title: Detecting ICRS grade 1 cartilage lesions in anterior cruciate ligament injury using T1ρ and T2 mapping.
abstract: OBJECTIVE
  The purpose of this study was to clarify the detectability of the International Cartilage Repair Society (ICRS) grade 1 cartilage lesions in anterior cruciate ligament (ACL)-injured knees using T1ρ and T2 mapping.
  
  
  METHODS
  We performed preoperative T1ρ and T2 mapping and 3D gradient-echo with water-selective excitation (WATS) sequences on 37 subjects with ACL injuries. We determined the detectability on 3D WATS based on arthroscopic findings. The T1ρ and T2 values (ms) were measured in the regions of interest that were placed on the weight-bearing cartilage of the femoral condyle. The receiver operating characteristic (ROC) curve based on these values was constructed using the arthroscopic findings as a reference standard. The evaluation of cartilage was carried out only in the weight-bearing cartilage. The cut-off values for determining the presence of a cartilage injury were determined using each ROC curve, and the detectability was calculated for the T1ρ and T2 mapping.
  
  
  RESULTS
  The cut-off values for the T1ρ and T2 were 41.6 and 41.2, respectively. The sensitivity and specificity of T1ρ were 91.2% and 89.5%, respectively, while those of T2 were 76.5% and 81.6%, respectively. For the 3D WATS images, the same values were 58.8% and 78.9%, respectively.
  
  
  CONCLUSIONS
  Our study demonstrated that the T1ρ and T2 values were significantly higher for ICRS grade 1 cartilage lesions than for normal cartilage and that the two mappings were able to non-invasively detect ICRS grade 1 cartilage lesions in the ACL-injured knee with a higher detectability than were 3D WATS images.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan. kinuhnishiok@fc.kuh.kumamoto-u.ac.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nishioka
authors.forename: Jun
authors.initials: J
authors.lastname: Hirose
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nakamura
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Okamoto
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Karasugi
authors.forename: Takuya
authors.initials: T
authors.lastname: Taniwaki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okada
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizuta
mesh_terms: D000465:Algorithms; D016118:Anterior Cruciate Ligament / Q000473:pathology*; D050724:Fractures, Cartilage / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007718:Knee Injuries / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Cartilage; Knee; Magnetic resonance imaging; T1ρ mapping; T2 mapping