Fig 6 - uploaded by Bart De Keersmaecker
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b.-MRI axial view of lobar holoprosencephaly in a fetus of 31 weeks. note the absent septum pellucidum, hypoplastic anterior interhemispheric fissure, non-separation of the frontal lobes, rudimentary developed anterior horns and partial fusion of the basal ganglia.
Source publication
The low prevalence of fetal central nervous system anomalies results in a restricted level of exposure and limited experience for most of the obstetricians involved in prenatal ultrasound. Sonographic guidelines for screening the fetal brain in a systematic way will probably increase the detection rate and enhance a correct referral to a tertiary c...
Citations
... This matches with our study where the most common anomaly was anencephaly, accounting for 20% of cases. But, Keersmaecker et al. (19) and Payam Saadai (20) mismatched with our study, suggested that ventriculomegaly was the most frequent anomaly, accounting for 30%. ...
... For 4th ventricle, the cerebellar peduncles form the lateral walls, while the roof is formed by the medullary velum, the cerebellar nodulus and part of the cerebellar peduncles, the floor is delineated by the surface of the pons and the medullar oblongata. At the end of the first trimester, 4th ventricle and the cisterna magna are visible in CUS (De Keersmaecker et al., 2011). According to our results, it was demonstrated that the dimensions of 4th ventricle showed good to very good increasing tendencies as GA increased (Fig. 9), which is similar to previous findings, and this may be due to the growth of the cerebellum, as the growth of cerebellum correlates with GA (da Graça et al., 2013). ...
To establish an unprovable diagnostic indicative index reference for ultrasound examination of the fetal cerebral ventricles, based on the morphological characteristics throughout fetal nervous system development. Key ultrasonic morphological indicators of fetal ventricular development, which includes frontal horn width (FHW), occipital horn width (OHW), width of 3rd ventricle, cavity of septum pellucidum (CSP), width and length of 4th ventricle and thalamo-occipital distance (TOD) had been measured and analyzed collectively. All data of the indicators was collected on singleton pregnant woman between 16-39 weeks of gestational age (GA), between November 2017 and June 2021 at the Second Hospital of Dalian Medical University. A total of 235 pregnant women were enrolled in the cross section study; another 36 pregnant women voluntarily joined a timeline-tracking follow-up study (cohort study) under the same examining criteria. A decrease of FHW and OHW of the lateral ventricles was observed as GA increased; while dimensional values of TOD, 3rd ventricle, CSP, as well as 4th ventricle increased with GA. Most of these indicators showed an enhanced variation tendency within a certain period of GA. Moreover, values of FHW and TOD showed asymmetry of the two hemispheres within the whole GA. Our findings revealed the morphological regularity of fetal ventricular development, which would instructively enhance the relative clinical ultrasound diagnosis; moreover, TOD also showed regularly changes as GA increased, suggesting that TOD should be considered as an additional routine ultrasonic indicator for fetal ventricular development.
... Considering the spectrum of fetal congenital malformations in late TOPs, our results support previous retrospective studies which confirmed brain malformations being the leading cause for late TOPs in many parts of the world [18][19][20][21][22]. One important reason for this is the late cortical formation and maturation and therefore delayed and progressive development of brain malformations up until the late second and third trimesters [23]. Several studies have already addressed the difficulty of predicting neonatal outcome following live birth of a child with congenital Content courtesy of Springer Nature, terms of use apply. ...
Purpose
To explore whether epidemiological shifts regarding reproduction and pregnancy have influenced the spectrum of indications for late termination of singleton pregnancies (TOP) above 17 weeks of gestation and to evaluate temporal changes in maternal demographics and fetal indications over the last 16 years.
Methods
Retrospective single-center cohort study involving all late TOPs preceded by feticide between 1 January 2004 and 31 December 2019 at a tertiary referral hospital in Austria. Outcome variables were retrieved and a time trend assessed between two 8-year intervals (2004–2011 versus 2012–2019).
