Postnatal clinical and imaging follow-up of infants with prenatal isolated mild ventriculomegaly: a series of 101 cases

Volumetric and surface-based 3D MRI analyses of fetal isolated mild ventriculomegaly: brain morphometry in ventriculomegaly

Diagnosis of fetal isolated mild ventriculomegaly (IMVM) is the most common brain abnormality on prenatal ultrasound. We have set to identify potential alterations in brain development specific to IMVM in tissue volume and cortical and ventricular local surface curvature derived from in utero magnetic resonance imaging (MRI). Multislice 2D T2-weighted MRI were acquired from 32 fetuses (16 IMVM, 16 controls) between 22 and 25.5 gestational weeks. The images were motion-corrected and reconstructed into 3D volumes for volumetric and curvature analyses. The brain images were automatically segmented into cortical plate, cerebral mantle, deep gray nuclei, and ventricles. Volumes were compared between IMVM and control subjects. Surfaces were extracted from the segmentations for local mean surface curvature measurement on the inner cortical plate and the ventricles. Linear models were estimated for age-related and ventricular volume-associated changes in local curvature in both the inner cortical plate and ventricles. While ventricular volume was enlarged in IMVM, all other tissue volumes were not different from the control group. Ventricles increased in curvature with age along the atrium and anterior body. Increasing ventricular volume was associated with reduced curvature over most of the ventricular surface. The cortical plate changed in curvature with age at multiple sites of primary sulcal formation. Reduced cortical folding was detected near the parieto-occipital sulcus in IMVM subjects. While tissue volume appears to be preserved in brains with IMVM, cortical folding may be affected in regions where ventricles are dilated.

Neurodevelopmental outcome of 31 patients with borderline fetal ventriculomegaly

AIM

We present the neurodevelopmental outcome of patients with isolated borderline fetal ventriculomegaly.

METHODS

The present study was carried out at the Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul University in July-December 2010. Prenatal second trimester detailed ultrasound examinations were performed by obstetricians at the Prenatal Diagnosis Department of Istanbul Medical School, and 31 consecutive patients aged 8-33 months have been included in the study. Four patients with atrial diameters of over 15 mm and three patients with central nervous system development anomalies were excluded from the study. In order to assess the neuromotor development of patients, neurologic examinations and the Bayley Scales of Infant Development (BSID-III) were used.

RESULTS

Nine patients were female (29%) and 22 were male (71%). In the postnatal period, tuberous sclerosis was found in one patient, Down syndrome in one, and equinovarus foot deformity in one. Atrial diameter was <12 mm in 18 patients and >12 mm in 13. Cranial ultrasounds done in the first postnatal month revealed persisting ventriculomegaly in nine patients. The two patients who scored significantly low in all areas on the Bayley Scales of Infant Development were the patients with Down syndrome and tuberous sclerosis. The one scoring low in the motor area was the patient with the equinovarus foot deformity. The BSID-III scores of the patients whose prenatal ventricle diameter was <12 mm were within normal limits. The four patients showing slight developmental delay were the ones whose cranial ultrasound in the first postnatal month showed persisting ventriculomegaly.

CONCLUSION

In patients with borderline fetal ventriculomegaly, atrial diameter being more than 12 mm, the condition persisting in the first postnatal month and the presence of accompanying syndromes and malformations all constitute clear risk factors for neurodevelopmental outcome.

Mid-term neurodevelopmental outcome in isolated mild ventriculomegaly diagnosed in fetal life

OBJECTIVE

To analyze mid-term neurodevelopment outcome in children with isolated mild ventriculomegaly (VM) ≤12 mm diagnosed in fetal life, using the Battelle Developmental Inventory Screening Test (BDIST).

METHODS

86 cases of mild VM were identified. 68 were excluded due to: other cerebral anomalies (n = 40), extra-cerebral anomalies (n = 3), chromosomal defects (n = 4), dysmorphic syndromes (n = 4), congenital infections (n = 2), termination of pregnancy (n = 9), stillbirth (n = 2) and incomplete follow-up (n = 4). 18 cases (range 1-8 years) of isolated mild VM were included for analysis. Seven neurodevelopment domains were assessed by BDIST.

