title: Integrity of articular cartilage on T2 mapping associated with meniscal signal change.
abstract: OBJECTIVE
  The purpose of this study was to investigate the relationship between T2 relaxation values (T2 RVs) within the superficial zone of articular cartilage and different types of meniscal degeneration/tear.
  
  
  METHODS
  A review of 310 consecutive knee MRIs which included an 8 echo T2 relaxation sequence, in patients referred for standard clinical indications, was performed independently and in blinded fashion by 2 observers. The posterior horns of the medial and lateral menisci were each evaluated and divided into 4 subgroups: Normal (control), Grade I/II meniscal signal, Grade III meniscal signal-simple tear (Grade III-S), and Grade III meniscal signal-complex tear (Grade III-C). After exclusion criteria were applied, the medial meniscal group consisted of 65 controls and 133 patients, while the lateral meniscal group consisted of 143 controls and 55 patients. T2 RVs were measured by an observer blinded to the clinical history and MRI grading. Measurements were obtained over the superficial zone of femoral and tibial articular cartilage adjacent to the center of the posterior horn of each meniscus to ensure consistency between measurements. Analysis of covariance adjusting for age and gender was used to compare T2 RVs between patients and controls.
  
  
  RESULTS
  T2 RVs were significantly increased in patients with Grade III-C meniscal tears compared to controls over the medial tibial plateau (MTP; p=0.0001) and lateral tibial plateau (LTP; p=0.0008). T2 RVs were not increased in patients with Grade III-C meniscal tears over the medial femoral condyle (MFC; p=0.11) or lateral femoral condyle (LFC; p=0.99). Grade I/II meniscal signal was not associated with elevated T2 RVs over the MFC (p=0.15), LFC (p=0.69), MTP (p=0.42), or LTP (p=0.50). Grade III-S meniscal signal was not associated with elevated T2 RVs over the MFC (p=0.54), LFC (p=0.43), MTP (p=0.30), or LTP (p=0.38).
  
  
  CONCLUSIONS
  Grade III-C meniscal tears are associated with elevated T2 RVs in adjacent tibial articular cartilage. The results may have an impact on prognostication and treatment in order to delay or prevent the onset of osteoarthritis.
authors.affiliation: Department of Radiology, University of British Columbia, UBC Hospital, Vancouver, BC, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Kai
authors.forename: Sumeer A
authors.initials: SA
authors.lastname: Mann
authors.forename: Chris
authors.initials: C
authors.lastname: King
authors.forename: Bruce B
authors.initials: BB
authors.lastname: Forster
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007718:Knee Injuries / Q000145:classification / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000517:prevention & control; D012307:Risk Factors; D000070600:Tibial Meniscus Injuries