Situs anomalies on prenatal MRI

Outcomes of pregnancies diagnosed with absent or abnormal fetal gallbladder in a tertiary center

OBJECTIVE

The objective of this study was to investigate the ultrasonographic characteristics and outcomes of fetuses with atypical and non-visualized fetal gallbladder in our tertiary care hospital.

METHODS

A retrospective analysis was conducted on cases in which the fetal gallbladder was not visualized or exhibited atypical characteristics at our institution over a four-year period. The patients were divided into two groups: absent gallbladder and atypical gallbladder. The groups with isolated and additional anomalies were analyzed according to their ante- and postnatal characteristics.

RESULTS

The study comprised 78 patients (37 absent, 41 atypical gallbladder). In the isolated fetal absence of gallbladder group, the gallbladder was visualized in three of 13 patients during antenatal ultrasonographic follow-up and in half of the remaining 10 patients during postnatal follow-up. In the postnatal period, five newborns with absent isolated gallbladder are being followed up with suspicion of biliary atresia and isolated gallbladder agenesis. In the absence of a gallbladder with an additional anomaly group, 58% of fetuses died during the intrauterine and neonatal period. Fetuses in the isolated atypical gallbladder group are being followed as healthy after birth. Pregnancies with atypical gallbladder appearance and additional anomalies resulted in 33% neonatal death, 12% intrauterine demise, and 25% termination of pregnancy.

CONCLUSION

In instances where the fetal gallbladder is not consistently discernible, it is imperative to exercise caution with regard to the possibility of biliary atresia. In the event that the fetal gallbladder exhibits unusual characteristics, a meticulous examination for the presence of additional anomalies is recommended.

The Fetal Spleen in Low-Risk Pregnancies and prior to Preterm Birth: Observational Study of the Role of Anatomical and Functional Magnetic Resonance Imaging

INTRODUCTION

Spontaneous preterm birth complicates ∼7% of pregnancies and causes morbidity and mortality. Although infection is a common etiology, our understanding of the fetal immune system in vivo is limited. This study aimed to utilize T2-weighted imaging and T2* relaxometry (which is a proxy of tissue oxygenation) of the fetal spleen in uncomplicated pregnancies and in fetuses that were subsequently delivered spontaneously prior to 32 weeks.

METHODS

Women underwent imaging including T2-weighted fetal body images and multi-eco gradient echo single-shot echo planar sequences on a Phillips Achieva 3T system. Previously described postprocessing techniques were applied to obtain T2- and T2*-weighted imaging of the fetal spleen and T2-weighted fetal body volumes.

RESULTS

Among 55 women with uncomplicated pregnancies, an increase in fetal splenic volume, splenic:body volume, and a decrease in splenic T2* signal intensity was demonstrated across gestation. Compared to controls, fetuses who were subsequently delivered prior to 32 weeks' gestation (n = 19) had a larger spleen when controlled for the overall size of the fetus (p = 0.027), but T2* was consistent (p = 0.76).

CONCLUSION

These findings provide evidence of a replicable method of studying the fetal immune system and give novel results on the impact of impending preterm birth on the spleen. While T2* decreases prior to preterm birth in other organs, preservation demonstrated here suggests preferential sparing of the spleen.

A Case Report of Dextrocardia with Situs Inversus: A Rare Condition and Its Clinical Importance

Situs inversus totalis (SIT) is a rare medical condition characterized by a complete mirror-image reversal of the normal positioning of the internal organs. Aristotle initially described situs inversus in animals, while Fabricius first characterized it in humans. Although the specific cause is uncertain, there is evidence of autosomal recessive and X-linked inheritance. Before seeking treatment for an unrelated ailment, many people with SIT are unaware of their distinct anatomy, as in our case. The presented case is a 30-year-old female patient from Central Ethiopia, presented to Hakim Gizaw Teaching Hospital outpatient department of medicine with the complaint of right-sided anterior chest pain for five days. Clinically, the apical beat was heard in the right 5th intercostal space. After undergoing an electrocardiogram (ECG), echocardiogram, chest X-ray, and abdominal ultrasound, she was diagnosed with situs inversus totalis. The clinical implications of SIT encompass challenges in diagnosis and procedures, potential congenital cardiac abnormalities, considerations for organ transplantation, and clinical decision-making, particularly in emergency scenarios. Key Clinical Messages. This case highlights the clinical implications of dextrocardia with situs inversus totalis, emphasizing the importance of awareness for accurate diagnosis, procedural challenges, and informed clinical decision-making. Understanding this rare condition is crucial for providing appropriate medical care and to navigate potential complications in affected individuals.

