Contribution of fetal magnetic resonance imaging and amniotic fluid digestive enzyme assays to the evaluation of gastrointestinal tract abnormalities

Fetal intestinal loop dilatation: Follow-up and outcome of a series of 133 consecutive cases (the DILDIG study)

OBJECTIVES

To define the prognostic markers of fetal dilated bowel loops.

METHODS

National non-interventional study of 133 consecutive prenatal observations of dilated loops including ultrasound examinations, complementary laboratory tests, magnetic resonance imaging (MRI), outcomes, and postnatal diagnosis.

RESULTS

One hundred twenty seven cases were classified according to outcome: Group 1, very severe (n = 43), Group 2, children needing specific care (n = 39), and Group 3, healthy children (n = 45). Prenatal ultrasound scan suggested duodenal obstruction in 30 cases, small bowel obstruction in 81, colonic obstruction in 11, and diffuse dilatation in 5. Diameter of dilated loops did not significantly differ between the groups. A poor prognosis was significantly associated with duodenal obstruction, genetic anomalies (53% vs. 21.8%), including aneuploidies or CFTR gene mutations and abnormal amniotic fluid biochemistry (86.4% vs. 38.7%). A good prognosis was associated with regression of dilatation and normal MRI.

CONCLUSION

In this study, postnatal outcomes for fetuses with intestinal dilatation were best predicted by assessing the level of obstruction with prenatal ultrasound and MRI, determining the presence of associated malformations, amniotic fluid biochemical and genetic testing, and monitoring for regression of bowel dilatation. These results should help inform future guidelines on the prenatal and neonatal management of congenital intestinal obstruction.

A Spectrum of Ultrasound and MR Imaging of Fetal Gastrointestinal Abnormalities: Part 1 Esophagus to Colon

Ultrasound (US) and magnetic resonance imaging (MRI) are two modalities for diagnosing fetal gastrointestinal (GI) anomalies. Ultrasound (US) is the modality of choice. MRI can be used as a complementary method. Despite its expanding utilization in central nervous system (CNS) fetal malformation, MRI has not yet been established for evaluation of fetal GI abnormalities. Therefore, more attention should be paid to the clinical implications of MRI investigations following screening by US.

MRI in Pregnancy and Precision Medicine: A Review from Literature

Magnetic resonance imaging (MRI) offers excellent spatial and contrast resolution for evaluating a wide variety of pathologies, without exposing patients to ionizing radiations. Additionally, MRI offers reproducible diagnostic imaging results that are not operator-dependent, a major advantage over ultrasound. MRI is commonly used in pregnant women to evaluate, most frequently, acute abdominal and pelvic pain or placental abnormalities, as well as neurological or fetal abnormalities, infections, or neoplasms. However, to date, our knowledge about MRI safety during pregnancy, especially about the administration of gadolinium-based contrast agents, which are able to cross the placental barrier, is still limited, raising concerns about possible negative effects on both the mother and the health of the fetus. Contrast agents that are unable to cross the placenta in a way that is safe for the fetus are desirable. In recent years, some preclinical studies, carried out in rodent models, have evaluated the role of long circulating liposomal nanoparticle-based blood-pool gadolinium contrast agents that do not penetrate the placental barrier due to their size and therefore do not expose the fetus to the contrast agent during pregnancy, preserving it from any hypothetical risks. Hence, we performed a literature review focusing on contrast and non-contrast MRI use during pregnancy.

How can we improve perinatal care in isolated multiple intestinal atresia? A retrospective study with a 30-year literature review

INTRODUCTION

Multiple intestinal atresia (MIA) is a rare cause of neonatal intestinal obstruction. To provide an overview of the current prenatal, surgical, and nutritional management of MIA, we report our experience and a literature review of papers published after 1990.

METHODS

All cases of isolated MIA (non-hereditary, not associated with apple-peel syndrome or gastroschisis) treated at our institution between 2005 and 2016 were reviewed and compared with cases found in the literature.

RESULTS

Seven patients were prenatally suspected of having intestinal obstruction and were postnatally diagnosed with MIA, with a mean 1.7 (1-2) resections-anastomoses (RA) and 6 (1-10) strictureplasties performed, resulting in a mean resected bowel length of 15.1cm (15-25 cm). Median time to full oral feed was 46 days (14-626 days). All patients were alive and none had orality disorder after a mean follow-up of 3.1 years (0.2-8.1 years). Three surgical strategies were found in the literature review: multiple RA (68%, 34/50) including Santulli's technique in four of 34 (12%) and anastomoses over a transanastomotic tube (32%, 16/50), with a 98% survival rate, and short-bowel syndrome for only two patients.

