T. Matsuda et al., AN ASYMMETRIC SLICE PROFILE - SPATIAL ALTERATION OF FLOW SIGNAL RESPONSE IN 3D TIME-OF-FLIGHT NMR ANGIOGRAPHY, Magnetic resonance in medicine, 29(6), 1993, pp. 783-789
We introduce an asymmetric slice profile technique, which alters the s
patial response of the flow signal in 3D time-of-flight NMR angiograph
y. By gradually increasing the flip angle from the inflow to the outfl
ow portions of the slab, the inflow refreshment effect is distributed
over a wide slab thickness. The asymmetric slice profile is simply pro
duced by using a Gaussian RF excitation with an overlapping presaturat
ion. The spatial distribution of steady flow signal in a phantom study
demonstrated an essential agreement with a numerical simulation. 3D t
ime-of-flight NMR angiography of volunteers' heads using this techniqu
e provided a smooth vascular depiction over a wide slab thickness.