NONLINEAR EXCITATION PROFILES FOR 3-DIMENSIONAL INFLOW MR-ANGIOGRAPHY

An RF excitation pulse for three-dimensional [3D] time-of-flight [TOF] MR angiography [MRA] with a nonlinear excitation profile was numerica lly calculated under the condition of uniform vessel signal across the excitation volume [slab], and the superiority of the optform pulse as compared with conventional RF pulses and TONE pulses was demonstrated , For this purpose we acquired MRA of the lower leg and of the carotid and vertebral arteries in a 30-year-old healthy volunteer. Although t he now velocity ranges in these two anatomic locations are different b y about a factor of 10, in both cases the corresponding optform pulse provided the best signal homogeneity at the highest level.