CONCLUSION

Bowel-sparing surgery and appropriate medical management are key to ensuring a favorable nutritional and gastrointestinal outcome and a good prognosis. Prenatal assessment and standardization of the surgical course of treatment remain challenging.

Vanishing Gastroschisis with a Favorable Outcome after a 3-Year Follow-Up: A Case Report and Literature Review

Vanishing gastroschisis (VG) is a severe complication of gastroschisis with a high mortality rate. We report here a case of VG with a favorable outcome after a 3-year follow-up. A 26-year-old primigravida woman was referred to Strasbourg University Hospital because her fetus was diagnosed with an isolated gastroschisis at 13-week gestation. The ultrasound evolution was marked by a progressive closure of the abdominal wall defect from 19-week gestation and the appearance of dilated intra-abdominal loops. The child was born with a closed abdominal wall except a small remnant at the level of the former gastroschisis orifice. Explorative laparotomy revealed extensive midgut atresia with only 50 cm of remaining midgut. A jejunocolic anastomosis was performed. The child is now 3 years old and has a favorable outcome with only 2 nights a week of parenteral nutrition. A total of 39 cases of VG type D from Perrone et al. classification are described in the literature from 1991 to 2019, among which 19 (48.7%) are alive at the time of publication but only 4 cases are described with a long-term follow-up of 3 years or more. This is the fifth case described with a favorable evolution after 3-year follow-up.

The use of fetal MRI for renal and urogenital tract anomalies

Fetal anomalies are detected in approximately 2% of all fetuses and, among these, genitourinary tract abnormalities account for 30% to 50% of all structural anomalies present at birth. Although ultrasound remains the first line diagnostic modality, fetal MRI provides important additional structural and functional information, especially with the development of faster sequences and the use of functional sequences. The added value of MRI-based imaging is three-fold: (a) improvement of diagnostic accuracy by adequate morphological examination, (b) detection of additional anomalies, and (c) in addition, MRI has the potential to provide information regarding renal function. In this review, we describe the role of fetal MRI in the anatomical evaluation of renal and urogenital tract anomalies, and we also touch upon the contribution of functional MRI to the diagnostic workup of these conditions.

Congenital Sodium Diarrhea by mutation of the SLC9A3 gene

Congenital Sodium Diarrhea (CSD) due to SLC9A3 mutation is a rare cause of neonatal diarrhea explained by dysfunction of the Na+/H+ antiporter 3 in intestine. To date only 10 patients have been described. We report a male patient with typical antenatal symptoms (polyhydramnios and intestinal dilation) and neonatal diarrhea with fecal sodium and bicarbonates loss. Next generation sequencing revealed a missense homozygous mutation in exon 6 of the SLC9A3 gene (NM_004174.3:c.1039G > A, NP_004165.2:p.Glu347Lys). Oral electrolytes supplements (Sodium and Bicarbonates) allowed a normal growth to the child currently aged twenty months. CSD symptomatology usually begins during third trimester of pregnancy. Antenatal signs are polyhydramnios and diffuse intestinal dilation. Main differential diagnoses are intestinal obstruction and Congenital Chloride Diarrhea. Diarrhea begins from the first days of life and its severity is variable. Based on the report and on the literature we suggest that non syndromic CSD can be detected during third trimester of pregnancy. With adequate electrolytes supplementation good evolution is possible.

Consanguinity and its relevance for the incidence of megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS): systematic review

BACKGROUND/PURPOSE

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a rare congenital and generally fatal cause of functional intestinal obstruction in the newborn. The cause of this syndrome is unknown. Familial occurrence and reports of consanguinity in MMIHS implies that genetic factors may have an important role in the pathogenesis of this syndrome. The aim of the study was to determine the consequence of consanguinity for the incidence of MMIHS.

METHODS

A literature search was performed using the keywords "megacystis microcolon intestinal hypoperistalsis" for studies published between 1976 and 2018. Retrieved articles, including additional studies from reference lists, were reviewed for consanguinity between parents and recurrence of MMIHS between siblings. Data were extracted for cases where familial MMIHS was present.

