Evaluation of the diffusion time dependence of the IVIM effect based on realistic capillary flow simulations

Evaluation of the diffusion time dependence of the IVIM effect based on realistic capillary flow simulations | 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 Research Article Evaluation of the diffusion time dependence of the IVIM effect based on realistic capillary flow simulations Franciszek Hennel, Manuel Fernández López, Franca Schmid This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8722317/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 The intra-voxel incoherent motion (IVIM) effect is an additional signal attenuation in in-vivo diffusion-weighted MRI due to blood microcirculation. The dependence of this effect on diffusion time is of high interest because it may inform about the architecture of blood vessels in perfusion studies and help optimizing diffusion scans to avoid the IVIM bias. This dependence is derived here using capillary blood trajectories obtained by realistic flow simulations in capillary bed samples of mouse brain cortex derived from two-photon microscopy. Using the gaussian phase approximation, NMR signal attenuation due to IVIM is derived for pulsed-gradient diffusion sequences at different diffusion times and for sequences with flow-compensated gradient shapes by calculating the product of the gradient moment spectra with the spectral density of the simulated blood velocity autocorrelation function. The results suggest that the microcirculation underlying the IVIM effect cannot be faithfully depicted by the commonly used models of diffusive or ballistic flow, but rather as a correlated random motion with a correlation time in the range of 60–120 milliseconds. Consequently, the correlation time appears to be an interesting, MRI-accessible endpoint to characterize microcirculation. Further, the flow compensation as a means of suppressing the IVIM effect in diffusion measurements may not be fully effective. Biophysics Perfusion Diffusion MRI IVIM blood velocity autocorrelation Full Text Additional Declarations The authors declare no competing interests. Supplementary Files ivimsupplementR1.2.docx Evaluation of the diffusion time dependence of the IVIM effect based on realistic capillary flow simulations – SUPPLEMENTARY FILE 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-8722317","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":581891127,"identity":"0456c362-93ef-447e-ac5b-2fcf6e2cede0","order_by":0,"name":"Franciszek 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