Neurite Orientation Dispersion and Density Imaging (NODDI) and duration of untreated psychosis in antipsychotic medication-naïve first episode psychosis patients

Neurite Density and Free Water in the Gray and White Matter of Early Psychosis Patients

“…Our lack of findings with ODI and NDI contrasts with previous reports (21,22). Rae et al, in particular, found extensive reductions of NDI which we failed to replicate.…”

Neurite Density and Free Water in the Gray and White Matter of Early Psychosis Patients

“…Our lack of findings with ODI and NDI contrasts with previous reports (21,22). Rae et al, in particular, found extensive reductions of NDI which we failed to replicate.…”

Microstructural Alterations of the Corpus Callosum in Patients with First-Episode Schizophrenia Revealed by NODDI: Dissociation Between Neurite Density and Orientation Dispersion in the Splenium

“…Advanced diffusion models such as NODDI are thought to provide a closer in vivo proxy of neurite density and orientation, complementing structural MRI and synaptic PET markers of reduced synaptic density. In this context, SCC NDI reductions in FES patients are consistent with a neurodevelopmental model, in which aberrant myelination and axonal pruning during adolescence lead to long-lasting dysconnectivity, particularly in large commissural tracts [ 17 , 18 , 31 ].…”

“…In this NODDI study of FES patients, regionally specific microstructural alterations of the corpus callosum (CC) were identified and shown to have distinct relationships with clinical symptoms. At the voxel-wise level, FES patients showed widespread increases in ODI across the genu (GCC), body (BCC), and splenium (SCC), together with a heterogeneous pattern of NDI changes, characterized by reduced NDI in the posterior SCC and increased NDI in portions of the GCC/BCC, consistent with prior NODDI work in antipsychotic-naïve FEP showing decreased ND in commissural/association fibers, with increased ND in projection fibers and largely increased ODI across fiber types [ 17 , 18 ]. ROI analyses confirmed significantly reduced SCC NDI in FES patients, whereas mean SCC ODI did not differ between groups.…”

“…Several methodological aspects strengthen the current findings. First, focusing on first-episode patients reduces confounds of chronicity and long-term antipsychotic exposure and aligns with other early-psychosis NODDI studies that report widespread NDI reductions and ODI increases [ 17 , 18 , 37 ]. Second, we used a multi-shell diffusion acquisition and the original NODDI toolbox, which is recommended for reliable estimation of NDI and ODI, and is consistent with technical recommendations from recent systematic reviews [ 6 , 17 , 19 ].…”

“…First, focusing on first-episode patients reduces confounds of chronicity and long-term antipsychotic exposure and aligns with other early-psychosis NODDI studies that report widespread NDI reductions and ODI increases [ 17 , 18 , 37 ]. Second, we used a multi-shell diffusion acquisition and the original NODDI toolbox, which is recommended for reliable estimation of NDI and ODI, and is consistent with technical recommendations from recent systematic reviews [ 6 , 17 , 19 ]. Third, restricting the analysis to a CC mask and subdividing it into the GCC, BCC, and SCC allowed us to detect regionally specific patterns that may be diluted in whole-brain approaches.…”

Neurite Density and Free Water in the Gray and White Matter of Early Psychosis Patients

“…Our lack of findings with ODI and NDI contrasts with previous reports (21,22). Rae et al, in particular, found extensive reductions of NDI which we failed to replicate.…”

Microstructural Alterations of the Corpus Callosum in Patients with First-Episode Schizophrenia Revealed by NODDI: Dissociation Between Neurite Density and Orientation Dispersion in the Splenium

“…Advanced diffusion models such as NODDI are thought to provide a closer in vivo proxy of neurite density and orientation, complementing structural MRI and synaptic PET markers of reduced synaptic density. In this context, SCC NDI reductions in FES patients are consistent with a neurodevelopmental model, in which aberrant myelination and axonal pruning during adolescence lead to long-lasting dysconnectivity, particularly in large commissural tracts [ 17 , 18 , 31 ].…”

