260 likes | 534 Views
Steady State Free Precession (SSFP) Transient Reduction. MR Study Group 2/29/2008 Thomas Sushil John. Introduction. General SSFP Pulse Sequence. Introduction. Flip = 30 degrees, T1=870ms, T2=100ms. Introduction. Flip = 60 degrees, T1=870ms, T2=100ms. Introduction.
E N D
Steady State Free Precession (SSFP) Transient Reduction MR Study Group 2/29/2008 Thomas Sushil John
Introduction General SSFP Pulse Sequence
Introduction Flip = 30 degrees, T1=870ms, T2=100ms
Introduction Flip = 60 degrees, T1=870ms, T2=100ms
Introduction Flip = 60 degrees, T1=500ms, T2=200ms
Introduction z y x
Introduction x y x y
Introduction z y y x
Introduction z y x x
Nishimura et. al., ISMRM 2000 T1 = 200 TR T2 = 40 TR Flip angle = 30 degrees a b c
Nishimura et. al., ISMRM 2000 Deimling & Heid’s method - Introduce zeroes at i and -i a b c
Nishimura et. al., ISMRM 2000 Nishimura & Vasanawala’s method - Introduce zeroes around the unit circle a b c
Hargreaves et. al., MRM 2001 Qk = Mk - Mss
Hargreaves et. al., MRM 2001 + : 0 Hz off-resonance x : 30 Hz off-resonance
Hargreaves et. al., MRM 2001 Pulse Sequence for Magnitude scaling
Hargreaves et. al., MRM 2001 SSFP Sequence: - 60 degrees flip angle - TR = 8 ms, TE = 4 ms - 12 s recovery between phase encodes
Le Roux, JMR 2003 Effective axis of rotation