Comparing the Effect of Mechanical Loading on Deep and Superficial Cartilage Using Quantitative UTE MRI

• Published in: Journal of magnetic resonance imaging Vol. 59; no. 6; pp. 2048 - 2057
• Main Authors: Wang, Hanqi, Li, Zhihui, Li, Qing, Sommer, Stefan, Chen, Tongtong, Sun, Yao, Wei, Hongjiang, Yan, Fuhua, Lu, Yong
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.06.2024; Wiley Subscription Services, Inc
• Subjects: Adult; Adults; Biomechanical Phenomena; Biomechanics; Body mass index; Body size; Body weight; Cartilage; Cartilage, Articular - diagnostic imaging; Cartilage, Articular - physiology; Correlation analysis; Evaluation; Exercise; Exercise - physiology; Female; Femur; Field strength; Humans; Image Processing, Computer-Assisted - methods; In vivo methods and tests; Knee; Knee Joint - diagnostic imaging; Knee Joint - physiology; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Mechanical loading; Mechanical properties; osteoarthritis; Physical activity; Physical fitness; Physical training; Prospective Studies; Reproducibility; Reproducibility of Results; Spatial discrimination; Spatial resolution; Statistical analysis; Statistical tests; Thickness; Tibia; ultrashort echo time (UTE); Weight-Bearing - physiology; Young Adult; mechanical loading; osteoarthritis; ultrashort echo time (UTE); cartilage
• ISSN: 1053-1807; 1522-2586; 1522-2586
• DOI: 10.1002/jmri.28980

Background The biomechanical properties of deep and superficial cartilage may be different, yet in vivo MRI validation is required. Purpose To compare the effect of mechanical loading on deep and superficial cartilage in young healthy adults using ultrashort echo time (UTE)‐T2* mapping. Study Type Prospective, intervention. Subjects Thirty‐one healthy adults (54.8% females, median age = 23 years). Field Strength/Sequence 3‐T, PD‐FS, and UTE sequences with four echo times (TEs = 0.1, 0.5, 2.8, and 4.0 msec; 0.6 mm isotropic spatial resolution) of the left knee, acquired before and after loading exercise. Assessment Quantitative UTE‐T2* maps of the entire knee were generated using UTE images of four TEs. In deep and superficial cartilage of patella, medial and lateral femur, medial and lateral tibia cartilage (PC, MFC, LFC, MTC, and LTC), which were segmented manually, cartilage thickness and T2* values before and after loading were measured, extracted, taken averages of, and compared. Scan–rescan repeatability was evaluated. Body weight and body mass index (BMI) data were collected. Physical activity levels were evaluated using International Physical Activity Questionnaire. Statistical Tests Paired sample t‐tests, paired Wilcoxon Mann–Whitney tests, Pearson and Spearman correlation analyses, Kruskal–Wallis tests with post‐hoc Bonferroni correction. A P‐value <0.05 was considered statistically significant. Results The scan–rescan repeatability was good (RMSA‐CV < 10%). After exercise, deep cartilage exhibited no significant differences in cartilage thickness (PPC = 0.576, PMTC = 0.991, PMFC = 0.899, PLTC = 0.861, PLFC = 0.290) and T2* values (PPC = 0.914, PMTC = 0.780, PMFC = 0.754, PLTC = 0.327, PLFC = 0.811), which both significantly decreased in superficial PC, MFC, LFC, and MTC. The T2* values of superficial MTC and deep MFC were moderately correlated with higher body weight (ρ = 0.431) and lower BMI (ρ = −0.499), respectively. Data Conclusion Deep and superficial cartilage may respond differently to mechanical loading as assessed by UTE‐T2*. Evidence Level 2 Technical Efficacy Stage 3