Qualitative assessment of cartilage degeneration and morphology of the sigmoid notch using T1rho and T2 mapping: a cross-sectional study

BackgroundThe morphology of radial sigmoid notch varies widely among individuals. It remains unclear whether variations in sigmoid notch morphology influence cartilage degeneration in this region. T1rho and T2 mapping, which are useful magnetic resonance imaging (MRI) methods to assess early cartilage degeneration, may help us evaluate the relationship between the morphology and cartilage degeneration of sigmoid notch.PurposeTo investigate the relationship between cartilage degeneration of radial sigmoid notch and its morphology.Material and MethodsWe investigated the dominant wrists of 40 healthy volunteers (mean age = 34.1 years) using 3-T MRI. We measured the inclination, depth, and width of the sigmoid notch on an axial multi-echo gradient-echo, and the ulnar head diameter on coronal T2-weighted images. T1rho and T2 values of the volar, central, and dorsal cartilages of the sigmoid notch were measured on coronal T1rho and T2 mapping. We evaluated the relationships of T1rho or T2 values of the three regions with age and morphological measurements using Pearson's correlation analysis and multiple linear regression analysis.ResultsThe T2 value of the dorsal sigmoid notch positively correlated with age and width of the sigmoid notch. Multiple linear regression analysis showed that older age and wider sigmoid notch significantly increased the dorsal T2 value.ConclusionA wider sigmoid notch and aging may induce cartilage degeneration in the dorsal sigmoid notch. This association can help future studies about distal radioulnar joint diseases.