Optimizing background suppression for dual-module velocity-selective arterial spin labeling: Without using additional...

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Medical Physics

Background:

• Background suppression (BS) is crucial for enhancing signal-to-noise ratio (SNR) in arterial spin labeling (ASL).
• Optimizing BS in velocity-selective ASL (VSASL) presents challenges.
• Dual-module VSASL (dm-VSASL) offers robust and SNR-efficient perfusion imaging with potential for effective BS.

Purpose of the Study:

• To investigate and optimize background suppression (BS) strategies in dual-module VSASL (dm-VSASL).
• To evaluate the effectiveness of using velocity-selective inversion (VSI) effects for BS in dm-VSASL.
• To compare BS performance, temporal noise, and SNR of different BS strategies in dm-VSASL.

Main Methods:

• Modeling of inversion effects from velocity-selective labeling pulses for BS optimization.
• In vivo experiments using dual-module VSI (dm-VSI) comparing conventional BS with additional pulses versus a novel strategy without BS pulses.
• Comparison of BS performance, temporal noise, and temporal SNR against pulsed and pseudo-continuous ASL (PASL and PCASL).

Main Results:

• BS modeling was validated in vivo, showing strong linear correlations between temporal noise and tissue signal.
• Optimal BS in dm-VSI was achieved without additional BS pulses, improving ASL signals in gray matter (8.5%) and white matter (12.2%).
• The dm-VSI method without additional BS pulses demonstrated significantly higher ASL signal and temporal SNR compared to PASL and PCASL.

Conclusions:

• Optimal background suppression in dm-VSASL can be achieved without additional BS pulses, guided by modeling.
• Eliminating extra BS pulses enhances ASL signal and improves overall SNR performance in dm-VSASL.
• This optimized approach simplifies dm-VSASL, leading to more efficient and robust perfusion imaging.