{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,14]],"date-time":"2025-12-14T05:16:08Z","timestamp":1765689368810,"version":"3.48.0"},"reference-count":51,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2025,12,12]],"date-time":"2025-12-12T00:00:00Z","timestamp":1765497600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"THERAD\u2014Microwave Theranostics for Alzheimer\u2019s Disease"},{"name":"INSIGHTFOOD\u2014An innovative microwave sensing system for the evaluation and monitoring of food quality and safety","award":["CUP E13C23000180005"],"award-info":[{"award-number":["CUP E13C23000180005"]}]},{"name":"Generalitat de Catalunya and European Regional Development Fund","award":["PDR-2014-2022\/56-30157-2021-2A"],"award-info":[{"award-number":["PDR-2014-2022\/56-30157-2021-2A"]}]},{"name":"Generalitat de Catalunya and European Regional Development Fund","award":["2021 SGR 01415 Q0818003F"],"award-info":[{"award-number":["2021 SGR 01415 Q0818003F"]}]},{"name":"Generalitat de Catalunya and European Regional Development Fund","award":["PLEC2021-007609"],"award-info":[{"award-number":["PLEC2021-007609"]}]},{"name":"Agencia Estatal de lnvestigacion, Spain","award":["CICYT PID2019-107885GBC31"],"award-info":[{"award-number":["CICYT PID2019-107885GBC31"]}]},{"name":"Agencia Estatal de lnvestigacion, Spain","award":["PID2022-136869NB-C3 l"],"award-info":[{"award-number":["PID2022-136869NB-C3 l"]}]},{"name":"Agencia Estatal de lnvestigacion, Spain","award":["PDC2022-133091-IO0"],"award-info":[{"award-number":["PDC2022-133091-IO0"]}]},{"DOI":"10.13039\/100031478","name":"Next Generation EU","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100031478","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Agritech National Research Center","award":["D.D. 1032 17\/06\/2022, CN00000022"],"award-info":[{"award-number":["D.D. 1032 17\/06\/2022, CN00000022"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Parkinson\u2019s disease (PD) is characterized by pathological changes in the substantia nigra, which in its early stages may manifest as structural and functional asymmetries between the two hemispheres. Microwave imaging has recently emerged as a promising non-invasive tool to detect subtle dielectric variations. In the context of Parkinson\u2019s disease, such contrasts are expected to arise from the underlying physiological alterations in brain tissue, although their magnitude has not yet been fully characterized. In this work, we investigate the feasibility of differential microwave imaging, where detection is based on permittivity contrasts, through a controlled phantom study. A simple two-dimensional head phantom was constructed using a 3D-printed cylindrical container filled with water, incorporating a Teflon tube to represent the substantia nigra. The tube was filled with hot water, whose gradual cooling emulated small dielectric changes. Since the dielectric properties of water vary linearly with temperature over 0.5\u20133 GHz, we first validated this dependence through both numerical analysis and experimental measurements. Four antennas were then employed in a differential imaging configuration, with image reconstruction performed via the multi-frequency bi-focusing algorithm. The results show that the system can successfully detect a dielectric contrast corresponding to a temperature variation as small as 0.4 \u00b0C, equivalent to approximately 0.17% in relative permittivity. While the exact dielectric changes associated with PD remain to be determined, these results demonstrate that the proposed approach is sensitive to very small contrasts, supporting the potential of differential microwave imaging as a candidate tool for future investigations into Parkinson\u2019s disease detection.<\/jats:p>","DOI":"10.3390\/s25247562","type":"journal-article","created":{"date-parts":[[2025,12,12]],"date-time":"2025-12-12T15:27:20Z","timestamp":1765553240000},"page":"7562","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Microwave Imaging for Parkinson\u2019s Disease Detection: A Phantom-Based Feasibility Study Using Temperature-Controlled Dielectric Variations"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4043-0182","authenticated-orcid":false,"given":"Leonardo","family":"Cardinali","sequence":"first","affiliation":[{"name":"Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Torino, Italy"},{"name":"Department of Communications and Signal Processing, Universitat Politecnica de Catalunya, 08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0408-9308","authenticated-orcid":false,"given":"David O.","family":"Rodriguez-Duarte","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Torino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4726-5017","authenticated-orcid":false,"given":"Jorge A.","family":"Tob\u00f3n Vasquez","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Torino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0791-9269","authenticated-orcid":false,"given":"Francesca","family":"Vipiana","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Torino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0547-901X","authenticated-orcid":false,"given":"Luis","family":"Jofre-Roca","sequence":"additional","affiliation":[{"name":"Department of Communications and Signal Processing, Universitat Politecnica de Catalunya, 08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"100074","DOI":"10.1016\/j.bionps.2023.100074","article-title":"Biomarkers in Parkinson\u2019s disease: A state of the art review","volume":"9","author":"Yamashita","year":"2023","journal-title":"Biomark. 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