Objective To explore the optimization for parameters of 5.0T pseudo continuous arterial spin labeling(pCASL)MRI of whole brain.Methods Nine healthy adults were prospectively enrolled,and single-delay pCASL scanning was performed based on a 5.0T MR scanner with 3 sets of labeling gradients:Group A,average gradient(Gavg)=1 mT/m and the ratio of maximum gradient(Gmax)to Gavg(Gratio)=10,group B,Gavg=0.6 mT/m and Gratio=10,group C,Gavg=0.3 mT/m and Gratio=9.The labeling efficiency and cerebral blood flow(CBF)of 3 groups were compared to screen the best labeling gradient group.Results When the marked average blood flow velocity was 40 cm/s,the gradient field tolerance of group C was better than that of group A and B at the situation of reduced B1+and larger B0 offset frequency range.Under the gradient field of group C,the level of labeled artery B1 ranged from 54.19％to 75.36％,with an average of 64.71％.The labeling efficiencies of group C were all ≥85％,and all ≥90％at the average B1 level(64.71％).In the whole gray matter and almost all brain regions,CBF on pCASL under gradient field of group C was significantly higher than that of group A and B(all P＜0.05).Conclusion Low Gavg and low Gmax were the optimal parameters for 5.0T whole brain pCASL MRI.
维普
万方数据