title: 3 Tesla high-resolution and delayed gadolinium enhanced MR imaging of cartilage (dGEMRIC) after autologous chondrocyte transplantation in the hip.
abstract: BACKGROUND
  To evaluate the feasibility of 3 Tesla (T) high-resolution and gadolinium enhanced MRI of cartilage (dGEMRIC) in the thin and rounded hip cartilage of patients after acetabular matrix-based autologous chondrocyte transplantation (MACT).
  
  
  METHODS
  Under general ethics approval, 24 patients were prospectively examined 6-31 months after acetabular MACT at 3T using high-resolution proton-density weighted (PDw) images (bilateral PD SPACE, 0.8 mm isotropic; unilateral PD-TSE coronal/sagittal, 0.8 × 0.8 resp. 0.5 × 0.5 × 2.5 mm) as well as T1 mapping (3D-FLASH, 0.78 mm isotropic) in dGEMRIC technique, and clinically scored. The cartilage transplant was evaluated using an adapted MOCART score (maximum 85 points). T1 relaxation times were measured independently by two radiologists. Here, regions of interest were placed manually in automatically calculated relaxation-maps, both in the transplant and adjacent healthy cartilage regions. Interobserver reliability was estimated by means of intraclass-correlation (ICC).
  
  
  RESULTS
  The transplant was morphologically definable in the PDw images of 23 patients with a mean MOCART score of 69 points (60-80 points, SD 6.5). T1 maps showed a clear differentiation between acetabular and femoral cartilage, but correlation with PDw images was necessary to identify the transplant. Mean T1 relaxation times of the transplant were 616.3 ms (observer 1) resp. 610.1 ms (observer 2), and of adjacent healthy acetabular cartilage 574.5 ms (observer 1) resp. 604.9 ms (observer 2). Interobserver reliability of the relaxation times in the transplant was excellent (ICC-coefficient 0.88) and in adjacent healthy regions good (0.77).
  
  
  CONCLUSIONS
  High-resolution PDw imaging with adapted MOCART scoring and dGEMRIC is feasible after MACT in the thin and rounded hip cartilage.
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Lazik
authors.affiliation: Facharztklinik Essen, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Körsmeier
authors.affiliation: Department of Orthopaedics, University Hospital Essen, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Claßen
authors.affiliation: Department of Orthopaedics, University Hospital Essen, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Jäger
authors.affiliation: Facharztklinik Essen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Kamminga
authors.affiliation: Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Kraff
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Lauenstein
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.
authors.forename: Jens M
authors.initials: JM
authors.lastname: Theysohn
authors.affiliation: Department of Orthopaedics, University Hospital Essen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Landgraeber
mesh_terms: D000328:Adult; D001182:Arthroscopy; D002358:Cartilage, Articular / Q000473:pathology*; D017690:Cell Transplantation; D019902:Chondrocytes / Q000166:cytology / Q000637:transplantation*; D003287:Contrast Media / Q000737:chemistry*; D005240:Feasibility Studies; D005260:Female; D005682:Gadolinium / Q000737:chemistry*; D019786:Gadolinium DTPA / Q000737:chemistry; D006615:Hip / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D003287:Contrast Media; D005682:Gadolinium; D019786:Gadolinium DTPA
keywords: MOCART; MRI; T1 mapping; autologous chondrocyte transplantation; dGEMRIC; hip