Today, in parallel with the use of imaging modalities increases in all fields, the use of imaging methods in pregnant women is increasing. Imaging has become an integral component of routine pregnancy follow-up. Imaging provides parents with an early opportunity to learn about the current situation, including prenatal detection of anomalies or diseases, etiology, prognosis, and the availability of prenatal or postnatal treatments. Various imaging modalities, especially ultrasonography, are frequently used for imaging both maternal and fetal imaging. The goal of this review was to address imaging modalities in terms of usefulness and safety, as well as to provide demonstrative examples for disorders. And this review provides current information on selecting a safe imaging modality to evaluate the pregnant and the fetus, the safety of contrast medium use, and summarizes major pathological situations with demonstrative sonographic images to assist radiologists and obstetricians in everyday practice.

Fetal ultrasonographic evaluation is a routine part of pregnancy follow-up, and examination of orbital structures is also part of the routine evaluation. Although orbital developmental anomalies are common in the neonatal period, diagnosis in the intrauterine period is not common. To our knowledge, three cases with a diagnosis of congenital orbital epidermal cysts have been reported in the literature, and two of them had fetal imaging findings. In this article, we present the prepostnatal imaging findings of a case diagnosed with orbital cyst in the fetal period and histopathologically diagnosed as epidermal cyst in the neonatal period.
A 25-year-old woman applied for ultrasonography (USG) examination at 22 weeks of gestation. A 35x45 mm cystic lesion causing proptosis, without solid component and vascularity, surrounding the optic nerve and causing its thinning was observed in the left orbit. In fetal magnetic resonance imaging (MRI), the intraorbital cystic lesion, which was hyperintense on T2W images and hypointense on T1W images, had no relationship with intracranial structures and no solid component. The lesion of the patient, followed up with a multidisciplinary approach, was shown similarly with computed tomography (CT) and magnetic resonance imaging (MRI) in the postnatal period. Subsequently, the patient underwent globe-sparing surgery, and the pathological diagnosis was made as the epidermal cyst.
Orbital epidermal cysts are rarely seen, and detection in the fetal period is even rarer. It should be considered in the differential diagnosis of orbital cystic lesions that cause proptosis in fetal and neonatal periods.

Congenital infections represent a challenging and varied clinical scenario in which the brain is frequently involved. Therefore, fetal and neonatal neuro-imaging plays a pivotal role in reaching an accurate diagnosis and in predicting the clinical outcome. Congenital brain infections are characterized by various clinical manifestations, ranging from nearly asymptomatic diseases to syndromic disorders, often associated with severe neurological symptoms. Brain damage results from the complex interaction among the infectious agent, its specific cellular tropism, and the stage of development of the central nervous system at the time of the maternal infection. Therefore, neuroradiological findings vary widely and are the result of complex events. An early detection is essential to establishing a proper diagnosis and prognosis, and to guarantee an optimal and prompt therapeutic perinatal management. Recently, emerging infective agents (i.e., Zika virus and SARS-CoV2) have been related to possible pre- and perinatal brain damage, thus expanding the spectrum of congenital brain infections. The purpose of this pictorial review is to provide an overview of the current knowledge on fetal and neonatal brain neuroimaging patterns in congenital brain infections used in clinical practice.

OBJECTIVE: To describe the correlation between fetal imaging (in vivo and ex vivo) and neuropathology in two fetuses at early gestational age (GA) with isolated thick corpus callosum (CC), a rare finding whose pathological significance and neuropathology data are scarce.
METHODS: Two fetuses at 21-week GA underwent fetal MRI (fMRI) for suspected callosal anomalies at ultrasound (US). After fMRI results, termination of pregnancy (TOP) was carried out and post-mortem MRI (pmMRI) was performed. Neuropathology correlation consisted in macro and microscopic evaluation with sections prepared for hematoxylin-eosin and immunohistochemistry staining.
RESULTS: Fetal imaging confirmed in both cases the presence of a shorter and thicker CC with respect to the reference standard at the same GA, without a clear distinction between its different parts. Moreover, on pmMRI, an abnormal slightly T2-weighted hyperintense layer along the superior and inferior surface of CC was noted in both cases. At histopathology, these findings corresponded to an increased amount of white matter tracts but also to an abnormal representation of embryological structures that contribute to CC development, naming induseum griseum (IG) and the glioepithelial layer (GL) of the \"callosal sling.\" After reviewing the literature data, we confirmed the recent embryological theory regarding the CC development and provide new insights into the pathophysiology of the abnormal cases.
CONCLUSIONS: An abnormally thick CC at the early fetal period could be associated to an abnormal representation of the midline glia structures, so to result in potential disturbance of the axon guidance mechanism of callosal formation and eventually in CC dysgenesis.

OBJECTIVE: The differential diagnosis for prenatal suprarenal masses (SRMs) is broad and includes neuroblastoma, adrenal hemorrhage, and subdiaphragmatic extralobar pulmonary sequestration (SEPS). We sought to elucidate the appropriate postnatal management for fetuses found to have an SRM.
METHODS: We conducted a retrospective review of patients prenatally diagnosed with SRM at our institution between 1998 and 2018. Prenatal characteristics, imaging, and neonatal outcomes were collected. We also performed a PubMed literature search and pooled analysis of all patients with a prenatally diagnosed SRM previously described in the literature.
RESULTS: The literature review yielded 32 studies, of which 19 were single case reports. In our case series, 12 patients were included. Seven patients were delivered vaginally, one was terminated. Postnatal diagnoses included: SEPS (n = 5), adrenal hemorrhage (n = 3), polycystic kidney (n = 2), splenic cyst (n = 1), and unknown for one patient. All but two of the final diagnoses had been on the initial diagnostic differential. With the exception of the terminated fetus, all remain alive today. On pooled analysis, patients who underwent operative management were diagnosed later 32 versus 24 weeks and had a significant predominance of left-sided lesions (59.5 versus 39.2%). The published literature demonstrates a trend toward observation versus resection over the past 30 years.
CONCLUSIONS: Patients prenatally diagnosed with an SRM have an excellent prognosis. Our series demonstrates a high incidence of SEPS, which were all resected, and adrenal hemorrhage, which were observed with repeat imaging. These patients can be followed with serial postnatal ultrasounds to determine the diagnosis prior to deciding the appropriate treatment.