Marzieh Nezamzadeh1,2, Gerald B. Matson2,3, Karl Young1,2, Michael W. Weiner1,2, Norbert Schuff1,2
1Radiology, University of California San Francisco, San Francisco, CA, USA; 2Center for Imaging of Neurodegenerative Diseases, CIND, VA medical center, San Francisco, san francisco, CA, USA; 3Pharmaceutical Chemistry, University of California San Francisco
Pseudo-continuous arterial spin labeling (pCASL) was previously introduced to overcome the limitations inherent with conventional continuous arterial spin labeling (CASL). However, the control scan (null pulse) in pCASL can be degraded by flow, diminishing the ASL signal. In this study we suggest a new version of pCASL, termed mpCASL, in which the immunity of the null pulse to flow is improved. This is demonstrated by simulations and in-vivo brain perfusion experiments on humans using either CASL, pCASL and the new mpCASL. The experimental findings that perfusion maps using mpCASL show generally better contrast and less blurring than those using CASL or pCASL is consistent with the hypothesis that mpCASL achieves more effective and consistent labeling in presence of variable blood velocity.