Postnatal Imaging Findings Research Articles

Imaging and outcomes of fetal adrenal hemorrhage: A systematic review.

To describe prenatal and postnatal imaging findings of fetal adrenal hemorrhage (FAH) and its associated perinatal outcomes, including frequency of postnatal surgical intervention. A systematic literature review of seven electronic databases was conducted from inception until January 2022, with 2008 articles identified reporting prenatally identified fetal adrenal masses. Studies with confirmed FAH diagnosis were included. Quality and risk assessment were evaluated. Thirty-five studies, including 102 FAH cases, were analyzed. FAH was commonly described as cystic (28/90, 31%), anechoic (25/90, 28%), or mixed echogenic (14/90, 16%) on ultrasound. Outcome data were available for 65 cases (64%) of FAH: 9% (6/65) resolved prenatally, 35% (23/65) resolved postnatally, 34% (22/65) regressed in size after birth, and 22% (14/65) persisted postnatally. Overall, 25% (16/65) of cases underwent postnatal surgical intervention. Neuroblastoma was suspected in all 16 surgical cases. Only one case (1/16, 6%) confirmed a cystic hematoma with microscopic islets of neuroblastoma in situ on pathology. Prenatal diagnosis of FAH is challenging due to the significant heterogeneity of ultrasound findings. Final pathology did not support the need for surgical intervention. Persistent postnatal FAH warrants shared decision making for further management based on the clinical presentation.

Fetal agenesis of the septum pellucidum: Ultrasonic diagnosis and clinical significance.

To describe the prenatal ultrasound (US) findings, genetic results, and clinical outcomes of fetuses with suspected agenesis of the septum pellucidum (ASP) in the Chinese population. This retrospective, single-center study included a cohort of fetuses with ASP diagnosed by prenatal imaging over a 10-year period. We evaluated US findings, associated anomalies, genetic results, and clinical outcomes. Prenatal and postnatal imaging findings were compared as well as the clinical outcome of delivery. Ninety patients were included, with a median follow-up time of 36months (1-96months). Thirty-six fetuses (40%) with isolated ASP were diagnosed by prenatal US or magnetic resonance imaging (MRI); 39 cases (43.3%) had ASP with central nervous system malformations and 15 cases (16.6%) had ASP with non-CNS abnormalities. Additional imaging findings were supplemented with prenatal MRI in 13 cases. Genetic tests were performed on 32 patients, of whom six had abnormalities. Prenatal US results of 40 patients (40/70) diagnosed by referral hospitals did not correspond to our findings. Of the 38 patients with postnatal records, 11 had abnormal neurological development. The outcome of an isolated ASP is usually favorable; however, neurological developmental delay is commonly observed if it is combined with other malformations.

Torcular Dural Sinus Malformation: Fetal and Postnatal Imaging Findings and Their Associations With Clinical Outcomes

BackgroundTorcular dural sinus malformations (tDSMs) are rare vascular malformations that present in fetuses and infants. Existing data on prognostic imaging features, as well as the associated morbidity and mortality, are limited and variable. We therefore reviewed cases of tDSMs diagnosed on fetal magnetic resonance imaging (MRI) at our referral center to identify pre- and postnatal MRI imaging features associated with long-term outcomes. MethodsWe searched our imaging database for fetal and postnatal MRI reports of tDSM cases. The electronic medical record was then reviewed for pre- and postnatal clinical data, including follow-up imaging. Neurological outcomes were characterized using the previously reported scale based on the Bicêtre Score. Imaging features association with outcome scores were compared using the Fisher exact test. ResultsSixteen cases of tDMS diagnosed by fetal MRI with postnatal clinical follow-up were identified, 11 of whom underwent postnatal MRI. The majority of cases of tDSM (73%) decreased in size or resolved on postnatal follow-up study without treatment. Restricted diffusion and parenchymal hemorrhage on fetal MRI were the only imaging features identified significantly associated with unfavorable neurological outcome or death, present in two patients with poor outcomes (two of two) and only one with a normal outcome (one of 14) (P = 0.025). ConclusionsFindings of tDSM on fetal MRI most often regress and/or resolve with normal or mild neurological outcomes, with the most significant predictor of poor outcome being the presence of parenchymal injury on fetal MRI. In addition, a subset will present with venolymphatic malformations.

