Multi-TI Arterial Spin Labeling MRI with Variable TR and Bolus Duration for Cerebral Blood Flow and Arterial Transit...

Area of Science:

• Radiology
• Medical Imaging
• Neuroscience

Background:

• Arterial spin labeling (ASL) is a key MRI technique for quantitative cerebral blood flow (CBF) measurement.
• Accurate estimation of arterial transit time (ATT) and tissue properties (T1, M0) is crucial for reliable CBF quantification.
• Conventional ASL methods can be time-consuming and sensitive to variations in ATT and T1.

Purpose of the Study:

• To develop and validate a multi-TI integrated ASL method for improved CBF and ATT estimation.
• To reduce scan time while maintaining or enhancing quantitative accuracy.
• To explore the clinical utility of derived M0, T1, and ATT maps.

Main Methods:

• A multi-TI integrated pseudo-continuous ASL sequence was implemented with variable post-labeling delays and TRs.
• Data were acquired at 7 TI times (100-4300 ms) in a single scan.
• Voxel-wise T1, M0, CBF, and ATT maps were generated using the integrated ASL data.

Main Results:

• The multi-TI method achieved a 41% reduction in scan time compared to conventional approaches.
• Estimated CBF and ATT values were consistent with physiological literature.
• The method demonstrated higher estimation efficiency and better model fit than other ATT acquisition techniques.
• CBF maps showed reduced sensitivity to ATT and T1 variations.

Conclusions:

• The multi-TI integrated ASL method offers efficient and accurate quantification of CBF and ATT within a clinically acceptable scan time.
• Derived M0, T1, and ATT maps hold potential for clinical applications.
• This technique provides robust perfusion imaging with reduced motion sensitivity.