RESULTS

Routine neuropediatrical evaluation detected neurological disorders in five children (28%; 3 with language impairment, one left hemiparesis and one intellectual retardation). BDIST showed some degree of neurodevelopmental delay in higher proportions: 66% in social-personal skills, 56% in gross motor skills, 39% in adaptive behavior and 28% in fine motor skills. Communicative and cognitive areas were the least affected (11 and 22% had moderate-to-severe involvement, respectively). A general trend towards worse outcomes was observed in the group of ≥4 years, although significant differences were only found for gross motor skills.

CONCLUSION

Subtle neurological delays may appear during the infant period in fetuses prenatally diagnosed of isolated mild VM. In consequence, adequate measures should be established for early detection and treatment.

Diffuse periventricular leukomalacia in preterm children: assessment of grey matter changes by MRI

BACKGROUND

Preterm children may have cognitive deficits and behavioural disorders suggestive of grey matter (GM) injury. The prevalence is higher in preterm children with diffuse periventricular leukomalacia (dPVL).

OBJECTIVE

Evaluate changes in the volume of 116 GM areas in preterm children with dPVL.

METHODS AND MATERIALS

Eleven preterm children with dPVL, gestational age 32.8 ± 2.6 weeks, examined at corrected age 22.0 ± 18.2 months and 33 matched preterm controls with normal brain MRI were studied. Volumes of 116 individual GM areas, and white matter/cerebrospinal fluid (WM/CSF) ratio were calculated on T1-weighted high-resolution images after segmentation.

RESULTS

Relative to controls, children with dPVL had decreased GM volume of the hippocampus, amygdala, and frontal lobes and temporal middle gyrus (P < 0.05); increased GM volume of the putamen, thalamus, globus pallidum, superior temporal gyrus and of the parietal and occipital lobes (P < 0.05) and lower WM volume/higher CSF volume (P < 0.05). WM/CSF ratios also differed (P < 0.05).

CONCLUSIONS

Preterm children with dPVL have increased regional GM volume in some areas probably related with a process of brain plasticity-regeneration and reduced GM volume in areas associated with cognition and memory.

Ultrasound and MRI of fetuses with ventriculomegaly: can cortical development be used to predict postnatal outcome?

OBJECTIVE

The purpose of this study was to assess the conspicuity of brain cortical maturation with sonography and MRI of fetuses referred because of ventriculomegaly and to determine whether sulcal visualization can be used to predict postnatal outcome.

SUBJECTS AND METHODS

Women with 374 fetuses referred because of ventriculomegaly underwent sonography and MRI. Four to six radiologists rated visualization of 19 fissures or sulci. Majority opinion regarding sulcal visualization was compared among fetuses categorized by CNS abnormality: normal, isolated ventriculomegaly, and ventriculomegaly with additional CNS abnormalities. Live-born infants were categorized as having normal or abnormal development. Logistic regression analysis was used to correlate sulcal visualization and postnatal development. A subanalysis was performed with fetuses who had been classified prenatally as having a normal brain or isolated ventriculomegaly.

RESULTS

Cortical sulci were visualized more frequently and at an earlier gestational age with MRI than with ultrasound. In the entire cohort, the odds ratio of normal development ranged from 3.1 to 10.0 whenever the calcarine, parietooccipital, cingulate, superior temporal, precentral, or postcentral sulcus was seen on MR images. In fetuses categorized as having a normal brain or having isolated ventriculomegaly, the odds ratio of normal development ranged from 3.5 to 9.0 whenever the parietooccipital, cingulate, or superior temporal sulcus was seen.

CONCLUSION

Visualization of the sulci in fetal brains depends on the imaging modality used and the gestational age at imaging. Information regarding sulcal visualization may aid in counseling patients carrying fetuses with ventriculomegaly.

Correlation between pre- and postnatal cerebral magnetic resonance imaging

OBJECTIVES

To evaluate the diagnostic accuracy of fetal cerebral magnetic resonance imaging (MRI) on a large cohort and to compare pre- and postnatal MRI data.

METHODS

This prospective study included all cases referred to our unit for fetal cerebral MRI examination between June 2006 and December 2009 and which underwent at least one postnatal MRI examination. Cases in which there was termination of pregnancy, fetal death or stillbirth were excluded. The pre- and postnatal diagnoses established by MRI were compared and divided into five subgroups: same diagnosis on pre- and postnatal MRI (Group 1); same diagnosis but different appearance related to the natural course of the disease (Group 2); different diagnosis (related to limitations of fetal MRI) (Group 3); same diagnosis but with additional findings discovered on postnatal MRI examination (Group 4); or same diagnosis but different appearance related to the natural course of the disease (as in Group 2) and associated with additional findings discovered on postnatal MRI examination (Group 5). The prognostic impact of a possible disagreement between pre- and postnatal findings was evaluated.

