{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T04:17:48Z","timestamp":1782188268826,"version":"3.54.5"},"reference-count":42,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2019,11,8]],"date-time":"2019-11-08T00:00:00Z","timestamp":1573171200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000070","name":"National Institute of Biomedical Imaging and Bioengineering","doi-asserted-by":"publisher","award":["R00EB017729-04"],"award-info":[{"award-number":["R00EB017729-04"]}],"id":[{"id":"10.13039\/100000070","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Photoacoustic computed tomography (PACT) has been widely explored for non-ionizing functional and molecular imaging of humans and small animals. In order for light to penetrate deep inside tissue, a bulky and high-cost tunable laser is typically used. Light-emitting diodes (LEDs) have recently emerged as cost-effective and portable alternative illumination sources for photoacoustic imaging. In this study, we have developed a portable, low-cost, five-dimensional (x, y, z, t,     \u03bb )     PACT system using multi-wavelength LED excitation to enable similar functional and molecular imaging capabilities as standard tunable lasers. Four LED arrays and a linear ultrasound transducer detector array are housed in a hollow cylindrical geometry that rotates 360 degrees to allow multiple projections through the subject of interest placed inside the cylinder. The structural, functional, and molecular imaging capabilities of the LED\u2013PACT system are validated using various tissue-mimicking phantom studies. The axial, lateral, and elevational resolutions of the system at 2.3 cm depth are estimated as 0.12 mm, 0.3 mm, and 2.1 mm, respectively. Spectrally unmixed photoacoustic contrasts from tubes filled with oxy- and deoxy-hemoglobin, indocyanine green, methylene blue, and melanin molecules demonstrate the multispectral molecular imaging capabilities of the system. Human-finger-mimicking phantoms made of a bone and blood tubes show structural and functional oxygen saturation imaging capabilities. Together, these results demonstrate the potential of the proposed LED-based, low-cost, portable PACT system for pre-clinical and clinical applications.<\/jats:p>","DOI":"10.3390\/s19224861","type":"journal-article","created":{"date-parts":[[2019,11,8]],"date-time":"2019-11-08T11:30:19Z","timestamp":1573212619000},"page":"4861","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Light-Emitting-Diode-Based Multispectral Photoacoustic Computed Tomography System"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5053-5896","authenticated-orcid":false,"given":"Sumit","family":"Agrawal","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, PA 16802, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher","family":"Fadden","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Pennsylvania State University, University Park, State College, PA 16802, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ajay","family":"Dangi","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, PA 16802, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinyi","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, PA 16802, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hussain","family":"Albahrani","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, PA 16802, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Neilesh","family":"Frings","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, PA 16802, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Heidari Zadi","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, PA 16802, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4010-1047","authenticated-orcid":false,"given":"Sri-Rajasekhar","family":"Kothapalli","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Pennsylvania State University, University Park, State College, PA 16802, USA"},{"name":"Penn State Cancer Institute, Pennsylvania State University, Hershey, PA 17033, USA"},{"name":"Graduate Program in Acoustics, The Pennsylvania State University, University Park, PA 16802, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"602","DOI":"10.1098\/rsfs.2011.0028","article-title":"Biomedical photoacoustic imaging","volume":"1","author":"Beard","year":"2011","journal-title":"Interface Focus"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"803","DOI":"10.1038\/nbt839","article-title":"Noninvasive laser-induced photoacoustic tomography for structural and functional in vivo imaging of the brain","volume":"21","author":"Wang","year":"2003","journal-title":"Nat. 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