David Dongsuk Shin1, Eric C. Wong1,
Youngkyoo Jung1, Ho-Ling Liu2, Thomas T. Liu1
1Center for Functional MRI,
University of California, San Diego, La Jolla, CA, United States; 2Department
of Medical Imaging & Radiological Sciences, Chang Gung University, Taiwan
Phase tracking errors in PCASL can lead to significant loss in inversion efficiency. This error can be significantly reduced by minimizing the duration of the RF-to-RF spacing of the PCASL pulse train. Based on a Bloch simulation study, we propose a set of tagging parameters that achieve a sub-millisecond RF-to-RF spacing while preserving high inversion efficiency over a wide range of flow velocities. These parameters were also chosen to be relatively insensitive to B1 and gradient imperfections. In-vivo measurements were used to compare the effectiveness of the new optimized tagging parameters with those from a previous study.