RESULTS

One hundred fetuses were included. Fetal MRI was performed at a mean gestational age of 33 (range, 24-39) weeks and postnatal MRI at a mean age of 3.5 months. There were 53 cases classified as Group 1, 32 in Group 2, four in Group 3, 10 in Group 4 and one in Group 5. Thus, in 15 cases (Groups 3-5), there were discrepancies between pre- and postnatal findings (mostly related to corpus callosum anatomy, cortical and migration disorders). The discrepancy was judged to have a prognostic impact in 9/15 cases. Two postnatal MRI examinations were performed in eight cases, in one of which the second examination showed subependymal heterotopia which were not detectable on the first examination.

CONCLUSION

Pre- and postnatal MRI data showed good agreement in 85% of cases. There was disagreement with a prognostic impact in 9% of cases.

Magnetic resonance volumetric assessments of brains in fetuses with ventriculomegaly correlated to outcomes

OBJECTIVES

The purpose of this study was to correlate 2-dimensional magnetic resonance (MR) measurements of lateral ventricular width and 3-dimensional measurements of lateral ventricular and supratentorial parenchymal volumes to postnatal outcomes in fetuses with ventriculomegaly.

METHODS

A total of 307 fetuses (mean gestational age, 26.0 weeks; range, 15.7-39.4 weeks) had MR volumetry after referral for ventriculomegaly. Fetuses were grouped into those with (n = 114) and without (n = 193) other central nervous system (CNS) anomalies. Pregnancy and postnatal neurodevelopmental outcomes up to 3 years of age were obtained. A subgroup analysis was performed excluding fetuses with other CNS anomalies. Logistic regression analysis was performed to assess which measurement was most predictive of outcomes.

RESULTS

There were 50 terminations, 2 stillbirths, and 255 live births. Seventy-five cases were lost to follow-up. Among 180 live-born neonates with follow-up, 140 had abnormal and 40 had normal outcomes. Atrial diameter (P < .0001), frontal horn diameter (P < .0001), and ventricular volume (P = .04) were predictive of live birth, with 92% specificity at 60% sensitivity. Among fetuses without other CNS anomalies, 180 of 193 pregnancies (93%) resulted in live deliveries, with atrial diameter (P < .0001), frontal horn diameter (P = .003), and ventricular volume (P = .008) associated with live birth and atrial diameter having the highest specificity (>99% at 60% sensitivity). Parenchymal volume was not associated with normal or abnormal outcomes (either live birth versus death or normal versus abnormal neurodevelopmental outcome). Among live-born neonates, no age-adjusted threshold for any of the measurements reliably distinguished between normal and abnormal neurodevelopmental outcomes.

CONCLUSIONS

Ventricular volume and diameter, but not parenchymal volume, correlate with live birth in fetuses with ventriculomegaly. However, once live born, neither 2- nor 3-dimensional measurements can distinguish a fetus that will have a normal outcome.

[Prenatal detection of brain anomalies with ultrasonography]

Ultrasound is the first-line imaging study of the fetal brain performed at 12, 22 and 32 weeks of gestation. The very structured evaluation of biometric and morphological data, facilitated by the use of a checklist, ensures a high quality examination. All patients where an anomaly of any key element is suspected should be referred to a center dedicated to prenatal diagnosis for confirmation irrespective of the gestational age. Prenatal diagnosis plays a significant role in France since medical interruption of pregnancy until term is authorized.

Fetuses with ventriculomegaly diagnosed in the second trimester of pregnancy by in utero MR imaging: what happens in the third trimester?

BACKGROUND AND PURPOSE

Although MR imaging of the fetal brain has been shown to provide additional diagnostic information, the optimal timing of the study and the value of repeat studies remain unclear. The primary purpose of this study was to look for structural abnormalities of the fetal brain shown at 30-32 weeks' gestational age but not on the 20-24 weeks' study in fetuses originally referred with isolated VM. In particular, we wished to study the hypothesis that third-trimester fetal MR imaging studies would not show extra brain abnormalities compared with the second-trimester studies in this group.

