Exponential decay

1
Exponential decay
? 30 ms
2
T2 decay of transverse magnetization after
excitation
TE 15 ms
TE 20 ms
? T2 30 ms
T2 50 ms
TE 30 ms
TE 60 ms
3
Inversion Recovery
B0
180º
Longitudinal magnetization relaxes back to
equilibrium with characteristic time constant, T1
M
4
T1
Inversion recovery
T1 900 ms
T1 1100 ms
T1 2000 ms
TI 50 ms
100 ms
800 ms
400 ms
1600 ms
3200 ms
4800 ms
5
Contrast in the brain
T1 (IR)
T2 (SE)