Fetal MRI of cloacal exstrophy

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.

Fetal uropathies: pre- and postnatal imaging, management and follow-up

Congenital uropathies are the most common fetal anomalies. They include a wide spectrum of anomalies ranging from mild pelvis dilation to complex urinary tract malformations. Prenatal imaging not only allows for their diagnosis but, in experienced hands, it can differentiate obstructive from refluxing or malformative uropathies. Such precise prenatal information allows for intervention before birth in select cases or for adapting the postnatal workup to provide a better long-term outcome. For the different types of congenital uropathies, we describe their prenatal presentations on US and the complementary role of fetal MRI where indicated. We correlate these findings with postnatal workup and summarize the updated neonatal diagnostic and clinical/surgical management.

Fetal and Newborn Management of Cloacal Malformations

Cloaca is a rare, complex malformation encompassing the genitourinary and anorectal tract of the female in which these tracts fail to separate in utero, resulting in a single perineal orifice. Prenatal sonography detects a few cases with findings such as renal and urinary tract malformations, intraluminal calcifications, dilated bowel, ambiguous genitalia, a cystic pelvic mass, or identification of other associated anomalies prompting further imaging. Multi-disciplinary collaboration between neonatology, pediatric surgery, urology, and gynecology is paramount to achieving safe outcomes. Perinatal evaluation and management may include treatment of cardiopulmonary and renal anomalies, administration of prophylactic antibiotics, ensuring egress of urine and evaluation of hydronephrosis, drainage of a hydrocolpos, and creation of a colostomy for stool diversion. Additional imaging of the spinal cord and sacrum are obtained to plan possible neurosurgical intervention as well as prognostication of future bladder and bowel control. Endoscopic evaluation and cloacagram, followed by primary reconstruction, are performed by a multidisciplinary team outside of the neonatal period. Long-term multidisciplinary follow-up is essential given the increased rates of renal disease, neuropathic bladder, tethered cord syndrome, and stooling issues. Patients and families will also require support through the functional and psychosocial changes in puberty, adolescence, and young adulthood.

Ultrasound of congenital spine anomalies

Ultrasonography (US) is the first-line imaging modality for screening neonates and young infants with suspected spinal abnormalities. Whether performed for a suspicious congenital skin lesion, such as a lumbosacral tract or lipomatous mass, or abnormal neurological findings, US can help define spinal anatomy, characterize congenital spine malformations, and direct further work-up and management. The purpose of this article is to review the diagnostic imaging approach to infant spine US, including technique and indications, normal anatomy and variants with a focus on embryological origins, and classification and diagnosis of congenital spine malformations.

Prenatal ultrasound findings of covered bladder exstrophy and persistent cloaca

Unlike classic exstrophy, covered bladder exstrophy is a rare variant characterized by a cycling bladder and intact abdominal wall. We present a case of covered bladder exstrophy diagnosed prenatally and associated persistent cloaca (PC) noted only after delivery. This case report demonstrates that prenatal diagnosis of covered bladder exstrophy is possible and PC can present without any abdominal cysts, bowel, or renal findings. Covered bladder exstrophy should be considered in the differential of cystic protrusion of the bladder to the abdominal wall.

Key anatomic findings on fetal ultrasound and MRI in the prenatal diagnosis of bladder and cloacal exstrophy

INTRODUCTION

Prenatal determination of bladder exstrophy (BE) or cloacal exstrophy (CE), known also as the omphalocele-exstrophy-imperforate anus-spinal anomaly complex (OEIS), is challenging. Distinguishing between BE and CE is important because children with CE have many more challenges initially and during their lifetime. An accurate diagnosis is critical when counselling expectant parents. We hypothesized that there are key imaging features that can distinguish BE from CE, and that there are areas of diagnostic concordance and discordance between fetal ultrasound (fUS) and fetal MRI (fMRI) among these entities.

MATERIALS AND METHODS

We queried a single institutional IRB-approved registry of children with BE and CE to identify those with accessible fetal imaging from 2000 to 2018, and formal interpretations were collected. Two pediatric radiologists performed independent retrospective blinded review of the images. Criteria evaluated included: genitalia, kidneys, bowel appearance, presence of anal dimple, location of insertion of umbilical cord into the abdomen relative to the abdominal wall defect, umbilical vessels, bladder protuberance, presence of omphalocele, and spine/neural cord abnormalities. We evaluated concordance between radiologic interpretations and postnatal diagnosis, as well as between specific findings in the two diagnostic modalities.