Use of magnetic resonance imaging in the diagnosis of fetal vertebral abnormalities in utero: a single-center retrospective cohort study.

Magnetic resonance imaging (MRI) has been used increasingly as an adjunct examination to ultrasound (US) for the evaluation of fetal anomalies. The purpose of this study was to determine whether the accuracy and confidence of diagnosing fetal vertebral anomalies are improved with MRI. We also assessed whether fetal MRI provides additional information when diagnosing fetal vertebral anomalies. We performed a single-center, retrospective study of 127 pregnant women with fetuses suspected of having vertebral anomalies on US examination; women also underwent fetal MRI scanning. Comparisons of diagnostic accuracy and confidence were made between MRI and US for the identification of fetal vertebral anomalies. We also assessed any additional information provided by MRI. McNemar's paired binomial test, chi-square test, or Fisher's exact test were used to compare the diagnostic ability between MRI and US. In all cases, postnatal or postmortem imaging findings were used as reference standards. A total of 127 participants were recruited between December 2015 and January 2021. Fetal vertebral anomalies were detected in 63.8% (81/127) cases and found to be negative in 36.2% (46/127) of cases at follow up. The diagnostic accuracy of vertebral anomalies was 46.9% (38/81) for US and 84.0% (68/81) for MRI [difference, 37.1%; 95% confidence interval (CI): 27% to 48%; P<0.001]. Both MRI and US were concordant and correct in 36.2% (46/127) of fetuses; MRI provided additional information for 16.5% (21/127) of fetuses, and corrected US diagnoses of 36.2% (46/127) of fetuses; both MRI and US were not consistent with postnatal findings in 10.2% (13/127) of fetuses, and the remaining fetus (0.8%, 1/127) was diagnosed correctly using US but failed to be diagnosed by MRI. Diagnoses were reported with high confidence using MRI in 95.3% (121/127) of cases and 73.2% (93/127) using US. Fetal vertebral MRI improves the accuracy and confidence of diagnosing fetal vertebral anomalies. This finding indicates that fetal MRI supplements the information provided by US and that MRI may be a good complement in selected fetuses, when US can either not achieve a definite diagnosis or there is doubt regarding its reliability. Thus, MRI may be used to inform prenatal counseling and management decisions.

Prenatal MR Imaging Phenotype of Fetuses with Tuberous Sclerosis: An Institutional Case Series and Literature Review.

Most patients with tuberous sclerosis complex (TSC) do not receive prenatal diagnosis. Our aim was to describe MR imaging findings to determine the following: 1. Whether normal fetal MR imaging is more common in fetuses imaged at ≤24 weeks' gestation compared with >24 weeks 2. The frequency of cardiac rhabdomyoma 3. The range of MR imaging phenotypes in fetal tuberous sclerosis complex. Our institutional fetal MR imaging data base was searched between January 1, 2011 and June 30, 2021, for cases of TSC confirmed either by genetic testing, postnatal imaging, postmortem examination, or composite prenatal imaging findings and family history. A MEDLINE search was performed on June 8, 2021. Forty-seven published cases and 4 of our own cases were identified. Normal findings on fetal MR imaging were seen at a lower gestational age (mean, 24.7 [SD, 4.5 ] weeks) than abnormal findings on MR imaging (mean, 30.0 [SD, 5.3] weeks) (P = .008). Nine of 42 patients with abnormal MR imaging findings were ≤24 weeks' gestation. Subependymal nodules were present in 26/45 cases (57.8%), and cortical/subcortical lesions, in 17/46 (37.0%). A foramen of Monro nodule was present in 15 cases; in 2/7 cases in which this was unilateral, it was the only abnormal cerebral finding. Cardiac rhabdomyoma was absent in 3/48 cases at the time of fetal MR imaging but was discovered later. Megalencephaly or hemimegalencephaly was observed in 3 cases. Fetuses with abnormal cranial MR imaging findings were older than those with negative findings. Fetal hemimegalencephaly and megalencephaly should prompt fetal echocardiography. Cardiac rhabdomyoma was not always present at the time of fetal MR imaging.

Pre- and Post-Natal Brain Imaging Findings detected in Twin Anemia Polycythemia Sequence

Twin Anemia Polycythemia Sequence (TAPS) carries a high risk for neurological morbidity, especially in the anemic twins. Our aim was to determine the rate and risk factors for fetal brain lesions in cases of TAPS.

Myelomeningocele-Chiari II malformation-Neurological predictability based on fetal and postnatal magnetic resonance imaging.

ObjectiveThis systematic comparison between pre‐ and postnatal imaging findings and postnatal motor outcome assesses the reliability of MRI accuracy in the prognostication of the future long‐term (mean, 11.4 years) ambulatory status in a historic group of postnatally repaired myelomeningocele (MMC) cases.MethodsA retrospective, single‐center study of 34 postnatally repaired MMC patients was performed. We used fetal and postnatal magnetic resonance imaging (MRI) to compare the fetal and postnatal radiological lesion level to each other and to the postnatal ambulatory level as a standard of reference and analyzed Chiari II malformation characteristics.ResultsIn 13/15 (87%) and 29/31 (94%) cases, the functional level was equal to or better than the prenatal and postnatal radiological lesion level. A radiological lesion level agreement within two segments could be achieved in 13/15 (87%) patients. A worse than expected functional level occurred in cases with Myelocele (2/3 patients), coexistent crowding of the posterior fossa (2/3 patients) and/or abnormal white matter architecture, represented by callosal dysgenesis (1/3 patients). In all patients (2/2) with a radiological disagreement of more than two segments, segmentation disorders and scoliosis were observed.ConclusionFetal and postnatal MRI are predictive of the long‐term ambulatory status in postnatally repaired MMC patients.

Imaging of fetal lymphangiectasias: prenatal and postnatal imaging findings.

Lymphangiectasias are lymphatic malformations characterized by the abnormal dilation and morphology of the lymphatic channels. The classification and treatment of these disorders can be challenging given the limited amount of literature available in children. Various imaging modalities are used to confirm suspected diagnosis, plan the most appropriate treatment, and estimate a prognosis. Prenatal evaluation is performed using both prenatal US imaging and fetal MRI. These modalities are paramount for appropriate parental counseling and planning of perinatal care. During the neonatal period, chest US imaging is a useful modality to evaluate pulmonary lymphangiectasia because other modalities such as conventional radiography and CT display nonspecific findings. Finally, the recent breakthroughs in lymphatic imaging with MRI have allowed us to better classify lymphatic disorders. Dynamic contrast-enhanced lymphangiography, conventional lymphangiography and percutaneous lymphatic procedures offer static and dynamic evaluation of the central conducting lymphatics in children, with excellent spatial resolution and the possibility to provide treatment. The purpose of this review is to discuss the normal and abnormal development of the fetal lymphatic system and how to best depict it by imaging during the prenatal and postnatal life.

Pseudo-Roberts Syndrome: An Entity or Not?

Background: Roberts syndrome is a genetic disorder characterized by tetra-phocomelia with abnormalities of ESCO2. We report a male stillborn with tetra-phocomelia and no ESCO2 mutation. Case report: Pre- and post-natal imaging and autopsy findings included schizencephaly, phocomelia of four limbs, micrognathia, oligodactyly, and cardiopulmonary malformations. Microcephaly on pre-natal imaging was not confirmed by autopsy examination. Karyotype, prenatal chromosome microarray and ESCO2 gene testing were normal. Conclusion: Given the various skeletal anomalies found on autopsy and imaging evaluations, at least phenotypically, our case appeared to conform into Roberts syndrome spectrum. Since the infant did not have the mutation associated with this disorder, this infant could be labeled as the first report of a pseudo-Roberts syndrome because many of his phenotypic anomalies are characteristic of Roberts syndrome in absence of the ESCO2 gene mutation.

Prenatal and postnatal MRI imaging findings of intracranial parasitic fetus: a case report

Fetus in fetu (FIF) is an extremely rare anomaly. It is predominantly seen retroperitoneally in 80% of cases but can present at atypical sites like the skull, sacrum, scrotum and the mouth. We reported a rare case of intracranial parasitic fetus. We described the prenatal and postnatal MRI findings of the case. There was no obvious spinal signal on the imaging findings at 35weeks of gestation. However, the postnatal MRI revealed spinal column signal at 5months and 11days.

