Arterial spin labeling angiography using a triple inversion recovery prepulse.

Arterial spin labeling is a well-known noninvasive angiography technique, which does not necessitate the use of a contrast agent. arterial spin labeling is still clinically underused because of several challenges: (1) long scan times because of the need for two acquisitions (labeled and nonlabeled datasets), (2) sensitivity to spatial misregistration because of the need for image subtraction, and (3) the need for precise planning and choice of an optimal inversion delay for best blood-to-background contrast. In this work, we propose a new arterial spin labeling method based on a triple-inversion-recovery sequence-arterial spin labeling. This approach exploits the ability of two nonselective inversion recovery prepulses to null the background signal over a wide range of T1 values, while maintaining the signal of labeled blood using a third slab selective inversion pulse. This technique therefore allows the acquisition of angiograms with a flexible inversion delay, easier planning procedure and no need for subtraction.