Cortical maturation in fetuses referred for 'isolated' mild ventriculomegaly: a longitudinal ultrasound assessment

Volume development changes in the occipital lobe gyrus assessed by MRI in fetuses with isolated ventriculomegaly correlate with neurological development in infancy and early childhood

OBJECTIVE

This study was to systematically assess the occipital lobe gray and white matter volume of isolated ventriculomegaly (IVM) fetuses with MRI and to follow up the neurodevelopment of participants.

METHOD

MRI was used to evaluate 37 IVM fetuses and 37 control fetuses. The volume of gray and white matter in each fetal occipital gyrus was manually segmented and compared, and neurodevelopment was followed up and assessed in infancy and early childhood.

RESULT

Compared with the control group, the volume of gray matter in occipital lobe increased in the IVM group, and the incidence of neurodevelopmental delay increased.

CONCLUSION

We tested the hypothesis that prenatal diagnosis IVM represents a biological marker for development in fetal occipital lobe. Compared with the control group, the IVM group showed differences in occipital gray matter development and had a higher risk of neurodevelopmental delay.

Asymmetric cortical development and prognosis in fetuses with isolated mild fetal ventriculomegaly: an observational prospective study

BACKGROUND

Assessments of cortical development and identifying factors that may result in a poor prognosis for fetuses with isolated mild ventriculomegaly (IMVM) is a hot research topic. We aimed to perform a constant, detailed assessment of cortical development in IMVM fetuses using ultrasound and determine whether asymmetric cortical development occurred. Moreover, we aimed to estimate the prognosis of IMVM fetuses and compare the difference in the prognosis of IMVM fetuses presenting symmetric and asymmetric cortical maturation.

METHODS

IMVM was diagnosed by regular ultrasound, neurosonography and fetal MRI. Genetic and TORCH examinations were conducted to exclude common genetic abnormalities and TORCH infection of fetuses. Ultrasound examinations were conducted at an interval of 2-3 weeks to record sulcus development in IMVM fetuses using a scoring system. The neonatal behavioral neurological assessment (NBNA), the Ages and Stages Questionnaire, Third Edition (ASQ-3) and the Bayley Scales of Infant Development, First Edition (BSID-I) were performed after birth.

RESULTS

Forty fetuses with IMVM were included: twenty showed asymmetric cortical maturation and twenty showed symmetric cortical maturation. For IMVM fetuses presenting asymmetric cortical maturation, the mean gestational age (GA) at the first diagnosis of relatively delayed development was 24.23 weeks for the parieto-occipital sulcus, 24.71 weeks for the calcarine sulcus, and 26.43 weeks for the cingulate sulcus. All the sulci with delayed development underwent 'catch-up growth' and developed to the same grade as the sulci of the other hemisphere. The mean GA at which the two sides developed to the same grade was 29.40 weeks for the parieto-occipital sulcus, 29.30 weeks for the calcarine sulcus and 31.27 weeks for the cingulate sulcus. The NBNA, ASQ-3 and BSID-I scores of all patients were in the normal range.

CONCLUSIONS

IMVM fetuses may show mild asymmetric cortical maturation in the second trimester, but the relatively delayed sulci undergo 'catch-up growth'. The neurodevelopment of IMVM fetuses presenting asymmetric cortical maturation and 'catch-up growth' is not statistically significantly different from IMVM fetuses presenting symmetric cortical maturation.

Lateral ventricular volume and calcarine sulcus depth: a fetal MRI analysis of mild ventriculomegaly: A STROBE compliant article

The aim of this study was to quantify changes in the lateral ventricular volume, the depth of the calcarine sulcus (CS), and apparent diffusion coefficient (ADC) values of occipital lobe in fetuses with isolated mild ventriculomegaly (IMVM) using MRI.Seventy-one fetuses with IMVM at 25 to 38 weeks gestational age (GA) and 58 fetuses with normal lateral ventricles at 25 to 38 weeks GA were enrolled. Volumes of the lateral ventricles were measured by 3D magnetic resonance hydrography. Depths of the CS and ADC values were also evaluated. All differences were tested by t test. Bivariate correlations were performed using Pearson method.Fetuses with IMVM had significantly larger lateral ventricular volumes and smaller CS depths than controls (volumes: 9.37 ± 2.20 mL vs 5.04 ± 1.33 mL, respectively, P < .001; depths: 8.27 ± 2.55 mm vs 10.30 ± 3.14 mm, respectively, P < .001). In IMVM cases, the CS depths were smaller on the side with the larger ventricle (8.10 ± 2.54 mm vs 9.59 ± 2.81 mm, P < .001). No differences were observed in occipital lobe ADC values between the2 groups (IMVM = 1.80 ± 0.24 μm/ms; controls = 1.78 ± 0.28 μm/ms, P > .05).Fetuses with IMVM had larger lateral ventricular volumes, shallower CS depths, but normal occipital lobe ADC values.

