{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,14]],"date-time":"2026-03-14T05:42:30Z","timestamp":1773466950535,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2022,12,16]],"date-time":"2022-12-16T00:00:00Z","timestamp":1671148800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000062","name":"National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH)","doi-asserted-by":"publisher","award":["R01DK130884"],"award-info":[{"award-number":["R01DK130884"]}],"id":[{"id":"10.13039\/100000062","id-type":"DOI","asserted-by":"publisher"}]},{"name":"American Association for the Study of Liver Diseases","award":["R01DK130884"],"award-info":[{"award-number":["R01DK130884"]}]},{"name":"Regenerative Medicine Minnesota","award":["R01DK130884"],"award-info":[{"award-number":["R01DK130884"]}]},{"name":"Gilead Research Scholar","award":["R01DK130884"],"award-info":[{"award-number":["R01DK130884"]}]},{"name":"GIH Division, Mayo Clinic","award":["R01DK130884"],"award-info":[{"award-number":["R01DK130884"]}]},{"name":"Department of Medicine, Mayo Clinic","award":["R01DK130884"],"award-info":[{"award-number":["R01DK130884"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The search for non-invasive, fast, and low-cost diagnostic tools has gained significant traction among many researchers worldwide. Dielectric properties calculated from microwave signals offer unique insights into biological tissue. Material properties, such as relative permittivity (\u03b5r) and conductivity (\u03c3), can vary significantly between healthy and unhealthy tissue types at a given frequency. Understanding this difference in properties is key for identifying the disease state. The frequency-dependent nature of the dielectric measurements results in large datasets, which can be postprocessed using artificial intelligence (AI) methods. In this work, the dielectric properties of liver tissues in three mouse models of liver disease are characterized using dielectric spectroscopy. The measurements are grouped into four categories based on the diets or disease state of the mice, i.e., healthy mice, mice with non-alcoholic steatohepatitis (NASH) induced by choline-deficient high-fat diet, mice with NASH induced by western diet, and mice with liver fibrosis. Multi-class classification machine learning (ML) models are then explored to differentiate the liver tissue groups based on dielectric measurements. The results show that the support vector machine (SVM) model was able to differentiate the tissue groups with an accuracy up to 90%. This technology pipeline, thus, shows great potential for developing the next generation non-invasive diagnostic tools.<\/jats:p>","DOI":"10.3390\/s22249919","type":"journal-article","created":{"date-parts":[[2022,12,19]],"date-time":"2022-12-19T09:31:01Z","timestamp":1671442261000},"page":"9919","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Machine Learning-Based Classification of Abnormal Liver Tissues Using Relative Permittivity"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0102-4093","authenticated-orcid":false,"given":"Poulami","family":"Samaddar","sequence":"first","affiliation":[{"name":"Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8489-0087","authenticated-orcid":false,"given":"Anup Kumar","family":"Mishra","sequence":"additional","affiliation":[{"name":"GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"}]},{"given":"Sunil","family":"Gaddam","sequence":"additional","affiliation":[{"name":"Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"}]},{"given":"Mansunderbir","family":"Singh","sequence":"additional","affiliation":[{"name":"Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA"}]},{"given":"Vaishnavi K.","family":"Modi","sequence":"additional","affiliation":[{"name":"Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"}]},{"given":"Keerthy","family":"Gopalakrishnan","sequence":"additional","affiliation":[{"name":"Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"}]},{"given":"Rachel L.","family":"Bayer","sequence":"additional","affiliation":[{"name":"Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3907-2872","authenticated-orcid":false,"given":"Ivone Cristina","family":"Igreja Sa","sequence":"additional","affiliation":[{"name":"Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA"},{"name":"Department of Biological and