Table 4:
Quantitative MR imaging parameters by tissue type and clinical groupa
| NAWM | DAWM | Lesions | Significant Pair-wise Comparisons between Tissue Types | Significant Comparisons between Disease Types | ||
|---|---|---|---|---|---|---|
| ADC (μm2 s−1) | PP | 805 ± 53 | 842 ± 48 | 1042 ± 216 | Lesions vs NAWM, P < .05 | – |
| SP | 798 ± 40 | 903 ± 77 | 1201 ± 131 | DAWM vs NAWM, P < .001; DAWM vs lesions, P < .001; lesions vs NAWM, P < .001 | ||
| FA | PP | 0.383 ± 0.058 | 0.350 ± 0.047 | 0.318 ± 0.110 | DAWM vs NAWM P < .01; DAWM vs lesions, P < .05; lesions vs NAWM, P < .001 | – |
| SP | 0.365 ± 0.033 | 0.322 ± 0.030 | 0.242 ± 0.054 | DAWM vs NAWM, P < .001; DAWM vs lesions, P < .001; lesions vs NAWM, P < .001 | ||
| MTR (%) | PP | 32.9 ± 0.6 | 31.1 ± 1.0 | 28.2 ± 3.6 | DAWM vs NAWM, P < .01; lesions vs NAWM, P < .05 | DAWM SP vs PP, P < .001; lesions SP vs PP, P < .01 |
| SP | 32.8 ± 1.2 | 28.8 ± 0.8 | 21.3 ± 3.3 | DAWM vs NAWM, P < .001; DAWM vs lesions, P < .001; lesions vs NAWM, P < .001 | ||
| T1 (ms) | PP | 759 ± 27 | 823 ± 38 | 1040 ± 185 | DAWM vs NAWM, P < .05 | DAWM SP vs PP, P < .001; lesions SP vs PP, P < .05 |
| SP | 815 ± 47 | 958 ± 67 | 1419 ± 298 | DAWM vs NAWM, P < .001; DAWM vs lesions, P < .001; lesions vs NAWM, P < .001 |
a
Means and SDs of ADC, FA, MTR, and T1 in NAWM, DAWM, and lesions by clinical group (PP or SPMS). Bonferroni-corrected P values derived from general linear mixed model analysis are indicated for statistically significant pair-wise differences between tissue types and disease types. Details of statistical analyses are provided in the text.