MATERIALS AND METHODS

Ninety-nine women were admitted for a fetal MR study between 20-24 weeks' gestational age, and 46 of these women agreed to return for a second MR imaging examination at 30-32 weeks' gestational age. The other women were either lost to follow-up or declined the invitation to return. Two experienced observers measured the width of the trigones, and the results were compared, to test reliability. Changes in the degree of VM are reported along with changes in the diagnosis of structural brain abnormalities.

RESULTS

There was excellent reproducibility of trigone measurements between the 2 observers, with a mean absolute difference of <1 mm in the 40 fetuses that were ultimately shown to have isolated VM. Twenty-eight of 40 fetuses studied had mild VM on the first iuMR imaging examination, but in just more than half, the category of VM changed between the studies (5 had become normal-sized, 7 had progressed to moderate, 3 had become severe, and 13 remained mild). In 1 case, hypogenesis of the corpus callosum was recognized at 30-32 weeks but had not been reported on the 20-24 weeks' examination; the other 5 fetuses had brain pathology recognized on both fetal MR studies.

CONCLUSIONS

Trigone measurements can be made in a highly repeatable fashion on iuMR imaging. We have not shown any major advantage in repeating iuMR imaging at 30-32 weeks' gestation in terms of improved diagnosis of other structural brain abnormalities. With the converse of that argument, however, our data suggest that there is no advantage in delaying iuMR imaging studies to 30-32 weeks in the hope of improving detection rates.

Frequency and cause of disagreements in imaging diagnosis in children with ventriculomegaly diagnosed prenatally

OBJECTIVES

To assess the frequency and cause of variability in diagnosis on cranial sonography and magnetic resonance imaging (MRI) in children referred following prenatal diagnosis of ventriculomegaly.

METHODS

Between 19 September 2003 and 16 March 2007, 119 infants with ultrasound and/or MRI studies performed within 13 months (median, 6 days) after birth, following prenatal referral for ventriculomegaly, were studied prospectively. There were 97 infants with ultrasound results and 53 with MRI, including 31 with both. Three sonologists and three pediatric neuroradiologists interpreted the postnatal ultrasound and MRI findings, blinded to prenatal diagnosis, and a final consensus diagnosis or group of diagnoses was obtained. Ventricular sizes as well as types of and reasons for any disagreement in diagnosis were recorded. Disagreements on a per patient basis were categorized as being major when they crossed diagnostic categories and had the potential to change patient counseling. Postnatal and prenatal diagnoses were compared.

RESULTS

There was prospective agreement on 42/97 (43%) ultrasound and on 9/53 (17%) MRI readings. Prospective consensus was more likely when the number of central nervous system (CNS) anomalies was lower (P < 0.001 and P = 0.002 for ultrasound and MRI, respectively). In 24/55 (44%) ultrasound and 11/44 (25%) MRI examinations with disagreement in diagnosis, there was disagreement concerning the presence of ventriculomegaly. In 22/97 (23%) ultrasound studies and 22/53 (42%) MRI studies the disagreements were potentially important. Reasons for discrepancies in the reporting of major findings included errors of observation as well as modality differences in depiction of abnormalities. In comparing prenatal with postnatal diagnoses, there were 11/97 (11%) ultrasound and 27/53 (51%) MRI examinations with newly detected major findings, the most common being migrational abnormalities, callosal dysgenesis/destruction and interval development of hemorrhage.

CONCLUSION

Variability in postnatal CNS diagnosis is common after a prenatal diagnosis of ventriculomegaly. This is due in part to a lack of standardization in the definition of postnatal ventriculomegaly.