RESULTS

Twenty-one infants born between 2000 and 2018 with BE or CE had fetal imaging for review: 15 had both fUS and fMRI, 2 had fUS alone, and 4 fMRI alone. There was 100% concordance between fUS and fMRI in evaluating kidneys, presence of anal dimple, location of abdominal insertion of umbilical cord relative to the defect, number of umbilical vessels, and spine abnormalities/level of neural cord termination. The following discrepancies were observed: 1) genitalia and bowel appearance, and bladder protuberance in 1/15 (6.7%); 2) presence of an omphalocele in 2/15 (13.3%). Of the initial radiologic interpretations, 4/17 (23.5%) of fUS and 2/19 (10.5%) of fMRI erroneously were interpreted as on the OEIS spectrum when the post-natal diagnosis was BE. Errors in diagnosis were due to a protuberant bladder plate extending beyond the plane of the abdominal wall with bowel loops posteriorly mimicking an omphalocele. In all of these BE cases, the abdominal wall defect was located inferior to the umbilical cord insertion on the abdominal wall.

CONCLUSION

An everting bladder plate with bowel loops posterior to the plate in classic BE may be misdiagnosed as CE. Identification of the location of umbilical cord insertion relative to the abdominal wall defect, with fetal US or MRI, results in the correct differentiation between BE and CE.

Clues and pitfalls in prenatal diagnosis of classic cloacal exstrophy using ultrasonography and magnetic resonance imaging: A case with sequential observation from 17 to 30 weeks' gestation and literature review

We observed a case of classic cloacal exstrophy (CE) from 17 to 30 weeks' gestation. At 17 weeks, an omphalocele and single umbilical artery (SUA) were diagnosed with a normal female karyotype on amniocentesis. A pelvic cystic adjacent to SUA, considered to be the bladder at 17 weeks, became swollen to form double cysts at 25 weeks. A phallus-like structure along the lower abdomen was additionally detected, leading to the diagnosis of CE. Fetal magnetic resonance imaging (MRI) at 30 weeks confirmed that the phallus-like structure was of intestinal origin. The presence of a non-visualizable bladder together with abdominal wall defect or omphalocele and an elephant trunk-like deformity are key findings in the prenatal diagnosis of classic CE. Fetal MRI was useful in confirming ultrasonographic findings and obtaining additional findings for the diagnosis of CE. We have discussed clues and potential pitfalls in diagnosing CE, with a review of the literature.

Prenatal and postnatal imaging techniques in the evaluation of disorders of sex development

Imaging of the reproductive tract is challenging and requires a general knowledge of congenital variations in anatomy. The anatomy of the developing fetus, whether a male phenotype or female phenotype, is also a dynamic process with many changes occurring during gestation. Families may ask details about the genitalia during prenatal imaging and when variations in what is thought to be normal are present, further investigation is sometimes needed to make sense of what is seen. This overview will describe categories of disorders of sex development (DSD), whether chromosomal or structural or both, and the current state of imaging of these anomalies.

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.

Highlights on MRI of the fetal body

Fetal MRI is a level III diagnostic tool performed subsequently a level II prenatal ultrasound (US), in cases of inconclusive ultrasonographic diagnosis or when a further investigation is required to confirm or improve the diagnosis, to plan an appropriate pregnancy management. Fetal MRI plays an increasingly important role in the prenatal diagnosis of fetal neck, chest and abdominal malformations, even if its role has been amply demonstrated, especially, in the field of fetal CNS anomalies. Due to its multiparametricity and multiplanarity, MRI provides a detailed evaluation of the whole fetal respiratory, gastrointestinal and genitourinary systems, especially on T2-weighted (W) images, with a good tissue contrast resolution. In the evaluation of the digestive tract, T1-W sequences are very important in relation to the typical hyperintensity of the large intestine, due to the presence of meconium. The objective of this review is to focus on the application of fetal MRI in neck, chest and abdominal diseases.

