{"doi":"10.1002/jmri.29834","title":"Evaluation of Interstitial Fluid Volume and Diffusivity in Patients With Idiopathic Normal Pressure Hydrocephalus Using Spectral Diffusion Analysis","abstract":"<jats:title>ABSTRACT</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Changes in interstitial fluid (ISF) dynamics are potential contributors to idiopathic normal pressure hydrocephalus (iNPH). Spectral diffusion analysis provides surrogate markers for ISF volume (<jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub>) and diffusivity (<jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub>).</jats:p></jats:sec><jats:sec><jats:title>Purpose</jats:title><jats:p>To compare <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> and <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> between patients with iNPH and healthy controls (HCs).</jats:p></jats:sec><jats:sec><jats:title>Study Type</jats:title><jats:p>Retrospective.</jats:p></jats:sec><jats:sec><jats:title>Population</jats:title><jats:p>34 patients with iNPH (24 males, 10 females; 76.9 ± 7.6 years) and 132 HCs (46 males, 86 females; 47.5 ± 16.9 years; three age groups: &lt; 40 years, 40–59 years, and ≥ 60 years).</jats:p></jats:sec><jats:sec><jats:title>Field Strength/Sequence</jats:title><jats:p>3.0 T/Single‐shot spin‐echo echo‐planar imaging.</jats:p></jats:sec><jats:sec><jats:title>Assessment</jats:title><jats:p>\n<jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> and <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> were computed using non‐negative least squares and measured in eight regions, including the centrum semiovale (CSO), frontal white matter (FWM), and lenticular nucleus (LN). The regions of interest of iNPH were categorized as either periventricular hyperintensity (PVH) regions (iNPH<jats:sub>PVH</jats:sub> group) or non‐PVH regions (iNPH group). <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> and <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> were compared among groups, and correlations with age were analyzed.</jats:p></jats:sec><jats:sec><jats:title>Statistical Tests</jats:title><jats:p>Kruskal–Wallis test with Dunn's multiple comparison post hoc test. Spearman correlation coefficient. <jats:italic>p</jats:italic> &lt; 0.05 was considered statistically significant.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>In the CSO, iNPH<jats:sub>PVH</jats:sub> group <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> values (40.3% ± 18.4%) exceeded those of other groups, while <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> values (1.53 ± 0.63 [× 10<jats:sup>−3</jats:sup> mm<jats:sup>2</jats:sup>/s]) were significantly higher than those in younger HCs and the iNPH group. In the FWM, both <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> (53.0% ± 18.9%) and <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> (1.64 ± 0.50 [× 10<jats:sup>−3</jats:sup> mm<jats:sup>2</jats:sup>/s]) were significantly higher in the iNPH<jats:sub>PVH</jats:sub> group than in the other groups. In the LN, <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> correlated positively with age, regardless of the iNPH group's inclusion (without iNPH, <jats:italic>ρ</jats:italic> = 0.2114; with iNPH, <jats:italic>ρ</jats:italic> = 0.3044).</jats:p></jats:sec><jats:sec><jats:title>Data Conclusion</jats:title><jats:p>Spectral diffusion analysis in iNPH demonstrated that ISF volume and diffusivity increased in PVH regions of the CSO and FWM, whereas ISF dynamics outside PVH regions may not differ significantly from those in HCs.</jats:p></jats:sec><jats:sec><jats:title>Evidence Level</jats:title><jats:p>3.</jats:p></jats:sec><jats:sec><jats:title>Technical Efficacy</jats:title><jats:p>Stage 1.</jats:p></jats:sec>","journal":"Journal of Magnetic Resonance Imaging","year":2025,"id":638052,"datarank":0.16479184330021646,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"self_citation_contribution":0.16479184330021646,"citation_network_contribution":0.0,"self_endowment_contribution":0.16479184330021646,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":90041,"name":"Shigeki Yamada","orcid":"0000-0001-7158-5569","position":1,"is_corresponding":false},{"id":1657010,"name":"Tatsuya Oki","orcid":null,"position":2,"is_corresponding":false},{"id":1657011,"name":"Tomohiro Otani","orcid":null,"position":3,"is_corresponding":false},{"id":1657012,"name":"Shinnosuke Hiratsuka","orcid":null,"position":4,"is_corresponding":false},{"id":1520765,"name":"Shigeo Wada","orcid":"0000-0001-8895-2839","position":5,"is_corresponding":false},{"id":1657013,"name":"Mitsuhito Mase","orcid":null,"position":6,"is_corresponding":false},{"id":1094114,"name":"Yoshiyuki Watanabe","orcid":"0000-0001-9037-3596","position":7,"is_corresponding":false},{"id":1657009,"name":"Shota Ishida","orcid":"0000-0002-0728-8057","position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Evaluation of Interstitial Fluid Volume and Diffusivity in Patients With Idiopathic Normal Pressure Hydrocephalus Using Spectral Diffusion Analysis","abstract":"<jats:title>ABSTRACT</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Changes in interstitial fluid (ISF) dynamics are potential contributors to idiopathic normal pressure hydrocephalus (iNPH). Spectral diffusion analysis provides surrogate markers for ISF volume (<jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub>) and diffusivity (<jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub>).</jats:p></jats:sec><jats:sec><jats:title>Purpose</jats:title><jats:p>To compare <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> and <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> between patients with iNPH and healthy controls (HCs).</jats:p></jats:sec><jats:sec><jats:title>Study Type</jats:title><jats:p>Retrospective.