Prenatal MRI evaluation of limb-body wall complex

MR Imaging of the Fetal Genitourinary Tract

Fetal MR imaging overcomes many of the technical barriers of ultrasound and is an important diagnostic tool for fetal genitourinary (GU) anomalies. It is suited for evaluation of GU anomalies because of the fluid-sensitive sequences and superior soft tissue contrast. Often GU malformations are part of a multisystem genetic or congenital condition, and imaging the entire fetus with MR adds additional clarity about the extent of disease. It adds confidence to diagnoses of renal agenesis, urinary tract dilation, cystic disease, and tumors. It is particularly useful to delineate anatomy in complex GU malformations. This additional information guides counseling.

Limb-body wall complex: Literature review and case report

INTRODUCTION

Body wall anomalies comprise a wide range of malformations. Limb-Body wall complex (LBWC) represents the most severe presentation of this group, with life threatening malformations in practically all the cases, including craniofacial, body wall defects, and limb anomalies. There is no consensus about its etiology and folding and gastrulation defects have been involved. Also, impaired angiogenesis has been proposed as a causative process.

CASE REPORT

We present the case of a masculine stillborn, product of the first pregnancy in a 15-year-old, apparently healthy mother. He was delivered at 31 weeks of gestation due to an early rupture of membranes. He presented with multiple malformations including a wide body wall defect with multiple organ herniation and meromelia of the lower right limb.

DISCUSSION AND CONCLUSIONS

LBWC represents a severe and invariably fatal pathology. There are no described risk factors, nevertheless, this case presented in a teenage mother, a well-described risk factor for other body wall anomalies. Its diagnosis allows us to discriminate between other pathologies that require prenatal or postnatal specialized treatment.

Current Perspectives of Prenatal Sonography of Umbilical Cord Morphology

The umbilical cord constitutes a continuation of the fetal cardiovascular system anatomically bridging between the placenta and the fetus. This structure, critical in human development, enables mobility of the developing fetus within the gestational sac in contrast to the placenta, which is anchored to the uterine wall. The umbilical cord is protected by unique, robust anatomical features, which include: length of the umbilical cord, Wharton’s jelly, two umbilical arteries, coiling, and suspension in amniotic fluid. These features all contribute to protect and buffer this essential structure from potential detrimental twisting, shearing, torsion, and compression forces throughout gestation, and specifically during labor and delivery. The arterial components of the umbilical cord are further protected by the presence of Hyrtl’s anastomosis between the two respective umbilical arteries. Abnormalities of the umbilical cord are uncommon yet include excessively long or short cords, hyper or hypocoiling, cysts, single umbilical artery, supernumerary vessels, rarely an absent umbilical cord, stricture, furcate and velamentous insertions (including vasa previa), umbilical vein and arterial thrombosis, umbilical artery aneurysm, hematomas, and tumors (including hemangioma angiomyxoma and teratoma). This commentary will address current perspectives of prenatal sonography of the umbilical cord, including structural anomalies and the potential impact of future imaging technologies.

Limb body wall complex complicating a dichorionic diamniotic twin pregnancy: MRI for demonstration of fetal morphology

Limb body wall complex (LBWC) is a rare, lethal malformation characterised by body wall defects, craniofacial and limb anomalies with or without various other organ anomalies. We report a case of dichorionic diamniotic twin pregnancy discordant for LBWC, diagnosed by ultrasound (US) and confirmed by MRI at 21 weeks' gestation, managed expectantly and delivered at 35 weeks by emergency caesarean section with a favourable outcome of the unaffected twin. The anomalous twin, who died soon after birth, had a sizeable thoracoabdominal wall defect, eviscerated liver and bowel loops attached to the placenta, short cord, ectopia cordis, lung hypoplasia, kyphoscoliosis, right upper limb amelia and left clubfoot with polydactyly. MRI helps to demonstrate the fetal morphology better when there are limitations to the US due to unfavourable fetal position, multifetal gestation, maternal obesity or reduced liquor. In twin pregnancies, the management will depend on ensuring the survival of the unaffected twin.