Long-term postnatal outcome of fetuses with prenatally suspected septo-optic dysplasia.

ABSTRACTObjectivesSepto‐optic dysplasia (SOD) is a clinical syndrome characterized by varying combinations of optic nerve hypoplasia, pituitary gland hypoplasia and abnormal cavum septi pellucidi. It is suspected on prenatal imaging when there is non‐visualization or hypoplasia of the septal leaflets. Long‐term postnatal outcomes of fetuses with prenatally suspected SOD have been documented poorly. The aims of this study were to describe the natural history of deficient septal leaflets, to quantify the incidence of postnatally confirmed SOD and to document the visual, endocrine and long‐term neurodevelopmental outcomes of these infants.MethodsThis was an observational retrospective study of all fetuses with prenatal imaging showing isolated septal agenesis, assessed at a single tertiary center over an 11‐year period. Pregnancy, delivery and neonatal outcomes and pre‐ and postnatal imaging findings were reviewed. Neonatal evaluations or fetal autopsy reports were assessed for confirmation of SOD. Ophthalmologic, endocrine, genetic and long‐term developmental evaluations were assessed. Imaging findings and outcome were compared between infants with and those without postnatally confirmed SOD.ResultsOf 214 fetuses presenting with septal absence on prenatal ultrasound and magnetic resonance imaging (MRI), 18 (8.4%) were classified as having suspected isolated septal agenesis suspicious for SOD. Uniform prenatal MRI findings in cases with suspected SOD included remnants of the leaflets of the cavum septi pellucidi, fused forniceal columns, normal olfactory bulbs and tracts and a normal optic chiasm. Twelve fetuses were liveborn and five (27.8%) had postnatally confirmed SOD. Only two of these five fetuses had additional prenatal imaging features (pituitary cyst, microphthalmia and optic nerve hypoplasia) supporting a diagnosis of SOD. The other three confirmed SOD cases had no predictive prenatal or postnatal imaging findings that reliably differentiated them from cases without confirmed SOD. Visual and endocrine impairments were present in two (40%) and four (80%) cases with confirmed SOD, respectively. In those with visual and/or endocrine impairment, developmental delay (median age at follow‐up, 2.5 (interquartile range, 2.5–7.0) years) was common (80%) and mostly severe. Neonates with isolated septal agenesis and a lack of visual or endocrine abnormalities to confirm SOD had normal development.ConclusionsOnly a quarter of fetuses with isolated septal agenesis suggestive of SOD will have postnatal confirmation of the diagnosis. Clinical manifestations of SOD are variable, but neurodevelopmental delay may be more prevalent than thought formerly. © 2020 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Clinical Outcome of Children With Corpus Callosum Agenesis

BackgroundAgenesis of the corpus callosum is a rare congenital brain malformation that can be associated with other cerebral malformations and/or underlying genetic causes. Prenatal counseling is hampered due to the lack of reliable long-term data on neurodevelopmental outcome. MethodsSince 2010, a total of 23 children with agenesis of the corpus callosum (mean age 3.8 years, range 0.7 to 9.7 years) were registered in our ACC outpatient clinic and diagnosed in a standardized manner; the data were analyzed retrospectively. Prenatal and postnatal imaging, associated malformations, genetic and clinical findings, and psychological testing (Bayley Scales, Kaufman Assessment Battery for Children II, Snijders-Oomen Non-verbal Test, Wechsler Preschool and Primary Scale I-III) were included. The clinical outcome was classified as “normal” (intelligence quotient 85 to 115, unremarkable motor skills), “moderate developmental delay” (intelligence quotient 70 to 85, mild motor abnormalities), and “severe developmental delay” (intelligence quotient less than 70, severe movement disorder). ResultsIsolated corpus callosum malformation was diagnosed in 15 of 23 (65%), associated cerebral malformations in four of 23 (17%), and associated cerebral malformations plus intracranial cyst in four of 23 (17%) children. Prenatal diagnosis changed in nine of 23 (39%) cases. Overall, a normal outcome or moderate or severe developmental delay was present in 15 of 23 (65%) or five of 23 (22%) or three of 23 (13%) children, respectively. Also six of eight children with associated cerebral malformations showed normal outcome. ConclusionOur findings support the notion that developmental outcome is favorable in about two-thirds of children with prenatally diagnosed agenesis of corpus callosum. However, the individual outcome in children with agenesis of corpus callosum is difficult to predict. Even children with correctly characterized phenotypes show a variety of outcomes, making prenatal counseling challenging.

