Prenatal assessment of brain malformations on neuroimaging: an expert panel review.

Brain malformations represent a heterogeneous group of abnormalities of neural morphogenesis, often associated with aberrations of neuronal connectivity and brain volume. Prenatal detection of brain malformations requires a clear understanding of embryology and developmental morphology through the various stages of gestation. This expert panel review is written with the central aim of providing an easy-to-understand roadmap to improve prenatal detection and characterization of structural malformations based on the current understanding of normal and aberrant brain development. The utility of each available neuroimaging modality including prenatal multiplanar neurosonography, anatomical magnetic resonance imaging (MRI), and advanced MRI techniques, as well as further insights from post-mortem imaging have been highlighted for every developmental stage.

Congenital orbital teratoma: A case report with foetal presentation.

Congenital orbital teratomas are rare entities with few case reports detailing their prenatal and perinatal imaging features. We present the case of a congenital orbital teratoma initially detected as cystic lesion on prenatal ultrasound, with foetal and postnatal imaging showing evolution of characteristic MRI appearances. Knowledge of these appearances and the ability to diagnose these rare entities in foetal life can aid management and operative planning in the immediate postnatal period.

Avoiding the antenatal counselling faux pas: bridging the gap between prenatal prognostication and postnatal outcome of closed spina bifida.

PURPOSE: Closed spina bifida (CSB) is rare in prenatal literature, and various lesions are grouped under this broad nosological entity CSB, leading to confusing and misleading prognostic conclusions. METHODS: This is a retrospective observational cohort study of prenatally detected CSB cases using two-dimensional ultrasound, complemented by three-dimensional ultrasonography and foetal MRI in indicated cases, from October 2014 to October 2021 in a tertiary-level single centre. RESULTS: The most common upper vertebral level of CSB was lumbar in 66.6% (10/15). The sub-classification of lesions based on prenatal ultrasound showed an agreement in 53% of the cases. Sixty percent had associated abnormalities identified postnatally, the most common being anorectal malformation seen in 33.3%. On postnatal follow-up, 46.6% had bowel incontinence and bladder dysfunction, and 33.3% developed lower limb deformities. CONCLUSIONS: All CSBs do not have a uniformly favourable prognosis. The prognosis of CSB depends on the pathological type, the presence of associated abnormalities and the management.

The prenatal ultrasonic character and postnatal follow-up of 227 microcystic and macrocystic congenital cystic adenomatoid malformations.

The objective of our study was to compare microcystic and macrocystic congenital cystic adenomatoid malformation (CCAMs) through prenatal characteristics, perinatal outcome, postnatal management and development after consultation in our prenatal diagnosis centre. We conducted a retrospective cohort study of 227 cases prenatally diagnosed as CCAM in our hospital within three years. One hundred and eighty-one cases continued their pregnancy and 46 pregnancies were terminated. One hundred and fifteen of 227 cases were microcystic and 112 were macrocystic. The prenatal ultrasound characteristics of two types showed no statistically significant differences, despite that CVR of macrocystic CCAMs was mildly greater than microcystic. None of recorded cases received surgical intervention in utero. Compared with healthy foetuses, CCAMs presented with higher percentage of polyhydramnios and male foetuses, larger amount of postpartum blood loss and longer duration of NICU hospitalisation. Compared with 46 legal abortions, continued pregnancy cases had a smaller CVR, less polyhydramnios, cardiac shift and hydrops. One hundred and seventy-nine cases were followed up after birth and 174 babies were asymptomatic. Thirty one cases received successful surgical resection. In conclusion, the prenatally diagnosed CCAMs have a good short-term prognosis and conservative management is a reasonable option in asymptomatic fetuses. Microcystic and macrocystic CCAMs both presented similar prenatal courses and perinatal prognoses. Conservative management, prenatally and postnatally, could be accepted in selected cases.Impact statementWhat is already known on this subject? Congenital cystic adenomatoid malformation is a well-known developmental abnormality of the lung. The prognosis for most CCAMs is good, but the prenatal and postnatal management remains controversial.What do the results of this study add? This study is one of the largest case cohorts to conclude that microcystic and macrocystic CCAMs both presented similar prenatal courses and perinatal prognoses. Conservative management is a reasonable option in asymptomatic babies.What are the implications of these findings for clinical practice and/or further research? A comprehensive assessment by an experienced multidisciplinary team is necessary to forbid blinding abortions of CCAMs. Conservative management prenatally and postnatally could be accepted in most asymptomatic cases.

