Maria A. Calvo-Garcia

Fetal MRI clues to diagnose cloacal malformations

BackgroundPrenatal US detection of cloacal malformations is challenging and rarely confirms this diagnosis.ObjectiveTo define the prenatal MRI findings in cloacal malformations.Materials and methodsWe performed a retrospective study of patients with cloacal malformations who had pre- and post-natal assessment at our institution. Fetal MRI was obtained in six singleton pregnancies between 26 and 32xa0weeks of gestation. Imaging analysis was focused on the distal bowel, the urinary system and the genital tract and compared with postnatal clinical, radiological and surgical diagnoses.ResultsThe distal bowel was dilated and did not extend below the bladder in five fetuses. They had a long common cloacal channel (3.5–6xa0cm) and a rectum located over the bladder base. Only one fetus with a posterior cloacal variant had a normal rectum. Three fetuses had increased T2 signal in the bowel and two increased T1/decreased T2 signal bladder content. All had renal anomalies, four had abnormal bladders and two had hydrocolpos.ConclusionAssessment of the anorectal signal and pelvic anatomy during the third trimester helps to detect cloacal malformations in the fetus. The specificity for this diagnosis was highly increased when bowel fluid or bladder meconium content was identified.

Prenatal MRI Findings of Fetuses with Congenital High Airway Obstruction Sequence

Objective To define the MRI findings of congenital high airway obstruction sequence (CHAOS) in a series of fetuses. Materials and Methods Prenatal fetal MR images were reviewed in seven fetuses with CHAOS at 21 to 27 weeks of gestation. The MRI findings were reviewed. The MRI parameters evaluated included the appearance of the lungs and diaphragm, presence or absence of hydrops, amount of amniotic fluid, airway appearance, predicted level of airway obstruction, and any additional findings or suspected genetic syndromes. Results All the fetuses viewed (7 of 7) demonstrated the following MRI findings: dilated airway below the level of obstruction, increased lung signal, markedly increased lung volumes with flattened or inverted hemidiaphragms, massive ascites, centrally positioned and compressed heart, as well as placentomegaly. Other frequent findings were anasarca (6 of 7) and polyhydramnios (3 of 7). MRI identified the level of obstruction as laryngeal in five cases and tracheal in two cases. In four of the patients, surgery or autopsy confirmed the MRI predicted level of obstruction. Associated abnormalities were found in 4 of 7 (genetic syndromes in 2). Postnatal radiography (n = 3) showed markedly hyperinflated lungs with inverted or flattened hemidiaphragms, strandy perihilar opacities, pneumothoraces and tracheotomy. Two fetuses were terminated and one fetus demised in utero. Four fetuses were delivered via ex utero intrapartum treatment procedure. Conclusion MRI shows a consistent pattern of abnormalities in fetuses with CHAOS, accurately identifies the level of airway obstruction, and helps differentiate from other lung abnormalities such as bilateral congenital pulmonary airway malformation by demonstrating an abnormally dilated airway distal to the obstruction.

Congenital lung lesions: prenatal MRI and postnatal findings

BackgroundCongenital lung lesions refer to a spectrum of malformations and developmental abnormalities of the foregut, pulmonary airways and vasculature. These lesions range from small, asymptomatic to large space-occupying masses that can increase risk of fetal death and respiratory compromise after birth. Prenatal sonography has been used for routine screening in pregnancy. The advent of prenatal magnetic resonance imaging leads to complementary use in the diagnosis of fetal anomalies, including in fetuses with congenital lung lesions.ObjectiveTo determine whether fetal MRI can differentiate congenital lung lesions by comparing prenatal diagnosis with postnatal imaging and pathology.Materials and methodsIn a 4-year period, 76 fetuses with suspected lung lesions were referred for fetal MRI. We retrospectively reviewed the MR exams and assigned a specific diagnosis based on predetermined criteria. We then compared the prenatal diagnosis to postnatal imaging and pathology.ResultsOf 76 cases, 7 were excluded because of an alternative diagnosis. Of the 69 remaining patients, 3 died and 13 were lost to follow-up. Among the 53 patients, there were 56 lung lesions. Four of these lesions were difficult to diagnose because of size and location. Based on imaging records we gave the remaining 52 lesions a specific prenatal diagnosis: 28 congenital pulmonary airway malformations (CPAM), 4 bronchopulmonary sequestrations (BPS), 9 cases of overinflation, 9 hybrid lesions and 2 bronchogenic cysts. The prenatal diagnosis was concordant with postnatal evaluation in 51 of the 52 lung lesions. One fetus given the diagnosis of CPAM prenatally was diagnosed with a hybrid lesion postnatally.ConclusionPrenatal MRI is highly accurate in defining congenital lung anomalies. When fetal MRI findings suggest a specific diagnosis, postnatal findings confirmed the prenatal MRI diagnosis in 98% of cases.

Allantoic cyst: a prenatal clue to patent urachus

A patent urachus, which is typically diagnosed as leakage from the umbilicus postnatally, can present as an allantoic cyst in the umbilical cord antenatally. We report a case of a patent urachus with an allantoic cyst diagnosed via fetal MR imaging at 24xa0weeks’ gestation. Early detection allowed for appropriate counseling and prompt corrective surgery after birth.

Congenital dacryocystocele: prenatal MRI findings

BackgroundCongenital dacryocystocele can be diagnosed prenatally by imaging. Prenatal MRI is increasingly utilized for fetal diagnosis.ObjectiveTo present the radiological and clinical features of seven fetuses with congenital dacryocystocele diagnosed with prenatal MRI.Materials and methodsThe institutional database of 1,028 consecutive prenatal MR examinations performed during a period of 4xa0years was reviewed retrospectively. The cases of congenital dacryocystocele were identified by reading the report of each MRI study.ResultsThe incidence of dacryocystocele diagnosed with prenatal MRI was 0.7% (nu2009=u20097/1,028). The dacryocystocele was bilateral in three fetuses. Mean gestational age at the time of diagnosis was 31xa0weeks. The indication for prenatal MRI was the presence or the suspicion of central nervous system abnormality in six fetuses and diaphragmatic hernia in one. Dacryocystocele was associated with an intranasal cyst in six of ten eyes. Prenatal sonography revealed dacryocystocele in only two of seven fetuses. Of eight eyes with postnatal follow-up, four did not have any lacrimal symptoms.ConclusionPrenatal MRI can delineate congenital dacryocystocele more clearly and in a more detailed fashion than ultrasonography. Presence of dacryocystocele was symptomatic in only 50% of our patients, supporting that prenatal diagnosis of dacryocystocele might follow a benign course.

Imaging evaluation of fetal vascular anomalies.

Vascular anomalies can be detected in utero and should be considered in the setting of solid, mixed or cystic lesions in the fetus. Evaluation of the gray-scale and color Doppler US and MRI characteristics can guide diagnosis. We present a case-based pictorial essay to illustrate the prenatal imaging characteristics in 11 pregnancies with vascular malformations (5 lymphatic malformations, 2 Klippel-Trenaunay syndrome, 1 venous-lymphatic malformation, 1 Parkes-Weber syndrome) and vascular tumors (1 congenital hemangioma, 1 kaposiform hemangioendothelioma). Concordance between prenatal and postnatal diagnoses is analyzed, with further discussion regarding potential pitfalls in identification.

Prenatal imaging of congenital malformations of the brain.

This article represents an overview of ultrasound (US) and magnetic resonance imaging (MRI) of the normal fetal brain during the second and third trimesters, followed by the description of congenital pathologic conditions. Fetal imaging of the brain requires an understanding of embryology that defines the normal anatomy of the brain at each gestational age. Without knowledge of the normal developmental milestones, it is impossible to accurately diagnose prenatal central nervous system (CNS) disorders. In the first section, a brief review of the normal anatomy and milestones by using US and fetal MRI will be described. The second part will provide a summary of congenital malformations with respect to embryologic event and their typical imaging patterns on prenatal US and MRI.

