title: Assessment of flow distribution in the mouse fetal circulation at late gestation by high-frequency Doppler ultrasound.
abstract: This study used high-frequency ultrasound to evaluate the flow distribution in the mouse fetal circulation at late gestation. We studied 12 fetuses (embryonic day 17.5) from 12 pregnant CD1 mice with 40 MHz ultrasound to assess the flow in 11 vessels based on Doppler measurements of blood velocity and M-mode measurements of diameter. Specifically, the intrahepatic umbilical vein (UVIH), ductus venosus (DV), foramen ovale (FO), ascending aorta (AA), main pulmonary artery (MPA), ductus arteriosus (DA), descending thoracic aorta (DTA), common carotid artery (CCA), inferior vena cava (IVC), and right and left superior vena cavae (RSVC, LSVC) were examined, and anatomically confirmed by micro-CT. The mouse fetal circulatory system was found to be similar to that of the humans in terms of the major circuit and three shunts, but characterized by bilateral superior vena cavae and a single umbilical artery. The combined cardiac output (CCO) was 1.22 ± 0.05 ml/min, with the left ventricle (flow in AA) contributing 47.8 ± 2.3% and the right ventricle (flow in MPA) 52.2 ± 2.3%. Relative to the CCO, the flow percentages were 13.6 ± 1.0% for the UVIH, 10.4 ± 1.1% for the DV, 35.6 ± 2.4% for the DA, 41.9 ± 2.6% for the DTA, 3.8 ± 0.3% for the CCA, 29.5 ± 2.2% for the IVC, 12.7 ± 1.0% for the RSVC, and 9.9 ± 0.9% for the LSVC. The calculated flow percentage was 16.6 ± 3.4% for the pulmonary circulation and 31.2 ± 5.3% for the FO. In conclusion, the flow in mouse fetal circulation can be comprehensively evaluated with ultrasound. The baseline data of the flow distribution in normal mouse fetus serve as the reference range for future studies.
authors: Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada; yqzhou@mouseimaging.ca.
authors: Yu-Qing
authors: YQ
authors: Zhou
authors: Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada;
authors: Lindsay S
authors: LS
authors: Cahill
authors: Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
authors: Michael D
authors: MD
authors: Wong
authors: Division of Cardiology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada;
authors: Mike
authors: M
authors: Seed
authors: Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
authors: Christopher K
authors: CK
authors: Macgowan
authors: Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
authors: John G
authors: JG
authors: Sled
mesh_terms: D000818:Animals; D001158:Arteries / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000196:embryology; D001783:Blood Flow Velocity; D005260:Female; D005333:Fetus / Q000098:blood supply*; D005865:Gestational Age; D006801:Humans; D051379:Mice; D008953:Models, Anatomic; D011247:Pregnancy; D018608:Ultrasonography, Doppler / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055114:X-Ray Microtomography
keywords: Doppler ultrasound; fetus; flow distribution; mice