Global and Regional Changes in Cortical Development Assessed by MRI in Fetuses with Isolated Nonsevere Ventriculomegaly Correlate with Neonatal Neurobehavior

BACKGROUND AND PURPOSE

Fetuses with isolated nonsevere ventriculomegaly (INSVM) are at risk of presenting neurodevelopmental delay. However, the currently used clinical parameters are insufficient to select cases with high risk and determine whether subtle changes in brain development are present and might be a risk factor. The aim of this study was to perform a comprehensive evaluation of cortical development in INSVM by magnetic resonance (MR) imaging and assess its association with neonatal neurobehavior.

MATERIALS AND METHODS

Thirty-two INSVM fetuses and 29 healthy controls between 26-28 weeks of gestation were evaluated using MR imaging. We compared sulci and fissure depth, cortical maturation grading of specific areas and sulci and volumes of different brain regions obtained from 3D brain reconstruction of cases and controls. Neonatal outcome was assessed by using the Neonatal Behavioral Assessment Scale at a mean of 4 ± 2 weeks after birth.

RESULTS

Fetuses with INSVM showed less profound and underdeveloped sulcation, including the Sylvian fissure (mean depth: controls 16.8 ± 1.9 mm, versus INSVM 16.0 ± 1.6 mm; P = .01), and reduced global cortical grading (mean score: controls 42.9 ± 10.2 mm, versus INSVM: 37.8 ± 9.9 mm; P = .01). Fetuses with isolated nonsevere ventriculomegaly showed a mean global increase of gray matter volume (controls, 276.8 ± 46.0 ×10 mm³, versus INSVM 277.5 ± 49.3 ×10 mm³, P = .01), but decreased mean cortical volume in the frontal lobe (left: controls, 53.2 ± 8.8 ×10 mm³, versus INSVM 52.4 ± 5.4 ×10 mm³; P = < .01). Sulcal depth and brain volumes were significantly associated with the Neonatal Behavioral Assessment Scale severity (P = .005, Nagelkerke R² = 0.732).

CONCLUSIONS

INSVM fetuses showed differences in cortical development, including regions far from the lateral ventricles, that are associated with neonatal neurobehavior. These results suggest the possible use of these parameters to identify cases at higher risk of altered neurodevelopment.

Role of magnetic resonance imaging in fetuses with mild or moderate ventriculomegaly in the era of fetal neurosonography: systematic review and meta-analysis

OBJECTIVES

To report the rate of additional central nervous system (CNS) anomalies detected exclusively on prenatal magnetic resonance imaging (MRI) in fetuses diagnosed with isolated mild or moderate ventriculomegaly (VM) on ultrasound, according to the type of ultrasound protocol adopted (dedicated neurosonography vs standard assessment of the fetal brain), and to explore whether the diagnostic performance of fetal MRI in detecting such anomalies is affected by gestational age at examination and laterality and degree of ventricular dilatation.

METHODS

MEDLINE, EMBASE, CINAHL and Clinicaltrials.gov were searched for studies reporting on the prenatal MRI assessment of fetuses diagnosed with isolated mild or moderate VM (ventricular dilatation of 10-15 mm) on ultrasound. Additional anomalies detected only on MRI were classified as callosal, septal, posterior fossa, white matter, intraventricular hemorrhage, cortical, periventricular heterotopia, periventricular cysts or complex malformations. The rate of additional anomalies was compared between fetuses diagnosed on dedicated neurosonography, defined as a detailed assessment of the fetal brain, according to the International Society of Ultrasound in Obstetrics and Gynecology guidelines, and those diagnosed on standard fetal brain assessment. The rate of additional CNS anomalies missed on prenatal MRI and detected only at birth was calculated and compared between fetuses that had early (at or before 24 weeks' gestation) and those that had late (after 24 weeks) MRI. Subanalysis was performed according to the laterality (uni- vs bilateral) and degree (mild vs moderate, defined as ventricular dilatation of 10-12 and 13-15 mm, respectively) of ventricular dilatation. Whether MRI assessment led to a significant change in prenatal management was explored. Random-effects meta-analysis of proportions was used.