“…In this NODDI study of FES patients, regionally specific microstructural alterations of the corpus callosum (CC) were identified and shown to have distinct relationships with clinical symptoms. At the voxel-wise level, FES patients showed widespread increases in ODI across the genu (GCC), body (BCC), and splenium (SCC), together with a heterogeneous pattern of NDI changes, characterized by reduced NDI in the posterior SCC and increased NDI in portions of the GCC/BCC, consistent with prior NODDI work in antipsychotic-naïve FEP showing decreased ND in commissural/association fibers, with increased ND in projection fibers and largely increased ODI across fiber types [ 17 , 18 ]. ROI analyses confirmed significantly reduced SCC NDI in FES patients, whereas mean SCC ODI did not differ between groups.…”

“…Several methodological aspects strengthen the current findings. First, focusing on first-episode patients reduces confounds of chronicity and long-term antipsychotic exposure and aligns with other early-psychosis NODDI studies that report widespread NDI reductions and ODI increases [ 17 , 18 , 37 ]. Second, we used a multi-shell diffusion acquisition and the original NODDI toolbox, which is recommended for reliable estimation of NDI and ODI, and is consistent with technical recommendations from recent systematic reviews [ 6 , 17 , 19 ].…”

“…First, focusing on first-episode patients reduces confounds of chronicity and long-term antipsychotic exposure and aligns with other early-psychosis NODDI studies that report widespread NDI reductions and ODI increases [ 17 , 18 , 37 ]. Second, we used a multi-shell diffusion acquisition and the original NODDI toolbox, which is recommended for reliable estimation of NDI and ODI, and is consistent with technical recommendations from recent systematic reviews [ 6 , 17 , 19 ]. Third, restricting the analysis to a CC mask and subdividing it into the GCC, BCC, and SCC allowed us to detect regionally specific patterns that may be diluted in whole-brain approaches.…”

Neurite Density and Free Water in the Gray and White Matter of Early Psychosis Patients

“…Our lack of findings with ODI and NDI contrasts with previous reports (21,22). Rae et al, in particular, found extensive reductions of NDI which we failed to replicate.…”

Microstructural Alterations of the Corpus Callosum in Patients with First-Episode Schizophrenia Revealed by NODDI: Dissociation Between Neurite Density and Orientation Dispersion in the Splenium

“…Advanced diffusion models such as NODDI are thought to provide a closer in vivo proxy of neurite density and orientation, complementing structural MRI and synaptic PET markers of reduced synaptic density. In this context, SCC NDI reductions in FES patients are consistent with a neurodevelopmental model, in which aberrant myelination and axonal pruning during adolescence lead to long-lasting dysconnectivity, particularly in large commissural tracts [ 17 , 18 , 31 ].…”

“…In this NODDI study of FES patients, regionally specific microstructural alterations of the corpus callosum (CC) were identified and shown to have distinct relationships with clinical symptoms. At the voxel-wise level, FES patients showed widespread increases in ODI across the genu (GCC), body (BCC), and splenium (SCC), together with a heterogeneous pattern of NDI changes, characterized by reduced NDI in the posterior SCC and increased NDI in portions of the GCC/BCC, consistent with prior NODDI work in antipsychotic-naïve FEP showing decreased ND in commissural/association fibers, with increased ND in projection fibers and largely increased ODI across fiber types [ 17 , 18 ]. ROI analyses confirmed significantly reduced SCC NDI in FES patients, whereas mean SCC ODI did not differ between groups.…”

“…Several methodological aspects strengthen the current findings. First, focusing on first-episode patients reduces confounds of chronicity and long-term antipsychotic exposure and aligns with other early-psychosis NODDI studies that report widespread NDI reductions and ODI increases [ 17 , 18 , 37 ]. Second, we used a multi-shell diffusion acquisition and the original NODDI toolbox, which is recommended for reliable estimation of NDI and ODI, and is consistent with technical recommendations from recent systematic reviews [ 6 , 17 , 19 ].…”

“…First, focusing on first-episode patients reduces confounds of chronicity and long-term antipsychotic exposure and aligns with other early-psychosis NODDI studies that report widespread NDI reductions and ODI increases [ 17 , 18 , 37 ]. Second, we used a multi-shell diffusion acquisition and the original NODDI toolbox, which is recommended for reliable estimation of NDI and ODI, and is consistent with technical recommendations from recent systematic reviews [ 6 , 17 , 19 ]. Third, restricting the analysis to a CC mask and subdividing it into the GCC, BCC, and SCC allowed us to detect regionally specific patterns that may be diluted in whole-brain approaches.…”