RESULTS

A total of 450 patients with the diagnosis of MMIHS have been reported in the literature. There were 56 (12%) cases in which familial MMIHS was confirmed, 25 families with multiple siblings and 3 families with single affected infant. Of the 25 families with multiple siblings, 22 families had 2 siblings with confirmed MMIHS and 3 families had 3 children each with MMIHS. Consanguinity between parents was confirmed in 30 cases (18 siblings and 12 individual cases). Female-to-male ratio in the 30 patients was 4.4:1.

CONCLUSION

The occurrence of MMIHS in the offspring of consanguineous parents and recurrence in siblings of healthy parents suggest that MMIHS is an autosomal recessive disorder. Pre-marital and pre-conception counselling of consanguineous populations is recommended to prevent harmful consequences.

How to Explore Fetal Sacral Agenesis Without Open Dysraphism: Key Prenatal Imaging and Clinical Implications

The estimated prevalence of fetal caudal dysgenesis is 1 per 100,000 births. The functional prognosis of sacral agenesis is dominated by the large spectrum of associated caudal malformations. Except for cases associated with hydrocephalus secondary to open spinal dysraphism or chromosomal anomalies, association with mental deficiency is rare. We propose a systematic prenatal approach to cases of fetal sacral agenesis based on 9 etiologic items: clinical context, type of sacral dysgenesis, associated spinal cord malformations, mobility of lower limbs, investigation of the presacral region, analysis of the gastrointestinal tract, analysis of the genitourinary tract, associated vertebral defects, and cytogenetic analysis.

Prenatal diagnosis of megacystis microcolon intestinal hypoperistalsis syndrome by biochemical analysis of fetal urine

OBJECTIVES

The objective of the study is to determine a model of fetal urine biochemical markers to differentiate megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) from other megacystis.

METHOD

This is a retrospective study of biochemical analysis of fetal urine in patients who presented prenatally with megacystis. We studied β2-microglobulin, sodium, calcium, and phosphorus. Twenty-six patients subsequently diagnosed with MMIHS were compared with 2 control groups: one of end-stage renal failure (64 fetuses) and the second of "good" postnatal renal function (control group, 64 fetuses).

RESULTS

Mean fetal urine β2-microglobulin was significantly higher (P < .001) in end-stage renal failure (15.7 mg/L) than in MMIHS (2.2 mg/L) and the control group (3.2 mg/L). Fetal urine profiles differed significantly (P < .001) between MMIHS and the control group: median sodium 46.5 and 51 mmol/L, median calcium 1.12 and 0.73 mmol/L, and median phosphorus 0.03 and 0.15 mmol/L respectively. Fetal urinary ionic index [ratio: calcium / (phosphorus × sodium)] gave an area under the ROC curve of 0.86, at 54% sensitivity and 97% specificity, with correct classification in 84% of cases. We defined a nomogram to obtain a probability for MMIHS.

CONCLUSION

Fetal urinalysis can be helpful in prenatal differentiation of MMIHS from posterior urethral valves with good postnatal renal function.

Evaluation of pre- and postnatally diagnosed gastrointestinal tract obstructions

Purpose: Signs of congenital obstruction of the gastrointestinal tract (GIT) organs may present on prenatal ultrasonography. Prenatal detection is influenced by several factors, including obstruction site, lesion degree (partial or complete), the occurrence of associated malformations, and gestational week at screening. Here, we aimed to evaluate the success of prenatal diagnosis of GIT obstructions in a tertiary center in Turkey. Materials and methods: The study included 34 prenatally and 22 postnatally diagnosed babies with different GIT malformations. GIT obstructions were divided into five groups according to the level of obstruction (A. esophagus, B. stomach and proximal duodenum, C. small intestine, D. large intestine, E. multiple obstructions). Results: The prenatal detection rate among all cases was 60.7%. The associated structural malformation and aneuploidy rates were 21.4 and 5.4%, respectively. Twelve neonates died within the first day after birth due to various reasons. The remaining 43 babies underwent surgery at different times according to their clinical conditions. The mean time between birth and surgery was 4.5 days (range, 1-56 days). There were 12 postoperative deaths due to various complications, and one case died at 2 years of age. Overall, 31 of the 56 (55.4%) babies were alive during the follow-up period. The successful prenatal diagnosis rates were 57.2, 85.8, 75, 25, and 80% in groups A, B, C, D, and E, respectively. The median birth weight increased significantly in groups A through D (p = .04). However, there were no intergroup differences in the Apgar scores, associated abnormality rates, time to surgery, and number of babies operated. Conclusions: These findings demonstrate the importance of prenatal ultrasonography and success of prenatal detection especially for upper GIT abnormalities. Although there are some prenatal signs of GIT obstructions, such as double bubble, polyhydramnios, enlarged bowel, and failure to visualize the stomach, early prenatal diagnosis is difficult and can be delayed, resulting in the detection of GIT obstruction after birth. When suspecting GIT obstruction, clinicians should evaluate the fetal anatomy carefully and be aware of associated chromosomal abnormalities.

