{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T05:04:59Z","timestamp":1790053499580,"version":"4.0.1"},"reference-count":37,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T00:00:00Z","timestamp":1790035200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Parkinson\u2019s disease motor subtypes, tremor-dominant (TD) and postural instability\/gait difficulty (PIGD), differ in disease trajectory and prognosis, yet their classification depends on MDS-UPDRS-based clinical ratings that are susceptible to inter-rater variability and medication state.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>This exploratory study investigated whether T1-weighted and FLAIR MRI radiomics show differential associations with TD and PIGD motor subtypes in Parkinson\u2019s disease, and whether the two sequences contribute complementary subtype-relevant information when combined in a multimodal framework.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Baseline 3\u202fT MRI data from 568 patients with Parkinson\u2019s disease in the PPMI cohort were analyzed (448 TD; 120 PIGD). Radiomics features were extracted from predefined basal ganglia and brainstem regions on T1-weighted and FLAIR images using PyRadiomics. Participants with only T1-weighted or only FLAIR MRI were used as sequence-specific development cohorts; those with both sequences formed a common evaluation cohort. ComBat harmonization was applied within each modality before cohort separation, followed by development-cohort-based feature selection and model fitting. L1-regularized logistic regression models were trained independently for each sequence and evaluated in the common cohort. A stacking model combined T1- and FLAIR-derived probability scores. Model performance was assessed using the area under the precision\u2013recall curve (PR-AUC), balanced accuracy, and F1-score, and Shapley Additive Explanations (SHAP) analysis was used for interpretation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      In the common evaluation cohort (\n                      <jats:italic>n<\/jats:italic>\n                      \u202f=\u202f148; 118 TD, 30 PIGD), the T1-weighted model achieved a PR-AUC of 0.814, balanced accuracy of 0.829, and F1-score of 0.750. The FLAIR model achieved a PR-AUC of 0.858, balanced accuracy of 0.832, and F1-score of 0.650. The stacked model showed higher performance, with a PR-AUC of 0.928, balanced accuracy of 0.912, and F1-score of 0.818. The T1-weighted model showed relatively better TD classification, whereas the FLAIR model showed higher PIGD sensitivity. SHAP analysis showed that T1-weighted contributions were mainly concentrated in the putamen, while FLAIR contributions were more broadly distributed across basal ganglia and brainstem regions.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>T1-weighted and FLAIR MRI radiomics showed distinct subtype-associated error profiles and preliminary evidence of cross-sequence complementarity in this PPMI-based exploratory analysis. These findings require external validation before clinical interpretation, but provide a hypothesis-generating framework for multimodal structural radiomics research in Parkinson\u2019s disease motor subtype characterization.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fneur.2026.1920363","type":"journal-article","created":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T04:24:45Z","timestamp":1790051085000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Exploratory radiomics analysis of T1-weighted and FLAIR MRI in relation to Parkinson\u2019s disease motor subtypes"],"prefix":"10.3389","volume":"17","author":[{"given":"Hyeongjin","family":"Lim","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, Korea University","place":["Seoul, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeongwon","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Korea University","place":["Seoul, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sangyoon","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Korea University","place":["Seoul, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongha","family":"Gi","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Korea University","place":["Seoul, Republic of Korea"]},{"name":"FieldCure Co., Ltd.","place":["Seoul, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seol-Hee","family":"Baek","sequence":"additional","affiliation":[{"name":"Department of Neurology, Korea University Ansan Hospital, Korea University College of Medicine","place":["Ansan, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Byung-Jo","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Neurology, Korea University Anam Hospital, Korea University College of Medicine","place":["Seoul, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Myonggeun","family":"Yoon","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Korea University","place":["Seoul, Republic of Korea"]},{"name":"FieldCure Co., Ltd.","place":["Seoul, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,22]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"1102","DOI":"10.3390\/s18041102","article-title":"Motor subtypes of Parkinson\u2019s disease can be identified by frequency component of postural 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