Skip to main content

Table 1 Summary of key differences between gradient echo and spin echo sequences

From: Cardiovascular magnetic resonance physics for clinicians: part I

  Spin echo Gradient echo
Gradient echo (bSSFP)
Flip angle (excitation pulse) 90° variable 5°-40° variable 50°-70°
180° refocusing pulse Yes No No
Contrast weighting T1, T2, 'proton density' T1, T2* T2/T1 ratio
Short Repetition time (T1- weighting) 400-800 ms 3-400 ms (depends on flip angle) 3-5 ms
Short echo time (minimise T2 or T2* weighting) 6-25 ms 1-3 ms 1-3 ms
Long echo time (for T2 or T2* weighting) 60-100 ms 7-15 ms N/A
Long Repetition time (minimises T1 weighting) 1500-2500 ms 100 ms - (depends on flip angle) N/A
Shortest practical TR 200 ms 2-5 ms 2-5 ms
Intra-voxel signal loss (susceptibility, iron) No Yes Yes
Signal from blood flowing through the slice Dark (spin washout) Bright (inflow enhancement) Bright (intrinsic T2/T1 contrast)
Cardiac Applications T1, T2 and 'proton density'-weighted anatomical imaging and tissue characterisation Fast cine imaging, Contrast-enhanced MR angiography,
flow imaging,
T2*-weighted imaging for iron loading.
Fast cine imaging