Perfusion imaging using spin-labeling methods: contrast-to-noise comparison in functional MRI applications

Area of Science:

• Magnetic Resonance Imaging
• Functional Perfusion Studies
• Neuroimaging

Background:

• Functional perfusion studies are crucial for understanding brain activity.
• Quantitative MRI methods aim to provide absolute perfusion measurements.
• Assessing perfusion changes during functional tasks requires sensitive techniques.

Purpose of the Study:

• To evaluate FLASH imaging with selective inversion for functional perfusion.
• To compare quantitative perfusion measurement with subtraction methods (BASE and FAIR).
• To assess the ability of different methods to detect activation in individual subjects.

Main Methods:

• Investigated FLASH imaging with selective inversion preparation.
• Measured absolute perfusion using global (T(1glob)) and selective (T(1sel)) inversion.
• Calculated absolute (BASE) and relative (FAIR) perfusion increases via image subtraction.

Main Results:

• Quantitative perfusion values agreed with PET and other MRI studies.
• Quantitative method showed high variability (around 100% SD) in individual visual cortex activation.
• BASE and FAIR methods successfully detected significant activation in single subjects.

Conclusions:

• FLASH imaging with selective inversion is a viable technique for functional perfusion.
• Subtraction methods (BASE, FAIR) are more sensitive for detecting individual subject activation than quantitative methods in this context.
• Further optimization may be needed for quantitative MRI to reliably detect individual functional brain activation.