Re: additional value of fetal magnetic resonance imaging in the prenatal diagnosis of central nervous system anomalies: a systematic review of the literature

Additional value of advanced neurosonography and magnetic resonance imaging in fetuses at risk for brain damage

OBJECTIVE

To assess the additional value of fetal multiplanar (axial, coronal and sagittal) neurosonography and magnetic resonance imaging (MRI) to that of the standard axial ultrasound planes in diagnosing brain damage in fetuses at high risk.

METHODS

This was a prospective, multicenter, observational study. Women were eligible for participation if their fetus was at risk for acquired brain anomalies. Risk factors were congenital infection, alloimmune thrombocytopenia, fetal growth restriction, trauma during pregnancy, fetal hydrops, monochorionic twins and prior ultrasound finding suggestive of an acquired brain anomaly. Examinations of the fetal brain before birth comprised axial ultrasound and advanced neurosonography biweekly and MRI once. After birth, neonatal cranial ultrasound was performed at < 24 h and at term-equivalent age. Neonatal brain MRI was performed once at term-equivalent age. An expert panel blinded to medical information, including imaging findings by the other methods, evaluated the presence of periventricular echogenicity (PVE) changes, peri- and intraventricular hemorrhage (IVH) and changes in basal ganglia and/or thalami echogenicity (BGTE) on ultrasound, and the equivalent signal intensity (SI) changes on MRI. Conclusions on imaging findings were generated by consensus. The children were followed up with examinations for psychomotor development at 1 year of age, using the Touwen examination and Alberta Infant Motor Scale, and at 2 years of age using Bayley Scale of Infant Development-III (BSID-III) and behavioral, sensory profile and linguistic questionnaires; scores > 1 SD below the mean were considered suspicious for neurodevelopmental sequelae.

RESULTS

Fifty-six fetuses were examined, and in 39/56 fetuses, all fetal-imaging modalities were available. PVE/SI changes were observed in 6/39, 21/39 and 2/39 fetuses on axial ultrasound planes, multiplanar neurosonography and MRI, respectively. IVH was found in 3/39, 11/39 and 1/39 fetuses, and BGTE/SI changes in 0/39, 12/39 and 0/39 fetuses, respectively. Outcome was suspicious for neurodevelopmental sequelae in 13/46 infants at 1 year, and at 2 years, 41/41 children had scores within 1 SD of the mean on BSID-III and 20 had scores > 1 SD below the mean on the behavioral (5/38), sensory profile (17/37) and/or linguistic (6/39) questionnaires.

CONCLUSIONS

In this cohort of fetuses at risk for brain damage, the severity of acquired brain anomalies was limited. Nevertheless, multiplanar neurosonography detected more fetal PVE changes, IVH and/or BGTE changes compared to the standard axial ultrasound planes and MRI. Fetal MRI did not demonstrate any anomalies that were not seen on neurosonography. Neurodevelopmental outcome at 2 years of age showed no or mild impairment in most cases. © 2019 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Clinical value of prenatal MRI for diagnosis of isolated ventriculomegaly and prediction of early postnatal developmental outcomes

OBJECTIVE

To investigate the relationship of ventriculomegaly (VM) with postnatal neurological development.

METHODS

Fetuses with isolated VM on MRI (n = 160; VM group) were separated into three subgroups according to lateral ventricle width: subgroup A (10.0-12.0 mm; n = 113), subgroup B (12.1-15.0 mm; n = 37), and subgroup C (>15.0 mm; n = 10). Fifty normal fetuses formed a control group. Post-delivery changes in ventricular width and neurological development were assessed with MRI/ultrasonography and the Gesell Development Schedules (GDS), respectively, at 3, 6, 12, and 18 months.

RESULTS

GDS scores of subgroup A and subgroup B did not differ from that of the controls at 3 and 6 months. Subgroup B scores differed significantly from the control scores at 12 and 18 months. Subgroup C scores differed from the control scores at all-time points (all P < 0.05). In the VM group, GDS scores at 12 and 18 months were significantly different from the scores at 3 months, and the score at 18 months was significantly different from the score at 6 months (P < 0.05 for all).

CONCLUSION

The milder the VM, the more likely it was to disappear or improve in the postnatal period. However, specific postnatal rehabilitation should be considered when fetal ventricular width is greater than 12.1 mm.

Fetal MRI, lower acceptance by women in research vs. clinical setting

AIM

To determine acceptance of pregnant women to undergo fetal magnetic resonance imaging (MRI) examination in research and clinical setting.

METHODS

A prospective study included a research group [part of a study comparing brain ultrasound (US) to MRI in fetuses at risk for acquired brain damage] and a clinical group [fetuses with suspected (brain) anomalies after structural US examination] from 2011 to 2014. All women were advised to use sedatives. MRI declinations, use of sedation, MRI duration and imaging quality were compared between both groups.

RESULTS

Study participation was accepted in 57/104 (55%) research cases. Fetal MRI was performed in 34/104 (33%) research and 43/44 (98%) clinical cases. Reasons to decline study participation were MRI related in 41%, and participation was too burdensome in 46%. Acceptance was highest for indication infection and lowest in alloimmune thrombocytopenia and monochorionic twin pregnancy. Sedatives were used in 14/34 research and 43/43 clinical cases. Scan duration and quality were comparable (21 and 20 min in research and clinical cases, respectively, moderate/good quality in both groups).

CONCLUSIONS

Pregnant women consider MRI more burdensome than professionals realize. Two-third of women at risk for fetal brain damage decline MRI examination. Future studies should evaluate which information about fetal MRI is supportive.