P27.05: Quantification of renal vascularity by 3D-power Doppler ultrasonography in normal fetuses (original) (raw)
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Ultrasound in Medicine & Biology, 2003
Renal blood flow is very important to fetal hemodynamics. To assess the development of fetal renal vascularization and blood flow in normal gestation, we measured the fetal renal vascularization and blood flow in healthy fetuses using three-dimensional (3-D) power Doppler sonography and quantitative 3-D power Doppler histogram analysis. This study was undertaken with a prospective, cross-sectional design. In total, 106 healthy singletons with gestational ages between 20 and 40 weeks were included. The 3-D power Doppler sonography and quantitative histogram analyses were used to assess the fetal renal vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) in each case. Our results showed that all the VI, FI and VFI increased significantly with gestational age (GA). Using GA as the independent variable, the linear regression equations for fetal renal VI, FI and VFI were VI = 0.214 x GA - 3.5289 (r = 0.84, n = 106, p < 0.0001); FI = 0.3326 x GA + 35.224 (r = 0.33, n = 106, p < 0.001); and VFI = 0.1047 x GA - 1.8064 (r = 0.82, n = 106, p < 0.0001). Our study indicates that normal fetal renal vasculature and blood flow increase with the advancement of gestational age. In addition to our previous study for fetal renal volume using 3-D sonography, our data in this series may serve as a reference for further studies of fetal renal blood flow in abnormal conditions.
Renal vein Doppler ultrasound of maternal kidneys in normal second and third trimester pregnancy
British Journal of Radiology, 2003
The flow pattern in intrarenal veins depends on renal parenchymal histology and cardiac physiology. The intrarenal venous impedance index obtained by Doppler ultrasound is related to compliance in vein, and can be helpful in the assessment of renal parenchymal compliance. The purpose of this study was to determine whether normal pregnancy has a significant effect on intrarenal venous blood flow, and assess if the physiological pyelocaliectasis causes a measurable reduction in venous impedance indexes in pregnant women. Doppler ultrasound of intrarenal veins was performed in 35 asymptomatic pregnant women in the second and third trimester of gestation, and in 24 non-pregnant healthy women. After grading the degree of hydronephrosis, venous impedance index was obtained from the interlobar veins. The venous waveforms in pregnant women showed diminished phasic oscillations owing to elevated pre-systolic flow. The mean venous impedance indexes in pregnant women were significantly lower than the values in non-pregnant subjects, 0.30¡0.10 versus 0.44¡0.06 in the right (p,0.001), and 0.36¡0.11 versus 0.41¡0.07 in the left kidney (p50.03). There was an inverse correlation between the grade of pelvicalyceal dilatation and the venous impedance indexes in both kidneys in pregnant women (r520.62, p,0.001 for the right kidney, and r520.38, p50.05 for the left kidney). An abnormally reduced venous impedance index in pregnant women can at least in part be explained by reduced vascular compliance from increased interstitial pressure subsequent to partial obstruction of ureters by the gravid uterus, and caution should be exercised in interpreting it as a sign of pathological ureteral obstruction.
Renal volumes measured by 3-dimensional sonography in healthy fetuses from 20 to 40 weeks
Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine, 2013
The purpose of this study was to establish reference values for fetal kidney volumes as a function of gestational age, estimated by 3-dimensional sonography using the Virtual Organ Computer-Aided Analysis (VOCAL) technique (GE Healthcare, Kretztechnik, Zipf, Austria). Volumes of right and left kidneys were assessed in 213 healthy fetuses by 3-dimensional sonography using the VOCAL technique. Inclusion criteria were healthy women with singleton pregnancies, unremarkable comprehensive fetal sonographic findings, well-known gestational age established by first-trimester sonography, and gestational ages between 20 and 40 weeks. Exclusion criteria were patients lost to follow-up and birth weight abnormalities. Each patient was scanned once during pregnancy. Regression analysis was used to calculate unified formulas. The mathematical models calculated in the study were as follows: expected right kidney volume = exp[-1.01 + (0.12 × gestational age)]; and expected left kidney volume = exp[-...
Doppler Study of the Fetal Renal Artery in Oligohydramnios with Post-term Pregnancy
Journal of Medical Ultrasound, 2014
The aim of the study was to investigate the fetal renal artery impedance and hemodynamics in the context of post-term pregnancy with oligohydramnios, using Doppler indices. Methods: This is a prospective study which took place between December 2011 and March 2013. Fetal renal artery Doppler was performed in women at gestational age between 40.1 weeks and 41.3 weeks with singleton pregnancies. The fetal renal artery Doppler resistance index (RI), pulsatility index (PI), systolic/diastolic ratio (S/D), acceleration time (AT), blood flow (BF), fetal renal volume, APGAR, and cesarean ratio were measured. Stepwise logistic regression and the two-tailed t test were used to determine whether the Doppler indices correlated with oligohydramnios (amniotic fluid index < 5 cm). Results: We studied 84 well-dated, singleton, post-term pregnancies, referenced from the high post-term pregnancy obstetric service. Forty-one patients (48.1%) had oligohydramnios. Patients with oligohydramnios had higher S/D, RI, and AT. The fetal renal artery BF (FRABF) was lower in patients with oligohydramnios than those without oligohydramnios (p Z 0.037). Stepwise logistic regression using renal artery Doppler indices found FRABF to be the only significant predictor of oligohydramnios: p Z 0.012, p < 0.005 [odds ratio Z 0.821, 95% confidence interval (CI) Z 0.769e0.912]. Conclusion: In oligohydramnios in the context of post-term pregnancies, there is an increased resistance in the fetal renal vascular bed. The reduced FRABF suggests that increased arterial impedance is an important factor in the development of oligohydramnios. This study supports the idea of increased vascular resistance in the fetal renal bed in patients in post-term Conflicts of interest: All contributing authors declare no conflicts of interest.
Radiologia Brasileira, 2015
Objective: Longitudinal study with B-mode ultrasonography and Doppler ultrasonography of maternal kidneys and liver in low-risk pregnancy, to establish and quantify normality parameters, correlating them with physiological changes. Materials and Methods: Twenty-five pregnant women were assessed and selected to participate in the study, each of them undergoing four examinations at the first, second, third trimesters and postpartum. Results: Findings during pregnancy were the following: increased renal volume, pyelocaliceal dilatation with incidence of 45.4% in the right kidney, and 9% in the left kidney; nephrolithiasis, 18.1% in the right kidney, 13.6% in the left kidney. With pyelocaliceal dilatation, mean values for resistivity index were: 0.68 for renal arteries; 0.66 for segmental arteries; 0.64 for interlobar arteries; 0.64 for arcuate arteries. Without pyelocaliceal dilatation, 0.67 for renal arteries; 0.64 for segmental arteries; 0.63 for interlobar arteries; and 0.61 for arc...
Renal vascularization indexes and fetal hemodynamics in fetuses with growth restriction
Prenatal diagnosis, 2017
To identify the correlation between the renal vascularization index (VI), the flow index (FI) and the vascularization and flow index (VFI) and placental and fetal hemodynamics in fetuses with growth restriction. Bidimensional ultrasound and three-dimensional power Doppler with the VOCAL technique were used to determine the renal vascular indexes and fetal and placental hemodynamics in fetuses below the 10th percentile for fetal weight. Partial correlation analysis (controlled for renal depth and gestational age) was performed. The fetuses were divided into four groups according to their hemodynamic picture, and renal indexes were compared between the groups. Eighty-one fetuses were evaluated. VI, FI and VFI showed negative correlation with the ductus venosus pulsatility index. VI and VFI showed positive correlations with the amniotic fluid index. The group of fetuses with the worst hemodynamic picture (abnormal umbilical artery, middle cerebral artery and ductus venosus pulsatility ...