1,720,969 research outputs found
Indications for MRI in fetal isolated mild ventriculomegaly... ‘And then, there were none’
No full textDifferentiating features of posterior fossa at 12–13 weeks' gestation in fetuses with Dandy–Walker malformation and Blake's pouch cyst
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Assessment of fetal optic chiasm: an echoanatomic and reproducibility study
No full textObjectives: Our aims were: (1) to perform an echoanatomic correlation study, in order to confirm that the structure identified as the optic chiasm (OC) on ultrasound (US) is indeed this anatomical structure; (2) to assess and compare the reproducibility of two- (2D) and three-(3D) dimensional US in measurement of the OC in normal fetuses; and (3) to assess whether the spatial orientation of the OC changes with increasing gestational age. Methods: For the echoanatomic study, the OC was studied in a neonatal specimen, deceased at 29 + 4 weeks, by passing a suture around the OC and visualizing the supposed OC structure on US while pulling gently on the suture. The reproducibility study included 39 women with normal pregnancy at 20â33 weeks undergoing routine obstetric US examination. After the routine exam, the OC was visualized on 2D-US, and a 2D image and 3D volume dataset were stored for offline measurement. On the 2D images, the diameters of the OC decussation and the optic tract proximal to the transducer were measured. For the 3D volume dataset, multiplanar image correlation with volume contrast imaging (VCI) was used to measure both these diameters and the chiasmocallosal angle (CCA). Two operators each took two sets of measurements of the diameters on 2D- and 3D-US, and intra- and interoperator variability were analyzed using Cronbach's alpha intraclass correlation coefficient (ICC), while a single operator took two sets of CCA measurements for assessment of intraoperator variability. Differences in CCA with increasing gestational age were also analyzed by regression, and CCA measurements were divided into three groups according to gestational age and their means compared by one-way ANOVA. Results: During the echoanatomic experiment, when the sling suture was pulled, the hyperechoic X-shaped structure just below the circle of Willis identified on 2D-US as the OC was displaced slightly and was eventually cut by the sling, confirming its identity as the OC. Intraoperator variability was low and almost identical for the two operators and the two imaging modalities for measurement of the decussation (ICC for 2D-US: 0.96 vs 0.95; 3D-US: 0.95 vs 0.96), but less so for the optic tract (ICC for 2D-US: 0.95 vs 0.91; 3D-US: 0.94 vs 0.83). Interoperator variability was low for the decussation (2D-US: 0.92; 3D-US: 0.92), but higher for the optic tracts (ICC for 2D-US: 0.80; 3D-US: 0.78). The difference between the mean measurement of the two operators was not statistically significantly different for the decussation, but it was for the optic tracts (P = 0.04). The CCA increased steadily between 20 and 30 gestational weeks and plateaued thereafter, at least until 33 weeks. Conclusions: The hyperechoic structure evident on 2D- and 3D-US, just below the circle of Willis, is indeed the OC. 2D-US is apparently as good as 3D-US for visualization of the OC. However, only measurement of the decussation showed low intra- and interoperator variability, whereas measurement of the optic tract is of questionable variability. As gestation advances between 20 and 30 weeks, the OC becomes more oblique in orientation. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd
Sonographic visualization of <i>in-vivo</i> formation of intervillous (Kline's) hemorrhage
No full textExternal cephalic version for breech presentation at term: an effective procedure to reduce the caesarean section rate
No full textAIM:
Although term breech presentation is a relatively rare condition (3-5% of all births), it continues to be an important indication for caesarean section and has contributed to its increased use. Risk of complications may be increased for both mother and foetus in such a situation. Vaginal delivery of a breech presenting foetus is complex and may involve many difficulties, so today there is a general consensus that planned caesarean section is better than planned vaginal birth for the foetus in breech presentation at term. External cephalic version is one of the most effective procedures in modern obstetrics. It involves the external manipulation of the foetus from the breech into the cephalic presentation. A successful manoeuvre can decrease costs by avoiding operative deliveries and decreasing maternal morbidity. The aim of the present study is to evaluate the effectiveness of this obstetric manoeuvre to increase the proportion of vertex presentation among foetuses that were formerly in the breech position near term, so as to reduce the caesarean section rate. The safety of the version is also showed.
METHODS:
From 1999 to 2002, 89 women with foetal breech presentation underwent external cephalic version at the Department of Obstetrics and Gynaecology of the Brescia University. The gestational age was 36.8+/-0.8 weeks. The following variables have been taken into consideration: breech variety, placental location, foetal back position, parity, amount of amniotic fluid and gestational age. Every attempt was performed with a prior use of an intravenous drip of Ritodrine, and foetal heart rate was monitored continuously with cardiotocogram.
RESULTS:
The success rate of the procedure was 42.7% (n=38). No maternal or foetal complication or side effects occurred, both during and after the manoeuvre, except a transient foetal bradycardia that resolved spontaneously. Only one spontaneous reversion of the foetus occurred before delivery. Of all the women that underwent a successful version, 84.2% (n=32) had a non complicated vaginal delivery. Five women (15.8%) had a caesarean section. There was no significant interaction between the variables assessed.
CONCLUSION:
The external cephalic version is a safe and effective manoeuvre reducing the risks of vaginal breech delivery and the rate of caesarean section
The third ventricle of the human fetal brain: Normative data and pathologic correlation. A 3D transvaginal neurosonography study
Full text linkObjective: The objective of the study are to describe (a) the technical aspects and (b) the anatomical boundaries of the fetal third ventricle (3V) on the midsagittal sonographic view and to assess (c) different biometric parameters in normal and abnormal fetuses and (d) and their reproducibility. Methods: This study included 67 normal and 50 CNS anomalies fetuses which include (1) obstructive severe ventriculomegaly (SVM; atrial width ≥ 15 mm), (2) moderate ventriculomegaly (10-14.9 mm), and (3) corpus callosum agenesis (ACC). All underwent transvaginal 3D neurosonography of the midsagittal view of the 3V. The following parameters were measured: area, perimeter, craniocaudal and anteroposterior (AP) diameters, interthalamic adhesion diameter (ITAD), wedge angle, and the ratio between the last 2 variables (ITAD/WA). Repeatability was also assessed. Results: The ITAD and the ITAD/WA are significantly different between normal fetuses and the SVM (P ≤.001). Interthalamic adhesion diameter of ≤7.1 mm is able to identify SVM with 98.6% accuracy (CI: 0.92-0.99). In ACC cases, the AP diameter is significantly shorter than both normal fetuses and ventriculomegaly. Intraobserver/interobserver reliability was good for most variables. Conclusions: Transvaginal neurosonography enables visualization of the normal and abnormal fetal third ventricle. An ITAD <7.1 identifies aqueductal stenosis as the likely etiology of severe ventriculomegaly with an accuracy of 98.6%
Prenatal Diagnosis of an Uncommon 48,XX,+18+21 Karyotype in a Fetus With Malformations Typical of Both Trisomies
No full textHindbrain morphometry and choroid plexus position in differential diagnosis of posterior fossa cystic malformations
Full text linkObjective: To assess the differential diagnostic significance of a series of quantitative and qualitative variables of the cerebellar vermis in fetuses with posterior fossa cystic malformation, including Dandy–Walker malformation (DWM), vermian hypoplasia (VH) and Blake's pouch cyst (BPC). Methods: This was a retrospective study of confirmed cases of DWM, VH and BPC, diagnosed at the Fetal Medicine and Surgery Unit of the Federico II University between January 2005 and June 2013 or the Fetal Medicine and Surgery Unit of G. Gaslini Hospital between July 2013 and September 2017. All included cases had good-quality three-dimensional (3D) volume datasets of the posterior fossa, acquired by transvaginal ultrasound through the posterior fontanelle. The midsagittal view of the posterior fossa was the reference view for the study. We assessed brainstem–tentorium angle and brainstem–vermis angle (BVA), as well as craniocaudal (CCVD) and anteroposterior (APVD) vermian diameters and vermian area (VA), which were normalized by biparietal diameter (BPD) to take into account gestational age (CCVD/BPD × 100, APVD/BPD × 100 and VA/BPD × 100, respectively). Finally, the position of the fourth ventricular choroid plexus (4VCP) was defined as normal (‘up’) or abnormal (‘down’), relative to the roof/cyst inlet of the fourth ventricle. Results: We analyzed 67 fetuses with posterior fossa malformations (24 cases of DWM, 13 of VH and 30 of BPC). The mean gestational age at diagnosis was 23.6 weeks. Regardless of gestational age, the BVA differed significantly between the three groups, and the VA/BPD was able to differentiate between VH and BPC. In differentiating between VH and BPC, the greatest areas under the receiver–operating characteristics curve were those for VA/BPD ratio. The 4VCP position was down in all cases of DWM and VH, while it was up in all cases of BPC. Conclusions: Our data support the concept that VA/BPD ratio and 4VCP position may be used to differentiate between DWM, VH and BPC in the fetus. In our series, the position of the 4VCP had the highest accuracy, but a larger number of VH cases should be evaluated to confirm that an up position of the 4VCP indicates BPC while a down position indicates DWM or VH. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd
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