title: Three-dimensional delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) for in vivo evaluation of reparative cartilage after matrix-associated autologous chondrocyte transplantation at 3.0T: Preliminary results.
abstract: OBJECTIVE
  To use a 3D gradient-echo (GRE) sequence with two flip angles for delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) to evaluate relative glycosaminoglycan content of repair tissue after matrix-associated autologous chondrocyte transplantation (MACT).
  
  
  METHODS
  In a phantom study, T1-mapping based on a 3D-GRE sequence with different flip angle combinations was compared with a standard inversion recovery (IR) sequence at 3.0T. Fifteen patients were examined after MACT in the knee at "3-13 months" (group I) and "19-42 months" (group II). The delta relaxation rate (deltaR1) calculated for repair tissue and normal hyaline cartilage was measured and mean values were compared in different postoperative intervals using analysis of variance.
  
  
  RESULTS
  The flip angle combination 35/10 degrees provided the best agreement with IR sequence for short and long T1 values. The mean deltaR1 for repair tissue was 2.49 versus 1.04 at the intact control site in group I and 1.90 compared with 0.81 in group II. Differences from repair tissue to control sites showed statistically significance for both groups; no significant difference was found between groups.
  
  
  CONCLUSIONS
  The 3D dual flip angle dGEMRIC technique optimized for cartilage imaging is comparable to standard T1 IR technique for T1 mapping. Furthermore, the preliminary in vivo study demonstrates the feasibility of the technique in the evaluation of MACT patients.
authors: MR Center, Highfield MR, Department of Radiology, Medical University of Vienna, Vienna, Austria.
authors: Siegfried
authors: S
authors: Trattnig
authors: Stefan
authors: S
authors: Marlovits
authors: Simone
authors: S
authors: Gebetsroither
authors: Pavol
authors: P
authors: Szomolanyi
authors: Goetz H
authors: GH
authors: Welsch
authors: Erich
authors: E
authors: Salomonowitz
authors: Atsuya
authors: A
authors: Watanabe
authors: Michael
authors: M
authors: Deimling
authors: Tallal Charles
authors: TC
authors: Mamisch
mesh_terms: D000328:Adult; D002356:Cartilage / Q000378:metabolism* / Q000473:pathology*; D017690:Cell Transplantation / Q000379:methods*; D019902:Chondrocytes / Q000378:metabolism*; D003287:Contrast Media / Q000494:pharmacology*; D005260:Female; D005682:Gadolinium / Q000494:pharmacology*; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D014945:Wound Healing
chemical_list: D003287:Contrast Media; D006025:Glycosaminoglycans; D005682:Gadolinium