Imaging of fetal ventriculomegaly

Diencephalic-mesencephalic junction dysplasia: case report and literature review

Diencephalic-mesencephalic junction (DMJ) dysplasia is a rare congenital brain malformation characterized by a poorly defined junction between the diencephalon and mesencephalon, often associated with a butterfly-like contour of the midbrain on magnetic resonance imaging (MR). We report the case of a newborn female diagnosed prenatally with DMJ dysplasia who presented with severe ventriculomegaly, hydrocephalus, and oligohydramnios. Prenatal MRI at 32 weeks revealed a thickened interthalamic adhesion, an elongated midbrain with ventral cleft, aqueductal stenosis, and corpus callosum dysgenesis. Postnatal MRI confirmed these findings, along with the characteristic "butterfly" midbrain morphology. Genetic analysis revealed a pathogenic 11.9 Mb terminal deletion in the 6q25.3q27 region, encompassing candidate neurodevelopmental genes, such as DLL1, and a 3.8 Mb partial duplication in 22q13.31q13.33, of unknown significance. Parental genetic testing revealed a maternal balanced reciprocal translocation between chromosomes 6 and 22 (asymptomatic carrier), which was inherited in an unbalanced form by the proband. A ventriculoperitoneal shunt was placed within the first 48 h of life to manage hydrocephalus, with subsequent adjustments and revisions as needed. This case highlights the importance of advanced prenatal imaging and genetic testing in the diagnosis of complex brain malformations as well as the need for multidisciplinary management of rare congenital anomalies. Further research is essential to elucidate the underlying genetic mechanisms and improve the outcomes in patients with DMJ dysplasia.

Anatomic Approach to Fetal Hydrocephalus

Hydrocephalus is an imprecise term and refers to the imbalance of brain parenchyma and cerebral spinal fluid in the cranial vault. Ventriculomegaly, or enlargement of the ventricular system, is often the more precise term and is therefore preferred. Appropriate imaging and measurement techniques are critical to detect ventriculomegaly and grade its severity. There is a broad differential diagnosis with resultant highly variable clinical outcomes. Furthermore, some causes have a substantial recurrence risk in future pregnancies. Therefore, accurate diagnosis of the underlying cause is essential for pregnancy management and patient counseling. Understanding ventricular anatomy and correct measurement technique is needed for assessing and grading ventriculomegaly. This is achieved through an anatomically based approach to reach the differential diagnosis, with a focus on key decision points for delineating causes of ventriculomegaly. In particular, the posterior fossa is first assessed for structural or developmental abnormalities; then, midline brain development abnormalities and associated pathologic conditions are reviewed; and last, the cortical mantle is assessed for developmental or destructive processes. In each category, different entities are highlighted, with a particular focus on illustrating the US and MRI findings of the underlying condition and tips to differentiate similar-appearing entities. Ultimately, the informed fetal radiologist can use the proposed algorithmic approach to hydrocephalus to narrow the differential and thus provide vital diagnostic information for pregnancy counseling and management discussions. ©RSNA, 2025.

Current Diagnostic, Counseling, and Treatment Options in Non-Severe and Severe Apparently Isolated Fetal Ventriculomegaly

The widening of the vestibular dimension of lateral ventricles > 10 mm should be considered a symptom rather than a definitive diagnosis. In fact, fetal ventriculomegaly (VM) is a defect with 'multifaceted' clinical consequences in the child's further neurodevelopment. Isolated fetal ventriculomegaly can cause neurological defects ranging from mild neurodevelopmental delay to severe complications in the form of ongoing palliative care to the death of patients at various developmental periods. The spectrum of compilations often depends on the severity of the ventriculomegaly. In the prenatal period, the combined diagnostic tools include the following: ultrasound/MRI and genetic, infectious tests that form the basis of reliable counseling. We hypothesize that advances in the diagnostic process allow the identification of 'probably' isolated forms of severe VM (ISVM). The review authors electronically searched MEDLINE, EMBASE, and the Cochrane Library databases, describing the evidence-based validity and option of prenatal decompression for ISVM. The purpose of this review is to present the evolution of diagnostic techniques and views indicating the possibility and limitations of implementing prenatal decompression in severe ISVM. In conclusion, after reviewing the available data, we want to introduce the idea that perinatal centers are close to or have reached the necessary capability, expertise, and competence to perform ISVM decompression procedures. Endoscopic ventriculostomy of the third ventricle (ETV) appears to be promising, as it seems to be associated with minimal perinatal complications and better neurological outcomes for the newborn. However, long-term follow-up results for the neurodevelopment of patients who underwent ETV have not been reported. Looking ahead, randomized trials with the long-term neurodevelopmental follow-up of children who underwent prenatal decompression due to ISVM are needed.

