta relaxation rates in RT (9.44 x 10(-4) s(-1)) and RC (8.04 x 10(-4) s(-1), P = 0.487). The mean relative delta relaxation rate was 1.34 +/- 0.83.
  
  
  CONCLUSIONS
  It is feasible to assess the thin cartilage layers of the ankle with dGEMRIC at 3 T; MACI can yield RT with properties similar to articular cartilage.
authors.affiliation: Department of Orthopedics, Medical University of Vienna, Austria.
authors.forename: Stephan E
authors.initials: SE
authors.lastname: Domayer
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
authors.forename: David
authors.initials: D
authors.lastname: Stelzeneder
authors.forename: Clemens
authors.initials: C
authors.lastname: Hirschfeld
authors.forename: Sebastian
authors.initials: S
authors.lastname: Quirbach
authors.forename: Ronald
authors.initials: R
authors.lastname: Dorotka
authors.forename: Stefan
authors.initials: S
authors.lastname: Nehrer
authors.forename: Katja
authors.initials: K
authors.lastname: Pinker
authors.forename: Jenny
authors.initials: J
authors.lastname: Chan
authors.forename: Tallal Charles
authors.initials: TC
authors.lastname: Mamisch
authors.forename: Martin
authors.initials: M
authors.lastname: Dominkus
authors.forename: Götz H
authors.initials: GH
authors.lastname: Welsch
mesh_terms: D000328:Adult; D016512:Ankle Injuries / Q000473:pathology* / Q000601:surgery*; D019902:Chondrocytes / Q000637:transplantation*; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D050724:Fractures, Cartilage / Q000473:pathology* / Q000601:surgery*; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010865:Pilot Projects; D011379:Prognosis; D054457:Tissue Scaffolds; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA