Rafael Oliveira Cavalcante

Fetal thigh volume by 3D sonography using XI VOCAL: reproducibility and reference range for Brazilian healthy fetuses between 20 and 40 weeks

To provide reference values for fetal thigh volume using three‐dimensional (3D) ultrasound and the eXtended Imaging Virtual Organ Computer‐aided AnaLysis (XI VOCAL) method.

Fetal thigh and upper arm volumes by 3D-sonography: comparison between multiplanar and XI VOCAL methods.

Abstract Objective. To compare fetal upper arm and thigh volume measurements acquired by three-dimensional (3D) ultrasound using the multiplanar and the eXtended Imaging Virtual Organ Computer-aided AnaLysis (XI VOCAL) methods with different number of sectional planes. Methods. This study enrolled 40 healthy pregnant women between 20 and 40 weeks of gestation. The volume of fetal limbs was calculated using the multiplanar (with 5.0 mm intervals) and the XI VOCAL (with 5, 10, 15, and 20 slice planes) methods. Comparison between the techniques was made by analysis of variance and Bonferroni statistical tests. Results. Mean fetal upper arm volume measured by the 15 sectional planes XI VOCAL method was lower than the same method using 5 and 10 planes instead (p = 0.025 and 0.039, respectively). Fetal thigh volume showed no statistically significant differences among all studied methods. Conclusion. The XI VOCAL using 15 sectional planes method underestimated the fetal upper arm volume by 5 and 10 planes XI VOCAL techniques.

Assessment of Intracranial Structure Volumes in Fetuses With Growth Restriction by 3-Dimensional Sonography Using the Extended Imaging Virtual Organ Computer-Aided Analysis Method

To assess intracranial structure volumes by 3‐dimensional (3D) sonography in fetuses with growth restriction.

Nomogram of fetal upper arm volume by three-dimensional ultrasound using extended imaging virtual organ computer-aided analysis (XI VOCAL)

Abstract Aim: To define the reference range of the fetal upper arm volume by three-dimensional (3D) ultrasound using the eXtended Imaging Virtual Organ Computer-aided AnaLysis (XI VOCAL) method. Methods: This prospective, cross-sectional study enrolled 425 healthy pregnant women with 20–40 weeks of gestation. The XI VOCAL technique was used for the volumetric calculations, considering 10 sequential sectional plane areas, performed along the axial plan of the fetal upper arm. The proximal and distal epiphyses were the beginning and final reference. Second degree polynomial regression models were created to evaluate the correlation between the volume of the fetal arm and the gestational age (GA), determining the 5th, 10th, 25th, 50th, 75th, 90th and 95th corresponding percentiles. The intraclass correlation coefficient (ICC) was used to evaluate the intra- and interobserver reproducibility. Results: The mean fetal upper arm volume ranged from 4.59±1.18 (3.10–7.40 cm3) to 53.87±10.72 cm3 (40.30–76.60 cm3). The fetal upper arm volume and GA were highly associated (R2=0.913). The intra- and interobserver reproducibility were reliable, with ICC=0.997 (95% CI 0.995–0.999) and 0.996 (95% CI 0.993–0.998), respectively. Conclusion: The reference range for the fetal upper arm volume was determined by 3D-ultrasound using the XI VOCAL method, and was found to be highly reproducible.

Reprodutibilidade do volume de membros fetais pela ultrassonografia tridimensional utilizando o método XI VOCAL

OBJECTIVE: To assess the reproducibility of fetal thigh and upper arm volumes measurement by threedimensional ultrasonography utilizing the eXtended Imaging Virtual Organ Computer-aided AnaLysis (XI VOCAL) method. MATERIALS AND METHODS: This reproducibility study enrolled 43 pregnant women with healthy singleton pregnancies between 20 and 37 gestational weeks. The XI VOCAL 10 planes was the method utilized for volumetric measurement of the fetal limbs. The calculation of the interobserver reproducibility was based on blind volumetric measurements of fetal thighs and upper-arms performed by two observers in 43 fetuses. Intraclass correlation coefficient (ICC), Bland-Altman plots and paired Students t-test (p) were utilized in the statistical analysis. RESULTS: A high interobserver reproducibility was observed. For the upper arm volume ICC was 0.996 (confidence interval [CI] 95%: 0.992; 0.998) and mean difference = 0.13 ± 1.29% (95% limits of agreement: -2.54; +2.54%). For the thigh volume, ICC was 0.997 (CI 95%: 0.995; 0.999) and mean difference = 0.24 ± 7.60% (95% limits of agreement: -7.6; +7.6%). CONCLUSION: Fetal thigh and upper arm volumes measured by three-dimensional ultrasonography with the XI VOCAL method presented a high interobserver reproducibility.

Assessment of modified myocardial performance index in foetuses with growth restriction

AIM To evaluate the modified myocardial performance index (Mod-MPI) in foetuses with growth restriction and compare this index with appropriate for gestational age foetuses. MATERIAL AND METHODS A prospective cross-sectional case-control study was conducted involving 76 singleton foetuses between 24 and 34 weeks of gestation divided into three groups (24 appropriate growth foetuses, 30 foetuses with estimated weight between the 3rd and 10th percentiles and 22 foetuses with estimated weight < 3rd percentile, according to the Hadlock table). The Mod-MPI was obtained in the plane of the four chamber view, and the spectral Doppler sample volume was placed in the lateral wall of the aorta, close to the mitral valve. Doppler of umbilical artery was normal in all cases. Analysis of variance (ANOVA) was used to compare the groups and the intra-class correlation coefficient (ICC) was used to assess intra- and inter-observer reproducibility. RESULTS The mean Mod-MPI in the groups of appropriate for gestational age, estimated weight between the 3rd and 10th percentiles, and estimated weight < 3rd percentile was 0.32 +/- 0.05, 0.35 +/- 0.05 and 0.36 +/- 0.06, respectively; there was no statistical difference between the groups (p = 0.072). There was good intra- and inter-observer reproducibility (ICC = 0.726 and 0.760, respectively). CONCLUSION Mod-MPI was not significantly different between foetuses appropriate for gestational age and those with growth restriction. Mod-MPI proved to be a feasible and reproducible technique.