How to read a fetal magnetic resonance image 101

Accurate antenatal diagnosis is essential for planning appropriate pregnancy management and improving perinatal outcomes. The provision of information vital for prognostication is a crucial component of prenatal imaging, and this can be enhanced by the use of fetal MRI. Image acquisition, interpretation and reporting of a fetal MR study can be daunting to the individual who has encountered few or none of these examinations. This article provides the radiology trainee with a general approach to interpreting a fetal MRI. The authors review the added value of prenatal MRI in the overall assessment of fetal wellbeing, discuss MRI protocols and techniques, and review the normal appearance of maternal and fetal anatomy. The paper concludes with a sample template for structured reporting, to serve as a checklist and guideline for reporting radiologists.

Fetal MRI in the Identification of a Fetal Ventral Wall Defect Spectrum

Objective  To ascertain if useful criteria for prenatal diagnosis of fetal ventral body wall defects (VBWDs) exists by reviewing published literature on diagnosis of VBWD as compared with our own diagnostic experience. Study Design  A comprehensive literature review of diagnostic criteria of fetal VBWD including pentalogy of Cantrell (POC), omphalocele, exstrophy, imperforate anus, spina bifida (OEIS), cloacal exstrophy, limb-body wall complex (LBWC), and body stalk anomaly was performed followed by a retrospective review of all fetal magnetic resonance imaging (MRI) examinations from our medical center over a 2-year period. Results  Classically, OEIS is omphalocele, bladder exstrophy, imperforate anus, and spina bifida. POC is defects of the supraumbilical abdomen, sternum, diaphragm, pericardium, and heart. LBWC is two of the following: exencephaly or enencephaly with facial clefts, thoracoschisis or abdominoschisis, and limb defects. Twenty-four cases of VBWD on MRI over a 24-month period were identified with seven cases involving defects of additional organ systems. Six of these seven cases demonstrated findings from two or more of the traditional diagnoses POC, OEIS, and LBWC making diagnosis and counseling difficult. Conclusion  There is a lack of consensus on useful diagnostic criteria within the published literature which is reflected in our own diagnostic experience and poses a challenge for accurate prenatal counseling.

Fetal anterior abdominal wall defects: prenatal imaging by magnetic resonance imaging

Abdominal wall defects range from the mild umbilical cord hernia to the highly complex limb-body wall syndrome. The most common defects are gastroschisis and omphalocele, and the rarer ones include the exstrophy complex, pentalogy of Cantrell and limb-body wall syndrome. Although all have a common feature of viscera herniation through a defect in the anterior body wall, their imaging features and, more important, postnatal management, differ widely. Correct diagnosis of each entity is imperative in order to achieve appropriate and accurate prenatal counseling and postnatal management. In this paper, we discuss fetal abdominal wall defects and present diagnostic pearls to aid with diagnosis.

Prenatal congenital vertical talus (rocker bottom foot): a marker for multisystem anomalies

BACKGROUND

Congenital vertical talus is a rare foot anomaly characterized by a prominent calcaneus and rigid forefoot dorsiflexion. While congenital vertical talus has been associated with anomalies such as trisomy 18, myelomeningocele and arthrogryposis, postnatal series have reported cases of isolated congenital vertical talus.

OBJECTIVE

The purpose of our study was to determine the incidence of isolated congenital vertical talus prenatally and identify the most common anomalies associated with this finding.

MATERIALS AND METHODS

A retrospective review was performed of congenital vertical talus cases identified in our fetal center from 2006 to 2015. The prenatal US and MR imaging appearance of congenital vertical talus was evaluated and differentiation from congenital talipes equinovarus was assessed. Studies were evaluated for additional abnormalities affecting the central nervous system, face, limbs, viscera, growth and amniotic fluid. Imaging findings were recorded and correlated with outcomes when available.

