Improved MR velocity measurements using high-order moment nulling instead of short TE

This paper compares flow measurements obtained from short-TE pulse sequences without gradient moment nulling against those obtained from longer TE pulse sequences with gradient moment nulling. Velocity-encoded phase imaging (modified VINNIE pulse sequence, GE Medical Systems) was performed in phantoms and normal subjects. Disturbed flow of graded severity was set up in the flow phantoms. Total flow measurements were compared with the actual flow. Measurements using similar pulse parameters were taken in axial sections through the ascending aorta in normal subjects. TE as short as 5 msec and nulling up to second order in the readout and phase-encode directions were tested