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.

Prenatal diagnosis of gastric and small bowel atresia: a case series and review of the literature

OBJECTIVE

To describe seven cases of gastrointestinal tract (GIT) obstructions and to report a skewed review of the literature.

METHODS

We performed a search of our permanent perinatal database about cases with prenatal ultrasound and MRI diagnosis of gastrointestinal tract obstructions between 2006 and 2013. All cases were followed until hospital discharge and pre-natal diagnosis were confirmed by fetal MRI, postnatal imaging and/or intra-operative findings. Maternal age, parity, gestational age at diagnosis, ultrasound findings, gestational age at delivery, Apgar scores at 1 and 5 min and postnatal outcome have been recorded.

RESULTS

We identified seven cases of gastric and small bowel atresia. Karyotype was normal in six cases and abnormal in one co-twin [46,XY dup (20) (qq13.1q13.3)dn] of a dichorionic-diamniotic pregnancy. The mean ± SD for maternal age, gestational age at diagnosis, gestational at delivery, birth weight and Apgar scores at 1 and 5 min were 30.8 ± 4.8 years, 29.8 ± 3.7 weeks, 2507.5 ± 727.5 g and 5.6 ± 2.1, 7.6 ± 1.6, respectively. All fetuses' undergone surgical procedures in the postnatal period and all of them were discharged live from the hospital.

CONCLUSION

Prompted antenatal detection of gastrointestinal tract obstruction using ultrasound proved to be diagnostic in all cases. Fetal MRI aid was a useful complementary diagnostic investigation. Correct pre-natal diagnosis allows adequate counseling, delivery planning and management care by a multidisciplinary team.

Accuracy of prenatal ultrasound in detecting jejunal and ileal atresia: systematic review and meta-analysis

OBJECTIVE

The accuracy of prenatal ultrasound examination in detecting jejunal and ileal atresia has been reported in the literature to be highly variable, at 25-90%. The aim of this systematic review was to evaluate the accuracy of prenatal ultrasound in detecting non-duodenal small bowel atresia (ND-SBA).

METHODS

MEDLINE, EMBASE and The Cochrane Library, including The Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE) and The Cochrane Central Register of Controlled Trials (CENTRAL), were searched electronically. The overall detection rate of jejunal or ileal atresia using ultrasound was reported. The accuracy of using polyhydramnios and dilated loops of bowel as diagnostic signs was also explored.

RESULTS

Sixteen studies involving 640 fetuses were included in this review. The detection rate of ND-SBA by prenatal ultrasound was highly variable, with values ranging from 10 to 100%, with an overall prediction of 50.6% (95% CI, 38.0-63.2%). When analyzed separately, the detection rates of jejunal and ileal atresia were 66.3%, (95% CI, 33.9-91.8%) and 25.9% (95% CI, 4.0-58.0%), respectively. Both dilated loops of bowel and polyhydramnios as diagnostic signs for ND-SBA provided a low overall detection rate.

CONCLUSIONS

The diagnostic performance of prenatal ultrasound in identifying ND-SBA is extremely variable. Large studies are needed in order to identify objective and combined criteria for the diagnosis of these anomalies.

