1. Psy 8960, Spring ‘07 Inversion Recovery1 Exponential decay  = 30 ms

2. Psy 8960, Spring ‘07 Inversion Recovery2 T 2 : decay of transverse magnetization after excitation  = T 2 = 30 ms T 2 = 50 ms TE = 15 ms TE = 20 ms TE = 30 ms TE = 60 ms

3. Psy 8960, Spring ‘07 Inversion Recovery3 180º M || B0B0 Longitudinal magnetization relaxes back to equilibrium with characteristic time constant, T 1

4. Psy 8960, Spring ‘07 Inversion Recovery4 T1T1 Inversion recovery TI = 50 ms100 ms800 ms400 ms1600 ms3200 ms4800 ms T 1 = 1100 ms T 1 = 2000 ms T 1 = 900 ms Negative magnetization looks like positive magnetization in magnitude images

5. Psy 8960, Spring ‘07 Inversion Recovery5 Contrast in the brain T 1 (IR)T 2 (SE)