Improving prenatal detection of abdominal supraumbilical anomalies: The sonographic examination of fetal anechoic spaces of upper abdomen revisited

Visualization of the axial plane of the fetal abdomen is mandatory to obtain abdominal biometry in the assessment of fetal growth in the second and third trimesters. The main anatomic landmarks that must be identified in this view include the fetal stomach and the intrahepatic portion of the umbilical vein, which are easily identifiable as they appear anechoic on ultrasound. The gallbladder is the other prominent anechoic structure in this plane. Focused study of the morphological characteristics of, and spatial relationship among, these three anechoic spaces is a simple technique to detect anomalies involving fetal upper abdominal organs. In this review, the sonographic features of those conditions that can be detected using this technique, which was termed the Fetal Examination of the Anechoic Spaces of upper abdomen Technique (FEAST), are classified and illustrated.

Care of the Fetus With Congenital Cardiovascular Disease: From Diagnosis to Delivery

BACKGROUND

The majority of congenital cardiovascular disease including structural cardiac defects, abnormalities in cardiac function, and rhythm disturbances can be identified prenatally using screening obstetrical ultrasound with referral for fetal echocardiogram when indicated.

METHODS

Diagnosis of congenital heart disease in the fetus should prompt assessment for extracardiac abnormalities and associated genetic abnormalities once maternal consent is obtained. Pediatric cardiologists, in conjunction with maternal-fetal medicine, neonatology, and cardiothoracic surgery subspecialists, should counsel families about the details of the congenital heart defect as well as prenatal and postnatal management.

RESULTS

Prenatal diagnosis often leads to increased maternal depression and anxiety; however, it decreases morbidity and mortality for many congenital heart defects by allowing clinicians the opportunity to optimize prenatal care and plan delivery based on the specific lesion. Changes in prenatal care can include more frequent assessments through the remainder of the pregnancy, maternal medication administration, or, in selected cases, in utero cardiac catheter intervention or surgical procedures to optimize postnatal outcomes. Delivery planning may include changing the location, timing or mode of delivery to ensure that the neonate is delivered in the most appropriate hospital setting with the required level of hospital staff for immediate postnatal stabilization.

CONCLUSIONS

Based on the specific congenital heart defect, prenatal echocardiogram assessment in late gestation can often aid in predicting the severity of postnatal instability and guide the medical or interventional level of care needed for immediate postnatal intervention to optimize the transition to postnatal circulation.

Antenatal diagnosis of chorioamnionitis: A review of the potential role of fetal and placental imaging

Chorioamnionitis is present in up to 70% of spontaneous preterm births. It is defined as an acute inflammation of the chorion, with or without involvement of the amnion, and is evidence of a maternal immunological response to infection. A fetal inflammatory response can coexist and is diagnosed on placental histopathology postnatally. Fetal inflammatory response syndrome (FIRS) is associated with poorer fetal and neonatal outcomes. The only antenatal diagnostic test is amniocentesis which carries risks of miscarriage or preterm birth. Imaging of the fetal immune system, in particular the thymus and the spleen, and the placenta may give valuable information antenatally regarding the diagnosis of fetal inflammatory response. While ultrasound is largely limited to structural information, MRI can complement this with functional information that may provide insight into the metabolic activities of the fetal immune system and placenta. This review discusses fetal and placental imaging in pregnancies complicated by chorioamnionitis and their potential future use in achieving non-invasive antenatal diagnosis. This article is protected by copyright. All rights reserved.

Characterization of phenotypic spectrum of fetal heterotaxy syndrome by combining ultrasound and magnetic resonance imaging

OBJECTIVE

Heterotaxy or isomerism of the atrial appendages is a congenital disorder with variable presentation, associated with both cardiac and non-cardiac anomalies, which may have a serious impact on fetal outcome. The aim of this exploratory study was to assess the value of fetal magnetic resonance imaging (MRI), as a complementary tool to ultrasound, for describing the morphological spectrum encountered in heterotaxy.

METHODS

This retrospective study included 27 fetuses that underwent fetal MRI following prenatal suspicion of heterotaxy on ultrasound from 1998 to 2019 in a tertiary referral center. Heterotaxy was classified as left atrial isomerism (LAI) or right atrial isomerism (RAI) based on fetal echocardiography (FE) examination. In addition to routine prenatal ultrasound, fetal MRI was offered routinely to enhance the diagnosis of non-cardiac anomalies, which might have been missed on ultrasound. Prenatal findings on ultrasound, FE and MRI were reviewed systematically and compared with those of postnatal imaging and autopsy reports.

