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

OBJECTIVES: To assess intracranial structure volumes by 3-dimensional (3D) sonography in fetuses with growth restriction. METHODS: We conducted a prospective cross-sectional case-control study involving 59 fetuses with growth restriction (38 fetuses with estimated weight <3rd percentile and 21 fetuses with estimated weight between 3rd and 10th percentiles, according to Hadlock et al [Radiology 1984; 150:535-540]) and 54 controls between 24 and 34 weeks' gestation. The following fetal intracranial structure volumes were assessed: cerebellum, brain, and frontal region. The volume was assessed by 3D sonography using the extended imaging virtual organ computer-aided analysis method with 10 sequential planes. Analysis of variance was used to compare fetal groups. The intraclass correlation coefficient was used to assess intraobserver and interobserver reproducibility. RESULTS: Statistical significance between the brain, frontal region, and cerebellar volumes and a relationship between the frontal region and the brain in fetuses with estimated weights below the 3rd percentile and controls were observed (P < .001; P < .001; and P = .002; and P = .008, respectively). Good intraobserver and interobserver reproducibility was observed for the fetal brain, frontal region, and cerebellar volumes, with intraclass correlation coefficients of 0.998, 0.997, 0.997, 0.999, 0.997, and 0.998, respectively. CONCLUSIONS: The intracranial structure volumes assessed by 3D sonography using the extended imaging virtual organ computer-aided analysis method were reduced in fetuses with growth restriction (estimated weight <3rd percentile).

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

OBJECTIVE: 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. METHODS: This is a cross-sectional study that enrolled 425 healthy pregnant women between the 20(th) and 40(th) weeks of gestation. The XI VOCAL was performed along the axial cross-section in ten sequential areas for the volumetric calculations, having the proximal and distal echogenic diaphysis as references. Second-degree polynomial regression models, with the determination of percentiles, were created to evaluate the relation between the fetal thigh volume and gestational age (GA). Intraoperator and interoperator reproducibility was evaluated using intraclass correlation coefficient. RESULTS: The mean fetal thigh volume varied from 8.00 (3.90-11.90 cm(3) ) to 122.14 cm(3) (105.0-153.50 cm(3) ) at 20 and 40 weeks of gestation, respectively. Fetal thigh volume was strongly correlated with gestational age, and the reference values can be obtained by the following mathematical equation: fetal thigh volume (cm(3) ) = 68.70-7.63 × GA + 0.23 × GA(2) (R(2) = 0.946). The intraoperator and interoperator reproducibility were excellent, with an intraclass correlation coefficient = 1.000 and 0.999, respectively. CONCLUSIONS: The reference range of fetal thigh volume was determined by 3D-ultrasound using the XI VOCAL method.

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

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 cm(3)) to 53.87-10.72 cm(3) (40.30-76.60 cm(3)). The fetal upper arm volume and GA were highly associated (R(2)=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.

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

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.

Reprodutibilidade do volume de membros fetais pela ultrassonografia tridimensional utilizando o método XI VOCAL / Reproducibility of fetal limbs volume by three-dimensional ultrasonography utilizing the XI VOCAL method

OBJETIVO: Avaliar a reprodutibilidade do volume do braço e coxa fetais aferido pela ultrassonografia tridimensional utilizando o método eXtended Imaging Virtual Organ Computer-aided AnaLysis (XI VOCAL). MATERIAIS E MÉTODOS: Realizou-se estudo de reprodutibilidade com 43 fetos normais entre 20 e 37 semanas. Para o cálculo do volume do braço e coxa fetais utilizou-se o método XI VOCAL com delimitação de 10 planos consecutivos. Para o cálculo da variabilidade interobservador, um examinador realizou uma medida do volume do braço e coxa dos 43 fetos, enquanto um segundo examinador, sem o conhecimento prévio dos resultados do primeiro examinador, realizou uma segunda medida dos mesmos volumes. Utilizaram-se, para os cálculos estatísticos, o coeficiente de correlação intraclasse (ricc), gráficos de Bland-Altman e teste t-Student pareado (p). RESULTADOS: Observou-se alta reprodutibilidade interobservador. Para o volume do braço, obtiveram-se ricc = 0,996 (intervalo de confiança [IC] 95 por cento: 0,992; 0,998) e média das diferenças = 0,13 ± 1,29 por cento (95 por cento limites de concordância: -2,54; +2,54 por cento). Para o volume da coxa, obtiveram-se ricc = 0,997 (IC 95 por cento: 0,995; 0,999) e média das diferenças = 0,24 ± 7,60 por cento (95 por cento limites de concordância: -7,6; +7,6 por cento). CONCLUSÃO: O volume do braço e coxa fetais aferido pela ultrassonografia tridimensional utilizando o método XI VOCAL apresentou elevada reprodutibilidade interobservador.

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 Student's 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 percent: 0.992; 0.998) and mean difference = 0.13 ± 1.29 percent (95 percent limits of agreement: -2.54; +2.54 percent). For the thigh volume, ICC was 0.997 (CI 95 percent: 0.995; 0.999) and mean difference = 0.24 ± 7.60 percent (95 percent limits of agreement: -7.6; +7.6 percent). CONCLUSION: Fetal thigh and upper arm volumes measured by three-dimensional ultrasonography with the XI VOCAL method presented a high interobserver reproducibility.