[Current events in fetal magnetic resonance]

The challenge of fetal imaging is crucial in France because of the law allowing termination of pregnancy (TOP) until the end of pregnancy. Fetal MRI is an imaging tool always used after ultrasonography (US). Its indications are pertinent only in relation with a prenatal center. Fetal MRI raises parental anxiety to take into account before and during the examination. To date, cerebral indications are predominant. Fetal brain maturation can be followed with MRI (gyration and myelination) but the optimal moment of a fetal MRI depends on the suspected pathology: the analysis of gyration is possible only by 28 WG, as before this time, the brain surface is smooth; in contrast, the posterior fossa demonstrates a definitive morphology since 20 WG. The ventriculomegaly is the most frequent call sign and includes various entities. MRI can disclose associated abnormalities (heterotopia, gyration, white matter, median line), which can suggest diagnosis and pronosis. A cystic pouch of the posterior fossa must lead to a careful analysis of cerebellum and brainstem to approach the diagnosis. Extracerebral indications become progressively larger and fetal MRI is a useful complementary tool after US to study tumors, particularly cervicothoracic masses. MRI can help to assess the level of bowel obstruction but multiple stenosis and post-stenotic bowel is difficult to evaluate. Fetal MRI can help to evaluate bilateral important pyelocalicial dilatation.

Prognosis of isolated mild to moderate fetal cerebral ventriculomegaly: a systematic review

AIMS

To ascertain risk of aneuploidy, infection and neurological abnormality for the fetus diagnosed with isolated mild (10.1-12.0 mm) to moderate (12.1-15.0 mm) cerebral ventriculomegaly and to compare the neurological outcome between symmetrical vs. asymmetrical and stable vs. progressive ventriculomegaly.

METHODS

A systematic review was conducted. Literature was identified by searching two bibliographical databases between 1980 and 2009 without language restrictions. The data extracted were inspected for heterogeneity. Overall rates and confidence intervals (CIs) for each prognostic factor were calculated. When comparative data existed, the odds ratio (OR) was calculated.

RESULTS

The search strategy yielded 2150 relevant citations of which 28 studies were included in the review. The overall rate of infection and chromosomal abnormality was 1.5 and 5% (95% CI 3, 7), respectively. The risk of neurological abnormality regardless of karyotype or infection screen was 14% (95% CI 10, 18) and this reduced to 12% (95% CI 9, 15) when both chromosomes and infection screen were normal. The risk of neurological abnormality was significantly lower in stable compared to progressive ventriculomegaly [OR 0.29 (95% CI 0.15, 0.58)]. No significant differences were detected when symmetrical vs. asymmetrical ventriculomegaly were compared [OR 0.91 (95% CI 0.34, 2.41)].

CONCLUSION

This systematic review provides the physician with some estimates of prognosis in cases of isolated mild to moderate ventriculomegaly.

Neurodevelopmental outcome of fetuses referred for ventriculomegaly

OBJECTIVE

To characterize the delivery and postnatal neurodevelopmental outcomes of fetuses referred for ventriculomegaly (VM).

METHODS

Under an internal review board-approved protocol, pregnant women were referred for magnetic resonance imaging (MRI) after sonographic diagnosis of VM and classified into one of four diagnostic groups: Group 1, normal central nervous system (CNS); Group 2, isolated mild VM (10-12 mm); Group 3, isolated VM > 12 mm; and Group 4, other CNS findings. Pregnancy outcome was obtained. Follow-up visits were offered with assessment of neurodevelopmental, adaptive and neurological functioning at 6 months and 1 year and/or 2 years of age. Atrial diameter and VM group differences in developmental outcomes were evaluated using repeated measures logistic regression and Fishers exact test, respectively.

RESULTS

Of 314 fetuses, 253 (81%) were liveborn and survived the neonatal period. Fetuses in Groups 4 and 3 were less likely to progress to live delivery and to survive the neonatal period (60% and 84%, respectively) than were those in Groups 2 or 1 (93% and 100%, respectively, P < 0.001). Of the 143 fetuses followed postnatally, between 41% and 61% had a Bayley Scales of Infant Development (BSID-II) psychomotor developmental index score in the delayed range (< 85) at the follow-up visits, whereas the BSID-II mental developmental index and Vineland Adaptive Behavior composite scores were generally in line with normative expectations. Among those that were liveborn, neither VM group nor prenatal atrial diameter was related to postnatal developmental outcome.

CONCLUSIONS

Diagnostic category and degree of fetal VM based on ultrasound and MRI measurements are associated with the incidence of live births and thus abnormal outcome. Among those undergoing formal postnatal testing, VM grade is not associated with postnatal developmental outcome, but motor functioning is more delayed than is cognitive or adaptive functioning.

