RESUMO
OBJECTIVES: To establish baseline T2* and T1Gd values of glenohumeral cartilage at 3 T. METHODS: Forty asymptomatic volunteers (mean age: 24.8 ± 2.2 years) without shoulder abnormalities were included. The MRI protocol comprised a double-echo steady-state (DESS) sequence for morphological cartilage evaluation, a gradient-echo multiecho sequence for T2* assessment, and a gradient-echo dual-flip-angle sequence for T1Gd mapping. Statistical assessment involved a one-way analysis of variance (ANOVA) to identify the differences between various regions of the glenohumeral joint and intraclass correlation (ICC) analysis comparing repetitive T2* and T1Gd measures to assess intra- and interobserver reliability. RESULTS: Both techniques revealed significant differences between superior and inferior glenohumeral cartilage demonstrating higher T2* (26.2 ms vs. 23.2 ms, P value < 0.001) and T1Gd (750.1 ms vs. 720.2 ms, P value = 0.014) values in the superior regions. No trend was observed in the anterior-posterior measurement (P value range: 0.279-1.000). High intra- and interobserver agreement (ICC value range: 0.895-0.983) was noted for both T2* and T1Gd mapping. CONCLUSIONS: T2* and T1Gd mapping are reliable in the assessment of glenohumeral cartilage. The values from this study can be used for comparison to identify cartilage degeneration in patients suffering from shoulder joint abnormalities. KEY POINTS: ⢠T2* mapping and dGEMRIC are sensitive to collagen degeneration and proteoglycan depletion. ⢠This study aimed to establish baseline T2*/dGEMRIC values of glenohumeral cartilage. ⢠Both techniques revealed significant differences between superior and inferior glenohumeral cartilage. ⢠High intra-/interreader agreement was noted for both T2* mapping and dGEMRIC. ⢠These baseline normal values should be useful when identifying potential degeneration.
