Double inversion-recovery (DIR) imaging has the potential to improve the detection of subcortical lesions through the use of voxel-based morphometry (VBM) analysis. The aim of this study was to clarify the characteristics of detectable lesions by performing a VBM analysis on DIR images of simulated lesions. Twenty healthy volunteers underwent magnetic resonance imaging using a head three-dimensional DIR sequence. The images were processed using SPM12; then, the selected images with simulated lesions were analyzed via VBM. The VBM results were evaluated using free-response receiver-operating characteristic curves and a receiver-operating characteristic analysis. The sensitivity was 100% (5/5), with 5.6 false-positive objects per case, in simulated lesions with a contrast of 0.6 and a size of 2.4 mm. The sensitivity was 80% (4/5), with 5.4 false-positive objects per case, in simulated lesions with a contrast of 0.5 and a size of 2.4 mm. The mean area under the curve value was increased from 0.783 to 0.883 using VBM, with a statistically significant difference (p < 0.01). The VBM analysis of the DIR images using SPM alone showed the potential to detect subcortical microscopic lesions. Early detection of Alzheimer's disease may be possible by adapting VBM in the clinical setting.
Keywords: DIR; MRI; SPM; VBM.