Detection of physiological changes in knee cartilage using parametric T2 relaxation maps estimated with a dictionary method

Abstract

Purpose To investigate half-marathon running and recovery effects on knee articular cartilage (KAC) health in athletes, using dictionary-matching T 2 maps, to detect changes and recovery patterns in KAC. Methods Eleven asymptomatic volunteers (4 females, 7 males; mean age 40 ± 5 years, mean BMI 22.7 ± 1.4 kg/m 2 ) completed a fixed-pace half-marathonwere studied. All were right-knee dominant and engaged in regular running. Sagittal T 2 -weighted Multi-Echo Spin-Echo images at 3 T were used to assess T 2 values pre-run, post-run, and one week later for global and compartmental KAC. Recovery programme included low-intensity running, strength training and rest. Repeated measures ANOVA or equivalent non-parametric tests with post-hoc comparisons compared T 2 values over time. Separate analyses were conducted based on laterality, gender and anatomical compartments. Significance was set at < 0.05. Results Post-run T 2 values decreased significantly by 0.9 ms (− 2.0%, p < 0.001), with up to 5.3% reductions in medial tibial (MT) and femoral (MF) compartments. Recovery patterns varied by compartment, sex and laterality. Most compartments returned to baseline within one week; the lateral condyle (LatC) showed incomplete recovery (− 4.7%, Proportional Recovery Index (PRI) = − 0,1); the right knee’s MT exhibited overcompensation (6.3%, PRI = 2.6). Males showed higher baseline T 2 values and more efficient recovery in the LatC compared to females (PRI = − 0.1 vs. − 0.4). Conclusion Half-marathon running induces reversible reductions in KAC hydration, with most compartments recovering or overcompensating within one week. Dictionary-matching T2 mapping offers a robust approach for monitoring cartilage integrity and guiding individualised recovery strategies.

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