Results
Between January 2004 and December 2019, a total of 209 singleton pregnancies (50.7% male; 46.9% female fetuses, 2.4% no disclosed sex) were terminated medically at a median gestational age of 25 ⁺¹ (17 ⁺³ –37 ⁺¹ ) weeks at our institution. Predominant conditions legally justifying the late medical abortion were abnormaltities of the brain/central nervous system ( n = 83; 39.7%), chromosomal aberrations ( n = 33; 15.8%), complex malformations ( n = 31; 4.8%) and abnormaltities of the musculosceletal system including diaphragmatic hernias ( n = 18; 8.6%), as reflected by the ICD-10- categories “C ongenital malformation of the central nervous system” , “ Other congenital malformations ” and “ Chromosomal abnormalities ”. No changes were observed with regards to maternal age (30.1 ± 5.9 vs. 31.0 ± 6.0 years; p = 0.315) nor frequency of assisted reproductive technologies (7.0% vs. 8.5%; p = 0.550). Despite a 2.5-fold increase in incidence of late TOPs, no epidemiological changes in maternal or fetal characteristics were observed over the last 16 years.
Conclusion
Population profile and indications for late TOPs followed by feticide remain unchanged over time.
... Fetal central nervous system (CNS) abnormalities are among the most commonly encountered congenital abnormalities (1). Many different methods can be used to obtain prenatal diagnoses, including ultrasound (US), which is one of the most commonly used methods (2). ...
... Fetal CNS abnormalities are the most commonly detected congenital abnormalities (1). Most fetuses with CNS abnormalities die in utero, some die after birth, and the remainder survive but may encounter psychomotor developmental abnormalities (9,24). ...
Background:
Most fetal abnormalities can be detected on ultrasound, the evaluation of fetal CNS abnormalities can be limited by various factors, including obesity, polyhydramnios, multiple pregnancies, and increased cranial ossification during the third trimester.
Objective:
This study aimed to evaluate the ability to detect fetal central nervous system (CNS) anomalies using in utero magnetic resonance imaging (iuMRI) and ultrasound (US) techniques.
Methods:
This prospective study was approved by the institutional review board (Ref: 2968/QĐ-ĐHYHN dated 11 July 2019), and the requirement to obtain the informed consent of patients was waived. This study included 66 fetuses with diagnosed or suspected CNS abnormalities based on the results of a prenatal screening US performed at the antenatal diagnosis center of the Central Obstetrics and Gynecology Hospital. All pregnant women with a suspected diagnosis of abnormal fetal CNS on US underwent 1.5-Tesla iuMRI within 14 days of the US at Hanoi Medical University Hospital between June 2019 and June 2020. Cohen's kappa coefficient (κ) was used to determine the agreement between US and iuMRI findings.
Results:
A total of 66 pregnant women were examined, including 66 fetuses, for which 79 abnormalities were detected by US and 98 abnormalities were detected by iuMRI. The average gestational age was 29 weeks and 6 days. The comparison of iuMRI and US findings revealed similar diagnoses for 71 abnormalities (67%) and different diagnoses for 35 abnormalities (33%). The level of agreement between US and iuMRI was almost perfect for ventriculomegaly and cystic lesions, with κ values 0.87 and 0.84, respectively. The level of agreement between US and iuMRI was the weakest for hemorrhage, with a κ value 0 (no agreement), and cortical abnormalities, with a κ value of 0.46 (weak agreement).
Conclusion:
The level of agreement between US and iuMRI diagnoses was almost perfect for the detection of ventriculomegaly and was weakest for the detection of hemorrhage and cortical abnormalities, which were abnormalities detected by iuMRI but not by ultrasound.
... These operator-dependent tasks may hamper the precise and early recognition of more subtle changes in cerebral anatomy, which impacts timely and informed decision making on extended genetic testing, amenability to fetal surgery, or termination of the pregnancy. The diagnostic value of volumetric 3D approaches for advanced assessments of the fetal CNS has been demonstrated in the literature [7,29]. With the recent introduction of the intelligent semiautomatic 5DCNS/ 5DCNS+ technology, a 3D volume assessment standardization via workflow-based axial, coronal, and sagittal plane reconstruction has been achieved, contributing to a further reduction of intra-and interobserver variability. ...