RESULTS

Twenty-seven fetuses with heterotaxy and cardiovascular pathology, of which 19 (70%) had LAI and eight (30%) had RAI, were included. Seven (7/19 (37%)) fetuses with LAI had normal intracardiac anatomy, whereas all fetuses with RAI had a cardiac malformation. All 27 fetuses had non-cardiac anomalies on fetal MRI, including situs and splenic anomalies. In 12/19 (63%) fetuses with LAI, a specific abnormal configuration of the liver was observed on MRI. In three fetuses, fetal MRI revealed signs of total anomalous pulmonary venous connection obstruction. An abnormal bronchial tree pattern was suspected on prenatal MRI in 6/19 (32%) fetuses with LAI and 3/8 (38%) fetuses with RAI.

CONCLUSIONS

Visualization on MRI of non-cardiac anomalies in fetuses with suspected heterotaxy is feasible and can assist the complex diagnosis of this condition, despite its limitations. This modality potentially enables differentiation of less severe cases from more complex ones, which may have a poorer prognosis. Fetal MRI can assist in prenatal counseling and planning postnatal management. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Situs Inversus Totalis in Association With Duodenal Atresia

Situs inversus totalis is the mirror image transposition of the abdominal-thoracic viscera. Approximately one in every 5,000 to 20,000 live births has situs inversus totalis. Most commonly, it is found incidentally and is asymptomatic. A number of malformations, including cardiac, splenic, and gastrointestinal, have been associated with this condition. Coexistence with duodenal atresia is extremely rare, reported in fewer than 30 cases worldwide and one case in Saudi Arabia. We report a preterm neonate who presented with bilious vomiting. Diagnosis of situs inversus totalis with duodenal atresia type III was established and other anomalies were ruled out. The patient was managed surgically by duodenal-duodenostomy and Ladd’s procedure. The report emphasizes the importance of identifying this condition and recognizing the "mirror anatomy" before carrying out an operation. Once the diagnosis is confirmed, surgical intervention must be performed as soon as possible to prevent complications.

Fetal cardiac MRI: a single center experience over 14-years on the potential utility as an adjunct to fetal technically inadequate echocardiography

Unlike ultrasound (US) imaging, foetal magnetic resonance imaging (MRI) is not significantly limited by maternal obesity, oligohydramnios, uterine myoma, twins, and foetal lie, which impair US visualization of the foetus. The present study aimed to introduce our foetal cardiac MRI scanning technology and over 14-years of experience on the potential utility of foetal cardiac MRI examination as an adjunct to foetal technically inadequate echocardiography (Echo). This retrospective review included 1,573 pregnant women [1,619 foetuses (46 twins)] referred for a foetal cardiac MRI because of technically limited Echo. Foetal cardiac MRI was performed using two 1.5 T units. Among the 1,619 foetuses referred for cardiac MRI, 1,379 (85.2%) cases were followed up using postnatal imaging and/or surgery, 240 (14.8%), including three twins, had no follow-up confirmation because of pregnancy termination without autopsy or loss to follow-up. The results of the present study indicated that foetal cardiac MRI examinations can be a useful adjunct to foetal echocardiography when the technical limitations of echocardiography make it inadequate for diagnosis.

Left atrial isomerism associated with aneurysmal enlargement of right atrial appendage: A case report with literature review

We present a prenatally diagnosed case of heterotaxy syndrome (HS) in which left atrial isomerism (LAI) was associated with an aneurysmal enlargement of the right atrial appendage (RAA). Although LAI is usually associated with complex cardiac and extracardiac anomalies, the association of LAI and right atrial appendage aneurysm (RAAA) is exceptional. Congenital RAAA itself is an idiopathic, very rare cardiac anomaly characterized by the enlargement of the appendage in the absence of any other cardiac or extra-cardiac defect. The prognosis of the heterotaxy is poor with associated major cardiac malformations and even cases with minor cardiac anomalies are at risk postnatally for complications like biliary atresia, intestinal rotational abnormalities, and immune disorders. In this case, the prenatal diagnosis of the isomerism was mainly based on the abnormalities of caval veins. Although no typical complex cardiac anomaly was present, the HS was associated with biliary atresia, polysplenia, and malrotation of the gut. Associated RAAA further imposed an additional risk of complications such as tachyarrhythmias, thromboembolic events, and aneurysmal rupture.

