Role of prenatal magnetic resonance imaging in fetuses with isolated mild or moderate ventriculomegaly in the era of neurosonography: international multicenter study

Abstract

Objectives To assess the role of fetal magnetic resonance imaging (MRI) in detecting associated anomalies in fetuses presenting with mild or moderate isolated ventriculomegaly (VM) undergoing multiplanar ultrasound evaluation of the fetal brain. Methods This was a multicenter, retrospective, cohort study involving 15 referral fetal medicine centers in Italy, the UK and Spain. Inclusion criteria were fetuses affected by isolated mild (ventricular atrial diameter, 10.0–11.9 mm) or moderate (ventricular atrial diameter, 12.0–14.9 mm) VM on ultrasound, defined as VM with normal karyotype and no other additional central nervous system (CNS) or extra‐CNS anomalies on ultrasound, undergoing detailed assessment of the fetal brain using a multiplanar approach as suggested by the International Society of Ultrasound in Obstetrics and Gynecology guidelines for the fetal neurosonogram, followed by fetal MRI. The primary outcome of the study was to report the incidence of additional CNS anomalies detected exclusively on prenatal MRI and missed on ultrasound, while the secondary aim was to estimate the incidence of additional anomalies detected exclusively after birth and missed on prenatal imaging (ultrasound and MRI). Subgroup analysis according to gestational age at MRI (< 24 vs ≥ 24 weeks), laterality of VM (unilateral vs bilateral) and severity of dilatation (mild vs moderate VM) were also performed. Results Five hundred and fifty‐six fetuses with a prenatal diagnosis of isolated mild or moderate VM on ultrasound were included in the analysis. Additional structural anomalies were detected on prenatal MRI and missed on ultrasound in 5.4% (95% CI, 3.8–7.6%) of cases. When considering the type of anomaly, supratentorial intracranial hemorrhage was detected on MRI in 26.7% of fetuses, while polymicrogyria and lissencephaly were detected in 20.0% and 13.3% of cases, respectively. Hypoplasia of the corpus callosum was detected on MRI in 6.7% of cases, while dysgenesis was detected in 3.3%. Fetuses with an associated anomaly detected only on MRI were more likely to have moderate than mild VM (60.0% vs 17.7%; P < 0.001), while there was no significant difference in the proportion of cases with bilateral VM between the two groups (P = 0.2). Logistic regression analysis showed that lower maternal body mass index (adjusted odds ratio (aOR), 0.85 (95% CI, 0.7–0.99); P = 0.030), the presence of moderate VM (aOR, 5.8 (95% CI, 2.6–13.4); P < 0.001) and gestational age at MRI ≥ 24 weeks (aOR, 4.1 (95% CI, 1.1–15.3); P = 0.038) were associated independently with the probability of detecting an associated anomaly on MRI. Associated anomalies were detected exclusively at birth and missed on prenatal imaging in 3.8% of cases. Conclusions The incidence of an associated fetal anomaly missed on ultrasound and detected only on fetal MRI in fetuses with isolated mild or moderate VM undergoing neurosonography is lower than that reported previously. The large majority of these anomalies are difficult to detect on ultrasound. The findings fr...

Role of prenatal magnetic resonance imaging in fetuses with isolated agenesis of corpus callosum in the era of fetal neurosonography: A systematic review and meta‐analysis

“…The results from this study support our previous findings on the diagnostic accuracy of neurosonography in isolated mild and moderate ventriculomegaly, 9,10 further highlighting the need for a detailed multiplanar assessment of fetal brain, as suggested by ISUOG 2007 guidelines, in the case of a suspected CNS structural defect. 11,39 Despite this, undetected anomalies at ultrasound TA B L E 5 Pooled proportions for the rate of different additional anomalies detected only at MRI in fetuses with isolated complete and partial ACC…”

“…previously reported when a state-of-the-art multiplanar assessment of the fetal brain (neurosonogram) was performed. [9][10][11] The primary aim of this systematic review was to report on the role of fetal MRI in detecting additional anomalies in fetuses with isolated ACC on ultrasound. The secondary aim was to elucidate the rate of additional anomalies detected at MRI according to gestational age at scan and type of ultrasound assessment performed (standard vs dedicated neurosonography).…”

“…We have recently reported that, in fetuses with isolated ventriculomegaly, the rate of additional anomalies found exclusively at fetal MRI was significantly lower than Results: Fourteen studies (798 fetuses) were included. In cases with isolated cACC, 10.9% (95% CI 4.1-20.6) and 4.3% (95% CI 1.4-8.8) additional anomalies were detected by fetal MRI and postnatally, respectively. Stratifying according to the type of ultrasound assessment, the rate of associated anomalies detected only on fetal MRI was 5.7% (95% CI 0.5-16.0) with dedicated neurosonography and 18.5% (95% CI 7.8-32.4) with a standard axial assessment.…”

Does fetal MR alter the management of pregnancy in the diagnosis of isolated corpus callosum agenesis?

“…There is a limited number of publications on the contribution of fetal MR to the gestational termination. In the review of Di Mascio et al, [30] the rate of gestational termination request after standard sonography was 5.1% while it was 2.9% after the fetal MR which was added later. Similar to our study, it can be concluded that we need to investigate other factors rather than the diagnosis type in terms of convincing patients.…”

“…It was reported that maternal body mass index (BMI), the cases with medium-severe level ventriculomegaly more than mild ventriculomegaly and fetal MR conducted after 24 weeks of gestation were among the factors affecting the detection of additional anomaly. [29,30] Although the fetal MR conducted before 24 weeks of gestation also performs well, the cortical and white matter anomalies and intracranial hemorrhage diagnoses were the diagnosis groups which made fetal MR superior at the third trimester. [28,29] According to the literature data, prognosis cannot be predicted in pCCA cases due to the uncertainty of antenatal, postnatal and newborn processes.…”