Objective
The aim of this study was to evaluate the validity of a semiautomated volumetric approach (5DCNS+) for the detailed assessment of the fetal brain in a clinical setting.Methods
Stored 3D volumes of > 1100 consecutive 2nd and 3rd trimester pregnancies (range 15–36 gestational weeks) were analyzed using a workflow-based volumetric approach 5DCNS+, enabling semiautomated reconstruction of diagnostic planes of the fetal central nervous system (CNS). All 3D data sets were examined for plane accuracy, the need for manual adjustment, and fetal-maternal characteristics affecting successful plane reconstruction. We also examined the potential of these standardized views to give additional information on proper gyration and sulci formation with advancing gestation.ResultsBased on our data, we were able to show that gestational age with an OR of 1.085 (95% CI 1.041–1.132) and maternal BMI with an OR of 1.022 (95% CI 1.041–1.054) only had a slight impact on the number of manual adjustments needed to reconstruct the complete volume, while maternal age and fetal position during acquisition (p = 0.260) did not have a significant effect. For the vast majority (958/1019; 94%) of volumes, using 5DCNS+ resulted in proper reconstruction of all nine diagnostic planes. In less than 1% (89/9171 planes) of volumes, the program failed to give sufficient information. 5DCNS+ was able to show the onset and changing appearance of CNS folding in a detailed and timely manner (lateral/parietooccipital sulcus formation seen in < 65% at 16–17 gestational weeks vs. 94.6% at 19 weeks).Conclusions
The 5DCNS+ method provides a reliable algorithm to produce detailed, 3D volume–based assessments of fetal CNS integrity through a standardized reconstruction of the orthogonal diagnostic planes. The method further gives valid and reproducible information regarding ongoing cortical development retrieved from these volume sets that might aid in earlier in utero recognition of subtle structural CNS anomalies.
... Suspicion of a CNS abnormality requires a multidisciplinary approach that includes imaging by prenatal US and MRI, as well as laboratory and genomics assessments. With the diagnosis of a congenital malformation, decisions are guided by the parent's personal background, education, and culture [7,8]. ...
Background
Foetal MR imaging is widely accepted as an adjunct to foetal ultrasonography; however, there are many controversies regarding its importance and indications. Therefore, this study aimed to evaluate foetuses with different midline cerebral abnormalities, to determine the prevalence of these anomalies, to define the role of foetal MRI, and to compare MRI and ultrasound (US) result with postnatal MRI findings. Seventy-eight pregnant women who had foetuses with CNS abnormalities detected by sonogram were included. Foetuses with midline anomalies were selected and evaluated by anomaly scan foetal US, pre- and postnatal MRI.
Results
Midline brain anomalies were found in 47.4% of foetuses with brain anomalies. Holoprosencephaly was found in 24.3% of midline anomaly foetuses, corpus callosum abnormalities (ACC) were detected in 40.5%, midline intracranial mass lesions in 2.7%, and midline posterior fossa anomalies in 32.4%. An agreement between MRI and US in the main diagnosis was in 56.76% of cases; MRI added information to US findings in 43.2% of cases, and US added information to MRI findings in 8.1% of cases.
Conclusion
In evaluating midline cerebral anomalies, US and MRI are complementary techniques. US is the primary survey, and MRI can add additional information and/or change the main diagnosis.
... Fast forward, current fetal imaging technology has the ability to safely observe through the maternal abdominal wall to directly assess fetal brain growth during pregnancy (13). Clinically, ultrasonography (US) is the primary imaging method for routine evaluation of the fetal brain during pregnancy as it is praised for its accessibility and ease of use (14). However, US image quality may be significantly limited by maternal obesity, oligohydramnios, and the fetal position (13). ...
Following the improvements in the clinical management of patients with congenital heart disease (CHD) and their increased survival, neurodevelopmental outcome has become an emerging priority in pediatric cardiology. Large-scale efforts have been made to protect the brain during the postnatal, surgical, and postoperative period; however, the presence of brain immaturity and injury at birth suggests in utero and peripartum disturbances. Over the past decade, there has been considerable interest and investigations on fetal brain growth in the setting of CHD. Advancements in fetal brain imaging have identified abnormal brain development in fetuses with CHD from the macrostructural (brain volumes and cortical folding) down to the microstructural (biochemistry and water diffusivity) scale, with more severe forms of CHD showing worse disturbances and brain abnormalities starting as early as the first trimester. Anomalies in common genetic developmental pathways and diminished cerebral substrate delivery secondary to altered cardiovascular physiology are the forefront hypotheses, but other factors such as impaired placental function and maternal psychological stress have surfaced as important contributors to fetal brain immaturity in CHD. The characterization and timing of fetal brain disturbances and their associated mechanisms are important steps for determining preventative prenatal interventions, which may provide a stronger foundation for the developing brain during childhood.
