TY - JOUR
T1 - Left-right difference in fetal liver oxygenation during hypoxia, as estimated by BOLD MRI in a fetal sheep model
AU - Sørensen, Anne Nødgård
AU - Holm, David
AU - Pedersen, Michael
AU - Tietze, Anna
AU - Stausbøl-Grøn, Brian
AU - Duus, Liv
AU - Uldbjerg, Niels
N1 - Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
PY - 2011/12
Y1 - 2011/12
N2 - OBJECTIVE: The purpose of this study was to measure the differences in oxygenation between the left and right side of the fetal liver during varying oxygenation levels. METHODS: Eight ewes carrying singleton fetuses at gestation 125 days (term 145 days) were included in the study. During anesthesia the ewes were ventilated with gas containing different levels of oxygen, thereby subjecting the fetuses to hyperoxia (mean maternal arterial pO2 = 23.2 ± 8.2 kPa (Mean ± SD)) as well as hypoxia (mean maternal arterial pO2 = 7.1 ± 0.5 kPa Mean ± SD)). Changes in oxygenation within the fetal liver were assessed by BOLD (Blood-Oxygen-Level-Dependent) MRI (Magnetic Resonance Imaging). RESULTS: During hyperoxia, there was no difference between the BOLD signal in the left and the right side of the fetal liver, ΔBOLDHyperoxia = -0.9 ± 3.7% (Mean ± SD). During hypoxia, however, the decrease in the BOLD signal was more pronounced in the right side as compared to the left side, thereby creating a significant increase in the left-right difference in the BOLD signal, Δ BOLDHypoxia= 5.2 ± 2.2% (Mean ± SD), (p.0.002, paired t-test). The left-right difference was directly proportional to the degree of hypoxia (R 2 = 0.85, p =0.007). CONCLUSIONS: To our knowledge, this is the first study demonstrating differences in oxygenation between the left and right side of the fetal liver during hypoxia. This left-right difference can be explained by increased ductus venosus shunting. Thus, the BOLD MRI technique is a promising non-invasive tool, which might be useful for the future monitoring of human fetuses. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
AB - OBJECTIVE: The purpose of this study was to measure the differences in oxygenation between the left and right side of the fetal liver during varying oxygenation levels. METHODS: Eight ewes carrying singleton fetuses at gestation 125 days (term 145 days) were included in the study. During anesthesia the ewes were ventilated with gas containing different levels of oxygen, thereby subjecting the fetuses to hyperoxia (mean maternal arterial pO2 = 23.2 ± 8.2 kPa (Mean ± SD)) as well as hypoxia (mean maternal arterial pO2 = 7.1 ± 0.5 kPa Mean ± SD)). Changes in oxygenation within the fetal liver were assessed by BOLD (Blood-Oxygen-Level-Dependent) MRI (Magnetic Resonance Imaging). RESULTS: During hyperoxia, there was no difference between the BOLD signal in the left and the right side of the fetal liver, ΔBOLDHyperoxia = -0.9 ± 3.7% (Mean ± SD). During hypoxia, however, the decrease in the BOLD signal was more pronounced in the right side as compared to the left side, thereby creating a significant increase in the left-right difference in the BOLD signal, Δ BOLDHypoxia= 5.2 ± 2.2% (Mean ± SD), (p.0.002, paired t-test). The left-right difference was directly proportional to the degree of hypoxia (R 2 = 0.85, p =0.007). CONCLUSIONS: To our knowledge, this is the first study demonstrating differences in oxygenation between the left and right side of the fetal liver during hypoxia. This left-right difference can be explained by increased ductus venosus shunting. Thus, the BOLD MRI technique is a promising non-invasive tool, which might be useful for the future monitoring of human fetuses. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
U2 - 10.1002/uog.9044
DO - 10.1002/uog.9044
M3 - Journal article
VL - 38
SP - 665
EP - 672
ER -