Table 1. Diffusion tensor and magnetization transfer MRI biomarker values in long-term hypoperfused (N=20) and sham (N=11) mice.
| Region of interest | Biomarker | Sham | Hypoperfused | Statistics | % Change |
|---|---|---|---|---|---|
| Corpus callosum | FA | 0.45±0.01 | 0.41±0.01 | F(1,25)=13.9, P=0.001 | −8.33 |
| MTR | 29.7±0.68 | 29.2±0.38 | F(1,25)=0.45, P=0.508 | −1.65 | |
| MD | 6.58±0.14 | 6.91±0.12 | F(1,25)=3.00, P=0.096 | +4.88 | |
| Internal capsule | FA | 0.50±0.01 | 0.37±0.02 | F(1,25)=21.9, P=0.000 | −33.0 |
| MTR | 30.2±1.00 | 30.0±0.42 | F(1,25)=0.36, P=0.792 | −0.82 | |
| MD | 7.15±0.29 | 7.23±0.25 | F(1,25)=0.00, P=0.956 | +1.23 | |
| Fimbria | FA | 0.56±0.02 | 0.42±0.03 | F(1,25)=10.5, P=0.004 | −35.5 |
| MTR | 29.1±0.64 | 24.7±1.40 | F(1,25)=14.4, P=0.001 | −17.9 | |
| MD | 9.14±0.22 | 10.6±0.02 | F(1,25)=2.39, P=0.136 | +4.00 | |
| Subcortex | FA | 0.26±0.01 | 0.28±0.01 | F(1,25)=8.34, P=0.008 | +7.14 |
| MTR | 27.2±0.61 | 27.9±0.39 | F(1,25)=1.04, P=0.317 | +2.26 | |
| MD | 7.23±0.12 | 7.30±0.09 | F(1,25)=0.03, P=0.866 | −0.95 |
Abbreviations: FA, fractional anisotropy; MD, mean diffusivity; MRI, magnetic resonance imaging; MTR, magnetization transfer ratio.
Cerebral hypoperfusion (6 months) results in significant reductions in FA in the corpus callosum, internal capsule, and fimbria, along with a significant atypical increase in the subcortex, suggesting underlying axonal disruption. MTR (%) is significantly reduced in the fimbria only, whereas MD ( × 10−4 mm2/s) is not significantly altered in any of the regions studied.