Jia Guo1, Eric C. Wong2
1Bioengineering, University of California San Diego, La Jolla, CA, USA; 2Department of Radiology & Psychiatry, University of California San Diego, La Jolla, CA, USA
In VSASL, arterial blood is tagged by velocity selective saturation (VSS). This method is inherently insensitive to transit delays and may be useful in applications where transit delay can be long, such as white matter and in stroke. In this work, we note that by using two or more VSS modules, T1 decay of the tag can be reduced, increasing the overall tagging efficiency and hence the SNR of VSASL. Dual VSS VSASL was implemented and tested in human volunteers, and the measured signal was approximately 40% higher using 2 VSS modules, in good agreement with theory.