摘要：SummaryBackground/Objective T1ρ and {T2} relaxation mapping in knee cartilage have been used extensively at 3 Tesla (T) as markers for proteoglycan and collagen, respectively. The objective of this study was to evaluate the feasibility of T1ρ and {T2} imaging of knee cartilage at 7T in comparison to 3T and to evaluate the ability of T1ρ and {T2} to determine differences between normal and osteoarthritis (OA) patients. Materials and methods Twenty patients, seven healthy patients (Kellgren–Lawrence = 0), and 13 patients with signs of radiographic {OA} (Kellgren–Lawrence > 0) were scanned at 3T and 7T. The knee cartilage was segmented into six compartments and the T1ρ and {T2} values were fit using a two-parameter model. Additionally, patients were stratified by the presence of cartilage lesions using the modified Whole Organ Magnetic Resonance Imaging Score classification of the knee. One-way analysis of variance was used to compare the healthy and {OA} groups at 3T and 7T. The specific absorption ratio was kept under Food and Drug Administration limits during all scans. Results T1ρ and {T2} values at 3T and 7T were significantly higher in the lateral femoral condyle and patella in patients with OA. However, more regions were significant or approached significance at 7T compared with 3T, with the differences between healthy and {OA} patients also larger at 7T. The signal to noise ratio across all cartilage and meniscus compartments was 60% higher on average at 7T compared to 3T. Conclusion T1ρ imaging at 7T has been established as a viable imaging method for the differentiation of degenerated cartilage despite previous concerns over specific absorption rate and imaging time. The potential increased sensitivity of T1ρ and {T2} imaging at 7T may be useful for future studies in the development of OA.
Loading...