Medical Sciences, Faculty of Pharmacy in Hradec Kr\u00e1lov\u00e9, Charles University, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5697-4061","authenticated-orcid":false,"given":"Shalil","family":"Khanal","sequence":"additional","affiliation":[{"name":"Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA"}]},{"given":"Petra","family":"Hirsova","sequence":"additional","affiliation":[{"name":"Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA"}]},{"given":"Enis","family":"Kostallari","sequence":"additional","affiliation":[{"name":"Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7435-6681","authenticated-orcid":false,"given":"Shuvashis","family":"Dey","sequence":"additional","affiliation":[{"name":"Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"},{"name":"Department of Electrical and Computer Engineering, North Dakota State University, Fargo, ND 58105, USA"}]},{"given":"Dipankar","family":"Mitra","sequence":"additional","affiliation":[{"name":"Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"},{"name":"Department of Computer Science, University of Wisconsin, La Crosse, WI 54601, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1428-8071","authenticated-orcid":false,"given":"Sayan","family":"Roy","sequence":"additional","affiliation":[{"name":"Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"},{"name":"Department of Electrical Engineering and Computer Science, South Dakota Mines, Rapid City, SD 57701, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3251-5415","authenticated-orcid":false,"given":"Shivaram P.","family":"Arunachalam","sequence":"additional","affiliation":[{"name":"Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"},{"name":"GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"},{"name":"Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA"},{"name":"Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2231","DOI":"10.1088\/0031-9155\/41\/11\/001","article-title":"The dielectric properties of biological tissues: I. Literature survey","volume":"41","author":"Gabriel","year":"1996","journal-title":"Phys. Med. Biol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2251","DOI":"10.1088\/0031-9155\/41\/11\/002","article-title":"The dielectric properties of biological tissues: II. Measurements in the frequency range 10 Hz to 20 GHz","volume":"41","author":"Gabriel","year":"1996","journal-title":"Phys. Med. Biol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2271","DOI":"10.1088\/0031-9155\/41\/11\/003","article-title":"The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues","volume":"41","author":"Gabriel","year":"1996","journal-title":"Phys. Med. Biol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s11517-018-1887-z","article-title":"Dielectric properties of bones for the monitoring of osteoporosis","volume":"57","author":"Amin","year":"2018","journal-title":"Med Biol. Eng. Comput."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Di Meo, S., Espin-Lopez, P., Martellosio, A., Pasian, M., Bozzi, M., Perregrini, L., Mazzanti, A., Svelto, F., Summers, P., and Renne, G. (2018, January 9\u201313). Dielectric properties of breast tissues: Experimental results up to 50 GHz. Proceedings of the 12th European Conference on Antennas and Propagation (EuCAP 2018), London, UK.","DOI":"10.1049\/cp.2018.0931"},{"key":"ref_6","unstructured":"Liewei, S., Ward, E.R., and Story, B. (2002, January 5\u20137). A review of dielectric properties of normal and malignant breast tissue. Proceedings of the IEEE SoutheastCon 2002, Columbia, SC, USA."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1109\/10.1374","article-title":"Dielectric properties of breast carcinoma and the surrounding tissues","volume":"35","author":"Surowiec","year":"1988","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"822","DOI":"10.1109\/LMWC.2007.910465","article-title":"Highly Accurate Debye Models for Normal and Malignant Breast Tissue Dielectric Properties at Microwave Frequencies","volume":"17","author":"Lazebnik","year":"2007","journal-title":"IEEE Microw. Wirel. Components Lett."