Prenatal diagnosis of antenatal midgut volvulus: Specific ultrasound features.

OBJECTIVE: To assess specific, direct, and indirect prenatal ultrasound features in cases of fetal midgut volvulus. METHODS: Retrospective case series of neonatal volvulus, based on postnatal and prenatal imaging findings that occurred from 2006-2017. Prenatal and postnatal signs including the specific "whirlpool sign" were computed. Postnatal volvulus was confirmed by pathology examination after surgery or neonatal autopsy. RESULTS: Thirteen cases of midgut volvulus were identified. Though not a specific sign, a decrease in active fetal movements was reported in eight patients (61.5%). The prenatal whirlpool sign was directly seen in 10 cases, while an indirect but suggestive sign, a fluid-filled level within the dilated loops, was present in five cases. No intestinal malrotation was observed. Pregnancy outcomes were two terminations of pregnancy, both associated with cystic fibrosis, one early neonatal death, three prenatal spontaneous regressions, and seven favorable outcomes after neonatal surgery with resection of midgut atresia. CONCLUSIONS: Identification of the whirlpool sign or of a fluid-filled level within the dilated loops improves the accuracy of ultrasound findings for suspected volvulus. In the absence of total volvulus (in cases of intestinal malrotation) or association with cystic fibrosis, the prognosis appears good.

Does prenatal MRI enhance fetal diagnosis of intra-abdominal cysts?

OBJECTIVE: The aim of this study was to evaluate the contribution of prenatal magnetic resonance imaging (MRI) to ultrasound (US) in the prenatal diagnosis of intra-abdominal cystic masses, correlated with the postnatal diagnosis. METHODS: In this retrospective, observational study, prenatal MRI and US diagnoses were compared with postnatal diagnoses. MRI was performed in 56 fetuses with intra-abdominal cyst diagnosed by US between 2004 and 2013. Final diagnosis, revealed by postnatal evaluation, was obtained for 49 of them and was taken as the reference. MRI was evaluated as superior, equal, or inferior to US. RESULTS: An accurate diagnosis was provided by US in 25 cases (51%) and by MRI in 36 out of the 49 cases (73.4%). MRI corrected the US diagnosis in 13 cases (26.5%) by providing a more precise localization or additional etiologic information. In two cases (4%), MRI wrongly changed the diagnosis correctly made by US. CONCLUSION: Prenatal MRI better characterized the nature of abdominal cystic lesions previously diagnosed by US in 13 cases. This enhanced postnatal therapeutic planning and so improved parental counseling and pregnancy management.

Association of periventricular nodular heterotopia with posterior fossa cyst: a prenatal case series.

OBJECTIVE: The association of periventricular nodular heterotopia (PVNH) with posterior fossa cyst (PFC) is documented after birth. We report this association in a series of fetuses. METHODS: Eleven cases (7 females) of PVNH and PFC diagnosed at prenatal imaging were collected in this retrospective multicenter study. The patients were referred to tertiary centers for targeted ultrasonography (US) and Magnetic Resonance Imaging (MRI) following detection of PFC on routine US. Mutations of the filamin A gene (FLNA) were searched for (n = 6). Maternal brain MRI was performed (n = 8). Post-mortem or postnatal data were recorded. RESULTS: Targeted US was performed at a mean gestational age of 29 (range; 23-35) weeks and identified PVNH in 4 cases. At MRI, performed at a mean gestational age of 31 (range; 29-35) weeks, PVNH and PFC were visible in all cases. Those findings were confirmed by postnatal MRI (n = 3), autopsy (n = 7) and/or post-mortem MRI (n = 2) or US (n = 1). Maternal brain MRI showed PVNH in one case. A de novo FLNA mutation was found in four cases. CONCLUSION: We describe a series of PVNH and PFC in fetuses, which underlines the importance of searching for PVNH when PFC is identified at prenatal US. © 2014 John Wiley & Sons, Ltd.

Thrombosis of torcular herophili: diagnosis, prenatal management, and outcome.

