MULTIPLE-READOUT SELECTIVE INVERSION RECOVERY ANGIOGRAPHY

We have developed a variation of selective inversion recovery (SIR) angiography that allows us to obtain a collection of several angiograms within the same acquisition time previously required to obtain a single image. In basic SIR, a single readout is performed after the tagging inversion pulse. In multiple‐readout SIR, a succession of readout pulses is applied following the inversion pulse. By varying the gradients appropriately during the successive readouts, we can obtain a set of multiple projection‐angle angiograms, or, by appropriately spacing the readouts throughout the cardiac cycle, we can obtain a set of time‐resolved angiograms. This technique allows us to obtain additional spatial or temporal information without increasing total scan time. A sequence of increasing flip‐angle read pulses is used to maintain a constant signal level across the images. A trade‐off exists between SNR and the number of images acquired. © 1991 Academic Press, Inc. Copyright © 1991 Wiley‐Liss, Inc., A Wiley Company