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Objective The aim of this research was to determine the prevalence and sonographic appearance of the hippocampal commissure in fetuses with isolated complete agenesis of the corpus callosum by three-dimensional neurosonography in the multiplanar mode. Methods This was a multicenter observational study. Stored volume datasets of fetuses with isolated complete agenesis of the corpus were retrospectively retrieved for analysis in three tertiary centers. The presence or absence of the hippocampal commissure was independently evaluated in the coronal and midsagittal planes by two operators. Postnatal follow-up was obtained in all cases. Results From November 2007 to February 2013, 41 cases between 19 and 30 weeks of gestation were retrieved for analysis. The hippocampal commissure was visible in the coronal and sagittal planes in 27/41 (65.8%), absent or not clearly recognizable in the remaining 14 cases. The qualitative analysis of the two operators was concordant in 100% of cases. Conclusions In more than half of fetuses with complete callosal agenesis, the hippocampal commissure may be visualized at prenatal ultrasound. This is a residual interhemispheric connection, which in normal cases is hidden by the corpus callosum itself. Further research is needed to establish if this has an impact on postnatal outcome. © 2015 John Wiley & Sons, Ltd.

Objective To perform a sequential analysis of the main cortical fissures in normal fetuses using 3D ultrasound. Methods A cohort of patients with uncomplicated singleton pregnancies underwent three consecutive transabdominal scans at 19–21, 26–28 and 30–34 weeks. Volumes of the fetal head were acquired and searched in the multiplanar mode for the following cortical fissures: sylvian, parieto-occipital, calcarine, hippocampus and cingulate. A qualitative analysis of these sulci was performed in each volume by an experienced operator (A) and a trainee (B). By placing the dot on the sulcus in one plane, it was evaluated whether it was visible also in other planes. Results Fifty patients were included in the study. At 19–21 weeks, the sylvian and parieto-occipital sulci were visualized on at least one plane by both operators in all cases. At 26–28 weeks, all fissures were visualized by both operators on at least one plane, with no significant difference between the performances of the two operators. At 30–34 weeks, a mild overall decline in the accuracy of identification of all the cerebral fissures was observed. Conclusions 3D multiplanar mode allows a systematic evaluation of the cortical fissures in normal fetuses since midtrimester. © 2015 John Wiley & Sons, Ltd.

OBJECTIVE: To perform a sequential analysis of the main cortical fissures in normal fetuses using 3D ultrasound. METHODS: A cohort of patients with uncomplicated singleton pregnancies underwent three consecutive transabdominal scans at 19-21, 26-28 and 30-34 weeks. Volumes of the fetal head were acquired and searched in the multiplanar mode for the following cortical fissures: sylvian, parieto-occipital, calcarine, hippocampus and cingulate. A qualitative analysis of these sulci was performed in each volume by an experienced operator (A) and a trainee (B). By placing the dot on the sulcus in one plane, it was evaluated whether it was visible also in other planes. RESULTS: Fifty patients were included in the study. At 19-21 weeks, the sylvian and parieto-occipital sulci were visualized on at least one plane by both operators in all cases. At 26-28 weeks, all fissures were visualized by both operators on at least one plane, with no significant difference between the performances of the two operators. At 30-34 weeks, a mild overall decline in the accuracy of identification of all the cerebral fissures was observed. CONCLUSIONS: 3D multiplanar mode allows a systematic evaluation of the cortical fissures in normal fetuses since midtrimester.

Objective To standardize the evaluation of normal tentorium insertion and normal rotation of the cerebellar vermis over the brainstem, using two novel measurements: the brainstem–tentorium angle (BT angle) and the brainstem–vermis angle (BV angle). We also aimed to test the reproducibility of these measurements. Methods Prospective observational study including normal fetuses at routine anomaly scan with confirmed normal follow-up. Three-dimensional volumes of the fetal head were acquired starting from standard trans-cerebellar views. In the sagittal plane, obtained by multiplanar reconstruction, the angle between the brainstem and the tentorium insertion in the fetal skull, and between the brainstem and the lower edge of the vermis were measured twice by two independent operators. Intraobserver and interobserver variations were calculated. Results Eighty cases were included. The estimated BT and BV angles lie in a wide interval among normal midtrimester fetuses with a median value (min–max) of 25.65 (20.13–47.39) and 9.29 (3.87–19.36) respectively. Intraobserver and interobserver variation were good for both measurements. Conclusion The BT and BV angle may be of help in assessing the fetal posterior fossa at midgestation and gives a standardized and reproducible measurement of normal tentorium insertion and normal rotation of the cerebellar vermis over the brainstem. © 2012 John Wiley & Sons, Ltd.

Objective The aim of the study was to evaluate the accuracy and reproducibility of fetal crown-rump length (CRL) measurement using three-dimensional ultrasound (3DUS). Methods We included a series of women with singleton pregnancy at 6–13 + 6 weeks. Following CRL measurement by the two-dimensional ultrasound (2DUS), a 3DUS volume was acquired. On the reconstructed midsagittal plane, CRL was measured twice by an operator and once by another. The correlation between CRL measured by 3DUS and 2DUS, as well as the intraobserver and interobserver agreement, was then calculated. Furthermore, the agreement between 2DUS and 3DUS CRL measurements together with intraobserver and interobserver agreement was calculated separately for the groups with a midsagittal acquisition plane (MSAP) and non-midsagittal acquisition plane (NMSAP). Results Overall, 137 pregnancies were included in the analysis. CRL measurements performed using 3DUS showed excellent correlation with 2DUS [intraclass correlation coefficient (ICC) = 0.992]. In addition, the 3DUS showed a high intraobserver and interobserver agreement (ICC = 0.999 and 0.993, respectively). Finally, when we divided the acquired volumes according to the plane of acquisition, excellent 2DUS–3DUS, as well as intraobserver and interobserver agreement, was maintained for both MSAP and NMSAP. Conclusion 3DUS is a highly accurate and reproducible tool for fetal CRL measurement regardless of the fetal position at the time of 3D volume acquisition. © 2012 John Wiley & Sons, Ltd.