title: Use of quantitative MRI for the detection of progressive cartilage degeneration in a mini-pig model of osteoarthritis caused by anterior cruciate ligament transection.
abstract: BACKGROUND
  To investigate the progression of cartilage degeneration using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and T2 mapping in a mini-pig model of osteoarthritis (OA) caused by anterior cruciate ligament transection (ACLT).
  
  
  METHODS
  Twelve mini-pigs underwent ACLT in the left knee and were monitored by dGEMRIC (T1, gadolinium [Gd]) and T2 mapping after 2, 4, or 6 weeks (n = 4 each). No ACLT surgery was performed in four healthy control mini-pigs, which were also monitored by dGEMRIC and T2 mapping. Cartilage samples from the weight-bearing regions of the left medial femoral condyles were collected for macroscopic, histological, immunohistochemical, and biochemical analysis. Correlations between biochemical contents and T1,Gd and T2 values were evaluated using Pearson correlation analysis.
  
  
  RESULTS
  T1,Gd values were gradually reduced and T2 values increased over time. Cartilage surfaces showed roughness at 4 weeks and additional defects at 6 weeks. Glycosaminoglycan (GAG) distribution and content gradually reduced over time (P < 0.05), and collagen distribution and anisotropy were obviously changed at 6 weeks. However, collagen content did not differ significantly among postoperative timepoints. GAG content was positively related to T1,Gd values (r = 0.888; P < 0.001) and negatively related to T2 values (r = -0.865; P < 0.001). Collagen content had no discernible correlation with T1,Gd or T2 values.
  
  
  CONCLUSIONS
  dGEMRIC and T2 mapping can monitor the progression of cartilage degeneration in a mini-pig model of ACLT-induced OA, permitting early detection of OA.
authors: Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.|Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.
authors: Bo
authors: B
authors: Wei
authors: Department of Radiology, the First Affiliated Hospital, Nanjing Medical University, Nanjing, 210006, People's Republic of China.
authors: Min
authors: M
authors: Zong
authors: Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.|Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.
authors: Chao
authors: C
authors: Yan
authors: Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.|Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.
authors: Fengyong
authors: F
authors: Mao
authors: Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.|Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.
authors: Yang
authors: Y
authors: Guo
authors: Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.|Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.
authors: Qingqiang
authors: Q
authors: Yao
authors: Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.|Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.
authors: Yan
authors: Y
authors: Xu
authors: Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.|Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, People's Republic of China.
authors: Liming
authors: L
authors: Wang
mesh_terms: D000465:Algorithms; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000473:pathology* / Q000601:surgery; D002357:Cartilage Diseases / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D020370:Osteoarthritis, Knee / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D013556:Swine, Miniature
keywords: ACL transaction; T2 mapping; dGEMRIC; mini-pig; osteoarthritis