Pd12-08 a Radiation-Free, Virtual Measurement of Mouse Bladder Blood Flow

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology (PD12)1 May 2024PD12-08 A RADIATION-FREE, VIRTUAL MEASUREMENT OF MOUSE BLADDER BLOOD FLOW Pradeep Tyagi, Anirban Ganguly, Lesley Foley, T. Kevin Hitchens, and Naoki Yoshimura Pradeep TyagiPradeep Tyagi , Anirban GangulyAnirban Ganguly , Lesley FoleyLesley Foley , T. Kevin HitchensT. Kevin Hitchens , and Naoki YoshimuraNaoki Yoshimura View All Author Informationhttps://doi.org/10.1097/01.JU.0001008772.30001.48.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Bladder barrier function is critically dependent on high metabolic rate of mucosa, nourished by a lion's share of bladder perfusion reaching mucosa instead of muscle during storage phase. However, this skewed blood flow to mucosa is not correctly measured by most widely used method of laser Doppler because the readout is sensitive to the variable distance between probe application site and deeper artery from dome to trigone. Past studies validated the principle of deriving blood flow from the relative concentration of fluorescent microspheres in bladder wall and femoral artery of animal sacrificed post-arterial injection of microspheres (PMID: 10992421). Same principle of microspheres infusion assay guides the virtual determination of the relative concentration of injected Gadolinium chelate in bladder wall (BW) and in iliac artery from the ratio of dynamic contrast enhancement (DCE) between bladder wall and iliac artery in DCE-MRI. Hence, we posited that DCE-MRI can generate a virtual readout of bladder blood flow without collecting blood or bladder tissue. METHODS: Under isoflurane anesthesia, three months old male and female C57BL6 mice (n=6) received 0.1 mL tail vein injection of Gadobutrol at dose of 0.1 mmol/kg for T1 weighted DCE-MRI at 7T Bruker BioSpec system with repetition time/echo time of 200/5.23 milliseconds, number of excitations=1, voxel volume of 0.156×0.156×0.8 mm3 and temporal resolution of 6.5-12 s between frames. RESULTS: BW and of internal iliac artery were visible on the same 0.8 mm thick axial slice acquired with a large field of view of 2×2 cm2 and high BW perfusion rate is evident from the equivalence in time to peak (TTP) enhancement of respective time-intensity curves. Tofts modelling of DCE computed that injected Gadobutrol 30 mM gets instantly diluted 15 fold and 75 fold to >2 mM and 0.4 mM in artery and BW, respectively. While >2 mM indexes the arterial input function of internal iliac artery with a reported blood flow rate of ∼2 mL/min (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4348007/), the ratio of 0.4:2 mM indexes that the relative bladder blood flow is 25% of iliac artery, or 0.4 mL/min. CONCLUSIONS: This is a first reliable measurement of mouse bladder perfusion in a radiation-free and non-tissue destructive fashion, a method amenable to repeated measurment on same animal for quantifying the impact of outlet obstruction, infection, or inflammation and treatment on bladder blood flow. Download PPT Source of Funding: Hillman Cancer foundation, P30CA047904 © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e259 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Pradeep Tyagi More articles by this author Anirban Ganguly More articles by this author Lesley Foley More articles by this author T. Kevin Hitchens More articles by this author Naoki Yoshimura More articles by this author Expand All Advertisement PDF downloadLoading ...