Fiber Density Index Correlates with Reduced Fractional Anisotropy in White Matter of Patients with Glioblastoma
Tim P.L. Robertsa,
Fang Liua,
Andrea Kassnera,
Susumu Morib and
Abhijit Guhaa
a From the Department of Medical Imaging, University of Toronto, Toronto, Canada
b Department of Radiology, Johns Hopkins University, Baltimore, MD
View larger version (50K):
[in a new window]
|
FIG 1. A representative example of a patient with a right hemispheric glioblastoma. ROIs placed in white matter regions encompassing corticospinal and corticopontine tracts both immediately adjacent to the tumor and in the contralateral hemisphere were interrogated for quantitation of FA and for evaluation of the FDi. Adjacent to the tumor, the number of fibers passing through the region (A) can be seen to be markedly fewer than in the contralateral region (C). The 2 ROIs are displayed without fibers in (B). In this case, peritumoral FA was 0.45, compared with 0.65 in the contralateral normal-appearing region. FDi was reduced from 5.38 in the contralateral white matter to 3.11 in the peritumoral white matter. Note the fiber colors themselves have no specific interpretation. Different colors are assigned to each fiber path as an aid to visualization.
| |
View larger version (13K):
[in a new window]
|
FIG 2. Plot of FDi against FA for all 20 ROIs (10 peritumoral white matter: open circles; 10 contralateral normal-appearing white matter: filled circles). A significant correlation between the 2 parameters is observed (r = 0.81) with both being reduced peritumorally.
| |
