Hybrid multi-delay PCASL of time-encoded and variable-TR schemes for the assessment of cerebral perfusion in Moyamoya disease

We have developed a multi-delay PCASL acquisition with a hybrid scheme, combining time-encoded and variable-TR schemes. This hybrid scheme combines the advantage of high SNR obtained with the time-encoded scheme with the timing flexibility of the variable-TR scheme. We investigated the abilities for CBF (cerebral blood flow) and ATT (arterial transit time) quantification in Moyamoya disease. The hybrid scheme provided a higher temporal SNR than the other two schemes. Although slight differences in the CBF and ATT measurements were found between the hybrid and the other two schemes, the differences were acceptable, considering the strong correlations and excellent agreements.