Selective saturation of volumes of tailored shape for black blood magnetic resonance angiography

Novel magnetic resonance imaging techniques are described for selectively saturating the magnetization signal from a multidimensional volume of interest (VOI) of tailored shape in a relatively large object. The techniques use a series of small-tip-angle saturation radio frequency pulses applied in the presence of a magnetic-field gradient rotating stepwise in a two- or three-dimensional space to define VOIs of saturated spins. Primary demonstration of these techniques for selectively tagging flow in a flow phantom and using it as a marker for ''black blood'' angiography is presented. Particular application of these techniques to tag blood flow spins to be used as natural markers for imaging human blood vessels in vivo noninvasively is emphasized. (C) 1996 John Wiley & Sons, Inc.