Observed mean values and slopes of R1, R2, and PD of the entire brain and gray and white matter as a function of subject age
| Brain | Gray Matter | White Matter | |
|---|---|---|---|
| R1 intercept (s−1) | 1.151 | 0.897 | 1.495 |
| R1 slope (s−1/y) | 0.00054 | 0.00015 | −0.00063 |
| R1 slope (95% CI) (s−1/y) | (0.0002–0.0010) | (−0.0001–0.0002) | (−0.0011–0.0002) |
| R1 slope P value | .04 | .4 | .2 |
| R2 intercept (s−1) | 11.44 | 10.57 | 12.62 |
| R2 slope (s−1/y) | −0.0001 | −0.0018 | −0.0056 |
| R2 slope (95% CI) (s−1/y) | (−0.004–0.002) | (−0.004–0.001) | (−0.009–0.000) |
| R2 slope P value | .5 | .3 | .05 |
| PD intercept (%) | 75.65 | 82.44 | 67.44 |
| PD slope (%/y) | −0.026 | −0.019 | 0.009 |
| PD slope (95% CI) (%/y) | (−0.039–0.013) | (−0.025 to −0.013) | (−0.003–0.020) |
| PD slope P value | <.001 | <.001 | .2 |
Note:—y indicates year.