RESULTS

Twenty-four cases of congenital vertical talus were identified prenatally (gestational age: 19-36 weeks). All 24 had prenatal US and 21 also underwent fetal MRI on the same day. There were no isolated cases of congenital vertical talus in this series; all 24 had additional anomalies identified prenatally. Sixteen cases had bilateral congenital vertical talus (67%). Additional anomalies were identified in the brain (15), spine (11), face (6), abdominal wall (3), heart (8) and other limbs (12). Chromosomal abnormalities were identified in 6 of 20 patients who underwent genetic testing. Overall, US held some advantage in detecting the abnormality: in 10 cases, US depicted congenital vertical talus more clearly than MRI; in 8 cases, US and MRI were equal in detection and in 3 cases, MRI was superior. In 9/15 cases with intracranial abnormalities, MRI was superior to US in demonstrating structural anomalies. Outcomes included termination (11), intrauterine fetal demise (1), stillbirth or immediate neonatal demise (5), lost to follow-up (1), and 6 survivors with postnatal follow-up.

CONCLUSION

In our series, there were no cases of isolated congenital vertical talus, with additional anomalies variably affecting multiple systems including the brain, spine, face, viscera and limbs. When congenital vertical talus is identified prenatally, a thorough search for additional anomalies is indicated. Fetal MRI can be a useful adjunct in confirming the diagnosis and further delineating additional anomalies, particularly in the brain and spine.

[Congenital anomalies of poor prognosis. Genetics Consensus Committee]

INTRODUCTION

The Genetic Branch of the Chilean Society of Paediatrics, given the draft Law governing the decriminalisation of abortion on three grounds, focusing on the second ground, which considers the "embryo or foetus suffering from a congenital structural anomaly or a genetic disorder incompatible with life outside the womb", met to discuss the scientific evidence according to which congenital anomalies (CA) may be included in this draft law.

METHODOLOGY

Experts in clinical genetics focused on 10 CA, reviewed the literature evidence, and met to discuss it.

RESULTS

It was agreed not to use the term "incompatible with life outside the womb", as there are exceptions and longer survivals, and change to "congenital anomaly of poor prognosis (CAPP)". Ten CA were evaluated: serious defects of neural tube closure: anencephaly, iniencephaly and craniorachischisis, pulmonary hypoplasia, acardiac foetus, ectopia cordis, non-mosaic triploidy, "limb body wall" complex, "body stalk" anomaly, trisomy 13, trisomy 18, and bilateral renal agenesis. Findings on the prevalence, natural history, prenatal diagnostic methods, survival, and reported cases of prolonged survival were analysed. Post-natal survival, existence of treatments, and outcomes, as well as natural history without intervention, were taken into account in classifying a CA as a CAPP.

CONCLUSION

A CAPP would be: anencephaly, severe pulmonary hypoplasia, acardiac foetus, cervical ectopia cordis, non-mosaic triploidy, limb body wall complex, body stalk anomaly, non-mosaic trisomy 13, non-mosaic trisomy 18, and bilateral renal agenesis. For their diagnosis, it is required that all pregnant women have access to assessments by foetal anatomy ultrasound and occasionally MRI, and cytogenetic and molecular testing.

Extrafetal Findings on Fetal Magnetic Resonance Imaging: A Pictorial Essay

Although US is the mainstay of fetal imaging, magnetic resonance imaging (MRI) has become an invaluable adjunct in recent years. MRI offers superb soft tissue contrast that allows for detailed evaluation of fetal organs, particularly the brain, which enhances understanding of disease severity. MRI can yield results that are similar to or even better than those of US, particularly in cases of marked oligohydramnios, maternal obesity, or adverse fetal positioning. Incidentally detected extrafetal MRI findings are not uncommon and may affect clinical care. Physicians interpreting fetal MRI studies should be aware of findings occurring outside the fetus, including those structures important for the pregnancy. A systematic approach is necessary in the reading of such studies. This helps to ensure that important findings are not missed, appropriate clinical management is implemented, and unnecessary follow-up examinations are avoided. In this pictorial essay, the most common extrafetal abnormalities are described and illustrated.