Clinical characteristics and perinatal outcome of fetuses with ventriculomegaly

PURPOSE

To assess the incidence of associated structural anomalies, chromosomal/genetic abnormalities, infections, and perinatal outcomes of fetuses with ventriculomegaly (VM), also to evaluate the role of fetal magnetic resonance imaging (MRI) in detecting associated intracranial anomalies.

METHODS

Retrospective cohort study of 149 prenatally diagnosed pregnancies with fetal VM. VM was classified as mild (Vp = 10-12 mm), moderate (Vp = 12.1-15 mm), and severe (Vp > 15 mm). Fetal MRI was performed to 97 pregnancies.

RESULTS

The incidences of an associated CNS, non-CNS, chromosomal anomaly, genetic abnormality and fetal infection were 42.3%, 11.4%, 6.1%, 2.1% and 1.3%, respectively. Fetal MRI identified additional CNS anomalies in 6.7% of cases, particularly in severe VM. The incidences of perinatal outcomes were 18.8% termination of pregnancy, 4% intrauterine and 8.1% neonatal or infant death. The rates of fetuses alive at > 12 months of age with neurological morbidity were 2.6%, 11.1% and 76.9% for mild, moderate and severe isolated VM, respectively.

CONCLUSION

The prognosis of fetuses with VM mostly depends on the severity and the associated anomalies. Mild to moderate isolated VM generally have favorable outcomes. Fetal MRI is particularly valuable in fetuses with isolated severe VM.

[Research Progress in Magnetic Resonance Imaging of Fetal Ventriculomegaly]

Fetal ventriculomegaly is a central nervous system disorder commonly seen in prenatal imaging, and the prognosis ranges from normal health to severe dysfunction. Currently, fetal predictive markers associated with postpartum individual neurodevelopmental function are still not available, which increases the difficulty of prenatal diagnosis and clinical management. Constant advancements in magnetic resonance imaging (MRI) technology have brought better accuracy and reliability of MRI applied in the diagnosis, prognosis assessment, and etiology investigation of ventriculomegaly. MRI plays a critical role in prognostic management and prenatal consultation. Nevertheless, due to the potential safety hazards and economic and technical constraints of MRI, it is not the first choice for prenatal imaging diagnosis. Moreover, there are different opinions regarding the measurement results and grading criteria of ultrasound and MRI. At present, it is accepted that three-dimensional volume may provide reliable information for prognosis. However, accurate segmentation and measurement of brain structure remain serious challenges, and no consensus on the MRI measurement of lateral ventricle volume has been reached. In this paper, based on the latest research reports from China and around the world, we reviewed the progress in applying MRI in the prenatal diagnosis and treatment of ventriculomegaly. This review offers a theoretical foundation for further exploration of the role of lateral ventricle volume measurement in disease diagnosis and management. We suggest that researchers combine two-dimensional width with three-dimensional volume in the future to identify the optimal cutoff value for prognostic prediction of fetal ventriculomegaly.

Paediatric hydrocephalus

Hydrocephalus is classically considered as a failure of cerebrospinal fluid (CSF) homeostasis that results in the active expansion of the cerebral ventricles. Infants with hydrocephalus can present with progressive increases in head circumference whereas older children often present with signs and symptoms of elevated intracranial pressure. Congenital hydrocephalus is present at or near birth and some cases have been linked to gene mutations that disrupt brain morphogenesis and alter the biomechanics of the CSF-brain interface. Acquired hydrocephalus can develop at any time after birth, is often caused by central nervous system infection or haemorrhage and has been associated with blockage of CSF pathways and inflammation-dependent dysregulation of CSF secretion and clearance. Treatments for hydrocephalus mainly include surgical CSF shunting or endoscopic third ventriculostomy with or without choroid plexus cauterization. In utero treatment of fetal hydrocephalus is possible via surgical closure of associated neural tube defects. Long-term outcomes for children with hydrocephalus vary widely and depend on intrinsic (genetic) and extrinsic factors. Advances in genomics, brain imaging and other technologies are beginning to refine the definition of hydrocephalus, increase precision of prognostication and identify nonsurgical treatment strategies.