RESULTS

Sixteen studies (1159 fetuses) were included in the systematic review. Overall, MRI detected an anomaly not identified on ultrasound in 10.0% (95% CI, 6.2-14.5%) of fetuses. However, when stratifying the analysis according to the type of ultrasound assessment, the rate of associated anomalies detected only on MRI was 5.0% (95% CI, 3.0-7.0%) when dedicated neurosonography was performed compared with 16.8% (95% CI, 8.3-27.6%) in cases that underwent a standard assessment of the fetal brain in the axial plane. The overall rate of an additional anomaly detected only at birth and missed on prenatal MRI was 0.9% (95% CI, 0.04-1.5%) (I² , 0%). There was no difference in the rate of an associated anomaly detected only after birth when fetal MRI was carried out before, compared with after, 24 weeks of gestation (P = 0.265). The risk of detecting an associated CNS abnormality on MRI was higher in fetuses with moderate than in those with mild VM (odds ratio, 8.1 (95% CI, 2.3-29.0); P = 0.001), while there was no difference in those presenting with bilateral, compared with unilateral, dilatation (P = 0.333). Finally, a significant change in perinatal management, mainly termination of pregnancy owing to parental request, following MRI detection of an associated anomaly, was observed in 2.9% (95% CI, 0.01-9.8%) of fetuses undergoing dedicated neurosonography compared with 5.1% (95% CI, 3.2-7.5%) of those having standard assessment.

CONCLUSIONS

In fetuses undergoing dedicated neurosonography, the rate of a CNS anomaly detected exclusively on MRI is lower than that reported previously. Early MRI has an excellent diagnostic performance in identifying additional CNS anomalies, although the findings from this review suggest that MRI performed in the third trimester may be associated with a better detection rate for some types of anomaly, such as cortical, white matter and intracranial hemorrhagic anomalies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Altered cortical development in fetuses with isolated nonsevere ventriculomegaly assessed by neurosonography

OBJECTIVES

To perform a comprehensive assessment of cortical development in fetuses with isolated nonsevere ventriculomegaly (INSVM) by neurosonography.

METHODS

We prospectively included 40 fetuses with INSVM and 40 controls. INSVM was defined as atrial width between 10.0 and 14.9 mm without associated malformation, infection, or chromosomal abnormality. Cortical development was assessed by neurosonography at 26 and 30 weeks of gestation measuring depth of selected sulci and applying a maturation scale from 0 (no appearance) to 5 (maximally developed) of main sulci and areas.

RESULTS

INSVM showed underdeveloped calcarine and parieto-occipital sulci. In addition, significant delayed maturation pattern was also observed in regions distant to ventricular system including Insula depth (controls 30.8 mm [SD 1.7] vs INSVM 31.7 mm [1.8]; P = .04), Sylvian fissure grading (>2 at 26 weeks: controls 87.5% vs INSVM 50%, P = .01), mesial area grading (>2 at 30 weeks: controls 95% vs INSVM 62.5%; P = .03), and cingulate sulcus grading (>2 at 30 weeks: controls 100% vs INSVM 80.5%; P = .01).

CONCLUSIONS

Fetuses with INSVM showed underdeveloped cortical maturation including also regions, where effect of ventricular dilatation is unlikely. These results suggest that in a proportion of fetuses with INSVM, ventricular dilation might be related with altered cortical architecture.

Perinatal and long-term outcomes in fetuses diagnosed with isolated unilateral ventriculomegaly: systematic review and meta-analysis

OBJECTIVES

The majority of studies on fetal ventriculomegaly have focused on the perinatal and long-term outcomes in fetuses with an antenatal diagnosis of bilateral ventriculomegaly. The aim of this study was to undertake a systematic review and meta-analysis to quantify the perinatal and long-term outcomes in fetuses diagnosed in the second or third trimester of pregnancy with isolated unilateral ventriculomegaly.

METHODS

MEDLINE, EMBASE and The Cochrane Library were searched electronically. Outcomes investigated included incidence of aneuploidy, congenital infection, progression of ventriculomegaly, associated brain and extracerebral abnormalities in the apparently isolated cases and neurodevelopmental delay in both apparently and truly isolated cases. Sensitivity analysis was performed according to whether the ventriculomegaly was mild/moderate (atrial width < 15 mm) or severe (atrial width ≥ 15 mm). Reference lists within relevant articles and reviews were hand-searched for additional reports. Cohort and case-control studies were included. Meta-analysis of proportions was used, and between-study heterogeneity was assessed using the I² test.