A boy with a congenital cerebellar mass

Tumorigenesis of medulloblastoma is believed to be associated with granule cell progenitor neurogenesis of the cerebellum. Nevertheless, congenital medulloblastomas are rarely found. Here, we report a case of congenital medulloblastoma that showed spontaneous albeit transient regression. A one-month-old baby presented with abnormal antenatal and postnatal imaging findings. Upon ultrasonography at 26 weeks of gestational age, Dandy-Walker malformation with vermian hypoplasia and cystic change was suspected. Brain MRI at 1 week after birth revealed gadolinium-enhancing lesions in the cerebellum with apparent infiltrative features along the cerebellar folia accompanied by three independent cysts in the upper and inferolateral sides of the lesion. Serial MRIs taken up to 5 months of age showed a decrease in the size and extent of enhancing solid portions. The baby did not show any abnormal signs or developmental delay. MRI at the age of 7 months showed enlargement of the lesion, and surgery was performed. The lesion was diagnosed as medulloblastoma with histologically extensive nodularity (MBEN), genetically SHH-activated and TP53-wildtype. This case provides an unusual chance of observing an early phase of medulloblastoma development and raises a suspicion that medulloblastoma may initiate itself very early in cerebellar organogenesis and progress later at a certain time of postnatal development.

Anterior urethral valves – A rare but challenging congenital pathology

Anterior urethral valves (AUV) and associated anterior urethral diverticula (AUD) are a rare cause of congenital lower urinary tract obstruction. They occur 25-30 times less frequently than posterior urethral valves (PUV) and historically tend to have a less aggressive presentation and outcome. However, due to the low incidence, little is known about management and long-term prognosis. We aim to evaluate the outcomes after AUV valve ablation and compare this group to a previously studied PUV cohort. In this IRB-approved study, we retrospectively identified all patients from 2002 to 2017 undergoing valve ablation using CPT code 52400. Charts were manually reviewed to identify AUV patients, their presenting symptoms, timing of diagnosis, pre and postnatal imaging findings, age at presentation and valve ablation, creatinine, recurrences, additional surgeries and follow-up. The AUV group was then compared to a previously studied PUV cohort of 104 patients from our institution. Nine AUV patients were identified. Only four (44%) patients were diagnosed prenatally. Three (33%) patients were diagnosed neonatally, one for weak stream/dribbling and two for febrile UTIs. The remaining two patients were diagnosed at ages 3 and 4 due to dysuria and penile swelling with micturition. Patients presenting later in life had no evidence of renal dysfunction or VUR. All patients underwent primary TUR-AUV (1 laser, 4 cold knife, 4 cautery), but 55% had residual valves and/or diverticula identified on routine postoperative imaging in two patients and due to development of clinic symptoms in three patients. All five patients with recurrences underwent repeat endoscopic evaluation, and thereafter two patients required urethral reconstruction. In contrast, only 15% (16/104) of PUV patients required re-TUR (p=0.01). At an average follow-up time of 4.24 years (range 0.6-11.4 years), 44% of patients had no evidence of CKD, and two patients (22%) had progressed to CKD of at least stage IIIA, compared to 21.4% in the PUV cohort at a mean follow-up of 2.3 years. The overall incidence of AUV is low, making it difficult to characterize these patients definitively. However, despite a milder phenotype and later presentation in most AUV patients, they do require more aggressive surgical treatment for complete resolution of the AUV. Furthermore, the long-term renal outcomes appear more severe than previously reported. The poorer outcomes of AUV patients both with respect to recurrence and long-term CKD indicate that close urologic follow-up is essential in this group.

