Name
Abstract | ||
|---|---|---|
Recent MRI studies at high field have observed that, in certain white matter fiber bundles, the signal in T2⁎-weighted MRI (i.e. MRI sensitized to apparent transverse relaxivity) is dependent on fiber orientation θ relative to B0. In this study, the characteristics of this dependency are quantitatively investigated at 7T using ex-vivo brain specimens, which allowed a large range of rotation angles to be measured. The data confirm the previously suggested variation of R2⁎ (=1/T2*) with θ and also indicate that this dependency takes the shape of a combination of sin2θ and sin4θ functions, with modulation amplitudes (=ΔR2⁎) reaching 6.44±0.15Hz (or ΔT2⁎=2.91±0.33ms) in the major fiber bundles of the corpus callosum. This particular dependency can be explained by a model of local, sub-voxel scale magnetic field changes resulting from magnetic susceptibility sources that are anisotropic. As an illustration of a potential use of the orientation dependence of R2⁎, the feasibility of generating fiber orientation maps from R2⁎ data is investigated. |
Year | DOI | Venue |
|---|---|---|
2011 | 10.1016/j.neuroimage.2011.04.026 | NeuroImage |
Keywords | DocType | Volume |
T2⁎ relaxation,R2⁎,Fiber tracking,Magnetic susceptibility anisotropy in white matter,Susceptibility tensor imaging (STI),Diffusion tensor imaging (DTI) | Journal | 57 |
Issue | ISSN | Citations |
1 | 1053-8119 | 23 |
PageRank | References | Authors |
1.38 | 2 | 6 |
Name | Order | Citations | PageRank |
|---|---|---|---|
| Jongho Lee | 1 | 71 | 6.17 |
| Peter van Gelderen | 2 | 403 | 35.74 |
| Li-Wei Kuo | 3 | 53 | 3.33 |
| Hellmut Merkle | 4 | 84 | 12.39 |
| Afonso C. Silva | 5 | 220 | 18.38 |
| Jeff H. Duyn | 6 | 839 | 48.39 |