</jats:p></jats:sec><jats:sec><jats:title>Population</jats:title><jats:p>34 patients with iNPH (24 males, 10 females; 76.9 ± 7.6 years) and 132 HCs (46 males, 86 females; 47.5 ± 16.9 years; three age groups: &lt; 40 years, 40–59 years, and ≥ 60 years).</jats:p></jats:sec><jats:sec><jats:title>Field Strength/Sequence</jats:title><jats:p>3.0 T/Single‐shot spin‐echo echo‐planar imaging.</jats:p></jats:sec><jats:sec><jats:title>Assessment</jats:title><jats:p>\n<jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> and <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> were computed using non‐negative least squares and measured in eight regions, including the centrum semiovale (CSO), frontal white matter (FWM), and lenticular nucleus (LN). The regions of interest of iNPH were categorized as either periventricular hyperintensity (PVH) regions (iNPH<jats:sub>PVH</jats:sub> group) or non‐PVH regions (iNPH group). <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> and <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> were compared among groups, and correlations with age were analyzed.</jats:p></jats:sec><jats:sec><jats:title>Statistical Tests</jats:title><jats:p>Kruskal–Wallis test with Dunn's multiple comparison post hoc test. Spearman correlation coefficient. <jats:italic>p</jats:italic> &lt; 0.05 was considered statistically significant.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>In the CSO, iNPH<jats:sub>PVH</jats:sub> group <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> values (40.3% ± 18.4%) exceeded those of other groups, while <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> values (1.53 ± 0.63 [× 10<jats:sup>−3</jats:sup> mm<jats:sup>2</jats:sup>/s]) were significantly higher than those in younger HCs and the iNPH group. In the FWM, both <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> (53.0% ± 18.9%) and <jats:italic>D</jats:italic>\n<jats:sub>int</jats:sub> (1.64 ± 0.50 [× 10<jats:sup>−3</jats:sup> mm<jats:sup>2</jats:sup>/s]) were significantly higher in the iNPH<jats:sub>PVH</jats:sub> group than in the other groups. In the LN, <jats:italic>F</jats:italic>\n<jats:sub>int</jats:sub> correlated positively with age, regardless of the iNPH group's inclusion (without iNPH, <jats:italic>ρ</jats:italic> = 0.2114; with iNPH, <jats:italic>ρ</jats:italic> = 0.3044).</jats:p></jats:sec><jats:sec><jats:title>Data Conclusion</jats:title><jats:p>Spectral diffusion analysis in iNPH demonstrated that ISF volume and diffusivity increased in PVH regions of the CSO and FWM, whereas ISF dynamics outside PVH regions may not differ significantly from those in HCs.</jats:p></jats:sec><jats:sec><jats:title>Evidence Level</jats:title><jats:p>3.</jats:p></jats:sec><jats:sec><jats:title>Technical Efficacy</jats:title><jats:p>Stage 1.</jats:p></jats:sec>","is_dataset_classified":null,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"40614019","pmcid":"PMC12435118","openalex_id":"https://openalex.org/W4412019439","authors":[],"funders":[{"funder_name":"JSPS KAKENHI","grant_id":"24K02557","title":null},{"funder_name":"Program for Promoting Researches on the Supercomputer Fugaku","grant_id":"JPMXP1020230118","title":null},{"funder_name":"JSPS KAKENHI","grant_id":"22H00190","title":null},{"funder_name":"JSPS KAKENHI","grant_id":"24K18778","title":null},{"funder_name":"JSPS KAKENHI","grant_id":"21K09098","title":null},{"funder_name":"Outstanding Research Group Support Program in Nagoya City University","grant_id":"2401101","title":null},{"funder_name":"JSPS KAKENHI","grant_id":"22H03020","title":null},{"funder_name":"Fujifilm Corporation","grant_id":"","title":null},{"funder_name":"Fujifilm Corporation","grant_id":"","title":null}],"total_grants":9,"fwci":0.9915,"citation_percentile":0.73482482,"influential_citations":0,"citation_trend":[{"year":2025,"count":1},{"year":2026,"count":1}],"oa_status":"hybrid","license":"cc-by","oa_locations":[{"url":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/jmri.29834","host_type":"journal"},{"url":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/jmri.29834","host_type":"publisher"},{"url":"https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmri.29834","host_type":"publisher"},{"url":"https://doi.org/10.1002/jmri.29834","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/40614019","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/12435118","host_type":"repository"},{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC12435118/","host_type":"repository"},{"url":"https://europepmc.org/articles/PMC12435118","host_type":"Europe_PMC"},{"url":"https://europepmc.org/articles/PMC12435118?pdf=render","host_type":"Europe_PMC"}],"fields_of_study":["Cerebrospinal fluid and hydrocephalus","Fetal and Pediatric Neurological Disorders","Neurological disorders and treatments","Humans","Female","Hydrocephalus, Normal Pressure","Male","Middle Aged","Aged","Extracellular Fluid","Adult","Retrospective Studies","Diffusion Magnetic Resonance Imaging","Aged, 80 and over","Echo-Planar Imaging","Image Processing, Computer-Assisted","White Matter","Brain"],"mesh_terms":["Adult","Aged","Aged, 80 and over","Brain","Female","Humans","Hydrocephalus, Normal Pressure","Image Processing, Computer-Assisted","Male","Middle Aged","Retrospective Studies","Echo-Planar Imaging","Diffusion Magnetic Resonance Imaging","Extracellular Fluid","White Matter"],"keywords":["Medicine","Nuclear medicine","Population","Internal medicine","Gastroenterology","Cardiology","Spectral analysis","Diffusion Imaging","Interstitial Fluid","Idiopathic Normal Pressure Hydrocephalus","Glymphatic System","Hakim Disease"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Good health and well-being"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-06T20:01:27.896201Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}