The current profile of persistent cloaca and cloacal exstrophy in Japan: the results of a nationwide survey in 2014 and a review of the literature

PURPOSE

The current profile of persistent cloaca (PC) and cloacal exstrophy (CE) in Japan was first examined in 2014.

MATERIALS AND METHODS

Information was obtained by sending a questionnaire to 244 university hospitals and children's hospitals.

RESULTS

Responses from 113 institutions reported 466 PC cases and 229 CE cases. The incidences of PC and CE from 1980 to 2012 were 0.97 and 0.49 per 100,000 live births, respectively. In the previous 5 years, antenatal abnormalities were found in 57.6% of PC and 72.7% of CE patients. Myelomeningocele was observed in 45.6% of CE patients. As a result of various surgical treatments used in the neonatal and infantile periods, the respective rates of bladder dysfunction, clean intermittent catheterization, and permanent enterostomy were 32.6, 22.5, and 7.3% in PC patients and 60.7, 28.4, and 73.8% in CE patients. Menstrual outflow obstruction was found in 22.5% of PC and 48.9% of CE patients with menstruation.

CONCLUSION

The clinical outcomes of PC and CE remain unsatisfactory. Therefore, the establishment of treatment guidelines might be a useful objective for improving the current status of PC and CE.

Imaging Evaluation of Fetal Megacystis: How Can Magnetic Resonance Imaging Help?

Evaluation of the kidneys, bladder, and amniotic fluid volume forms part of any standard obstetrical ultrasound. When a fetal genitourinary anomaly is suspected, a more detailed evaluation is necessary. This detailed imaging can be challenging in the setting of decreased or absent amniotic fluid or large maternal body habitus, and in complex malformations. In these situations, magnetic resonance imaging can help to better define the fetal anatomy and provide a more confident and specific prenatal diagnosis.

When Closure Fails: What the Radiologist Needs to Know About the Embryology, Anatomy, and Prenatal Imaging of Ventral Body Wall Defects

Ventral body wall defects (VBWDs) are one of the main categories of human congenital malformations, representing a wide and heterogeneous group of defects sharing a common feature, that is, herniation of one or more viscera through a defect in the anterior body wall. Gastroschisis and omphalocele are the 2 most common congenital VBWDs. Other uncommon anomalies include ectopia cordis and pentalogy of Cantrell, limb-body wall complex, and bladder and cloacal exstrophy. Although VBWDs are associated with multiple abnormalities with distinct embryological origins and that may affect virtually any system organs, at least in relation to anterior body wall defects, they are thought (except for omphalocele) to share a common embryologic mechanism, that is, a failure involving the lateral body wall folds responsible for closing the thoracic, abdominal, and pelvic portions of the ventral body wall during the fourth week of development. Additionally, many of the principles of diagnosis and management are similar for these conditions. Fetal ultrasound (US) in prenatal care allows the diagnosis of most of such defects with subsequent opportunities for parental counseling and optimal perinatal management. Fetal magnetic resonance imaging may be an adjunct to US, providing global and detailed anatomical information, assessing the extent of defects, and also helping to confirm the diagnosis in equivocal cases. Prenatal imaging features of VBWDs may be complex and challenging, often requiring from the radiologist a high level of suspicion and familiarity with the imaging patterns. Because an appropriate management is dependent on an accurate diagnosis and assessment of defects, radiologists should be able to recognize and distinguish between the different VBWDs and their associated anomalies. In this article, we review the relevant embryology of VBWDs to facilitate understanding of the pathologic anatomy and diagnostic imaging approach. Features will be illustrated with prenatal US and magnetic resonance imaging and correlated with postnatal and clinical imaging.

Disorders of the bladder and cloacal anomaly

The incidence of congenital urachal, bladder, and cloacal anomalies is low. Urachal remnants are the result of failure or delay in obliteration of the allantois. Exstrophy of the bladder or cloaca can be diagnosed on prenatal ultrasonography and represent a deviation from the normal embryologic sequence. Persistent cloaca is an anomaly occurring in girls, in which a common cavity exists into which the intestinal, urinary, and reproductive tracts all open. It is also often diagnosed on prenatal imaging.