Regional perfusion imaging using pTILT.

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Neuroimaging
• Cerebrovascular Physiology

Background:

• Pseudo-continuous arterial spin labeling (pCASL) is a standard for regional cerebral blood flow (CBF) imaging.
• The pseudo-continuous transfer insensitive labeling technique (pTILT) offers an alternative MRI approach.
• Adapting pTILT for regional perfusion imaging could expand its clinical utility.

Purpose of the Study:

• To assess the feasibility of modifying the pTILT sequence for regional perfusion imaging.
• To develop vessel-encoded and vessel-selective pTILT methods analogous to pCASL.
• To evaluate the ability of modified pTILT to delineate specific cerebral perfusion territories.

Main Methods:

• Static phantom experiments were conducted to evaluate region-specific labeling efficiency and selectivity.
• Four healthy subjects underwent imaging using modified pTILT sequences.
• Perfusion territories of major cerebral arteries (ICA, ACA, MCA) were examined.

Main Results:

• Vessel-encoded and vessel-selective pTILT demonstrated high labeling efficiency (0.92 and 0.88, respectively) in phantom studies.
• Modified pTILT sequences clearly delineated individual cerebral arterial territories (ACA, MCA branches).
• Estimated CBF values for ACA and MCA territories were successfully measured, confirming regional perfusion assessment.

Conclusions:

• The pTILT sequence can be successfully adapted for regional perfusion imaging using vessel-encoded and vessel-selective approaches.
• Region-specific pTILT effectively separates perfusion territories of major cerebral arteries.
• This adaptation offers a viable alternative to pCASL for regional CBF quantification.