biostudies-literatureUnknown16Bergamino M<h4>Introduction</h4>Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor and non-motor symptoms. Levodopa remains the primary treatment, temporarily restoring dopamine levels and improving motor symptoms. Advanced diffusion MRI techniques, such as free-water corrected diffusion tensor imaging (fw-DTI) and neurite orientation dispersion and density imaging (NODDI), provide insights into PD-related microstructural changes beyond conventional DTI.<h4>Methods</h4>This study investigates white matter alterations in PD using multi-shell fw-DTI and NODDI to compare voxel-wise differences between PD patients both OFF and ON levodopa, with comparison to healthy controls (HC). Effect sizes and receiver operating characteristic (ROC) analyses assessed the discrFrontiers in neurology1605753https://www.ebi.ac.uk/biostudies/studies/S-EPMC12283281biostudies-literatureInvestigating white matter alterations in Parkinson's disease using multi-shell free-water DTI and NODDI: insights into neurodegeneration and levodopa effects.PMC12283281Stokes AMBergamino MShill HAZhu SfalseInvestigating white matter alterations in Parkinson's disease using multi-shell free-water DTI and NODDI: insights into neurodegeneration and levodopa effects.<h4>Introduction</h4>Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor and non-motor symptoms. Levodopa remains the primary treatment, temporarily restoring dopamine levels and improving motor symptoms. Advanced diffusion MRI techniques, such as free-water corrected diffusion tensor imaging (fw-DTI) and neurite orientation dispersion and density imaging (NODDI), provide insights into PD-related microstructural changes beyond conventional DTI.<h4>Methods</h4>This study investigates white matter alterations in PD using multi-shell fw-DTI and NODDI to compare voxel-wise differences between PD patients both OFF and ON levodopa, with comparison to healthy controls (HC). Effect sizes and receiver operating characteristic (ROC) analyses assessed the discr2025-01-01T00:00:00Z20252026-03-16T05:29:36.326Z2025-08-14T03:06:13.019ZS-EPMC122832814070377810.3389/fneur.2025.1605753