OBJECTIVES: The objective of this article is to describe and assess prenatal imaging findings, fetal and postnatal outcomes of thrombosis of torcular herophili, and to determine diagnostic features, pathophysiology, prognosis, and optimal management. METHODS: Over a decade, we compiled the largest single-center retrospective study of outcomes. Fetal magnetic resonance imaging (MRI) was used to confirm the sonographic suspicion and monitor thrombosis of torcular herophili. We noted prenatal and postnatal imaging specifications, pregnancy outcomes, and clinical and radiological pediatric monitoring. Analysis of findings and review of the literature allowed us to define prognostic factors. RESULTS: In eight cases of prenatal diagnosis of thrombosis of torcular herophili, MRI outcomes were specific. There were five deliveries at full term, two terminations of pregnancy, and one fetal demise in utero. Neonates had a good clinical and radiological outcome. Factors of poor prognosis were deep venous sinus thrombosis, enduring mass effect, brain parenchymal injury, and heart failure related to dural arteriovenous shunt. CONCLUSION: Among dural sinus malformations, thrombosis of torcular herophili with or without extension at the posterior segment of the longitudinal sinus frequently has a good prognosis. It is urgent to wait because the prognosis can only be ascertained over time by means of ultrasound scan and MRI monitoring.

US assessment of neonatal bowel (necrotizing enterocolitis excluded).

US plays a main role in evaluating neonatal gastrointestinal disorders. The authors describe the US appearance of normal neonatal bowel, midgut volvulus, small bowel atresia, meconium ileus, meconium peritonitis, different meconium plug syndromes, Hirschsprung disease, intestinal duplication cysts, some other abdominal cysts, some intraperitoneal infections, excluding necrotizing enterocolitis, and anorectal anomalies. The use of sonography in the imaging diagnostic strategies of these congenital and acquired anomalies is emphasized.

Prenatal diagnosis of Lowe syndrome in a male fetus with isolated bilateral cataract.

Background: Lowe syndrome is a rare disease characterized by the association of congenital cataract, hypotonia, followed by global psychomotor delay and intellectual disability, as well as progressive renal dysfunction, and renal failure occurring at around 20 years of age. Case presentation: We discuss the case of a male fetus diagnosed with isolated bilateral cataract on the sonography performed at 21 + 5 weeks of gestation, confirmed by a fetal MRI at 23 weeks of gestation.After ruling out infectious etiologies, a genetic consult was conducted at 26 weeks of gestation, and an amniocentesis was realized to search for a chromosomal cause, Norrie's disease and Lowe syndrome by Sanger analysis. A c.1351G > A (p.Asp451Asn) hemizygous mutation in OCRL gene was identified, inherited from the mother, which led to the diagnosis of Lowe syndrome in the fetus. Conclusions: This is the first case of Lowe syndrome diagnosed prenatally on an isolated cataract, which allows the discussion of a more extensive etiological research when a male fetus is diagnosed with isolated bilateral cataract, by including notably a systematic analysis of the OCRL gene.

Fetal gastrointestinal MRI: all that glitters in T1 is not necessarily colon.

BACKGROUND: It has been described that both the colon and distal ileum present with a physiological hypersignal on T1-weighted sequences during the second and third trimesters of pregnancy because of their protein-rich meconium content, it was unclear whether the normal characteristics that have been described on fetal MRI can be applied to gastrointestinal (GI) obstructions. OBJECTIVE: To analyse the localisation value of T1 hypersignal within dilated bowel loops in fetuses with gastrointestinal tract obstruction. MATERIALS AND METHODS: A retrospective 4-year multicentre study analysing cases of fetal GI obstruction in which MRI demonstrated T1 hypersignal content in the dilated loops. Data collected included gestational age (GA) at diagnosis, bowel appearance on US, CFTR gene mutations and amniotic levels of gastrointestinal enzymes. The suggested prenatal diagnosis was eventually compared to postnatal imaging and surgery. RESULTS: Eleven patients were included. The median GA at US diagnosis was 23 weeks (range 13-32). In eight cases there was a single dilated loop, while several segments were affected in three. The median GA at MRI was 29 weeks (range 23-35). One case presented with cystic fibrosis mutations. Final prenatally suspected diagnoses were distal ileal atresia or colon in nine cases and proximal atresia in two. Postnatal findings were proximal jejunal atresia in nine cases and meconium ileus in two. In five cases the surgical findings demonstrated short bowel syndrome. CONCLUSION: In cases of fetal occlusion, T1 hypersignal should not be considered as a sign of distal ileal or colonic occlusion. The obstruction may be proximal, implying a risk of small bowel syndrome, which requires adequate parental counselling.

Organ volume measurements: comparison between MRI and autopsy findings in infants following sudden unexpected death.

OBJECTIVE: To assess the accuracy of a semiautomated 3D volume reconstruction method for organ volume measurement by postmortem MRI. METHODS: This prospective study was approved by the institutional review board and the infants' parents gave their consent. Postmortem MRI was performed in 16 infants (1 month to 1 year of age) at 1.5 T within 48 h of their sudden death. Virtual organ volumes were estimated using the Myrian software. Real volumes were recorded at autopsy by water displacement. The agreement between virtual and real volumes was quantified following the Bland and Altman's method. RESULTS: There was a good agreement between virtual and real volumes for brain (mean difference: -0.03% (-13.6 to +7.1)), liver (+8.3% (-9.6 to +26.2)) and lungs (+5.5% (-26.6 to +37.6)). For kidneys, spleen and thymus, the MRI/autopsy volume ratio was close to 1 (kidney: 0.87±0.1; spleen: 0.99±0.17; thymus: 0.94±0.25), but with a less good agreement. For heart, the MRI/real volume ratio was 1.29±0.76, possibly due to the presence of residual blood within the heart. The virtual volumes of adrenal glands were significantly underestimated (p=0.04), possibly due to their very small size during the first year of life. The percentage of interobserver and intraobserver variation was lower or equal to 10%, but for thymus (15.9% and 12.6%, respectively) and adrenal glands (69% and 25.9%). CONCLUSIONS: Virtual volumetry may provide significant information concerning the macroscopic features of the main organs and help pathologists in sampling organs that are more likely to yield histological findings.

Prevalence and timing of pregnancy termination for brain malformations.

OBJECTIVE: To determine the prevalence and the timing of pregnancy termination relative to the type of central nervous system (CNS) malformations. Design Retrospective cohort study. SETTING: Multidisciplinary centre for prenatal diagnosis in the Languedoc-Roussillon region, France. POPULATION: A cohort of 481 pregnancy terminations performed between 2005 and 2009. METHODS: Detailed post-termination fetal and neuropathological analyses were carried out to identify the CNS malformations. Then, the prevalence and timing of pregnancy termination were assessed relative to the identified malformations. RESULTS: About one-third of pregnancy terminations (143/481) were performed for severe CNS malformations. Up to 24 weeks of gestation (WG), pregnancy terminations (56.6%) were carried out mainly for defects occurring during the two major first steps of CNS development (neurulation and differentiation of cerebral vesicles). After 24 WG, pregnancy terminations (43.3%) were mainly performed for corpus callosum agenesis (16/17), vermian agenesis (10/12) and gyral anomalies (13/15). For hindbrain malformations and gyral anomalies, there was a significant relationship between the timing of pregnancy termination and the presence of a severe ventriculomegaly at prenatal diagnosis (p=0.002 and p=0.02, respectively). CONCLUSION: By classifying CNS malformations according to the neuropathological analysis, the authors show that the timing and prevalence of pregnancy termination are distributed in a manner that is consistent with what is currently known on the development of brain. They are also influenced by the French prenatal screening policy and the variable expressivity of the brain malformations and associated lesions.

Dural sinus malformation (DSM) in fetuses. Diagnostic value of prenatal MRI and follow-up.

Dural sinus malformations (DSM) are rare malformations mainly reported after birth. The objectives of this study are to describe their prenatal patterns and to focus on their possible favorable outcome. This multicenter retrospective study reported 13 cases of DSM prenatally diagnosed. The admission criterion was a dural mass posterior to the vermis. In 12 patients, MRI was performed after US. Follow-up in 10 born babies (mean: 8 months) and three neuropathological examinations were available. In all fetuses, DSM presented as a well-delimited round mass involving the torcular. The follow-up examinations (n = 10) revealed progressive thrombosis of the DSM marked by a heterogeneous pattern (US and MRI) with concentric rings. The volume of the mass decreased, with complete regression in seven patients (five before and two after birth). One child died at the age of 5 months in the context of major hydrocephalus and another developed atrophy of the frontal lobes. The eight other babies were doing well (5 days to 3 years) without any treatment (n = 6) or following treatment for hydrocephalus (n = 2). Prenatal DSM may have a typical MR pattern, and the prognosis might not be as bad as has previously been reported. In the absence of criterion to predict the hydrovenous cerebral imbalance, it is mandatory to check the parenchyma and the ventricles during the pregnancy.

Brain ultrasonography in the premature infant.

