{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T18:17:58Z","timestamp":1785435478130,"version":"3.56.0"},"posted":{"date-parts":[[2026,1,16]]},"group-title":"Neuroscience","reference-count":41,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T00:00:00Z","timestamp":1768521600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"award":["P01NS131131"],"award-info":[{"award-number":["P01NS131131"]}],"id":[{"id":"https:\/\/ror.org\/01s5ya894","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,1,16]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>Cerebrospinal fluid (CSF) circulation is tightly coupled to cerebral blood flow under the fixed-volume constraint of the cranial vault, with cardiac pulsations and respiration acting as dominant physiological drivers. Disruption of these flow dynamics has been implicated in various neurological disorders, motivating the need for imaging methods that capture CSF and vascular flow simultaneously and in real time. Conventional phase contrast MRI (PC-MRI) provides quantitative CSF velocity measurements but relies on cardiac gating and velocity encoding, which limit temporal resolution, dynamic range, and sensitivity to non-cardiac fluctuations. Here, we introduce self-gated ultrafast real-time flow-weighted echo-planar imaging (SURF-EPI), an inflow-weighted approach in which signal intensity reflects the replacement of saturated spins by freshly inflowing, unsaturated water molecules, yielding higher signal with higher flow. This allows simultaneous assessment of arterial inflow, venous outflow, and CSF motion at high temporal resolution. SURF-EPI was acquired at the C2\u2013C3 spinal level, enabling real-time imaging of CSF flow dynamics in the cervical spinal canal alongside arterial and venous blood flow in major cervical vessels (frame-rate: 21.7 Hz). In addition to frequency-domain analyses, we leveraged intrinsic arterial signal fluctuations as a timing reference to reconstruct cardiac-resolved CSF dynamics for individual cardiac cycles without external physiological recordings. Frequency-domain analysis revealed distinct spectral signatures in CSF flow compared with neurovascular flow, including broadened cardiac peaks and enhanced respiratory modulation, particularly within the ventral spinal canal. In contrast, dorsal CSF showed increased power within the cardiac frequency band, higher coherence with cervical vasculature at the cardiac frequency, and reduced non-cardiac contributions. Time-domain analysis showed strong correlation between CSF flow waveforms derived from SURF-EPI and PC-MRI. Beyond ensemble-averaged waveforms, SURF-EPI enabled beat-to-beat analysis, revealing substantial cycle-to-cycle variability in CSF flow that is not captured by time-averaged gated approaches. Together, these findings establish SURF-EPI as a rapid, complementary framework to PC-MRI, enabling real-time neurofluid imaging with integrated time\u2013 and frequency-domain characterization of CSF and neurovascular flow dynamics.<\/jats:p>","DOI":"10.64898\/2026.01.15.699612","type":"posted-content","created":{"date-parts":[[2026,1,17]],"date-time":"2026-01-17T01:00:17Z","timestamp":1768611617000},"source":"Crossref","is-referenced-by-count":0,"title":["Simultaneous Real-time Imaging of Neurofluid and Neurovascular Dynamics Using Ultrafast Flow-weighted Echo-Planar Imaging"],"prefix":"10.64898","author":[{"given":"Amir H.","family":"Shaker","sequence":"first","affiliation":[{"name":"Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO"},{"name":"Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO"},{"name":"Imaging Science Program, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amir H. G.","family":"Arani","sequence":"additional","affiliation":[{"name":"Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO"},{"name":"Imaging Science Program, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bryn A.","family":"Martin","sequence":"additional","affiliation":[{"name":"University of Idaho, Department of Chemical and Biological Engineering, Moscow, ID"},{"name":"Flux Neuroscience, LLC., Troy, ID"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aristeidis","family":"Sotiras","sequence":"additional","affiliation":[{"name":"Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO"},{"name":"Institute for Informatics, Data Science & Biostatistics, Washington University