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Early and accurate diagnosis of Covid-19 is crucial in reducing the spread of the disease and its accompanied mortality. Currently, detection by reverse transcriptase-polymerase chain reaction (RT-PCR) is the gold standard of outpatient and inpatient detection of Covid-19. RT-PCR is a rapid method; however, its accuracy in detection is only ~70\u201375%. Another approved strategy is computed tomography (CT) imaging. CT imaging has a much higher sensitivity of ~80\u201398%, but similar accuracy of 70%. To enhance the accuracy of CT imaging detection, we developed an open-source framework, CovidCTNet, composed of a set of deep learning algorithms that accurately differentiates Covid-19 from community-acquired pneumonia (CAP) and other lung diseases. CovidCTNet increases the accuracy of CT imaging detection to 95% compared to radiologists (70%). CovidCTNet is designed to work with heterogeneous and small sample sizes independent of the CT imaging hardware. To facilitate the detection of Covid-19 globally and assist radiologists and physicians in the screening process, we are releasing all algorithms and model parameter details as open-source. Open-source sharing of CovidCTNet enables developers to rapidly improve and optimize services while preserving user privacy and data ownership.<\/jats:p>","DOI":"10.1038\/s41746-021-00399-3","type":"journal-article","created":{"date-parts":[[2021,2,20]],"date-time":"2021-02-20T09:32:45Z","timestamp":1613813565000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":85,"title":["CovidCTNet: an open-source deep learning approach to diagnose covid-19 using small cohort of CT images"],"prefix":"10.1038","volume":"4","author":[{"given":"Tahereh","family":"Javaheri","sequence":"first","affiliation":[]},{"given":"Morteza","family":"Homayounfar","sequence":"additional","affiliation":[]},{"given":"Zohreh","family":"Amoozgar","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1323-8942","authenticated-orcid":false,"given":"Reza","family":"Reiazi","sequence":"additional","affiliation":[]},{"given":"Fatemeh","family":"Homayounieh","sequence":"additional","affiliation":[]},{"given":"Engy","family":"Abbas","sequence":"additional","affiliation":[]},{"given":"Azadeh","family":"Laali","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7462-118X","authenticated-orcid":false,"given":"Amir Reza","family":"Radmard","sequence":"additional","affiliation":[]},{"given":"Mohammad Hadi","family":"Gharib","sequence":"additional","affiliation":[]},{"given":"Seyed Ali Javad","family":"Mousavi","sequence":"additional","affiliation":[]},{"given":"Omid","family":"Ghaemi","sequence":"additional","affiliation":[]},{"given":"Rosa","family":"Babaei","sequence":"additional","affiliation":[]},{"given":"Hadi Karimi","family":"Mobin","sequence":"additional","affiliation":[]},{"given":"Mehdi","family":"Hosseinzadeh","sequence":"additional","affiliation":[]},{"given":"Rana","family":"Jahanban-Esfahlan","sequence":"additional","affiliation":[]},{"given":"Khaled","family":"Seidi","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9938-7476","authenticated-orcid":false,"given":"Mannudeep K.","family":"Kalra","sequence":"additional","affiliation":[]},{"given":"Guanglan","family":"Zhang","sequence":"additional","affiliation":[]},{"given":"L. 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