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4707","DOI":"10.1088\/0031-9155\/52\/15\/022","article-title":"Dielectric properties of human normal, malignant and cirrhotic liver tissue: In vivo and ex vivo measurements from 0.5 to 20 GHz using a precision open-ended coaxial probe","volume":"52","author":"Lazebnik","year":"2007","journal-title":"Phys. Med. Biol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3193","DOI":"10.1109\/TMTT.2014.2365019","article-title":"Towards Accurate Dielectric Property Retrieval of Biological Tissues for Blood Glucose Monitoring","volume":"62","author":"Yilmaz","year":"2014","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1109\/TBME.2004.836514","article-title":"Hematocrit measurement by dielectric spectroscopy","volume":"52","author":"Treo","year":"2005","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"103366","DOI":"10.1016\/j.compbiomed.2019.103366","article-title":"Microwave dielectric property based classification of renal calculi: Application of a kNN algorithm","volume":"112","author":"Sacli","year":"2019","journal-title":"Comput. Biol. Med."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Gaddam, S., Samaddar, P., Khan, M., Damani, D., Shivaram, S., Roy, S., Dey, S., Mitra, D., and Arunachalam, S.P. (2022, January 10\u201315). On the Non-invasive Sensing of Arterial Waveform and Hematocrit using Microwaves. Proceedings of the IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (AP-S\/URSI), Denver, CO, USA.","DOI":"10.1109\/AP-S\/USNC-URSI47032.2022.9886974"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"S-1206","DOI":"10.1016\/S0016-5085(22)62442-9","article-title":"Tu1660: The Dielectric Properties of Upper Gastrointestinal Tissue Types\u2014An Ex-Vivo Feasibility Study","volume":"162","author":"Samaddar","year":"2022","journal-title":"Gastroenterology"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Gaddam, S., Samaddar, P., Khan, M., Damani, D., Shivaram, S., Roy, S., Mitra, D., Dey, S., and Arunachalam, S.P. (2022, January 10\u201315). Towards Non-Invasive Mapping of Blood Flow Velocity using Microwaves. Proceedings of the IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (AP-S\/URSI), Denver, CO, USA.","DOI":"10.1109\/AP-S\/USNC-URSI47032.2022.9886579"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/LSENS.2020.2999031","article-title":"Towards a Machine-Learning-Assisted Dielectric Sensing Platform for Point-of-Care Wound Monitoring","volume":"4","author":"Rahmani","year":"2020","journal-title":"IEEE Sens. Lett."},{"key":"ref_17","unstructured":"Helwana, A., Idokob, J.B., and Abiyev, R.H. (2017, January 24\u201325). Machine learning techniques for classification of breast tissue. Proceedings of the 9th International Conference on Theory and Application of Soft Computing, Computing with Words and Perception, ICSCCW 2017 Procedia Computer Science, Budapest, Hungary."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5089","DOI":"10.1088\/0031-9155\/61\/13\/5089","article-title":"Machine learning aided diagnosis of hepatic malignancies through in vivo dielectric measurements with microwaves","volume":"61","author":"Yilmaz","year":"2016","journal-title":"Phys. Med. Biol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"La Gioia, A., Porter, E., Merunka, I., Shahzad, A., Salahuddin, S., Jones, M., and O\u2019Halloran, M. (2018). Open-Ended Coaxial Probe Technique for Dielectric Measurement of Biological Tissues: Challenges and Common Practices. Diagnostics, 8.","DOI":"10.3390\/diagnostics8020040"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Samaddar, P., Gaddam, S., K, P.S., Khan, M., Mitra, D., Leggett, C., Roy, S., and Arunachalam, S.P. (2022, January 10\u201315). On the Effects of the Measured Dielectric Properties at Variable Thickness of Biological Tissue Samples using Open-Ended Coaxial Probe Method. Proceedings of the IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (AP-S\/URSI), Denver, CO, USA.","DOI":"10.1109\/AP-S\/USNC-URSI47032.2022.9886949"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Samaddar, P., Gaddam, S., Khan, M., Roy, S., Mitra, D., and Arunachalam, S.P. (2022, January 10\u201315). On the Dielectric Characterization of Biological Samples for Microwave Imaging Reconstruction. Proceedings of the IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (AP-S\/URSI), Denver, CO, USA.","DOI":"10.1109\/AP-S\/USNC-URSI47032.2022.9887074"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1144","DOI":"10.1016\/j.jhep.2020.04.044","article-title":"Hepatic stellate cell autophagy inhibits extracellular vesicle release to attenuate liver