Brain ultrasonography plays a central role in the detection and management of neonatal disease in the preterm infant. Although morphological study, using high-frequency transducers, remains the cornerstone of imaging, pulsed and colour Doppler scans provide additional information and improve the diagnostic and prognostic accuracy of ultrasonography. Particular features of normal brain US in the extremely preterm infant are reported. Cerebral haemorrhage and its different patterns (intraventricular haemorrhage and periventricular hemorrhagic infarction) are described. The value of Doppler techniques is emphasized, e.g. demonstration of coloured signal within the aqueduct of Sylvius, visualization of patency of the terminal veins, demonstration of Doppler spectrum fluctuations, recognition of low blood flow, and the detection of vasodilatation. The sonographic diagnosis of periventricular leucomalacia and its difficulties are documented. Some uncommon brain lesions of the premature infant are illustrated, e.g. gangliothalamic ischaemic damage, cortical necrosis, focal infarcts, etc. The importance of repeating the US examinations until near term is highlighted.

MRI of the fetal gastrointestinal tract.

OBJECTIVE: To determine the MRI patterns of the gastrointestinal (GI) tract in normal fetuses and some GI tract abnormalities. MATERIALS AND METHODS: A retrospective (1996-1998) and prospective (1999-2000) study of 48 fetal abdominal MRI scans was performed between 23 and 38 weeks of gestation. T1-weighted (T1-W) fast gradient-echo (Flash 2D) and T2-weighted (T2-W) HASTE sequences were obtained on a 1.5-T unit, in frontal and sagittal planes, after maternal premedication. Fresh meconium was also studied. RESULTS: Normal patterns (40 cases): the rectum was seen in all cases and exhibited meconium-like high signal on T1-W images and low signal on T2-W images. It was close to the bladder whatever the fetal gender with its cul-de-sac being at least 10 mm below the bladder neck. The large bowel had a same signal; the distal colon was demonstrated more frequently than the proximal colon. The small bowel was transiently hyperintense on TI-W images early in gestation and then hyperintense on T2-W images. Normal measurements were obtained. GI tract abnormalities (eight cases): cysts close to normal bowel ( n=2), atresias ( n=5; microcolon, dilated small bowel with abnormal signal, one with a meconium cyst) and a cloacal malformation with midgut malrotation ( n=1; abnormal liquid signal in the rectum separated from the bladder wall and colon located on the left side). CONCLUSIONS: MRI provided complete visualisation of the fetal GI tract, showed specific signal intensities, identified the level of an obstruction, detected a microcolon, and demonstrated communication between urinary and GI tracts. It shows great potential.

The value of colour Doppler ultrasonography for identification of crossing vessels in children with pelvi-ureteric junction obstruction.

BACKGROUND: Pelvi-ureteric junction (PUJ) obstruction is caused by the presence of an aperistaltic dysplastic segment at the PUJ. Besides this intrinsic aetiology, extrinsic abnormalities, mainly crossing vessels, may be an associated factor. OBJECTIVE: To determine the reliability of colour Doppler US in the detection of crossing vessels in children with surgically proven PUJ obstruction. MATERIALS AND METHODS: Forty-eight patients (50 kidneys) with PUJ obstruction, surgically treated from 1998 to 2001, were prospectively studied by colour Doppler US prior to open pyeloplasty. There were 33 boys and 15 girls (age 2 months-12 years; median 3.5 years). There were 24 right kidneys and 26 left kidneys. The indication for surgery was according to the usual criteria. The crossing vessel was considered as present when depicted on colour Doppler US at the PUJ. RESULTS: Colour Doppler assessment of the crossing vessels was correct in all but two patients. At surgery, a crossing vessel was found in 14 kidneys (i.e. 28%). Colour Doppler US results were correlated with intra-operative findings in 50 renal units. Surgically proven vessels in 14 kidneys were identified by colour Doppler US in 13, and not shown in 1. In PUJ obstruction without a crossing vessel ( n=36), US findings were concordant in 26, discordant in 8 and inconclusive in 2 (with kidney malrotation) cases. Colour Doppler US had a sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and accuracy of 92.8%, 76.5%, 62%, 96.3% and 78%, respectively. The reliability of colour Doppler US was greatly improved with the increasing experience of the sonographer, as shown by the results of the last 2 years (26 kidneys):Se=100%, Sp=87.5%, PPV=81.8%, NPV=100%, accuracy=88.5%. CONCLUSIONS: Colour Doppler US is reliable in the detection of crossing vessels at the PUJ.