抄録
Background: The objective of this study was to prospectively quantify the fatty degeneration of supraspinatus (SSP) muscle by using Dixon technique of MRI, and to evaluate the correlation with clinical findings including rotator cuff tears.
Methods: 258 patients with shoulder pain examined with 2-point Dixon technique of 3.0T-MRI were included in this study. Fatty degeneration was quantified after measurement of signal intensity value within the region of interest (ROI) placed over SSP muscle. Each signal intensity value of the image of in phase and fat image was defined as S(In) and S(Fat). The amount of fat contained in SSP was calculated as S(Fat)/S(In). Radiologists and orthopaedic surgeons evaluated the degree of rotator cuff tears in 3 categories: no tear, partial tear, complete tear. Statistical analysis was performed for correlation between the amount of fat in SSP and age, the degree of rotator cuff tears by using SSPS.
Results: The patients with full-thickness tear, partial-thickness tear and no tear are 47, 41 and 170 respectively. Correlation coefficient is 0.416 between age and fat amount in SSP. The degree of fat degeneration of SSP in the three groups showed statistically-significant difference (p< 0.001).
Conclusion: We can quantify and evaluate the degree of fatty degeneration within SSP by using Dixon technique of MRI objectively. Increased supraspinatus fatty infiltration was correlated with the age and severity of a supraspinatus tear.
