Multi-band echo planar imaging (MB-EPI), a new approach to increase data acquisition efficiency and/or temporal resolution, has the potential to overcome critical limitations of standard acquisition strategies for obtaining high-resolution whole brain perfusion imaging using arterial spin labeling (ASL). However, the use of MB also introduces confounding effects, such as spatially varying amplified thermal noise and leakage contamination, which have not been evaluated to date as to their effect on cerebral blood flow (CBF) estimation. In this study, both the potential benefits and confounding effects of MB-EPI were systematically evaluated through both simulation and experimentally using a pseudo-continuous arterial spin labeling (pCASL) strategy. These studies revealed that the amplified noise, given by the geometry factor (g-factor), and the leakage contamination, assessed by the total leakage factor (TLF), have a minimal impact on CBF estimation. Furthermore, it is demonstrated that MB-EPI greatly benefits high-resolution whole brain pCASL studies in terms of improved spatial and temporal signal-to-noise ratio efficiencies, and increases compliance with the assumptions of the commonly used single blood compartment model, resulting in improved CBF estimates.
Bibliographical noteFunding Information:
This work was supported by grants P41 RR008079 , P41 EB015894 , P30 NS076408 and Human Connectome Project ( 1U54 MH091657 ) from the 16 Institutes and Centers of the National Institutes of Health that support the NIH Blueprint for Neuroscience Research. The research reported in this publication was also supported by the National Center for Advancing Translational Sciences of the National Institutes of Health Award Number UL1TR000114 . The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
- Arterial spin labeling (ASL)
- Cerebral blood flow (CBF)
- Leakage evaluation via acquired dummy slices (LEADS)
- Multi-band echo planar imaging (MB-EPI)
- Pseudo-continuous arterial spin labeling (pCASL)
- Total leakage factor (TLF)