Outcome of prenatally diagnosed fetal heterotaxy: systematic review and meta-analysis

OBJECTIVES

The main aim of this systematic review was to evaluate the prevalence and type of associated anomalies in fetuses with heterotaxy diagnosed prenatally on ultrasound; the perinatal outcome of these fetuses was also studied.

METHODS

An electronic search of MEDLINE, EMBASE and CINAHL databases was performed. Only studies reporting the prenatal diagnosis of isomerism were included. Outcomes observed included associated cardiac and extracardiac anomalies, fetal arrhythmia, abnormal karyotype, type of surgical repair and perinatal mortality. The analysis was stratified according to the type of heterotaxy syndrome (left (LAI) or right (RAI) atrial isomerism). Meta-analyses of proportions were used to combine data. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale for cohort studies.

RESULTS

Sixteen studies (647 fetuses) were included in the analysis. Atrioventricular septal defect was the most common associated major cardiac anomaly found both in fetuses with LAI (pooled proportion (PP), 59.3% (95% CI, 44.0-73.7%)), with obstructive lesions of the right outflow tract occurring in 35.5% of these cases, and in fetuses with RAI (PP, 72.9% (95% CI, 60.4-83.7%)). Fetal arrhythmias occurred in 36.7% (95% CI, 26.9-47.2%) of cases with LAI and were mainly represented by complete atrioventricular block, while this finding was uncommon in cases with RAI (PP, 1.3% (95% CI, 0.2-3.2%)). Abnormal stomach and liver position were found, respectively, in 59.4% (95% CI, 38.1-79.0%) and 32.5% (95% CI, 11.9-57.6%) of cases with LAI, and in 54.5% (95% CI, 38.5-70.1%) and 45.9% (95% CI, 11.3-83.0%) of cases with RAI, while intestinal malrotation was detected in 14.2% (95% CI, 2.5-33.1%) of LAI and 27.1% (95% CI, 7.9-52.0%) of RAI cases. Hydrops developed in 11.8% (95% CI, 2.9-25.6%) of fetuses diagnosed prenatally with LAI. Biventricular repair was accomplished in 78.2% (95% CI, 64.3-89.4%) of cases with LAI, while univentricular repair or palliation was needed in 17.0% (95% CI, 9.7-25.9%); death during or after surgery occurred in 26.8% (95% CI, 4.6-58.7%) of LAI cases. Most children with RAI had univentricular repair and 27.8% (95% CI, 15.5-42.1%) died during or after surgery.

CONCLUSIONS

Fetal heterotaxy is associated with a high prevalence of cardiac and extracardiac anomalies. Approximately one quarter of fetuses with heterotaxy died during or after surgery. Abnormal heart rhythm, especially heart block, is common in fetuses with LAI, while this finding is uncommon in RAI. Biventricular repair was common in LAI while univentricular repair was required in the majority of children affected by RAI. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Situs, Isomerism, Heterotaxy Syndrome: Diagnostic Evaluation and Implication for Postnatal Management

OPINION STATEMENT

A hallmark of vertebrate anatomy is asymmetry of structures, especially internal organs, on the left and right side of the body. Heterotaxy syndrome is the combination of correct-sided, and incorrect-sided organs. The establishment of the left-right axis is an early event in vertebrate embryogenesis. Failure to establish this axis has numerous consequences for later development and can result in a wide range of potential defects. Congenital heart disease is among the more frequent and serious problems. Heterotaxy syndrome is diagnosed prenatally with increasing frequency due to improved screening practices. The key to proper management of fetal heterotaxy syndrome is reliable determination of left and right in the fetus, a thorough understanding of associated defects and comprehensive imaging.

Congenital in situ malrotation of the liver in an asymptomatic adult: a rare entity

Congenital malformations of the liver are rare occurrences. We are reporting a case of insitu malrotation of the liver. The patient was asymptomatic and had undergone a non-contrast CT scan of the upper abdomen, which showed malrotation of the liver. The purpose of submitting this case report is to make radiologists and surgeons aware of this unusual anatomical variation. Malrotation of the liver as a part of heterotaxy syndrome or situs ambiguous has been reported, but isolated malrotation of the liver without polysplenia in an adult male is a rare entity. A similar case has been reported in the literature as an incidental autopsy finding. Relevant references to this case are given below.

