MRI and US in the evaluation of fetal anomalies: The need to work together

Case Series of Acute Meconium Peritonitis Secondary to Perforation of the Ileum in the Antepartum Period

Perforation of the ileum in the antepartum period resulting in meconial peritonitis is a condition that, although rare, is burdened by several complications. In 80-90% of cases, meconial ileus is the first manifestation of a disease, cystic fibrosis. In the remaining 10-20% of cases, it is caused by other situations, such as prematurity. In most cases, the diagnosis of meconial ileus occurs after birth, although in some cases it can be suspected prenatally, with the finding of a hyperechoic intestine on second trimester ultrasound. The prognosis depends on the gestational age, the location of the obstruction and the presence of fetal abnormalities. Mortality is very high and the recovery of intestinal function in the postoperative course is very high risk. In this case series, we describe two meconial peritonitis and our experience at the center.

Fusion imaging in brain structure measurements on a fetus phantom, combining real-time ultrasound with magnetic resonance imaging

Objectives

To assess synchronisation of MRI and US in measuring foetus phantom head structures; inter‐method, intra‐ and inter‐observer differences on biparietal diameter (BPD), head diameter, anterio‐posterior head diameter (HAP) and lateral ventricle structures (VS).

Methods

Fusion Imaging (FI) has been performed by combining MRI and US simultaneously. Axial scans of 1.5 Tesla MRI on a foetus phantom were acquired and uploaded on a US machine (EPIQ 7G, Philips). A PercuNav US tracker allowed the system to recognise and display the position of the transducer. A fetal phantom tracker was used as a phantom reference. Real‐time US of the phantom head was performed by synchronising the uploaded MRI images using different landmarks. Synchronisation has been assessed by taking measurements after rotating the US probe by 90. Measurements were taken by three different observers twice. Differences in measurements between MRI and US, inter‐, intra‐observer differences in all measurements were assessed.

Results

BPD, HAP and VS measurements before rotation were 0.13 ± 0.06 cm, 0.46 ± 0.09 cm and 0.4 ± 0.23 cm (width) and mean 0.6 ± 0.25 cm (length) larger at MRI than at US using any number of landmarks. After US probe rotation VS were 0.3 ± 0.24 cm in width and 0.3 ± 0.27 cm in length. Intra‐ and inter‐observer differences in all measurements were small.

Conclusions

FI showed good synchronisation in measurements. BPD, HAP and VS were larger at MRI than US, likely a result of the way images are generated. Intra‐, inter‐observer differences between measurements were small. This can be important when reporting geometric measures from FI.

Peste des petits ruminants virus non-structural C protein inhibits the induction of interferon-β by potentially interacting with MAVS and RIG-I

Peste des petits ruminants virus (PPRV) causes an acute and highly contagious disease in domestic and wild small ruminants throughout the world, mainly by invoking immunosuppression in its natural hosts. It has been suggested that the non-structural C protein of PPRV helps in evading host responses but the molecular mechanisms by which it antagonizes the host responses have not been fully characterized. Here, we report the antagonistic effect of PPRV C protein on the expression of interferon-β (IFN-β) through both MAVS and RIG-I mediated pathways in vitro. Dual luciferase reporter assay and direct expression of IFN-β mRNA analysis indicated that PPRV C significantly down regulates IFN-β via its potential interaction with MAVS and RIG-I signaling molecules. Results further indicated that PPRV C protein significantly suppresses endogenous and exogenous IFN-β-induced anti-viral effects in PPRV, EMCV and SVS infections in vitro. Moreover, PPRV C protein not only down regulates IFN-β but also the downstream cytokines of interferon stimulated genes 56 (ISG56), ISG15, C-X-C motif chemokine (CXCL10) and RIG-I mediated activation of IFN promoter elements of ISRE and NF-κB. Further, this study deciphers that PPRV C protein could significantly inhibit the phosphorylation of STAT1 and interferes with the signal transmission in JAK-STAT signaling pathway. Collectively, this study indicates that PPRV C protein is important for innate immune evasion and disease progression.

The use of image fusion in prenatal medicine

Fusion imaging (FI), the simultaneous display of the same anatomical region using two imaging modalities, has been used in other areas of medicine for both diagnosis and guiding interventions. Examples include positron emission tomography-computed tomography (PET-CT) imaging in oncology and ultrasound-magnetic resonance imaging (US-MRI) fusion in biopsies of the prostate gland. The underlying principle is to take advantage of the complementary information in each modality to improve accuracy, be it diagnostic accuracy or targeting accuracy in biopsies. For example, PET-CT overlays the metabolic activity of lesions on the superb spatial and anatomical detail of CT. While the historical mainstay of fetal imaging has been ultrasound, advances in ultrafast MR imaging together with advances in fetal MRI over the past two decades, have resulted in the opportunity to explore fusion imaging in fetal medicine. We present an overview of the principles of US-MRI fusion imaging in prenatal medicine, report our local experience, and review the literature in this emerging area. We share our perspective on how FI can improve diagnostic confidence, be used as an educational tool, and potentially enhance guidance in certain fetal procedures.

Congenital jugular vein phlebectasia or aneurysma: A rare entity in prenatal diagnosis

Vascular malformations arising from the wall of the external jugular vein are rare and appeared most commonly in pediatric population. Here, we present a case of vascular malformation in the left external jugular vein diagnosed in a fetus during third trimester ultrasound. This is the first described case in prenatal diagnosis.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Prenatal diagnosis of congenital heart disease

This review article will guide the reader through the background of prenatal screening for congenital heart disease. The reader will be given insight into the normal screening views, common abnormalities, risk stratification of lesions and also recent advances in prenatal cardiology.

Fetal dental panorama on three-dimensional ultrasound imaging of cleft lip and palate and other facial anomalies

OBJECTIVES

Craniofacial deformities have a high psychosocial impact. The aim of this paper is to improve obstetric ultrasonography and prenatal detection of facial anomalies by providing a new fetal dental panorama.

MATERIAL AND METHODS

The present study describes a new modality to visualize the fetal tooth germs and an easy step-by-step diagnostic approach. Image acquisition was performed between 23 and 32 weeks of gestation using a Voluson E10 GE ultrasound machine with an RM6C transducer (GE Medical Systems, Zipf, Austria). Reconstruction was performed using Omniview from the axial image. Volume contrast imaging (VCI) was used with a thickness of 20 mm, and a render mode that combined "Rx mode" and "surface texture."

RESULTS

The resulting imaging allows a more precise visualization of the fetal dental arch and can be obtained between 14 and 28 weeks of gestation. The presence of dental anomalies can be a clue for the diagnosis of various congenital defects, in particular conditions with a shortage of other physical abnormalities, such as ectodermal dysplasia and Binder syndrome.

CONCLUSIONS

The creation of a precise fetal dental panorama allows an improved detection of facial deformities.

CLINICAL RELEVANCE

With the current paper, we want to increase prenatal diagnostics facial anomalies, and help to establish a tailored multidisciplinary treatment plan. This paper should be of interest to readers who are currently treating patients with craniofacial malformations and readers who are performing diagnostic prenatal sonography.