Maternal hyperoxygenation and foetal cardiac MRI in the assessment of the borderline left ventricle.

Using phase-contrast MRI in a foetus with borderline left ventricular hypoplasia at 37 weeks' gestation we showed an increase in pulmonary blood flow during maternal hyperoxygenation. The associated increase in venous return to the left atrium, however, resulted in reversal of the atrial shunt, with no improvement in left ventricular output. The child initially underwent single ventricle palliation with a neonatal hybrid procedure, but following postnatal growth of the left ventricle tolerated conversion to a biventricular circulation at 5 months of age. We conclude that when there is significant restriction of filling or outflow obstruction across the left heart, neither prenatal nor postnatal acute pulmonary vasodilation can augment left ventricular output enough to support a biventricular circulation. Chronic pulmonary vasodilation may stimulate the growth of the left-sided structures allowing biventricular repair, raising the intriguing question of whether chronic maternal oxygen therapy might obviate the need for neonatal single ventricle pallation in the setting of borderline left ventricular hypoplasia.

Prenatal diagnosis of colpocephaly with absent corpus callosum.

Colpocephaly is a rare abnormality of the brain, described as persistence of primitive foetal configuration of lateral ventricles. It has been found in association with several abnormalities of the brain. Herein we report a case of colpocephaly with absent corpus callosum, confirmed antenatally with foetal MRI following diagnostic suspicion based on absent septum pellucidum at prenatal sonography.

Fetal Magnetic Resonance Imaging in Association With Antenatal Ultrasound in the Diagnosis of Caudal Dysgenesis: Report of Two Cases.

Caudal regression syndrome is a relatively rare congenital disorder that consists of a constellation of caudal developmental growth abnormalities and associated soft tissue anomalies. The severity of its spectrum ranges from lumbosacral agenesis to isolated absent coccyx. We report two cases of caudal regression syndrome that were diagnosed in utero at different gestational ages by prenatal ultrasound followed by fetal MRI for a complete assessment of the associated imaging features. When used in association with antenatal ultrasonography, fetal MRI is particularly instructive in the prenatal diagnosis of caudal regression syndrome since it overcomes the limits of obstetric ultrasound, provides additional information, including associated local soft tissue abnormalities and manifestations of syndromic processes, and allows for a more accurate evaluation of the spinal cord.

Foetal magnetic resonance imaging: A necessity or adjunct? A modality comparison of in-utero ultrasound and ultrafast foetal magnetic resonance imaging.

BACKGROUND: Congenital anomalies occur in approximately 2% of newborns, resulting in severe medical, physical and social disabilities. Managing clinicians, therefore, require more confidence in their diagnosis and prognostic accuracy before appropriately counselling the parents regarding termination of pregnancy. OBJECTIVE: The aim of this study was to investigate the role of magnetic resonance imaging (MRI) following the diagnosis of foetal anomalies at a foetomaternal unit of a tertiary South African institution. METHODS: Eighty-eight pregnant women in their late second/third trimester who underwent both an ultrasound (US) at the foetomaternal unit and foetal MRI at the Radiology Department from 01 July 2013 to 30 September 2019 were included in this clinical study conducted at Steve Biko Academic Hospital. RESULTS: Despite the high degree of concurrence (73.9%) between both modalities regarding the main diagnoses, MRI provided additional information in 45.5% of patients and changed the diagnosis in 25% of the patients. It further demonstrated superiority in providing diagnostic information in 97% of cases where the US alone was inadequate to counsel parents regarding the termination of pregnancy, and it completely changed the clinical management in 42% of cases. CONCLUSION: It is clearly evident from this study that foetal MRI is a necessity when termination of pregnancy is being considered following an US conducted by the foetomaternal unit. This allows for a complete foetal assessment and gives the managing clinician sufficient diagnostic confidence to prognosticate the future quality of life of the child.

Overcoming foetal motion using interactive real-time magnetic resonance imaging.