Fetal MRI of hereditary multiple intestinal atresia with postnatal correlation

Hereditary multiple intestinal atresia (HMIA) is an extremely uncommon cause of congenital bowel obstruction. The morbidity and mortality of this disease differ significantly from those of isolated intestinal atresias and non-hereditary forms of multiple intestinal atresia. Most notably, despite successful operative repairs of the atresias found in this disease, HMIA maintains a 100% lethality rate from continued post-operative intestinal failure and an associated severe immunodeficiency. We present a case of HMIA evaluated with fetal MRI and subsequently diagnosed by a combination of corroborative postnatal imaging with surgical exploration and pathological examination.

Classification and diagnostic criteria of variants of Hirschsprung's disease

"Variants of Hirschsprung's disease" are conditions that clinically resemble Hirschsprung's disease (HD), despite the presence of ganglion cells in rectal suction biopsies. The diagnosis and management of these patients can be challenging. Specific histological, immunohistochemical and electron microscopic investigations are required to characterize this heterogeneous group of functional bowel disorders. Variants of HD include intestinal neuronal dysplasia, intestinal ganglioneuromatosis, isolated hypoganglionosis, immature ganglia, absence of the argyrophil plexus, internal anal sphincter achalasia and congenital smooth muscle cell disorders such as megacystis microcolon intestinal hypoperistalsis syndrome. This review article systematically classifies variants of HD based on current diagnostic criteria with an additional focus on pathogenesis, epidemiology, clinical presentation, management and outcome.

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS): report of a case with prolonged survival and literature review

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) was first described in 1976. A rare congenital autosomal recessive alteration that predominantly affects females (4:1 ratio), it is characterized by the presence of distended bladder (without distal urinary tract obstruction), microcolon, and decreased or absent intestinal peristalsis. Inconsistent and non-specific histological changes affecting the bladder and intestinal smooth muscle, and intrinsic innervations, have been reported most frequently. MMIHS usually has a fatal prognosis in the first year of life; nevertheless there are some case reports of longer survival. Here is presented the case report of a boy with a diagnosis of MMIHS who has achieved prolonged survival, followed by a review of the literature.

Variants of Hirschsprung disease

Variants of Hirschsprung disease are conditions that clinically resemble Hirschsprung disease, despite the presence of ganglion cells in rectal suction biopsies. The characterization and differentiation of various entities are mainly based on histologic, immunohistochemical, and electron microscopy findings of biopsies from patients with functional intestinal obstruction. Intestinal neuronal dysplasia is histologically characterized by hyperganglionosis, giant ganglia, and ectopic ganglion cells. In most intestinal neuronal dysplasia cases, conservative treatments such as laxatives and enema are sufficient. Some patients may require internal sphincter myectomy. Patients with the diagnosis of isolated hypoganglionosis show decreased numbers of nerve cells, decreased plexus area, as well as increased distance between ganglia in rectal biopsies, and resection of the affected segment has been the treatment of choice. The diagnosis of internal anal sphincter achalasia is based on abnormal rectal manometry findings, whereas rectal suction biopsies display presence of ganglion cells as well as normal acetylcholinesterase activity. Internal anal sphincter achalasia is either treated by internal sphincter myectomy or botulinum toxin injection. Megacystis microcolon intestinal hypoperistalsis is a rare condition, and the most severe form of functional intestinal obstruction in the newborn. Megacystis microcolon intestinal hypoperistalsis is characterized by massive abdominal distension caused by a largely dilated nonobstructed bladder, microcolon, and decreased or absent intestinal peristalsis. Although the outcome has improved in recent years, survivors have to be either maintained by total parenteral nutrition or have undergone multivisceral transplant. This review article summarizes the current knowledge of the aforementioned entities of variant HD.

Outcome of prenatally detected bilateral higher urinary tract obstruction or megacystis: sex-related study on a series of 709 cases

OBJECTIVE

To compare the sex specific outcome of fetuses with prenatally detected urinary tract dilatation, with the exclusion of pyelectasia.

METHOD

Included in the study were 709 cases of major dilatation of the fetal urinary tract, diagnosed at routine ultrasound scan. For each sex group, cases were divided into two subgroups depending on the level of dilatation. Final diagnosis was based on postnatal evaluation or on fetal autopsy. Postnatal renal function was evaluated using serum creatinine at two years of age.

