title: Subregional Anatomical Distribution of T2 Values of Articular Cartilage in Asymptomatic Hips.
abstract: OBJECTIVE
  A standardized definition of normative T2 values across the articular surface of the hip must be defined in order to fully understand T2 values for detecting early degeneration. Therefore, in this article, we seek to lay foundational methodology for reproducible quantitative evaluation of hip cartilage damage using T2 mapping to determine the normative T2 values in asymptomatic individuals.
  
  
  METHODS
  Nineteen prospectively enrolled asymptomatic volunteers (age 18-35 years, males 10, females 9, alpha angle 49.3º ± 7.2º) were evaluated with a sagittal T2 mapping sequence at 3.0 T magnetic resonance imaging. Acetabular and femoral cartilage was manually segmented directly on the second echo of the T2 mapping sequence by 3 raters, twice. Segmentations were divided into 12 subregions modified from the geographic zone method. Median T2 values within each subregion were compiled for further analysis and interrater and intrarater reliability was assessed.
  
  
  RESULTS
  In the femur, the posterior-superior subregion was significantly higher (P ≤ 0.05) than those in the posterior-inferior and anterior-inferior subregions. In the acetabulum, the anterior-inferior subregion was significantly higher (P ≤ 0.001) than in the anterior-superior, middle, and posterior-inferior subregions. T2 values of the posterior-superior subregion were significantly higher (P ≤ 0.05) than the anterior-superior, middle, and posterior-inferior subregions. Interrater agreement was generally fair to good.
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Charles P
authors.initials: CP
authors.lastname: Ho
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Rachel K
authors.initials: RK
authors.lastname: Surowiec
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Ferro
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Erin P
authors.initials: EP
authors.lastname: Lucas
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Adriana J
authors.initials: AJ
authors.lastname: Saroki
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Grant J
authors.initials: GJ
authors.lastname: Dornan
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Eric K
authors.initials: EK
authors.lastname: Fitzcharles
authors.affiliation: The Steadman Clinic, Vail, CO, USA.
authors.forename: Adam W
authors.initials: AW
authors.lastname: Anz
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: W Sean
authors.initials: WS
authors.lastname: Smith
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Katharine J
authors.initials: KJ
authors.lastname: Wilson
authors.affiliation: The Steadman Clinic, Vail, CO, USA.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Philippon
keywords: articular cartilage; diagnostics; hip; joint involved; magnetic resonance imaging; tissue