Utility of fetal magnetic resonance imaging in assessing the fetus with cardiac malposition

OBJECTIVE

Abnormal cardiac axis and/or malposition prompts evaluation of congenital heart disease; however, etiology may be difficult to clarify using obstetrical ultrasound or fetal echocardiography (echo) alone. We aimed to use fetal magnetic resonance imaging (MRI) as a complementary tool to identify causes of cardiac malposition.

METHODS

Review of fetuses diagnosed with cardiac malposition by fetal ultrasound and echo was performed. Etiology was classified as either because of heterotaxy syndrome or extracardiac masses. Reclassification was then performed with fetal MRI findings. Results were compared with postnatal diagnoses.

RESULTS

Forty-two fetuses were identified as having abnormal cardiac axis and/or malposition. Twenty three of 42 cases (55%) had extracardiac anomalies, while 19 (45%) were because of heterotaxy. Twelve of 42 (29%) cases were reassigned by fetal MRI (five in heterotaxy group and seven in the lung anomaly group). Four cases (33%) had both cardiac disease and extracardiac masses, not previously recognized. Fetal MRI clarified heterotaxy subtype or removed heterotaxy diagnosis in five (26%) patients. Fetal MRI findings were confirmed in 8 of these 12 cases postnatally.

CONCLUSION

Fetal MRI is a useful complementary tool to define etiology of cardiac malposition in complex cases for informative prenatal counseling and planning. © 2016 John Wiley & Sons, Ltd.

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

OBJECTIVE

The goal of this study was to investigate the capability of T2-weighted magnetic resonance imaging (MRI) in revealing fetal bowel malposition.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

T2-weighted fetal MR images are useful for the prenatal diagnosis of bowel malposition, even when they are unsuspected on ultrasound examination.

Diagnosis and treatment of fetal cardiac disease: a scientific statement from the American Heart Association

BACKGROUND

The goal of this statement is to review available literature and to put forth a scientific statement on the current practice of fetal cardiac medicine, including the diagnosis and management of fetal cardiovascular disease.

METHODS AND RESULTS

A writing group appointed by the American Heart Association reviewed the available literature pertaining to topics relevant to fetal cardiac medicine, including the diagnosis of congenital heart disease and arrhythmias, assessment of cardiac function and the cardiovascular system, and available treatment options. The American College of Cardiology/American Heart Association classification of recommendations and level of evidence for practice guidelines were applied to the current practice of fetal cardiac medicine. Recommendations relating to the specifics of fetal diagnosis, including the timing of referral for study, indications for referral, and experience suggested for performance and interpretation of studies, are presented. The components of a fetal echocardiogram are described in detail, including descriptions of the assessment of cardiac anatomy, cardiac function, and rhythm. Complementary modalities for fetal cardiac assessment are reviewed, including the use of advanced ultrasound techniques, fetal magnetic resonance imaging, and fetal magnetocardiography and electrocardiography for rhythm assessment. Models for parental counseling and a discussion of parental stress and depression assessments are reviewed. Available fetal therapies, including medical management for arrhythmias or heart failure and closed or open intervention for diseases affecting the cardiovascular system such as twin-twin transfusion syndrome, lung masses, and vascular tumors, are highlighted. Catheter-based intervention strategies to prevent the progression of disease in utero are also discussed. Recommendations for delivery planning strategies for fetuses with congenital heart disease including models based on classification of disease severity and delivery room treatment will be highlighted. Outcome assessment is reviewed to show the benefit of prenatal diagnosis and management as they affect outcome for babies with congenital heart disease.

CONCLUSIONS

Fetal cardiac medicine has evolved considerably over the past 2 decades, predominantly in response to advances in imaging technology and innovations in therapies. The diagnosis of cardiac disease in the fetus is mostly made with ultrasound; however, new technologies, including 3- and 4-dimensional echocardiography, magnetic resonance imaging, and fetal electrocardiography and magnetocardiography, are available. Medical and interventional treatments for select diseases and strategies for delivery room care enable stabilization of high-risk fetuses and contribute to improved outcomes. This statement highlights what is currently known and recommended on the basis of evidence and experience in the rapidly advancing and highly specialized field of fetal cardiac care.

An unusual congenital in situ malrotation of the liver

Congenital anomaly of the liver is an uncommon and usually incidental finding. This report describes a case of in situ liver malrotation that has never been reported in the literature. Published literature relevant to the finding are briefly discussed.