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Chenevert et al., J Natl Cancer Inst 2000; 92:2029–36
ADC and cellularity
Three principal axes: A second look
DWI assesses also preferential direction of movement of water molecules
Tensor imaging/ tractography Fractional anisotropy
Fiber tracking with Diffusion Tensor Imaging
•
Diffusion: tractography and fractional
anisotropy
Stieltjes et al. 2002
Fiber tracking
•
Diffusion: tractography
Fractional anisotropy
•
Degree of preferential movement along
one axis
–
FI = 0: Equal movement in all directions
–
FI = 1: Movement in one direction only
•
Measures the degree of architectural
disturbance in organized tissues
–
Tumor infiltration in white matter
FA
,000
,900
Possition of the CC
genu 1st body 2nd body 3rd body splenium
Healthy controls (n=5)
pat 1
Quantifying disorder in fiber arrangement
•
Diffusion: fractional anisotropy