RESULTS

The search yielded 2053 citations. The full text was retrieved for 202, and 11 studies were included in the systematic review. In fetuses with apparently isolated unilateral ventriculomegaly, no chromosomal abnormalities were identified and the pooled prevalence of congenital infection was 8.2% (95% CI, 3.6-14.5%). The pooled prevalence of additional brain abnormalities detected prenatally and postnatally by magnetic resonance imaging was 5.1% (95% CI, 0.2-16.1%) and 6.4% (95% CI, 0.3-19.4%), respectively. The pooled prevalence of abnormal neurodevelopment was 5.9% (95% CI, 2.2-11.2%) in apparently isolated cases with an atrial width of < 15 mm, and it was 7.0% (95% CI, 3.2-12.2%) in fetuses with truly isolated unilateral ventriculomegaly. Most cases with apparently isolated ventriculomegaly were classified as mild/moderate (93.5%) and therefore the outcomes in this group were similar to those in the whole cohort of apparently isolated ventriculomegaly.

CONCLUSIONS

The prevalence of aneuploidy, congenital infection and neurodevelopmental delay in fetuses with a prenatal diagnosis of isolated unilateral ventriculomegaly is likely to be low. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Magnetic resonance imaging based correlation analysis between calcarine sulcus development and isolated fetal ventriculomegaly

Fetal ventriculomegaly development leads to neurological, motor, and/or cognitive impairment, and is presently diagnosed based on the width of the atrium in the lateral ventricle. But in this study, we have tried to assess the relationship between the development of calcarine sulcus and width of fetal lateral ventricles, to assess if calcarine sulcus can also be used for fetal ventriculomegaly diagnosis. We conducted a retrospective analysis of the magnetic resonance imaging (MRI) data from 45 subjects with isolated mild fetal ventriculomegaly (IMVM). The calcarine sulcus development was divided into three categories based on the depth; Grade 1 (undeveloped), Grade 2 (underdeveloped), and Grade 3 (fully developed), and its correlation with fetal ventriculomegaly was analyzed based on Spearman's partial rank correlation test. Based on this analysis, the width of left and right lateral ventricles showed significant downward trend with the calcarine sulcus maturation [undeveloped (Left 13.88 ± 2.70 mm, Right 14.27 ± 3.13 mm) → underdeveloped (Left 12.95 ± 1.93 mm, Right 11.93 ± 2.24 mm) → fully developed (Left 11.06 ± 2.10 mm, Right 10.42 ± 2.10 mm)] (F_Left  = 5.12, P = 0.01; F_Right  = 10.72, P = 1.73 × 10^-4 ). In addition, significant correlations were also observed between the width of the lateral ventricles and the maturity of the calcarine sulcus (Spearman's rank correlation coefficient; -0.47 for the left lateral ventricles and -0.56 for the right, both P < 0.001). Overall, our data indicated a negative correlation between the fetal morphological development of calcarine sulcus and the width of lateral ventricles in subjects having isolated fetal ventriculomegaly.

Reduced fetal brain fissures depth in fetuses with congenital heart diseases

OBJECTIVE

To screen and detect cortex gyration in fetuses with congenital heart disease (CHD) using Ultrasonography (US) during routine obstetric scans.

METHODS

The depth of the Sylvian fissure (SF), parieto-occipital fissure (POF), and calcarine (CF) fissure were prospectively serially measured and compared in 45 fetuses with CHD and 45 normal fetuses. Cardiac hemodynamic parameters, including aortic valve diameter (AV), pulmonary valve diameter (PV), velocity time integral of the aortic valve (VTIav), and velocity time integral of the pulmonary valve (VTIpv), were recorded. Correlations between the fissure depths and the prenatal cardiac hemodynamic parameters and postnatal neurodevelopmental scores were assessed.

RESULTS

SF, POF, and CF were decreased in CHD fetuses compared with the controls in late of pregnancy (P < 0.01). The diagnostic category was independently associated with smaller fissure depths in fetuses with CHD (adjusted R²  = 0.472 for SF, 0.465 for POF, and 0.425 for CF). Correlations were observed between small fissure depths and decreased left heart hemodynamic parameters (AV and VTIav) in fetuses with CHD. The SF depth was positively correlated with the neurodevelopmental scores (P < 0.01).

CONCLUSIONS

US can be used to screen for abnormal fetal brain cortex development during routine obstetric scans and to evaluate the maturation progress during close follow-up. © 2016 John Wiley & Sons, Ltd.