Table 2. Mean ADC values (×10−3 mm2/s), ADCSD, and homogeneity indices of pleomorphic adenomas (PAs), Warthin tumors (WTs) and normal parotid parenchyma measured by using 12 concentric round ROIs and comparisons of the parameters among the three groups.
| ROI size (mm2) | ADC | ADCSD | Homogeneity index | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PA (n=37) | WT (n=36) | Normal parotid parenchyma (n=56) | P#,* | PA (n=37) | WT (n=36) | Normal parotid parenchyma (n=56) | P#,§ | PA (n=37) | WT (n=36) | Normal parotid parenchyma (n=56) | P#,* | |||
| 9 | 1.72±0.39 | 1.17±0.46 | 0.94±0.24 | <0.001 | 0.09±0.05 | 0.11±0.07 | 0.14±0.07 | <0.001 | 0.05±0.03 | 0.10±0.06 | 0.16±0.09 | <0.001 | ||
| 28 | 1.73±0.38 | 1.17±0.47 | 0.94±0.22 | <0.001 | 0.12±0.07 | 0.15±0.09 | 0.19±0.08 | <0.001 | 0.07±0.04 | 0.12±0.06 | 0.21±0.10 | <0.001 | ||
| 34 | 1.73±0.38 | 1.17±0.47 | 0.94±0.21 | <0.001 | 0.13±0.07 | 0.15±0.10 | 0.20±0.08 | <0.001 | 0.08±0.04 | 0.13±0.07 | 0.22±0.11 | <0.001 | ||
| 50 | 1.73±0.38 | 1.17±0.46 | 0.94±0.20 | <0.001 | 0.15±0.07 | 0.17±0.11 | 0.21±0.08 | <0.001 | 0.09±0.04 | 0.14±0.06 | 0.23±0.10 | <0.001 | ||
| 60 | 1.73±0.38 | 1.17±0.46 | 0.94±0.19 | <0.001 | 0.15±0.07 | 0.17±0.11 | 0.22±0.08 | <0.001 | 0.09±0.04 | 0.14±0.07 | 0.24±0.11 | <0.001 | ||
| 82 | 1.73±0.38 | 1.17±0.45 | 0.94±0.19 | <0.001 | 0.17±0.07 | 0.19±0.13 | 0.23±0.08 | <0.01 | 0.10±0.04 | 0.16±0.07 | 0.25±0.11 | <0.001 | ||
| 93 | 1.73±0.38 | 1.16±0.45 | 0.94±0.19 | <0.001 | 0.18±0.07 | 0.19±0.13 | 0.23±0.09 | <0.01 | 0.11±0.04 | 0.16±0.07 | 0.25±0.10 | <0.001 | ||
| 98 | 1.73±0.38 | 1.16±0.44 | 0.95±0.19 | <0.001 | 0.18±0.07 | 0.20±0.13 | 0.23±0.08 | <0.01 | 0.11±0.05 | 0.16±0.07 | 0.25±0.10 | <0.001 | ||
| 115 | 1.72±0.38 | 1.16±0.43 | 0.95±0.18 | <0.001 | 0.19±0.08 | 0.21±0.13 | 0.24±0.09 | <0.01 | 0.12±0.05 | 0.17±0.08 | 0.26±0.10 | <0.001 | ||
| 130 | 1.72±0.38 | 1.16±0.43 | 0.94±0.18 | <0.001 | 0.20±0.08 | 0.21±0.14 | 0.24±0.08 | <0.01 | 0.12±0.06 | 0.18±0.08 | 0.26±0.10 | <0.001 | ||
| 136 | 1.72±0.37 | 1.16±0.42 | 0.94±0.18 | <0.001 | 0.20±0.08 | 0.22±0.14 | 0.24±0.18 | <0.01 | 0.12±0.06 | 0.18±0.08 | 0.26±0.10 | <0.001 | ||
| 149 | 1.71±0.37 | 1.15±0.42 | 0.94±0.18 | <0.001 | 0.21±0.09 | 0.23±0.14 | 0.25±0.18 | 0.019 | 0.13±0.06 | 0.19±0.08 | 0.27±0.10 | <0.001 | ||
*, Post-hoc analyses show significant differences of ADCs between any two groups (all P<0.017); §, no significant differences in mean ADCSDs with each ROI between PA and WT (all P>0.017); #, Kruskal-Wallis tests. ADC, apparent diffusion coefficient; SD, standard deviation; ROI, region of interest.