P01.12: Reference ranges of fetal length and area of corpus callosum by three‐dimensional ultrasonography

Abstract

with abnormal measurements of the fourth ventricle (intracranial translucency -IT) that provided the morphological support to evaluate the efficiency and specificity of posterior brain parameters. Prospectively we evaluated mean values and repeatability of most efficient and specific considered parameters of the posterior brain complex -brain stem diameter (BS), brain stem to occipital bone distance (BSOB) and BS to BSOB ratio were performed in 112 fetuses in 2D before obtaining 3D volumes, used to measure the parameters by the same examiner twice and by another examiner once. Results: Abnormal IT aspects were found in both OSB cases examined in the first trimester, but also in holoprosencephaly and hydrocephalus fetuses. BS and BSOB ratio were found with higher specificity for OSB detection. In the prospective study mean values increased with crown-rump length (CRL) for IT, BS, BSOB and BS to BSOB ratio decreased; the difference between measurements performed by the same sonographer was < 5% in 91% of the cases and between two sonographers < 5% in 88.4% of the paired 3D ultrasound measurements. Conclusions: Preliminary results show that abnormalities in the posterior brain may offer the possibility of first trimester diagnosis of OSB. IT abnormalities should be followed by careful CNS evaluation because false positive aspects of IT are likely to appear in fetuses with other CNS severe anomalies; BS and BSOB ratio ruled out spine anomaly in these cases. Posterior brain measurements are reproducible and the results obtained by 3D and 2D ultrasound are similar. P01.11Correlation of fetal length and area of corpus callosum by 3D sonography with 2D biometric parameters Department of Obstetrics, São Paulo Federal University (UNIFESP), São Paulo, BrazilObjectives: To correlate of fetal length and area of corpus callosum (CC) by three-dimensional (3D) ultrasonography with two-dimensional (2D) biometric parameters. Methods: This cross-sectional study involved 250 normal pregnancies with gestational age between 20 and 33 weeks. An Accuvix XQ equipment (Medison, Seoul, Korea) with a convex volumetric transducer (3-5 MHz) was used. To assess the CC, a transfrontal plane was obtained using the metopic suture as an acoustic window. Length was obtained by measuring the distance between the proximal and distal extremities of the CC. Area was obtained through manual tracing of the external CC surface. Scatter graphs were created to analyze the correlation between CC length and area and biparietal diameter (BPD), abdominal circumference (AC), head circumference (HC) and femur length (FL), the quality adjustments was realized according to the determination coefficient (R2). Results: There was a strong correlation between CC length and area and BPD, AC, HC and FL, with the best model represented by linear equation (R2 = 0. 84, 0.82, 0.86, 0.83, 0.71, 0.68, 0.72 and 0.69, respectively). Conclusions: The fetal CC length and area using transfrontal view by 3D-ultrasonography showed strong correlation with 2D-biometric parameters bet...

Reference Values for the Length and Area of the Fetal Corpus Callosum on 3‐Dimensional Sonography Using the Transfrontal View

“…However, they did not provide reference ranges for the cavum septi pellucidi. In a preliminary study performed previously by our group, which evaluated 70 pregnant women between 20 and 33 weeks, the mean corpus callosum length ranged from 21.7 to 38.7 mm 13 . The results of this study are very similar to those observed in the previous study but with more power.…”

“…All patients agreed to voluntarily participate in the study. Seventy patients were evaluated in our previous study, 13 which showed a strong correlation between corpus callosum measurements and gestational age, motivating our group to continue the study.…”

Reference Ranges for Corpus Callosum and Cavum Septi Pellucidi Biometry on Prenatal Ultrasound: Systematic Review and Meta‐Analysis

“…Of the 32 papers, 6 were excluded from further review. The remaining 26 articles [4][5][6][7][8][9][10][11][12][13]15,17,18,[20][21][22]24,25,27,30,31,33,44,45 were reviewed qualitatively (Tables 1 and 2) and of these, 10 were included for quantitative review. 4,5,7,9,12,15,21,24,30,33 We contacted the corresponding author of all of the articles excluded for quantitative review due to the way in which the data were reported (eg, only graphically or not reported by gestational age); however, only one author sent us data suitable for analysis.…”

“…A large number of published nomograms exist for both CSP and CC biometry on prenatal ultrasound 4–33 . However, many of these studies have small sample sizes, unclear measurement techniques, or unconventional reporting standards.…”

Role of 3-D Ultrasound in Clinical Obstetric Practice: Evolution Over 20 Years

“…3). Visentainer et al (2010) established reference ranges for corpus callosum length and area in fetuses between 20 and 33 wk of gestation using 3-DUS. These authors reported that mean corpus callosum length increased from 21.7 to 38.7 mm between 20 and 33 wk of gestation and that mean corpus callosum area increased from 55.2 to 142.2 mm 2 between 20 and 33 wk of gestation.…”