Investigating spatial resolution in regional homogeneity analysis

Abstract

The spatial resolution in functional MRI (fMRI) determines the accuracy by which functional correlations are localised. However, voxel volumes in fMRI are typically large (≅33 mm3) causing poor spatial resolution. Consequently, fMRI studies that focus on local correlations (such as ReHo, the Vogt-Bailey (VB) index, and MVPA studies) are susceptible to the partial volume effect (PVE) resulting in reduced accuracy by which functional correlations are localised. Reductions in the PVE necessitate voxel volume reductions, causing a lower signal-to-noise ratio (SNR). Hence, this work aims to investigate further local homogeneity in task-based fMRI across voxel volumes.