Association of Layer-specific Knee Cartilage T2 Relaxation Measurements with Age, Sex, and Cartilage Lesions in the Large Population-based Cohort Study of Health in Pomerania

Purpose or Learning Objective: (1) To assess the association between knee cartilage T2 values and age and sex in healthy subjects without magnetic resonance imaging (MRI)-based evidence of cartilage degeneration (i.e., modified Noyes grading of zero in all cartilage compartments and without visible posttraumatic or postoperative changes). (2) To compare cartilage T2 relaxation times between subjects with those subjects without osteoarthritis (OA) risk factors and articular cartilage lesions as depicted by MRI. (3) To establish an age- and sex-specific reference database of knee cartilage T2 values for 1.5-T MRI.

Methods or Background: A total of 929 subjects (n = 1,842 knees) from the population-based Study in Health in Pomerania (SHIP)-Trend-1 cohort aged 28 to 89 years underwent 1.5-T MRI. Cartilage T2 measurements were conducted in seven compartments (medial and lateral central femur, medial and lateral posterior femur, patella, medial and lateral tibia) over three different layers (superficial, deep, and whole cartilage). Cartilage morphology was analyzed using the modified Noyes grading in eight compartments (medial and lateral central femur, medial and lateral posterior femur, patella, medial and lateral tibia, and trochlea). Cartilage T2 maps were generated using sagittal two-dimensional multiecho spin-echo images. The 5th to 95th percentile values for T2 measurements were calculated.

Results or Findings: Among the subjects, 300 showed no cartilage lesions in morphological MRI (healthy cohort); 629 subjects had cartilage lesions and/or evidence of postoperative or posttraumatic changes in either knee (incidence cohort). T2 values were significantly higher in subjects with OA risk factors and cartilage lesions compared with those without (P < 0.001). There was significant variation in T2 values between joint compartments (P < 0.001), with the highest values in femoral cartilage (mean: 40.9 ms) and the lowest in the tibial cartilage (mean: 27.1 ms). Additionally, both the superficial layer and the medial compartment had higher T2 values than the deep cartilage layer (P < 0.001) and the lateral compartment (P < 0.001). T2 values increased with age (P < 0.001; a 0.42 ms mean increase per 10 years) and were higher in women for all femoral and tibial compartments (mean difference: 0.42 ms).

Conclusion: This study established a reference database of 1.5-T MRI T2 values in 21 knee cartilage subregions for subjects with normal cartilage morphology and without MRI-based evidence of cartilage degeneration or OA risk factors.

Publication History

Article published online:
22 May 2024