Influence of Mild White Matter Lesions on Voxel-based Morphometry
Masami Goto1, Akifumi Hagiwara2, Shohei Fujita2,3
1Department of Radiological Technology, Faculty of Health Science, Juntendo University.
Purpose:
The aim of this study was to investigate whether the detectability of brain volume change in voxel-based morphometry (VBM) with gray matter images is affected by mild white matter lesions (MWLs).
Methods:
Three-dimensional T1-weighted images (3D-T1WIs) of 11 healthy subjects were obtained using a 3T MR scanner. We initially created 3D-T1WIs with focal cortical atrophy simulated cortical atrophy in left amygdala (type A) and the left medial frontal lobe (type B) from control 3D-T1WIs. Next, the following three types of MWL images were created: type A + 1L and type B + 1L images, only one white matter lesion; type A + 4L and type B + 4L images, four white matter lesions at distant positions; and type A + 4L* and type B + 4L* images, four white matter lesions at clustered positions. Comparisons between the control group and the other groups were performed with VBM using segmented gray matter images.
Results:
The gray matter volume was significantly lower in the type A group than in the control group, and similar results were observed in the type A + 1L, type A + 4L, and type A + 4L* groups. Additionally, the gray matter volume was significantly lower in the type B group than in the control group, and similar results were observed in the type B + 1L, type B + 4L, and type B + 4L* groups, but the cluster size in type B + 4L* was smaller than that in type B.
Conclusion:
Our study showed that the detectability of brain volume change in VBM with gray matter images was not decreased by MWLs as lacunar infarctions. Therefore, we think that group comparisons with VBM should be analyzed by groups including and excluding subjects with MWLs, respectively.
Insights
Mild white matter lesions (MWLs) do not decrease the detectability of brain volume changes using voxel-based morphometry (VBM) on gray matter images. Analysis should consider groups with and without MWLs separately for accurate VBM comparisons.
Area of Science:
- Neuroimaging
- Brain Anatomy
- Morphometry
Background:
- Voxel-based morphometry (VBM) is a neuroimaging technique used to analyze localized statistical differences in MRI brain scans.
- Mild white matter lesions (MWLs) are common in aging populations and may potentially affect VBM results.
- Investigating the impact of MWLs on VBM detectability is crucial for accurate brain volume change analysis.
Purpose of the Study:
- To determine if mild white matter lesions (MWLs) affect the detectability of brain volume changes using voxel-based morphometry (VBM) on gray matter images.
- To assess the influence of lesion load and distribution on VBM analysis of simulated brain atrophy.
Main Methods:
- Simulated focal cortical atrophy was introduced into 3D T1-weighted MRI scans of healthy subjects.
- Mild white matter lesions (MWLs) were simulated in varying numbers (1 or 4) and clustered or distant positions.
- Voxel-based morphometry (VBM) analysis was performed on segmented gray matter images to compare control and lesion groups.
Main Results:
- VBM detected significant gray matter volume reduction in simulated atrophy regions (type A and B) compared to controls.
- The presence of simulated MWLs (single or multiple, clustered or distant) did not decrease the detectability of gray matter volume changes.
- A slight reduction in cluster size was observed in one case with clustered lesions (type B + 4L*).
Conclusions:
- Mild white matter lesions (MWLs), similar to lacunar infarctions, do not impair the detectability of brain volume changes in VBM analyses using gray matter images.
- It is recommended to conduct VBM group comparisons separately for groups including and excluding subjects with MWLs to ensure robust findings.
- This finding supports the continued use of VBM in populations with white matter lesions, with appropriate analytical considerations.