MR imaging of the fetal brain

Fetal MRI is clinically performed to evaluate the brain in cases where an abnormality is detected by prenatal sonography. These most commonly include ventriculomegaly, abnormalities of the corpus callosum, and abnormalities of the posterior fossa. Fetal MRI is also increasingly performed to evaluate fetuses who have normal brain findings on prenatal sonogram but who are at increased risk for neurodevelopmental abnormalities, such as complicated monochorionic twin pregnancies. This paper will briefly discuss the common clinical conditions imaged by fetal MRI as well as recent advances in fetal MRI research.

A prospective study of fetuses with isolated ventriculomegaly investigated by antenatal sonography and in utero MR imaging

BACKGROUND AND PURPOSE

Fetal ventriculomegaly (VM) is important because of its high prevalence and high risk of association with other brain abnormalities. The purpose of this article was to investigate the hypotheses that including in utero MR imaging (iuMR) in the diagnostic pathway for fetuses with isolated VM on antenatal imaging will show other brain abnormalities in a high proportion of cases and that these will have a significant effect on clinical management.

MATERIALS AND METHODS

One hundred forty-seven pregnant women were recruited prospectively from 8 fetomaternal centers in Britain. All of the fetuses had VM diagnosed on sonography but no other abnormality. iuMR was performed, and the results of the examinations were compared with those of sonography. Two fetomaternal experts made independent assessments of the effects of any new diagnoses on clinical management.

RESULTS

Categoric assessments of ventricular size were the same in approximately 90% of fetuses. Other abnormalities were shown in 17% of fetuses. The most frequent additional brain abnormality shown on iuMR was agenesis of the corpus callosum. Severe VM was associated with an approximately 10-fold increase in the risk of another brain abnormality being present when compared with fetuses with mild VM. The most profound effects on clinical management, however, were found in cases of mild VM.

CONCLUSIONS

This work supports our hypotheses by showing a high detection rate of other brain pathology when iuMR was used to supplement antenatal sonography (17%). In a high proportion of cases, the detection of the extra pathology would have led to significant changes in clinical management.

Magnetic Resonance Imaging of the Fetal Central Nervous System in Singapore

The dual energy CT (DECT) technology has been recently employed in the form of two X-ray sources of different energies to enhance the contrast between adjacent structures. Its use in the cardiac arena has been widely highlighted due to the higher temporal resolution. However, it may also be used in the craniocervical and peripheral vasculature for better differentiation between contrast-enhanced vascular lumina and calcified plaques, in the characterisation of ureteric stones, and in the evaluation of hepatic lesions. The objective of this paper is to revisit DECT physics, review the literature and discuss its use in CT neuroangiography with case illustrations from our institution, and impact on dose savings. Key words: Craniocervical CT angiography, Intracranial aneurysms, Radiation dosage, Vascular stenosis

Counseling in isolated mild fetal ventriculomegaly

In this Review we aim to provide up-to-date and evidence-based answers to the common questions regarding the diagnosis of isolated mild fetal ventriculomegaly (VM). A literature search was performed to identify all reports of antenatal VM in the English language literature. In addition, reference lists of articles identified using the search were scrutinized to further identify relevant articles. Fetal mild VM is commonly defined as a ventricular atrial width of 10.0-15.0 mm, and it is considered isolated if there are no associated ultrasound abnormalities. There is no good evidence to suggest that the width of the ventricular atria contributes to the risk of neurodevelopmental outcome in fetuses with mild VM. The most important prognostic factors are the association with other abnormalities that escape early detection and the progression of ventricular dilatation, which are reported to occur in about 13% and 16% of cases, respectively. Most infants with a prenatal diagnosis of isolated mild VM have normal neurological development at least in infancy. The rate of abnormal or delayed neurodevelopment in infancy is about 11%, and it is unclear whether this is higher than in the general population. Furthermore, the number of infants that develop a real handicap is unknown. There are limitations of existing studies of mild VM. Although they address many of the relevant questions regarding the prognosis and management of fetal isolated mild VM, there is a lack of good-quality postnatal follow-up studies. The resulting uncertainties make antenatal counseling for this abnormality difficult.

The neurocognitive outcome of mild isolated fetal ventriculomegaly verified by prenatal magnetic resonance imaging

OBJECTIVE

Neurocognitive outcome of preschool children, prenatal diagnosis of isolated mild ventriculomegaly compared with 2 control groups.