School of Medicine, St. Louis, MO"},{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cihat","family":"Eldeniz","sequence":"additional","affiliation":[{"name":"Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Helia","family":"Hosseini","sequence":"additional","affiliation":[{"name":"Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua S.","family":"Shimony","sequence":"additional","affiliation":[{"name":"Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"suffix":"Jr.","given":"David D.","family":"Limbrick","sequence":"additional","affiliation":[{"name":"Department of Pediatric Neurosurgery, Virginia Commonwealth University, Richmond, VA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer M.","family":"Strahle","sequence":"additional","affiliation":[{"name":"Imaging Science Program, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6983-0641","authenticated-orcid":false,"given":"Arash","family":"Nazeri","sequence":"additional","affiliation":[{"name":"Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO"},{"name":"Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO"},{"name":"Department of Biomedical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026020607323421000_2026.01.15.699612v1.1","doi-asserted-by":"publisher","DOI":"10.1152\/physrev.00031.2020"},{"key":"2026020607323421000_2026.01.15.699612v1.2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-fluid-120720-011638"},{"key":"2026020607323421000_2026.01.15.699612v1.3","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-031-43482-2_1"},{"key":"2026020607323421000_2026.01.15.699612v1.4","first-page":"1","article-title":"Cerebrospinal fluid dynamics and intracranial pressure elevation in neurological diseases","volume":"16","year":"2019","journal-title":"Fluids and Barriers of the CNS"},{"key":"2026020607323421000_2026.01.15.699612v1.5","first-page":"2025","article-title":"Characterizing the spatial patterns and determinants of cerebrospinal fluid pseudorandom flow in the human brain with low b-value diffusion MRI","volume":"3","year":"2025","journal-title":"Imaging Neuroscience"},{"key":"2026020607323421000_2026.01.15.699612v1.6","doi-asserted-by":"publisher","DOI":"10.1016\/J.NEUROIMAGE.2022.119362"},{"key":"2026020607323421000_2026.01.15.699612v1.7","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.3246-14.2015"},{"key":"2026020607323421000_2026.01.15.699612v1.8","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.2754-16.2017"},{"key":"2026020607323421000_2026.01.15.699612v1.9","doi-asserted-by":"publisher","DOI":"10.3174\/ajnr.A4030"},{"key":"2026020607323421000_2026.01.15.699612v1.10","doi-asserted-by":"publisher","DOI":"10.1148\/rg.2020190039"},{"key":"2026020607323421000_2026.01.15.699612v1.11","doi-asserted-by":"publisher","DOI":"10.1002\/jmri.26181"},{"key":"2026020607323421000_2026.01.15.699612v1.12","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2015.07.073"},{"key":"2026020607323421000_2026.01.15.699612v1.13","doi-asserted-by":"publisher","DOI":"10.1002\/jmri.25591"},{"key":"2026020607323421000_2026.01.15.699612v1.14","first-page":"1","article-title":"Validating the accuracy of real-time phase-contrast MRI and quantifying the effects of free breathing on cerebrospinal fluid dynamics","volume":"21","year":"2024","journal-title":"Fluids Barriers CNS"},{"key":"2026020607323421000_2026.01.15.699612v1.15","first-page":"1","article-title":"Cardiovascular magnetic resonance phase contrast imaging","volume":"17","year":"2015","journal-title":"Journal of Cardiovascular Magnetic Resonance"},{"key":"2026020607323421000_2026.01.15.699612v1.16","doi-asserted-by":"publisher","DOI":"10.1126\/science.aax5440"},{"key":"2026020607323421000_2026.01.15.699612v1.17","doi-asserted-by":"publisher","DOI":"10.1002\/nbm.5200"},{"key":"2026020607323421000_2026.01.15.699612v1.18","doi-asserted-by":"publisher","DOI":"10.1162\/imag_a_00078"},{"key":"2026020607323421000_2026.01.15.699612v1.19","doi-asserted-by":"crossref","unstructured":"Ashenagar B , Gomez DEP , Lewis LD . Modeling dynamic inflow effects in fMRI to quantify cerebrospinal fluid flow. Imaging Neuroscience 