Abstract: A subtraction MRA image is formed by subtracting a mask image formed from diastolic MR image data from an angiographic image formed from systolic MR image data. To permit acquisition of diastolic MR image data during regurgitation of arterial bloodflow, a saturation slab is established immediately adjacent the slice of interest and slightly overlapping it on its arterially downstream side.

Abstract: Techniques for conducting two-dimensional fat-saturated multislice MR studies are disclosed. The frequency of saturation pulses is varied on a slice-by-slice basis. In a second preferred embodiment, the phase, or the phase and frequency, of one or more elements of a spatially and spectrally selective MR pulse sequence are varied on a slice-by-slice basis. In a third preferred embodiment, the order in which MR image data is acquired from a plurality of slices is changed so as not to minimize the time between inadvertent saturation of the water signal in a particular slice and the acquisition of MR image data from that slice.

Abstract: MR angiography method and apparatus either moves the saturation slab or eliminates it during a predetermined portion of the patient's cardiac cycle. This permits an MR image of a slice of interest to contain information relating to arterial bloodflow without becoming degraded by regurgitated bloodflow and information relating to venous bloodflow.

Abstract: A method for removing unwanted signal components acquired by applying a three dimensional magnetic resonance imaging pulse sequence to a sample, wherein signal acquisition is desired from a selected planar slice, but unwanted signal components are also acquired from a plurality of planar slices located outside the boundaries of the selected slice. According to the method, both a radio frequency saturation pre-pulse and a linear field gradient are applied to the sample. The pre-pulse and field gradient create a comb-like pattern of planar nuclear magnetic saturation regions in the sample, each of the regions being spatially positioned between a respective pair of contiguous planer slices. Next, a 3-D imaging sequence is applied to the sample. The timing of the 3-D imaging sequence is such that the comb-like saturation pattern of the pre-pulse sequence is imposed upon the 3-D imaging sequence so as to reduce the acquisition of signal originating from the regions when acquiring signal from the selected slice.