Table 4.
Average R1 and R2 values of Gd-DTPA (Gd) with different concentrations of macromolecular materials. N is the number of imaging sessions. The hydrogels and MR instrumentation showed stability over time as indicated by the small standard deviation obtained from measurements performed repeatedly over several months. Relaxivities are compared to Gd-DTPA in PBS with statistically significant differences achieved in HA at concentrations above 50 g/l and in CO at 100 g/l. The R1 of Gd-DTPA in 100 g/l HA, GE and CO is 18, 31, and 20%, respectively, larger than in PBS. HA hyaluronan; GE gelatin; CO composite, 1:1 HA:GE
| Sample (g/l) | R1 (mM−1 s−1) | N | p-value (R1) | R2 (mM−1 s−1) | N | p-value (R2) | |
|---|---|---|---|---|---|---|---|
| HA | 6.25 | 4.34±0.08 | 3 | 0.471 | 4.88±0.16 | 3 | 0.470 |
| 12.5 | 4.31±0.10 | 3 | 0.421 | 4.92±0.16 | 3 | 0.615 | |
| 25 | 4.41±0.12 | 3 | 0.204 | 4.96±0.19 | 3 | 0.625 | |
| 50 | 4.51±0.10 | 3 | 0.038 | 5.09±0.21 | 3 | 0.341 | |
| 100 | 4.99±0.11 | 3 | <0.001 | 5.43±0.34 | 3 | 0.021 | |
| GE | 6.25 | 4.22 | 1 | 4.71 | 1 | ||
| 12.5 | 4.34 | 1 | 4.80 | 1 | |||
| 25 | 4.45 | 1 | 4.99 | 1 | |||
| 50 | 4.90 | 1 | 5.34 | 1 | |||
| 100 | 5.55 | 1 | 6.27 | 1 | |||
| CO | 6.25 | 4.28±0.12 | 3 | 0.783 | 4.60±0.44 | 3 | 0.810 |
| 12.5 | 4.29±0.08 | 3 | 0.933 | 4.81±0.32 | 3 | 0.659 | |
| 25 | 4.38±0.10 | 3 | 0.773 | 5.03±0.28 | 3 | 0.459 | |
| 50 | 4.64±0.16 | 3 | 0.103 | 5.46±0.33 | 3 | 0.059 | |
| 100 | 5.10±0.35 | 3 | <0.001 | 6.11±0.36 | 3 | 0.002 | |
| PBS | 4.24±0.08 | 3 | 4.75±0.18 | 3 | |||