Long-term repeatability, accuracy, and brain size dependence of automatic VOI localization in single-voxel MRS

Area of Science:

• Neuroimaging
• Magnetic Resonance Spectroscopy (MRS)

Background:

• Precise localization of the volume of interest (VOI) is critical for reliable MRS data collection.
• The automatic localization tool ALLVOI's repeatability and accuracy were evaluated.
• The influence of subject brain size on VOI localization was examined.

Purpose of the Study:

• To assess the repeatability and accuracy of the automatic VOI localization tool (ALLVOI).
• To investigate the impact of subject brain size on VOI localization accuracy.
• To compare fixed-size versus variable-size VOI strategies.

Main Methods:

• Repeatability assessed using Dice coefficient (DCrep) in 51 subjects over 10-25 months.
• Accuracy evaluated using Dice coefficient (DCacc) in 127 subjects.
• Compared fixed-size VOI strategy with a variable-size VOI strategy.

Main Results:

• High repeatability (DCrep 0.92-0.94) was observed across brain regions.
• Fixed-size VOI strategy showed accuracy (DCacc 0.75-0.83) correlated with brain volume.
• Variable-size VOI strategy improved accuracy (DCacc 0.84-0.88) and reduced brain size dependence.

Conclusions:

• A variable-size VOI strategy enhances anatomical precision in MRS.
• This approach offers advantages for studies requiring accurate spatial targeting.
• ALLVOI with a variable-size strategy provides reliable and accurate VOI localization.