Fetal MRI of cloacal exstrophy

BackgroundPrenatal ultrasonographic (US) diagnosis of cloacal exstrophy (CE) is challenging.ObjectiveTo define the fetal MRI findings in CE.Materials and methodsWe performed a retrospective review of eight patients with CE. Imaging was performed between 22xa0weeks and 36xa0weeks of gestation with US in four and MRI in eight fetuses. Abdominal wall, gastrointestinal/genitourinary, and spine and limb abnormalities detected were compared with postnatal evaluation.ResultsUS failed to display CE in one of the four fetuses. Fetal MRI confirmed CE in all eight fetuses by demonstrating absence of a normal bladder and lack of meconium-filled rectum/colon, associated with protuberant pelvic contour and omphalocele. These findings correlated postnatally with CE, atretic hindgut and omphalocele. One fetus had imaging before rupture of the cloacal membrane, showing a protruding pelvic cyst. Absent bladder was noted in the remaining seven fetuses. Confirmed skin-covered spinal defects were noted in seven fetuses, low conus/tethered cord in one and clubfoot in three. Six fetuses had renal anomalies, two had hydrocolpos and one had ambiguous genitalia.ConclusionFetal MRI provides a confident diagnosis of CE when a normal bladder is not identified, there is a protuberant abdominopelvic contour and there is absence of meconium-filled rectum and colon. Genitourinary and spinal malformations are common associations.

Prenatal counseling for cloaca and cloacal exstrophy—challenges faced by pediatric surgeons

IntroductionWith the advance of prenatal imaging, more often pediatric surgeons are called for prenatal counseling in suspected cases of cloaca or cloacal exstrophy. This presents new challenges for pediatric surgeons since no specific guidelines have been established so far. The purpose of this review is to analyze our experience in prenatally diagnosed cloaca or cloacal exstrophy and to provide some guidelines for prenatal counseling of these complex congenital anomalies.MethodsA retrospective review of the medical charts of patients with prenatally diagnosed cloaca and cloacal exstrophy who received postnatal care in our institution between July 2005 and March 2012 was performed. Representative images of prenatal studies were selected from 13 cases to illustrate different scenarios and the recommendations given. In addition, a review of the literature was performed to support our advice to parents.ResultsEleven patients were female and two patients were male. The postnatal diagnoses were cloacal exstrophy (6), cloaca (5), posterior cloaca variant (1), and covered cloacal exstrophy (1). The selected abnormal prenatal imaging findings in these 13 patients included hydronephrosis (12), neural tube defect (8), omphalocele (7), lack of meconium at expected rectal location (7), vertebral anomaly (7), non-visualize bladder (5), distended bladder (5), hydrocolpos (4), dilated or echogenic bowel (3), umbilical cord cyst (3), separated pubic bones (2), and the “elephant trunk” sign (2). The prenatal diagnosis was correct in 10 cases, partially correct in two cases, and it was missed in one case. All parents received prenatal counseling depending on the specific diagnosis.ConclusionThe continuous technologic innovations in prenatal imaging make it possible to prenatally diagnose more complex anomalies including cloaca and cloacal exstrophy with increased levels of confidence and enhance the benefit of prenatal counseling. Together, these allow the parents to be better prepared for the condition and the care team to provide the best possible initial management in order to improve the outcomes of these challenging patients.

Brain malformations associated with epignathus: a clue for the correct prenatal diagnosis

We present a case of epignathus (oral teratoma) with midline intracranial associated malformations. This is a rare report of epignathus diagnosed in utero with fetal MRI description of these midline brain malformations, including duplication of the pituitary gland. This case is an example of how these intracranial findings led to the correct diagnosis of a small fetal oral mass.