Fetal thigh and upper-arm volumes by three-dimensional ultrasound to predict low postnatal body mass index

Abstract Objective: To assess the usefulness of estimating fetal upper arm and thigh volumes as predictors of low postnatal body mass index (BMI) using three-dimensional ultrasonography (3DUS) with extended imaging virtual organ computer-aided analysis (XI VOCAL). Methods: This prospective cross-sectional study analyzed 300 singleton pregnancies between 33 and 41 weeks of gestation. The Hadlock 4 formula was used to estimate fetal weight. The XI VOCAL 10 planes method was used to assess fetal upper arm and thigh volumes. After delivery, the newborns’ BMI was evaluated and considered low (≤10th percentile) or normal (>10th percentile). We determined receiver operating characteristics (ROC) curves and respective areas under the curves for the percentiles of fetal weight and fetal thigh and upper arm volumes. Results: Of the 300 newborns, BMI was ≤10th percentile for 21 and >10th percentile for 279 newborns. The area under the ROC curve for fetal weight, obtained using the Hadlock formula, and fetal upper arm and thigh volumes, obtained by 3DUS, were 0.801, 0.930 and 0.924, respectively. We determined the sensitivity and specificity of the three parameters for predicting low postnatal BMI and found values of 85.70% and 65.60%, respectively, for fetal weight, 90.48% and 88.17%, respectively, for fetal thigh volume, and 76.19% and 92.47%, respectively, for fetal upper arm volume. Conclusion: Fetal upper arm and thigh volumes estimated using 3DUS with XI VOCAL were effective predictors of low postnatal BMI.

P16.16: Fetal growth restriction: obstetrics and neonatal outcomes

Results: For renal volumes, a high correlation between 2 and 3D measurements, and between 3D measurements on the left and right side was observed. Bladder volume assessment correlated well between the sono AVC and VOCAL technique. Urine production gradually increased with gestational age with a large interfetal difference late in gestation. Fetal venous and arterial doppler flow measurements in the left and right kidney did not differ significantly; the PSV increases gradually with gestational age. The PI for renal veins remains almost constant. There was a good correlation between renal volume, fetal urine production and PSV of the renal artery. Conclusions: Reference curves for renal volume, fetal urine production and renal Dopplers flow measurements in normal pregnancies are provided. These will serve as potential predictors for renal function in fetuses with renal and urinary tract pathology.

OP17.08: Assessment of fetal brain volume by tridimensional ultrasound in fetal growth restriction

Objectives: Our purpose was to evaluate the brain volume in fetal growth restriction (FGR) by 3D ultrasound (3DUS) and to compare these values with those from adequate for gestational age (AGA) fetuses. Methods: This was a longitudinal prospective study involving 18 pregnancies complicated by FGR (fetal weight < P10), with 9 under the third percentile of weight, 9 between the third and tenth percentile and 10 controls, from 30 to 34 weeks of gestation, all of them with normal umbilical Doppler. The assessments of the fetal brain volume were carried out using XI VOCAL (Virtual Organ Computer-aided AnaLysis) in the biparietal diameter plane. Volumes were estimated and differences between FGR and AGA fetuses were calculated. Results: Brain volumes were satisfactorily obtained in all fetuses. The average brain volume was 224.901 cm3 in < P3 group, 252,698 cm3 in FGR between P3 and P10 and 292,153 cm3 in AGA fetus. The brain volume was significantly smaller in FGR< P3 (P = 0.000547) and in FGR between P3 and P10 (0, 007464) than controls. Comparing the two FGR groups, the volume was significantly smaller in < P3 group (0, 04438). Conclusions: Fetuses with growth restriction have smaller brain volume than AGA fetus even without brain sparring effect. These findings are important since recent studies show that the size of the head circumference is the main risk factor for neurological adverse outcome in fetal growth restriction, associated with psychomotor and cognitive retardation, school delay and behavioral disorders in childhood and adult life.

OP20.09: Reproducibility of fetal upper‐arm and thigh volume by three‐dimensional ultrasonography using XI VOCAL method

Results: Median maternal age was 31.2 ± 5 years, the median gestational age at the time of the first scan was 24.2 ± 5 weeks of gestation (wg). MRI was performed at 25.2 ± 5.2 wg. 10/110 (9.1%) requested further MRI control during the pregnancy (29 ± 3.5 wg). In 81/110 (73.6%) MRI confirmed the US diagnosis, in 25/110 (22.7%) MRI added some details without changing the diagnosis and our obstetric management. In 2/110 (1.8%) cases of monolateral borderline ventriculomegaly, MRI was performed 4–6 weeks later than US and it was discordant from US because of spontaneous resolution of the pathology. MRI and US differed in 2/110 (1.8%), in one case the autopsy confirmed the US diagnosis (partial absence of the skull) and in the other one the MRI specified the arachnoid origin of a cyst. Conclusions: In our experience when using a transabdominal high resolution probe for cerebral malformations, MRI diagnosis is identical to US diagnosis in a large proportion of cases (73.6%) and in 22.7% the MRI added just some details without changing the main diagnosis and the obstetric management. In 1.8% MRI and US, respectively, showed better accuracy, this could be related to the nature of the malformation. Although the transabdominal US with high resolution probe could be appropriate for the study of the fetal cerebral morphology, MRI is useful as second test to confirm such a critical diagnosis.