To exclude or not to exclude: white matter hyperintensities in diffusion tensor imaging research.

Area of Science:

• Neuroimaging
• Diffusion Tensor Imaging (DTI)
• White Matter Hyperintensities (WMHI)

Background:

• Incidental findings, such as white matter hyperintensities (WMHI), present a methodological challenge in diffusion tensor imaging (DTI) research.
• Decisions on including or excluding subjects with WMHIs can impact study outcomes.

Purpose of the Study:

• To investigate the effect of white matter hyperintensities (WMHI) on whole-brain diffusion tensor imaging (DTI) metrics in healthy control subjects.
• To compare DTI results between healthy controls with and without WMHIs.

Main Methods:

• Thirty healthy adult subjects (mean age 37.7 years, 70% female) were recruited.
• Diffusion tensor imaging (DTI) was performed using a 3 Tesla MRI scanner.
• Fractional anisotropy (FA) was calculated for 19 regions of interest (ROIs), with the 10th percentile defining low FA scores.

Main Results:

• White matter hyperintensities (WMHI) were identified in 26.7% of subjects.
• Subjects with incidental findings were more likely to have low FA scores (37.5%) compared to those without (9.1%).
• Excluding subjects with multiple WMHIs improved DTI metric consistency, with 8.3% meeting low FA criteria versus 50.0% in the excluded group.

Conclusions:

• The inclusion or exclusion criteria for subjects with incidental findings, specifically white matter hyperintensities (WMHI), significantly influence diffusion tensor imaging (DTI) study results.
• Careful consideration of incidental findings is crucial for robust and reproducible DTI research.