title: Multicomponent T2 analysis of articular cartilage with synovial fluid partial volume correction.
abstract: OBJECTIVE
  To investigate the use of a three-pool model to account for the confounding effects of synovial fluid on multicomponent T2 analysis of articular cartilage using Multicomponent Driven Equilibrium Single Shot Observation of T1 and T2 (mcDESPOT).
  
  
  METHODS
  mcDESPOT was performed on the knee of eight asymptomatic volunteers and eight patients with osteoarthritis at 3.0T with multicomponent T2 maps created using the two-pool model and a three-pool model containing a nonexchanging synovial fluid water pool. The fraction of the fast-relaxing water component (FF ) and the T2 relaxation times for the fast-relaxing (T2F ) and slow-relaxing (T2S ) water components were measured in the superficial and deep layers of patellar cartilage using the two-pool and three-pool models in asymptomatic volunteers and patients with osteoarthritis and were compared using Wilcoxon signed rank tests.
  
  
  RESULTS
  Within the superficial layer of patellar cartilage, FF was 22.5% and 25.6% for asymptomatic volunteers and 21.3% and 22.8% for patients with osteoarthritis when using the two-pool and three-pool models, respectively, while T2S was 73.9 msec and 62.0 msec for asymptomatic volunteers and 72.0 msec and 63.1 msec for patients with osteoarthritis when using the two-pool and three-pool models, respectively. For both asymptomatic volunteers and patients with osteoarthritis, the two-pool model provided significantly (P < 0.05) lower FF and higher T2S than the three-pool model, likely due to the effects of synovial fluid partial volume averaging.
  
  
  CONCLUSIONS
  The effects of partial volume averaging between superficial cartilage and synovial fluid may result in biased multicomponent T2 measurements that can be corrected using an mcDESPOT three-pool model containing a nonexchanging synovial fluid water pool.
authors.affiliation: Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, USA.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Chaudhary
authors.affiliation: Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, USA.|Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, USA.
authors.forename: Walter F
authors.initials: WF
authors.lastname: Block
authors.affiliation: Department of Radiology, University of Wisconsin - Madison, Madison, Wisconsin, USA.
authors.forename: Alexey
authors.initials: A
authors.lastname: Samsonov
authors.affiliation: Department of Radiology, University of Wisconsin - Madison, Madison, Wisconsin, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Kijowski
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007091:Image Processing, Computer-Assisted; D007719:Knee Joint / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000473:pathology / Q000503:physiopathology*; D010329:Patella / Q000000981:diagnostic imaging / Q000473:pathology; D015203:Reproducibility of Results; D013582:Synovial Fluid / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water
keywords: T2 relaxation time; cartilage; knee; multicomponent T2 analysis; synovial fluid