Pulmonary thrombi clearly visualized on non-contrast electron density images using dual-source, dual-energy computed tomography: a case report

Pulmonary thrombi clearly visualized on non-contrast electron density images using dual-source, dual-energy computed tomography: a case report | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Pulmonary thrombi clearly visualized on non-contrast electron density images using dual-source, dual-energy computed tomography: a case report Satoshi Okayama, Tomohito Inoue, Satoharu Hattori, Makoto Watanabe This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7237720/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract A 77-year-old man was diagnosed with pulmonary embolism in the central-right and lower-left pulmonary arteries on chest contrast computed tomography (CT) scan at a local hospital, and was referred to our institution. We performed a 1-week follow-up study using dual-source CT (SOMATOM Pro.Pulse; Siemens Healthineers, Germany). Non-contrast-enhanced images were taken using the dual-energy mode, generating images equivalent to 120 kVp (Figure 1A–C); however, we were unable to conclusively identify any thrombi in them. Electron density images were therefore generated and processed using a denoising filter, which facilitated the clear identification of residual thrombi in the right pulmonary artery (Figure 1D–F). Finally, contrast-enhanced CT-angiography images were also acquired in the dual-energy mode, which confirmed the presence of residual thrombi (Figure 1G–I). Lung perfusion maps showed extensive perfusion defects in the right lung (Figure 1J). We therefore decided to continue anticoagulant therapy. To our knowledge, this is the first study to demonstrate that electron density images generated by dual-source CT systems can enhance the visualisation of pulmonary artery thrombi without the need for intravenous iodinated contrast agents, suggesting that the electron density images may be safe alternatives for patients in whom contrast-enhanced CT angiography is contraindicated. thrombus computed tomography dual-source dual-energy electron density Figures Figure 1 Manuscript A 77-year-old man was diagnosed with pulmonary embolism in the central-right and lower-left pulmonary arteries on chest contrast computed tomography (CT) scan at a local hospital, and was referred to our institution. We performed a 1-week follow-up study using dual-source CT (SOMATOM Pro.Pulse; Siemens Healthineers, Germany). Non-contrast-enhanced images were taken using the dual-energy mode, generating images equivalent to 120 kVp (Figure 1A–C); however, we were unable to conclusively identify any thrombi in them. Electron density images were therefore generated and processed using a denoising filter, which facilitated the clear identification of residual thrombi in the right pulmonary artery (Figure 1D–F). Finally, contrast-enhanced CT-angiography images were also acquired in the dual-energy mode, which confirmed the presence of residual thrombi (Figure 1G–I). Lung perfusion maps showed extensive perfusion defects in the right lung (Figure 1J). We therefore decided to continue anticoagulant therapy. To our knowledge, this is the first study to demonstrate that electron density images generated by dual-source CT systems can enhance the visualisation of pulmonary artery thrombi without the need for intravenous iodinated contrast agents, suggesting that the electron density images may be safe alternatives for patients in whom contrast-enhanced CT angiography is contraindicated. Declarations Conflicts of interest: None declared. Consent: Informed consent was obtained from the patient for the submission and publication of the images and associated text. Funding: None declared. Author Contribution Okayama S and Watanabe M wrote the main manuscript text. Inoue T and Hattori S are this patient's primary physician and prepared the figures. All authors reviewed the manuscript. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7237720","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":501472533,"identity":"aca5de22-1b02-4dda-8bb5-ad5645142549","order_by":0,"name":"Satoshi Okayama","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4UlEQVRIiWNgGAWjYDCCA1DagJkZxJSQIVJLAkgLWwJICw8JWhh4DEBMwlr4bh9g/vDzh429OTvP51c3aix4GNgPH92AT4vkuQQ2yZ6EtMSdzbzbrHOOAR3Gk5Z2A58WgzMMbAw8CYcTDA7zbjPOYQNqkeAxI6SF+eOfhMP2Bod5nhnn/CNOC4M00BbGDYd5mB/nthGhRfIMY5u0TFpa4obDbGbMuX0SPGyE/MJ3hvnwxzc2NvYG5w8//pzzrU6On/3wMbxaGBgYG2AsNgkwiV85KmD+QIrqUTAKRsEoGDkAAA1WREw++QD+AAAAAElFTkSuQmCC","orcid":"","institution":"Nara Prefectural Seiwa Medical Center","correspondingAuthor":true,"prefix":"","firstName":"Satoshi","middleName":"","lastName":"Okayama","suffix":""},{"id":501472534,"identity":"2ba3c830-6dca-415d-bd55-215fc90eef2a","order_by":1,"name":"Tomohito Inoue","email":"","orcid":"","institution":"Nara Prefectural Seiwa Medical Center","correspondingAuthor":false,"prefix":"","firstName":"Tomohito","middleName":"","lastName":"Inoue","suffix":""},{"id":501472535,"identity":"49ea0a5f-dbf5-4e36-96ba-ee23d9a50417","order_by":2,"name":"Satoharu Hattori","email":"","orcid":"","institution":"Nara Prefectural Seiwa Medical Center","correspondingAuthor":false,"prefix":"","firstName":"Satoharu","middleName":"","lastName":"Hattori","suffix":""},{"id":501472536,"identity":"833e2f6d-6865-4e15-80f4-5544e7bc3424","order_by":3,"name":"Makoto Watanabe","email":"","orcid":"","institution":"Nara Prefectural Seiwa Medical Center","correspondingAuthor":false,"prefix":"","firstName":"Makoto","middleName":"","lastName":"Watanabe","suffix":""}],"badges":[],"createdAt":"2025-07-29 00:53:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7237720/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7237720/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":89980117,"identity":"50260a89-b97e-420b-8f6c-9bddea385164","added_by":"auto","created_at":"2025-08-27 06:22:09","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":5411310,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version.\u003c/p\u003e","description":"","filename":"FigurePTonnoncontrastEDimages.png","url":"https://assets-eu.researchsquare.com/files/rs-7237720/v1/7e32edf302c46bb4379db3e7.png"},{"id":90718668,"identity":"b6806197-dfc2-4f48-8737-b893679fdd54","added_by":"auto","created_at":"2025-09-06 10:31:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":9174154,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7237720/v1/c7617b21-c755-463a-a25b-7bb4e4534bd7.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Pulmonary thrombi clearly visualized on non-contrast electron density images using dual-source, dual-energy computed tomography: a case report","fulltext":[{"header":"Manuscript","content":"\u003cp\u003eA 77-year-old man was diagnosed with pulmonary embolism in the central-right and lower-left pulmonary arteries on chest contrast computed tomography (CT) scan at a local hospital, and was referred to our institution. 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We therefore decided to continue anticoagulant therapy.\u003c/p\u003e\n\u003cp\u003eTo our knowledge, this is the first study to demonstrate that electron density images generated by dual-source CT systems can enhance the visualisation of pulmonary artery thrombi without the need for intravenous iodinated contrast agents, suggesting that the electron density images may be safe alternatives for patients in whom contrast-enhanced CT angiography is contraindicated.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflicts of interest:\u003c/strong\u003e None declared.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent:\u003c/strong\u003e Informed consent was obtained from the patient for the submission and publication of the images and associated text.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e None declared.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eOkayama S and Watanabe M wrote the main manuscript text. 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