2025;3.","DOI":"10.1162\/IMAG.a.9"},{"key":"2026020607323421000_2026.01.15.699612v1.20","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pbio.3002035"},{"key":"2026020607323421000_2026.01.15.699612v1.21","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1522-2594(199911)42:5<952::AID-MRM16>3.0.CO;2-S"},{"key":"2026020607323421000_2026.01.15.699612v1.22","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2011.09.015"},{"key":"2026020607323421000_2026.01.15.699612v1.23","doi-asserted-by":"crossref","unstructured":"Egnor, Michael . The Cerebral Windkessel as a Dynamic Pulsation Absorber. BIOcomplexity 2019;2019.","DOI":"10.5048\/BIO-C.2019.3"},{"key":"2026020607323421000_2026.01.15.699612v1.24","doi-asserted-by":"crossref","unstructured":"Wagshul ME , Eide PK , Madsen JR . The pulsating brain: A review of experimental and clinical studies of intracranial pulsatility. Fluids Barriers CNS 2011;8:5.","DOI":"10.1186\/2045-8118-8-5"},{"key":"2026020607323421000_2026.01.15.699612v1.25","doi-asserted-by":"publisher","DOI":"10.3171\/PED\/2008\/2\/7\/083"},{"key":"2026020607323421000_2026.01.15.699612v1.26","doi-asserted-by":"publisher","DOI":"10.1002\/hbm.25547"},{"key":"2026020607323421000_2026.01.15.699612v1.27","doi-asserted-by":"crossref","first-page":"e70092","DOI":"10.1002\/nbm.70092","article-title":"Ultrafast Imaging of Physiological Brain Pulsations With Magnetic Resonance Encephalography\u2014From Noise to Predictive Clinical Biomarker","volume":"38","year":"2025","journal-title":"NMR Biomed"},{"key":"2026020607323421000_2026.01.15.699612v1.28","doi-asserted-by":"publisher","DOI":"10.1113\/JP279458"},{"key":"2026020607323421000_2026.01.15.699612v1.29","doi-asserted-by":"crossref","first-page":"756","DOI":"10.3171\/2019.4.SPINE19404","article-title":"Anatomy of the human spinal cord arachnoid cisterns: applications for spinal cord surgery","volume":"31","year":"2019","journal-title":"J Neurosurg Spine"},{"key":"2026020607323421000_2026.01.15.699612v1.30","doi-asserted-by":"crossref","first-page":"e91888","DOI":"10.1371\/journal.pone.0091888","article-title":"The Impact of Spinal Cord Nerve Roots and Denticulate Ligaments on Cerebrospinal Fluid Dynamics in the Cervical Spine","volume":"9","year":"2014","journal-title":"PLoS One"},{"key":"2026020607323421000_2026.01.15.699612v1.31","doi-asserted-by":"crossref","first-page":"e52284","DOI":"10.1371\/journal.pone.0052284","article-title":"Comparison of 4D Phase-Contrast MRI Flow Measurements to Computational Fluid Dynamics Simulations of Cerebrospinal Fluid Motion in the Cervical Spine","volume":"7","year":"2012","journal-title":"PLoS One"},{"key":"2026020607323421000_2026.01.15.699612v1.32","doi-asserted-by":"publisher","DOI":"10.1186\/2045-8118-10-1"},{"key":"2026020607323421000_2026.01.15.699612v1.33","doi-asserted-by":"publisher","DOI":"10.3174\/ajnr.A3509"},{"key":"2026020607323421000_2026.01.15.699612v1.34","doi-asserted-by":"publisher","DOI":"10.3174\/ajnr.A4629"},{"key":"2026020607323421000_2026.01.15.699612v1.35","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-021-92626-w"},{"key":"2026020607323421000_2026.01.15.699612v1.36","doi-asserted-by":"publisher","DOI":"10.1016\/j.acra.2019.06.015"},{"key":"2026020607323421000_2026.01.15.699612v1.37","doi-asserted-by":"crossref","first-page":"1465","DOI":"10.1007\/s10554-011-9957-4","article-title":"Cardiac magnetic resonance imaging and its electrocardiographs (ECG): Tips and tricks","volume":"28","year":"2012","journal-title":"International Journal of Cardiovascular Imaging"},{"key":"2026020607323421000_2026.01.15.699612v1.38","doi-asserted-by":"publisher","DOI":"10.1002\/jmri.25591"},{"key":"2026020607323421000_2026.01.15.699612v1.39","doi-asserted-by":"crossref","first-page":"703","DOI":"10.1002\/mrm.23273","article-title":"Shared velocity encoding: A method to improve the temporal resolution of phase-contrast velocity measurements","volume":"68","year":"2012","journal-title":"Magn Reson Med"},{"key":"2026020607323421000_2026.01.15.699612v1.40","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.25897"},{"key":"2026020607323421000_2026.01.15.699612v1.41","doi-asserted-by":"publisher","DOI":"10.1002\/nbm.1585"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.01.15.699612","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T15:32:45Z","timestamp":1770391965000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.01.15.699612"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,16]]},"references-count":41,"URL":"https:\/\/doi.org\/10.64898\/2026.01.15.699612","relation":{},"subject":[],"published":{"date-parts":[[2026,1,16]]},"subtype":"preprint"}}