Table 2. Mean values ± standard deviation of the proton density fat fraction (PDFF, in %) and cross-sectional area (CSA, in cm2) of the erector spinae muscles of the segments L3–L5, T12–L2, and T9–T11 as well as the psoas muscles for subjects younger and older than 38 years, respectively. Furthermore, the CSA divided by the body mass index (BMI, in kg/m2) is provided.
| Variable | Value | Age <38 years (n=38) | Age >38 years (n=38) | P |
|---|---|---|---|---|
| Erector spinae muscles L3–L5 | PDFF (in %) | 12.3±5.6 | 19.4±8.2 | <0.001 |
| CSA (in cm2) | 191.6±41.3 | 198.3±38.9 | >0.05 | |
| CSA/BMI | 8.2±1.4 | 7.4±1.4 | 0.015 | |
| Erector spinae muscles T12–L2 | PDFF (in %) | 4.2±2.5 | 9.2±5.0 | <0.001 |
| CSA (in cm2) | 159.9±52.5 | 164.6±35.5 | >0.05 | |
| CSA/BMI | 6.8±2.3 | 6.2±1.5 | >0.05 | |
| Erector spinae muscles T9–T11 | PDFF (in %) | 4.1±2.7 | 9.6±6.0 | <0.001 |
| CSA (in cm2) | 94.5±27.8 | 87.6±21.4 | >0.05 | |
| CSA/BMI | 4.0±1.1 | 3.4±1.1 | 0.008 | |
| Psoas muscles | PDFF (in %) | 4.5±1.5 | 6.9±2.9 | <0.001 |
| CSA (in cm2) | 115.1±34.7 | 103.1±26.6 | >0.05 | |
| CSA/BMI | 4.9±1.6 | 3.9±1.2 | 0.002 |