MR insights into fetal brain development: what is normal and what is not

Fetal brain development is a complex, rapid, and multi-dimensional process that can be documented with MRI. In the second and third trimesters, there are predictable developmental changes that must be recognized and differentiated from disease. This review delves into the key biological processes that drive fetal brain development, highlights normal developmental anatomy, and provides a framework to identify pathology. We will summarize the development of the cerebral hemispheres, sulci and gyri, extra-axial and ventricular cerebrospinal fluid, and corpus callosum and illustrate the most common abnormal findings in the clinical setting.

Automatic biometry of fetal brain MRIs using deep and machine learning techniques

Linear biometric measurements on magnetic resonance images are important for the assessment of fetal brain development, which is expert knowledge dependent and laborious. This study aims to construct a segmentation-based method for automatic two-dimensional biometric measurements of fetal brain on magnetic resonance images that provides a fast and accurate measurement of fetal brain. A total of 268 volumes (5360 images) magnetic resonance images of normal fetuses were included. The automatic method involves two steps. First, the fetal brain was segmented into four parts with a deep segmentation network: cerebrum, cerebellum, and left and right lateral ventricles. Second, the measurement plane was determined, and the corresponding biometric parameters were calculated according to clinical guidelines, including cerebral biparietal diameter (CBPD), transverse cerebellar diameter (TCD), left and right atrial diameter (LAD/RAD). Pearson correlation coefficient and Bland-Altman plots were used to assess the correlation and agreement between computer-predicted values and manual measurements. Mean differences were used to evaluate the errors quantitatively. Analysis of fetal cerebral growth based on the automatic measurements was also displayed. The experiment results show that correlation coefficients for CBPD, TCD, LAD and RAD were as follows: 0.977, 0.990, 0.817, 0.719, mean differences were - 2.405 mm, - 0.008 mm, - 0.33 mm, - 0.213 mm, respectively. The correlation between the errors and gestational age was not statistically significant (p values were 0.2595, 0.0510, 0.1995, and 0.0609, respectively). The proposed automatic method for linear measurements on fetal brain MRI achieves excellent performance, which is expected to be applied in clinical practice and be helpful for prenatal diagnosis and clinical work efficiency improvement.

Characterisation of ASD traits among a cohort of children with isolated fetal ventriculomegaly

Fetal ventriculomegaly is the most common antenatally-diagnosed brain abnormality. Imaging studies in antenatal isolated ventriculomegaly demonstrate enlarged ventricles and cortical overgrowth which are also present in children with autism-spectrum disorder/condition (ASD). We investigate the presence of ASD traits in a cohort of children (n = 24 [20 males/4 females]) with isolated fetal ventriculomegaly, compared with 10 controls (n = 10 [6 males/4 females]). Neurodevelopmental outcome at school age included IQ, ASD traits (ADOS-2), sustained attention, neurological functioning, behaviour, executive function, sensory processing, co-ordination, and adaptive behaviours. Pre-school language development was assessed at 2 years. 37.5% of children, all male, in the ventriculomegaly cohort scored above threshold for autism/ASD classification. Pre-school language delay predicted an ADOS-2 autism/ASD classification with 73.3% specificity/66.7% sensitivity. Greater pre-school language delay was associated with more ASD symptoms. In this study, the neurodevelopment of children with isolated fetal ventriculomegaly, associated with altered cortical development, includes ASD traits, difficulties in sustained attention, working memory and sensation-seeking behaviours.

Concordance between US and MRI Two-Dimensional Measurement and Volumetric Segmentation in Fetal Ventriculomegaly

We provide a study comparison between two-dimensional measurement and volumetric (3D) segmentation of the lateral ventricles and brain structures in fetuses with isolated and non-isolated ventriculomegaly with 3D virtual organ computer-aided analysis (VOCAL) ultrasonography vs. magnetic resonance imaging (MRI) analyzed with 3D-Slicer software. In this cross-sectional study, 40 fetuses between 20 and 38 gestational weeks with various degrees of ventriculomegaly were included. A total of 71 ventricles were measured with ultrasound (US) and with MRI. A total of 64 sonographic ventricular volumes, 80 ventricular and 40 fetal brain MR volumes were segmented and analyzed using both imaging modalities by three observers. Sizes and volumes of the ventricles and brain parenchyma were independently analyzed by two radiologists, and interobserver correlation of the results with 3D fetal ultrasound data was performed. The semiautomated rotational multiplanar 3D VOCAL technique was performed for ultrasound volumetric measurements. Results were compared to manually extracted ventricular and total brain volumes in 3D-Slicer. Segmentation of fetal brain structures (cerebral and cerebellar hemispheres, brainstem, ventricles) performed independently by two radiologists showed high interobserver agreement. An excellent agreement between VOCAL and MRI volumetric and two-dimensional measurements was established, taking into account the intraclass correlation coefficients (ICC), and a Bland-Altman plot was established. US and MRI are valuable tools for performing fetal brain and ventricular volumetry for clinical prognosis and patient counseling. Our datasets could provide the backbone for further construction of quantitative normative trajectories of fetal intracranial structures and support earlier detection of abnormal brain development and ventriculomegaly, its timing and progression during gestation.

