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Perfusion MRI
= Dynamic contrast susceptibility imaging
Transient signal loss by intravascular CM
T2*w Perfusion MRT
T2*-weighted MRI
Signal (a.u.)
40,0000
72,5000
105,0000
137,5000
170,0000
t (s)
0,0000 26,2500 52,5000 78,7500 105,0000
Diffusion
Diffusion MRI: How it works
•
First gradient field induces dephasing
»
Signal loss
•
Inverted gradient field induces
rephasing
»
Restoration of signal
•
Effect:
–
Stationary protons:
»
Return into phase and regain signal
–
Moving protons
»
Incomplete restoration of signal
»
Persistant signal loss
First Gradient: Dephasing
Second gradient: Rephasing
Stationary protons