OBJECTIVE: Foetal MRI has become an established image modality in the prenatal diagnosis of CNS anomalies, but image quality can be severely affected by foetal movements. The objective was to overcome these inherent motion problems by applying interactive real-time MRI and to evaluate the diagnostic usefulness of the applied real-time MRI sequence in relation to standard protocols. METHODS: Ten healthy foetuses (gestation week 21·3 ± 0·5) were scanned using a system, which allowed visual feedback and interactive slice positioning in real time. The data were compared to a control group of 14 healthy foetuses (gestation week 21·0 ± 0·8) who had previously been scanned using standard MRI. Comparisons were carried out by two radiologists with regard to cerebral anthropometric sizes, presence of important brain structures, degree of movement, clinical image value, image quality and ability to obtain correct slice planes. RESULTS: Two out of eight anthropometric sizes were statistically different between the two groups. Representation of cerebral structures was found in 70-100% in the real-time group. No statistically differences were found in clinical image value and image quality. The mean ability to obtain optimal slice planes was higher in the real-time group, but it was not significant. CONCLUSION: Imaging of the foetal brain using the proposed interactive real-time MRI system is a promising alternative to traditional foetal MRI for anthropometrics or as a supplement for the representation of foetal brain structures in cases in which foetal motion causes challenges in relation to obtaining optimal slice planes using conventional MRI techniques.

Antenatal diagnosis and outcome of agenesis of corpus callosum: A retrospective review of 33 cases.

OBJECTIVE: To present antenatal sonographic findings and postnatal outcome of a population of foetuses diagnosed with agenesis of corpus callosum. MATERIAL AND METHODS: The database of our ultrasound laboratory was retrospectively searched for cases of agenesis of the corpus callosum suspected at antenatal sonography between 2002 and 2012. The following variables were assessed: maternal age, gestational age at diagnosis, gender, any additional cerebral and extra-cerebral malformations, results of karyotype analysis and pregnancy and foetal/neonatal outcomes. RESULTS: During the study period, 33 foetuses with agenesis of the corpus callosum were identified antenatally, with a male preponderance. The mean maternal age was 28.48 years. In all cases, pre/postnatal MRI and/or necropsy were performed in order to confirm the diagnosis. Among those, there were additional brain findings in 23 (69.7%) and additional extra-cerebral anomalies in 3 (9.1%) foetuses. Karyotype analysis was performed in 21 of 33 (63.6%) cases. As for pregnancy outcome, the pregnancy was terminated in 14 (42.4%) of the remaining 19 foetuses; eighteen (54.5%) were delivered near term and one (3.1%) who was delivered prematurely died during the neonatal period. CONCLUSION: The diagnosis of congenital brain malformation is a challenging issue, since additional findings have a considerable effect on prognosis; detailed examination with genetic counselling should be performed.

Comparison of foetal US and MRI in the characterisation of congenital lung anomalies.

OBJECTIVES: To compare the accuracy of prenatal ultrasonography (US) to magnetic resonance imaging (MRI) in the characterisation of congenital lung anomalies, and to assess their agreement with final diagnosis. To evaluate the influence of additional MRI information on therapeutic management. METHODS: 26 prenatal congenital lung anomalies detected consecutively between 2006 and 2012 were retrospectively evaluated. Lesions were initially observed at prenatal US and further investigated with MRI. Prenatal US and MRI imaging findings, and suggested diagnosis were compared with the final diagnosis, obtained from autopsies (4), pathological evaluation following surgical resection (15) and postnatal imaging studies (7). RESULTS: Postnatal diagnoses included 7 congenital pulmonary airway malformations, 8 complex lesions, 7 overinflations, 1 sequestration, 1 bronchogenic cyst, 1 blastoma and 1 bilateral lymphangioma. Suggested prenatal US and MRI diagnosis was correct in 34.6% and 46.2% of patients, respectively, mainly isolated lung lesions with typical imaging findings. Nonspecific imaging findings at US and MRI studies were observed in 38.4% of cases. In 42% of the operated anomalies, pathological dissection revealed the presence of complex anomalies. MRI changed the US diagnosis, but not the further management in 9.7% of the lesions. CONCLUSIONS: Prenatal US and MRI showed a high accuracy in the diagnosis of isolated congenital lung lesions with typical imaging findings. However, overall characterisation rates were low, because of both a high percentage of complex lesions and of lesions with nonspecific imaging findings. MRI was better than US in characterising complex lesions, but its additional information did not influence therapy decisions.