... • cranium (BPD, occipito-frontal diameter-OFD, head circumference-HC) The ultrasound detection rate of spina biida is almost 100% thanks to the speciic markers: banana and lemon signs (Figure 2), small posterior fossa, small cerebellum, and ventriculomegaly. Also, there is a V-shaped appearance to the posterior elements of the spine [10,11]. ...
... When present with other anomalies, chromosomal examination is also due. The postnatal management is shunt implantation in most cases [4,5,11]. ...
... Agenesis of the corpus callosum (ACC) (Figure 3) is among the most frequent malformations of the developing brain with an incidence of around 5:1000 [8,11]. Corpus callosum can be visualized at the end of the irst trimester using the Doppler low technic [2]. ...
... Fetal CNS evaluation requires examination in the transthalamic, transcerebellar, and transventricular planes [17]. These planes allow the visualization of skull contour, falx cerebri, cavum septum pellucidum, cerebellum, cisterna magna, thalamus, posterior and lateral horns of the ventricles [6,[18][19][20][21]. At this gestational age, examination of the entire length of the spinal cord may be difficult, depending also on the fetal position, thus the diagnosis of spina bifida aperta is often based on intracranial indirect findings as the fetal head is easier to examine [1,8,16,22]. ...
Open spina bifida, also known as spina bifida aperta is a neural tube defect involving the lack of closure of vertebral arches and associated meninges and/or spinal cord abnormalities.Ultrasound examination is the gold standard for the diagnosis of spina bifida aperta. It represents the main imaging tool used to ascertain this diagnosis early in gestation. Three-dimensional ultrasound is necessary to detect the level and the size of the defect. Magnetic resonance imaging (MRI) represents a more sensitive tool, giving specific information of the defect and associated anomalies, playing an important role in ruling out differential diagnosis. Due to the advent of MRI use, it is possible today to achieve in utero treatment of fetuses with this pathology. The aim of the current review is to provide an update of literature regarding the role of ultrasound and MRI in the prenatal diagnosis of spina bifida aperta.
... Despite an overall low incidence of fetal central nervous system (CNS) abnormalities, CNS malformations remain a very common indication for termination of pregnancy [1,2]. Abnormalities of the fetal cerebrospinal fluid (CSF) spaces are often the first markers of abnormal fetal brain development and are the most common nonspecific findings of prenatal CNS screening [3]. For example, fetal ventriculomegaly may be secondary to obstruction of the CSF spaces, decreased parenchymal volumes due to destructive processes or abnormal parenchymal development due to anomalies in the formation of the CNS, or in neuronal proliferation and migration -all of which could result in abnormal clinical neurodevelopment. ...
Objective:
The objective of this study was to apply quantitative magnetic resonance imaging to characterize absolute cerebrospinal fluid (CSF) development, as well as its relative development to fetal brain parenchyma in the healthy human fetus.
Design:
We created three-dimensional high-resolution reconstructions of the developing brain for healthy fetuses between 18 and 40 weeks' gestation, segmented the parenchymal and CSF spaces, and calculated the volumes for the lateral, third, and fourth ventricles; extra-axial CSF space; and the cerebrum, cerebellum, and brainstem. From these data, we constructed normograms of the resulting volumes according to gestational age and described the relative development of CSF to fetal brain parenchyma.
Results:
Each CSF space demonstrated major increases in volumetric growth during the second half of gestation: third ventricle (23-fold), extra-axial CSF (11-fold), fourth ventricle (8-fold), and lateral ventricle (2-fold). Total CSF volume was related to total brain volume (p < 0.01), as was lateral ventricle to cerebral volume (p < 0.01); however, the fourth ventricle was not related to cerebellar or brainstem volume (p = 0.18-0.19).
Relevance:
Abnormalities of the CSF spaces are the most common anomalies of neurologic development detected on fetal screening using neurosonography. Normative values of absolute CSF volume, as well as relative growth in comparison to intracranial parenchyma, provide valuable insight into normal fetal neurodevelopment. These data may provide important biomarkers of early deviations from normal growth, better distinguish between benign variants and early disease, and serve as reference standards for postnatal growth and development in the premature infant.