Short-Term and Long-Term Outcomes of Fetal Ventriculomegaly beyond Gestational 37 Weeks: A Retrospective Cohort Study

Birth defects have brought about major public health problems, and studying the clinical outcomes of the most common prenatal central nervous system abnormality, namely, fetal ventriculomegaly (VM), is helpful for improving reproductive health and fertility quality. This is a retrospective cohort study from 2011 to 2020 in the West China Second University Hospital, Sichuan University, aiming to evaluate the short-term and long-term outcomes of VM over 37 weeks' gestation to exclude the influence of preterm birth. The study analyzed data from 401 term pregnancies, with 179 VM and 222 controls. From the short-term outcomes, the rate of the neonatal intensive care unit (NICU) admission under the VM group (10.06%) was comparatively higher than the control (0.45%), but Apgar scores between both groups at 1 min, 5 min and 10 min were not significantly different. From the long-term outcomes, there were more infants with abnormal neurodevelopment under the VM group than control (14.53% vs. 2.25%, p < 0.001). In addition, NICU admission (p = 0.006), peak width of lateral ventricles (p = 0.030) and postnatal cranial ultrasound suggestive with VM (p = 0.002) were related to infants' long-term outcomes. NICU admission during the perinatal period was an independent risk factor for the adverse long-term outcomes (OR = 3.561, 95% CI 1.029-12.320, p = 0.045). In conclusion, VM impairs short-term and long-term outcomes of term infants. Short-term outcome, especially NICU admission, could predict their adverse long-term outcomes.

Maternal blood inflammatory marker levels increased in fetuses with ventriculomegaly

Background

Fetal ventriculomegaly (VM) is one of the most common abnormalities of the central nervous system (CNS), which can be significantly identified by brain anomalies prenatally by magnetic resonance imaging (MRI). Aberrant white blood cells (WBCs) levels indicate that the maternal is suffering from the infection. Previous studies have confirmed that prenatal infection can affect fetal brain structure, but there is no research revealed the association between maternal blood parameters with fetal VM until now.

Methods

We measured the width of the lateral ventricle of 142 fetuses, which were divided into the fetal VM group (n = 70) and the normal lateral ventricle group (n = 72). We compared maternal blood cell levels between the two groups and investigate potential biomarkers of fetal VM.

Result

High levels of maternal WBC and neutrophil (NE#) levels were observed in fetuses with VM (p < 0.001), while lymphocyte percentage, monocytes (MO#), neutrophil/lymphocyte ratio (NLR), and platelet were also increased in the fetal VM group (p = 0.033, 0.027, 0.034, and 0.025, respectively). receiver-operator curve (ROC) analysis suggested that WBC and NE# counts might be useful to distinguish fetuses with enlarged lateral ventricles (AUC = 0.688, 0.678, respectively).

Conclusion

The current study emphasizes the importance of maternal infection for fetal brain growth, which could provide important information for prenatal diagnosis of CNS anomalies. Future research needs longitudinal analysis and exploration of the influence of maternal blood inflammatory marker levels on fetal brain development.

Perinatal Ischemic Stroke: Etiology and Imaging

Perinatal ischemic stroke is a common cause of lifelong disability.

Imaging of Macrocephaly

Macrocephaly is a common diagnosis in the pediatric population, particularly in the infantile time period. There is a wide range of causes of macrocephaly, from benign to malignant, for which imaging plays a key role in the diagnosis and clinical guidance. Our aim is to review the distinct and prevalent neuroimaging findings in the evaluation of the macrocephalic infant.

Fetal Neuroimaging Updates

MR imaging is used in conjunction with ultrasound screening for fetal brain abnormalities because it offers better contrast, higher resolution, and has multiplanar capabilities that increase the accuracy and confidence of diagnosis. Fetal motion still severely limits the MR imaging sequences that can be acquired. We outline the current acquisition strategies for fetal brain MR imaging and discuss the near term advances that will improve its reliability. Prospective and retrospective motion correction aim to make the complement of MR neuroimaging modalities available for fetal diagnosis, improve the performance of existing modalities, and open new horizons to understanding in utero brain development.