Extending the Adaptive Sequential Design (ASD) Approach for Real-Time T1 Optimisation in Arterial Spin Labelling

Alexander Graeme Gardener¹, Stuart Clare¹, Peter Jezzard¹

Adaptive Sequence Design ASL optimises multi-TI timings in real-time whilst the subject is within the scanner. Previously, a voxel mask based on difference signal was used; this study uses prior-acquired and stored GM-weighted DIR images loaded into the ASL acquisition to generate perfusion-independent masks. It is shown in healthy adult subjects that both approaches give similar TI optimisation and perfusion quantification, with simple online regional segmentation showing later inflow from PCA. This technique will be of use when dealing with diseased subjects, such as stroke patients, where perfusion may be altered, for which the original approach would not be sensitive.