Accuracy of prenatal and postnatal imaging for management of congenital lung malformations

PurposeThe purpose of this study was to compare the accuracy of prenatal and postnatal imaging modalities for evaluation and management of congenital lung malformations (CLMs). MethodsA retrospective review was performed of all fetuses evaluated for a CLM between December 2001 and January 2018. Pre and postnatal imaging findings, operative treatment, and patient outcomes were collected. Patients were included in analysis if they had fetal imaging (US and/or fetal MRI), a postnatal chest CT, and surgical pathology. ResultsOver the study period, we identified 157 patients with prenatal imaging that also had a follow-up with postnatal chest CT at a median age of 2.1 [1.4, 3.2] months. Of these, 75% (n = 117) had surgical resection. Diagnostic accuracy (DA) for localization of unilobar lesions was 100% for pre- and postnatal imaging and 97% vs 98% for multilobar disease, respectively. On comparison for identification of aberrant vasculature and pathology prediction, pre- and postnatal imaging DAs were similar. However, postnatal CT had the highest specificity for diagnosing lesions overall (p < 0.05). ConclusionPrenatal imaging provides valuable information for counseling and possible fetal intervention. However, this study suggests that postnatal CT scan continues to provide important information for preoperative counseling and surgical management. Type of studyRetrospective study. Level of evidenceLevel IV.

Ductus Venosus Agenesis and Fetal Malformations: Report of Four Cases

Background: The agenesis of the ductus venosus (DVA) is a rare condition with a variable prognosis that relies partly on the presence of associated conditions. Therefore, the prenatal evaluation should include a careful examination of fetal circulation, particularly the umbilical and portal venous malformations.Methods In this study, we describe four cases of DVA diagnosed at our institution. For each case, we access the patient’s files in order to extract the following information: gestational age, umbilical vein connection, pre-natal imaging findings, gestational age at delivery or at pregnancy termination, fetal outcomes, post-natal imaging findings, post-mortem findings and karyotype.Results From the four cases included, two were diagnosed in the first trimester and the other two cases in the second trimester of gestation. Prenatal ultrasound studies revealed an intrahepatic shunt in one case and an extrahepatic shunt in three cases. In one case, the karyotype was not performed, whereas the other three had a normal karyotype. Cardiac anomalies were found in three of the four fetuses. All but one case presented with extracardiac abnormalities. None of the cases developed hydrops. Two cases are currently alive and well, one termination of pregnancy occurred at 25 weeks of gestation and one case died at 14 days during surgical correction of a complex cardiac malformation.Conclusions Clinicians should be aware of different and important findings during the fetal examination, which can be indicative of a DVA, and, when suspected, serial revaluations should be scheduled in order to identify any malformation.

Neurodevelopmental outcomes in children with prenatally diagnosed corpus callosal abnormalities

ObjectiveAlthough corpus callosal abnormalities are among the most common brain malformations detected prenatally, few previous studies have described the neurodevelopmental outcomes of children with this condition. The aim of our study was to evaluate the neurodevelopmental outcomes and associated clinical features of children with corpus callosal abnormalities diagnosed by prenatal ultrasonography. MethodsBetween July 2011 and July 2016, forty-nine children with corpus callosal abnormalities were born in Asan Medical Center Children’s Hospital. Neurodevelopmental assessments were conducted in 40 patients at a median age of 24.8 months using the Bayley Scales of Infant Development II or the Korean Infant and Child Development Test. Patients were categorized according to their postnatal magnetic resonance imaging (MRI) findings and accompanying anomalies. Baseline characteristics and developmental outcomes of each group were compared. ResultsIsolated agenesis or hypoplasia of the corpus callosum was found in 16 (32.7%) patients, other associated central nervous system (CNS) abnormalities were found in 28 (57.1%) patients, and non-CNS abnormalities were found in 11 (22.4%) patients. Among the 40 patients who underwent developmental assessment, 18 (45.0%) showed normal development and 10 (25.0%) showed moderate-to-severe global developmental delay. Seven of the twelve (58.3%) patients with isolated corpus callosal abnormalities showed normal development. The combination of corpus callosal abnormalities with non-CNS anomalies was significantly associated with developmental delay (odds ratio 2.5, 95% confidence interval 1.6–3.9, p = 0.001). Conversely, children with isolated corpus callosal abnormalities showed relatively favorable neurodevelopmental outcomes. ConclusionAppropriate evaluation and comprehensive therapeutic approaches are strongly recommended for neonates who present with corpus callosal abnormalities combined with additional anomalies.

Central Nervous System Effects of Intrauterine Zika Virus Infection: A Pictorial Review.

