{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T05:48:43Z","timestamp":1788414523389,"version":"build-2803163510"},"posted":{"date-parts":[[2026,6,22]]},"group-title":"Radiology and Imaging","reference-count":27,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T00:00:00Z","timestamp":1782086400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.medrxiv.org\/about\/FAQ#license"}],"funder":[{"award":["P30 DA046345"],"award-info":[{"award-number":["P30 DA046345"]}],"id":[{"id":"https:\/\/ror.org\/00fq5cm18","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/100006108","name":"National Center for Advancing Translational Sciences","doi-asserted-by":"crossref","award":["UL1TR001878"],"award-info":[{"award-number":["UL1TR001878"]}],"id":[{"id":"10.13039\/100006108","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,6,22]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>\n                    Mu-opioid receptors (MORs) are expressed throughout the body including in the brain and gastrointestinal (GI) tract. Total-body PET imaging of the brain and GI tract offers a promising approach for cross-sectional\n                    <jats:italic>in vivo<\/jats:italic>\n                    evaluation of the MOR brain-GI axis. However, intestinal motility and bladder filling introduce motion throughout the GI tract over the scan window. Here we establish analysis methodology to account for motion for dynamic imaging of the brain-GI axis, to further characterize peripheral MORs throughout the body and provide a framework for semi-automatic total-body PET modeling.\n                  <\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>\n                    4 subjects underwent 90-min dynamic [\n                    <jats:sup>11<\/jats:sup>\n                    C]-carfentanil (cfn) total-body PET acquisitions at baseline, after intravenous naloxone (central antagonist) administration, and after orally administered loperamide (peripheral agonist and P-glycoprotein substrate). Thalamic MOR availability was measured using the Logan reference tissue model. Using CT-based segmentation, the GI tract was subdivided into anatomical segments, in addition to other peripheral organs (e.g., liver, psoas muscle). Frame-by-frame semi-automatic motion correction was performed with three distinct reference frames (11-14 min post-injection, p.i., 35-40 min p.i., and 85-90 min p.i.). The performance of these three were compared to manual correction. Compartment modeling and Logan graphical analysis were performed to estimate relevant kinetic parameters (K1, VT, VTLogan).\n                  <\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Across the 4 subjects and regions, kinetic parameter estimates were highly correlated (r&gt;0.7) for K1, VT and VT Logan when comparing semi-automatic (reference frame at 35-40 min p.i.) and manual correction. With semi-automatic motion correction, graphical-based estimation of VTLogan in the gastrointestinal tract was significantly decreased with loperamide relative to baseline (p&lt;0.05). As expected, naloxone decreased brain thalamic MOR availability but loperamide did not.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>\n                    With semi-automatic motion correction and [\n                    <jats:sup>11<\/jats:sup>\n                    C]-cfn total-body PET, pharmacologic perturbations of MOR brain-GI axis can be quantitatively characterized, reducing the burden of image analysis for these studies.\n                  <\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.06.17.26355893","type":"posted-content","created":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T16:25:47Z","timestamp":1782145547000},"source":"Crossref","is-referenced-by-count":1,"title":["Brain-gut axis imaging, motion correction with [\n                  <sup>11<\/sup>\n                  C]-carfentanil total-body PET"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2365-0594","authenticated-orcid":false,"given":"Elizabeth J","family":"Li","sequence":"first","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sophie","family":"Lammers","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chia-Ju","family":"Hsieh","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua","family":"Pascale","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joseph","family":"Chang","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erin","family":"Schubert","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hsiaoju","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7645-2869","authenticated-orcid":false,"given":"Robert H.","family":"Mach","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joel S.","family":"Karp","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Corinde","family":"Wiers","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Henry R.","family":"Kranzler","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States"},{"name":"Mental Illness Research, Education and Clinical Center, Crescenz VAMC, Philadelphia, PA 19104, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0732-2374","authenticated-orcid":false,"given":"Jacob","family":"Dubroff","sequence":"additional","affiliation":[{"name":"Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United 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