STUDY DESIGN

Case-controlled study at the University Hospital of Tel Aviv between October 1999 and December 2002. Study groups consisted of 12 children with bilateral isolated mild ventriculomegaly, and 16 children with unilateral isolated mild ventriculomegaly, mean age 4.4 years, prenatally diagnosed by both ultrasound and fetal magnetic resonanace imaging. Control groups consisted of 16 children with normal prenatal magnetic resonance imaging and 16 regular kindergarten children. A neurodevelopmental examination and the Kaufman Assessment Battery for Children were performed.

RESULTS

The neurodevelopmental and Kaufman scores were within normal range in the study groups. No significant differences between the study and control groups for most measures; however, Kaufman achievement score was significantly lower for the bilateral isolated mild ventriculomegaly group (P < .05) compared with the kindergarten children.

CONCLUSION

Preschool children with isolated mild ventriculomegaly performed within normal range compared with the controls. Nevertheless, a significant percentage of the children demonstrated developmental difficulties, lower achievement scores, justifying early school years follow-up.

The significance of fetal ventriculomegaly: etiology, short- and long-term outcomes

Fetal cerebral ventriculomegaly (VM) is diagnosed when the width of one or both ventricles, measured at the level of the glomus of the choroid plexus (atrium), is > or = 10 mm. VM can result from different processes: abnormal turnover of the cerebrospinal fluid (CSF), neuronal migration disorders, and destructive processes. In a high percentage of cases, it is associated with structural malformations of the central nervous system (CNS), but also of other organs and systems. The rate of associated malformations is higher (> or =60%) in severe VM (>15 mm) and lower (10-50%) in cases of borderline VM (10-15 mm). When malformations are not present, aneuploidies are found in 3-15% of borderline VM; the percentage is lower in severe VM. The neurodevelopmental outcome of isolated VM is normal in > 90% of cases if the measurement of ventricular width is between 10 and 12 mm; it is less favorable when the measurement is > 12 mm.

MRI of the fetal central nervous system and body

MRI is being increasingly used to assess for fetal abnormalities. Although significant progress in the field of fetal MRI has occurred during the past 20 years, continued technical advances will likely contribute to significant growth of the field. Moreover, with continued hardware and software improvements, additional MRI sequences will likely become available. Prenatal MRI complements ultrasound because of larger field-of-view, superior soft tissue contrast, easier and more precise volumetric measurement, and greater accuracy in the demonstration of intracranial and spinal abnormalities. While ultrasound remains the primary modality for fetal imaging, these advantages of MRI make it a valuable adjunct to fetal surgery. Because fetal MRI involves many disciplines, the future of fetal MR will best be achieved through collaborative efforts.

Prenatal mild ventriculomegaly predicts abnormal development of the neonatal brain

BACKGROUND

Many psychiatric and neurodevelopmental disorders are associated with mild enlargement of the lateral ventricles thought to have origins in prenatal brain development. Little is known about development of the lateral ventricles and the relationship of prenatal lateral ventricle enlargement with postnatal brain development.

METHODS

We performed neonatal magnetic resonance imaging on 34 children with isolated mild ventriculomegaly (MVM; width of the atrium of the lateral ventricle >/= 1.0 cm) on prenatal ultrasound and 34 age- and sex-matched control subjects with normal prenatal ventricle size. Lateral ventricle and cortical gray and white matter volumes were assessed. Fractional anisotropy (FA) and mean diffusivity (MD) in corpus callosum and corticospinal white matter tracts were determined obtained using quantitative tractography.

RESULTS

Neonates with prenatal MVM had significantly larger lateral ventricle volumes than matched control subjects (286.4%; p < .0001). Neonates with MVM also had significantly larger intracranial volumes (ICV; 7.1%, p = .0063) and cortical gray matter volumes (10.9%, p = .0004) compared with control subjects. Diffusion tensor imaging tractography revealed a significantly greater MD in the corpus callosum and corticospinal tracts, whereas FA was significantly smaller in several white matter tract regions.

CONCLUSIONS

Prenatal enlargement of the lateral ventricle is associated with enlargement of the lateral ventricles after birth, as well as greater gray matter volumes and delayed or abnormal maturation of white matter. It is suggested that prenatal ventricle volume is an early structural marker of altered development of the cerebral cortex and may be a marker of risk for neuropsychiatric disorders associated with ventricle enlargement.