Relatively few agents have been associated with congenital infections involving the brain. One such agent is the Zika virus, which has caused several outbreaks worldwide and has spread in the Americas since 2015. The Zika virus is an arbovirus transmitted by infected female mosquito vectors, such as the Aedes aegypti mosquito. This virus has been commonly associated with congenital infections of the central nervous system and has greatly increased the rates of microcephaly. Ultrasonography (US) remains the method of choice for fetal evaluation of congenital Zika virus infection. For improved assessment of the extent of the lesions, US should be complemented by magnetic resonance (MR) imaging. Postnatal computed tomography and MR imaging can also unveil additional findings of central nervous system involvement, such as microcephaly with malformation of cortical development, ventriculomegaly, and multifocal calcifications in the cortical-subcortical junction, along with associated cortical atrophy. The calcifications may be punctate, dystrophic, linear, or coarse and may follow a predominantly bandlike distribution. A small anterior fontanelle with prematurely closed sutures is also observed with Zika virus infection. In this review, the prenatal and postnatal neurologic imaging findings of congenital Zika virus infection are covered. Radiologists must be aware of this challenging entity and have knowledge of the various patterns that may be depicted with each imaging modality and the main differential diagnosis of the disease. As in other neurologic infections, serial imaging is able to help demonstrate the progression of the findings. ©RSNA, 2017.

Prenatal diagnosis of bowel malposition using T2-weighted fetal MRI sequences.

The goal of this study was to investigate the capability of T2-weighted magnetic resonance imaging (MRI) in revealing fetal bowel malposition. All fetal MRI examinations (excluding central nervous system MRI examinations) performed in our department from January 2005 to January 2014 were retrospectively studied by 2 independent observers for situs, stomach and jejunum location on T2-weighted images. Patients data were also reviewed for results of ultrasound examinations, MRI indication, and gestational age. Abnormally positioned jejunums were classified into 3 groups: intrathoracic (A), extra-fetal (B) and abnormal intra-fetal (C). Prenatal data were compared to postnatal imaging, surgery or autopsy findings that served as standard of reference. A total of 709 fetal MRI examinations were analyzed. In 64 fetus (9%), the jejunum was not present in the left subgastric area on T2-weighted MR images. In these 64 fetuses, proximal jejunum was intrathoracic (41/64, 64%, group A), extra-fetal (11/64, 17%, group B), or intra-abdominal but abnormally positioned (12/64, 19%, group C). Interobserver agreement was 100%. All diagnoses for fetuses in groups A and B (52 cases) were confirmed postnatally (41 cases) or at autopsy (11 cases). In group C, bowel malposition was suspected after ultrasound in only 2/12 fetuses (16.6%); it was confirmed postnatally in 1 fetus but not confirmed in the remaining one. In the 10 remaining fetuses (83%), malposition was confirmed postnatally although not initially suspected. T2-weighted fetal MR images are useful for the prenatal diagnosis of bowel malposition, even when they are unsuspected on ultrasound examination.

Diagnostic Value of Prenatal MR Imaging in the Detection of Brain Malformations in Fetuses before the 26th Week of Gestational Age.

In several countries, laws and regulations allow abortion for medical reasons within 24-25 weeks of gestational age. We investigated the diagnostic value of prenatal MR imaging for brain malformations within 25 weeks of gestational age. We retrospectively included fetuses within 25 weeks of gestational age who had undergone both prenatal and postnatal MR imaging of the brain between 2002 and 2014. Two senior pediatric neuroradiologists evaluated prenatal MR imaging examinations blinded to postnatal MR imaging findings. With postnatal MR imaging used as the reference standard, we calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the prenatal MR imaging in detecting brain malformations. One-hundred nine fetuses (median gestational age at prenatal MR imaging: 22 weeks; range, 21-25 weeks) were included in this study. According to the reference standard, 111 malformations were detected. Prenatal MR imaging failed to detect correctly 11 of the 111 malformations: 3 midline malformations, 5 disorders of cortical development, 2 posterior fossa anomalies, and 1 vascular malformation. Prenatal MR imaging misdiagnosed 3 findings as pathologic in the posterior fossa. The diagnostic value of prenatal MR imaging between 21 and 25 weeks' gestational age is very high, with limitations of sensitivity regarding the detection of disorders of cortical development.