Longitudinal Structural MRI in Neurologically Healthy Adults.

Area of Science:

• Neuroimaging
• Radiology
• Biomedical Engineering

Background:

• Structural brain MRI measures are crucial for studying both healthy and clinical populations.
• Understanding the temporal stability of these measures is essential for accurate longitudinal research.

Purpose of the Study:

• To evaluate the long-term stability of various structural brain MRI metrics.
• To determine if these measures are reliable over a 3-year period.

Main Methods:

• A retrospective analysis of prospectively acquired 3T MRI data from 112 healthy volunteers across four sites.
• Assessment of diffusion, cortical thickness, and volume data from the sensorimotor network using intraclass correlation coefficients (ICC) and ANOVA.
• Comparison of data acquired from Siemens and Philips MRI scanners.

Main Results:

• High reliability (ICC ≥0.80) was observed for all tested structural MRI measures, including cortical thickness, gray matter volume, and diffusion metrics.
• Significant differences in most measures were found between scanners, with a trend for Siemens scanners to yield larger values than Philips scanners.
• Despite inter-scanner differences, the overall stability of measures over time was high.

Conclusions:

• Structural brain MRI measures, including diffusion and volumetric data, demonstrate high reliability over a 3-year period in healthy individuals.
• The high reliability suggests that observed changes over time are more likely to reflect genuine biological variations than methodological inconsistencies.
• Scanner type can influence specific measurement values, highlighting the importance of consistent scanner use or careful cross-scanner analysis in longitudinal studies.