fibrosis","volume":"73","author":"Gao","year":"2020","journal-title":"J. Hepatol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1002\/hep.29803","article-title":"Hepatic stellate cell-derived platelet-derived growth factor receptor-alpha-enriched extracellular vesicles promote liver fibrosis in mice through SHP2","volume":"68","author":"Kostallari","year":"2018","journal-title":"Hepatology"},{"key":"ref_24","first-page":"G234","article-title":"Stiffness is associated with hepatic stellate cell heterogeneity during liver fibrosis","volume":"322","author":"Kostallari","year":"2022","journal-title":"Am. J. Physiol. Liver Physiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"365","DOI":"10.3109\/15368378.2015.1120221","article-title":"Accurate in vivo dielectric properties of liver from 500 MHz to 40 GHz and their correlation to ex vivo measurements","volume":"35","author":"Farrugiaa","year":"2016","journal-title":"Electromagn. Biol. Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2191","DOI":"10.1109\/TDEI.2018.007346","article-title":"Characterization of the dielectric properties of biological tissues and their correlation to tissue hydration","volume":"25","author":"Pollacco","year":"2018","journal-title":"IEEE Trans. Dielectr. Electr. Insul."},{"key":"ref_27","unstructured":"(2022, November 11). N1501A Dielectric Probe Kit, Keysight Technologies. Available online: https:\/\/www.keysight.com\/us\/en\/support\/N1501A\/dielectric-probe-kit.html."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Cavagnaro, M., and Ruvio, G. (2020). Numerical Sensitivity Analysis for Dielectric Characterization of Biological Samples by Open-Ended Probe Technique. Sensors, 20.","DOI":"10.3390\/s20133756"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"3290","DOI":"10.1109\/TDEI.2017.006690","article-title":"Modeling of the Dielectric Properties of Biological Tissues within the Histology Region","volume":"24","author":"Porter","year":"2017","journal-title":"IEEE Trans. Dielectr. Electr. Insul."},{"key":"ref_30","unstructured":"Andreuccetti, D., Fossi, R., and Petrucci, C. (2022, December 01). An Internet Resource for the Calculation of the Dielectric Properties of Body Tissues in the Frequency Range 10 Hz\u2013100 GHz. Available online: http:\/\/niremf.ifac.cnr.it\/tissprop\/."},{"key":"ref_31","first-page":"2825","article-title":"Scikit-learn: Machine Learning in Python","volume":"12","author":"Pedregosa","year":"2011","journal-title":"J. Mach. Learn. Res."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1093\/oxfordjournals.pan.a004868","article-title":"Logistic Regression in Rare Events Data","volume":"9","author":"King","year":"2001","journal-title":"Political Anal."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"20552076211020240","DOI":"10.1177\/20552076211020240","article-title":"Diagnostic digital pathology implementation: Learning from the digital health experience","volume":"7","author":"Betmouni","year":"2021","journal-title":"Digit. Health"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1684","DOI":"10.1016\/j.ajpath.2020.10.018","article-title":"Challenges in the Development, Deployment, and Regulation of Artificial Intelligence in Anatomic Pathology","volume":"191","author":"Cheng","year":"2020","journal-title":"Am. J. Pathol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Gabriel, C., and Peyman, A. (2018). Dielectric Properties of Biological TissuesVariation with Age. Conn\u2019s Handbook of Models for Human Aging, Elsevier. [2nd ed.].","DOI":"10.1016\/B978-0-12-811353-0.00069-5"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"468","DOI":"10.1038\/s41598-019-41124-1","article-title":"Breast cancer cells exhibits specific dielectric signature in vitro using the open-ended coaxial probe technique from 200 MHz to 13.6 GHz","volume":"9","author":"Hussein","year":"2019","journal-title":"Sci. Rep."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/24\/9919\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:42:50Z","timestamp":1760146970000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/24\/9919"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,16]]},"references-count":36,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["s22249919"],"URL":"https:\/\/doi.org\/10.3390\/s22249919","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,16]]}}}