AI Article Synopsis
- The study explores the limitations of traditional pulsed arterial spin labeling (PASL) methods that affect temporal resolution and signal-to-noise ratio (SNR).
- A new wedge-shaped adiabatic inversion pulse is introduced, which modifies the labeling process to achieve better control over bolus thicknesses while preserving desired properties.
- The results demonstrate that this new wedge-shaped pulse significantly improves the consistency of bolus timings across varying flow velocities, enhancing the effectiveness of PASL techniques.
Article Abstract
Purpose: In pulsed arterial spin labeling (PASL) methods, arterial blood is labeled by inverting a slab with uniform thickness, resulting in different temporal widths of boluses in vessels with different flow velocities. This limits the temporal resolution and signal-to-noise ratio (SNR) efficiency gains in PASL-based methods intended for high temporal resolution and SNR efficiency, such as turbo-ASL and turbo-QUASAR.
Theory And Methods: A novel wedge-shaped (WS) adiabatic inversion pulse is developed by adding in-plane gradient pulses to a slice-selective (SS) adiabatic inversion pulse to linearly modulate the inversion thicknesses at different locations while maintaining the adiabatic properties of the original pulse. A hyperbolic secant (HS)-based WS inversion pulse was implemented. Its performance was tested in simulations and in phantom and human experiments and compared with an SS HS inversion pulse.
Results: Compared with the SS inversion pulse, the WS inversion pulse was capable of inducing different inversion thicknesses at different locations. It could be adjusted to generate a uniform temporal width of boluses in arteries at locations with different flow velocities.
Conclusion: The WS inversion pulse can be used to control the temporal widths of labeled boluses in PASL experiments. This should benefit PASL experiments by maximizing labeling duty cycle and improving temporal resolution and SNR efficiency. Magn Reson Med 76:838-847, 2016. © 2015 Wiley Periodicals, Inc.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4826647 | PMC |
| http://dx.doi.org/10.1002/mrm.25989 | DOI Listing |
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