Comparison of a hybrid multi-delay pseudo-continuous arterial spin labelling scheme with time-encoded and variable-TR schemes

To accurately calculate cerebral blood flow (CBF) and arterial transit time (ATT), there are two kinds of time-efficient approaches in use for multi-delay pseudo-continuous arterial spin labelling: time-encoded and sequential variable-TR. Hybrid schemes have recently been proposed that exploit the strengths of these approaches, but they have not been evaluated head-to-head, and the purpose of this study is therefore to investigate the clinical validity of hybrid schemes. The SNR, CBF and ATT were measured and compared in seven healthy subjects. A higher SNR was obtained in the hybrid scheme with high correlation coefficients with other ATT schemes, suggesting quantitative ability.