Abstract
BACKGROUND: Magnetic resonance fingerprinting (MRF) techniques have been recently described for simultaneous multiparameter cartilage mapping of the knee although investigation of their ability to detect early cartilage degeneration remains limited. PURPOSE: To investigate age-dependent changes in knee cartilage T(1) , T(2) , and T(1p) relaxation times measured using a three-dimensional (3D) MRF sequence in healthy volunteers. STUDY TYPE: Prospective. SUBJECTS: The study group consisted of 24 healthy asymptomatic human volunteers (15 males with mean age 34.9 ± 14.4 years and 9 females with mean age 44.5 ± 13.1 years). FIELD STRENGTH/SEQUENCE: A 3.0 T gradient-echo-based 3D-MRF sequence was used to simultaneously create proton density-weighted images and T(1) , T(2) , and T(1p) maps of knee cartilage. ASSESSMENT: Mean global cartilage and regional cartilage (lateral femur, lateral tibia, medial femur, medial tibia, and patella) T(1) , T(2) , and T(1ρ) relaxation times of the knee were measured. STATISTICAL TESTS: Kruskal-Wallis tests were used to compared cartilage T(1) , T(2) , and T(1ρ) relaxation times between different age groups, while Spearman correlation coefficients was used to determine the association between age and cartilage T(1) , T(2) , and T(1ρ) relaxation times. The value of P < 0.05 was considered statistically significant. RESULTS: Higher age groups showed higher global and regional cartilage T(1) , T(2) , and T(1ρ) . There was a significant difference between age groups in global cartilage T(2) and T(1ρ) but no significant difference (P = 0.13) in global cartilage T(1.) Significant difference was also present between age groups in cartilage T(2) and T(1ρ) for medial femur cartilage and medial tibia cartilage. There were significant moderate correlations between age and T(2) and T(1ρ) for global cartilage (R(2) = 0.63-0.64), medial femur cartilage (R(2) = 0.50-0.56), and medial tibia cartilage (R(2) = 0.54-0.66). CONCLUSION: Cartilage T(2) and T(1p) relaxation times simultaneously measured using a 3D-MRF sequence in healthy volunteers showed age-dependent changes in knee cartilage, primarily within the medial compartment.