RESULTS

Bilateral higher urinary tract dilatation was prenatally observed in 148 (20.8%) and lower urinary tract obstruction or bladder dilatation in 561 (79.1%) of the 709 cases (121 female and 588 male fetuses) (P <0.001). Bladder dilatation was less frequent in female fetuses (62%) than in males (82.6%) (P <0.001). At final diagnosis, associated malformations were observed in 53.7% of female fetuses versus 11% in males (P <0.001). The survival rate was 42.7%. Postnatal renal function, evaluated in 289/303 live infants, was impaired in 29.7% of cases and depended on the level of obstruction, but not on the sex.

CONCLUSION

Prenatally detected urinary tract dilatation has a poor prognosis both in male and female fetuses. Associated malformations are observed more frequently in female than in male fetuses.

Fetal bowel anomalies--US and MR assessment

The technical quality of prenatal US and fetal MRI has significantly improved during the last decade and allows an accurate diagnosis of bowel pathology prenatally. Accurate diagnosis of bowel pathology in utero is important for parental counseling and postnatal management. It is essential to recognize the US presentation of bowel pathology in the fetus in order to refer the patient for further evaluation or follow-up. Fetal MRI has been shown to offer some advantages over US for specific bowel abnormalities. In this paper, we review the normal appearance of the fetal bowel on US and MRI as well as the typical presentations of bowel pathologies. We discuss more specifically the importance of recognizing on fetal MRI the abnormalities of size and T1-weighted signal of the meconium-filled distal bowel.

Isolated hyperechoic fetal colon before 36 weeks' gestation reveals cystinuria

OBJECTIVES

To determine whether there is an association between the fetal ultrasound finding of hyperechoic colon and the gestational age at which it presents and cystinuria.

METHODS

A prospective national survey was performed in France including all observations of isolated fetal hyperechoic colon detected at routine second- and third-trimester ultrasound over a 2-year period. Collected images were reviewed by experts. Colon was defined as being hyperechoic when its echogenicity was at least equal to that of the iliac bone. It was diagnosed when large tubular echogenic portions of the colon, without a focal mass and without posterior acoustic shadows, were observed at the periphery of the abdomen. Urinary amino acid analysis was performed after birth in the cases identified to test for cystinuria.

RESULTS

Nineteen fetuses with ultrasound findings of hyperechoic colon were included, and the mothers of 16 of these agreed to participate in the study. In eight of nine cases of hyperechoic colon observed before 36 weeks' gestation cystinuria was confirmed at birth. In the seven remaining cases, observed after 36 weeks, none was found to have cystinuria and all had normal images at previous routine ultrasound scans at 22 and 33 weeks. When present, no difference in the sonographic appearance of hyperechoic colon was noted between the two groups. In the cystinuria-affected cases, the length of the hyperechoic mass appeared to increase with gestational age.

CONCLUSIONS

In our experience, the presence of a hyperechoic colon at routine ultrasound scan before 36 weeks' gestation should prompt screening for cystinuria at birth, while later observation (> 36 weeks) of this finding does not appear to be related to any disease.

Megacystis microcolon intestinal hypoperistalsis syndrome: systematic review of outcome

PURPOSE

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a rare and the most severe form of functional intestinal obstruction in the newborn. This congenital condition is associated with non-obstructed urinary bladder, microcolon and decreased or absent intestinal peristalsis. This study was designed to determine the incidence and outcome of MMIHS.

METHODS

A systematic review of the literature (1976-2011) was performed for key words "megacystis microcolon intestinal hypoperistalsis". Resulting publications were reviewed for epidemiology and outcome. Reference lists were screened for additional cases.

RESULTS

A total number of 227 MMIHS cases were reported from 1976 to 2011. A clear preponderance for female infants was found (female 70.6 vs. male 29.4%). One or more surgical interventions were reported in 115 patients (including gastrostomy, ileostomy, jejunostomy, segmental resections of small bowel, adhesiolysis and internal sphincter myectomy). For decompression of the megacystis, vesicostomy was performed in 41 patients. Outcome was reported in a total of 218 patients. Survival rate was 19.7% (survivors: n = 43, non-survivors: n = 175), the oldest survivor being 24 years old. The vast majority of the surviving patients had to be maintained by total or partial parenteral nutrition (TPN). Main causes of death were sepsis, malnutrition and multiple organ failure. Twelve multivisceral transplantations have been reported to date in patients with MMIHS. The majority of the survivors are reported to be free of parenteral nutrition and show improving gastric emptying. However, intermittent catheterisation remains obligatory due to persistent bladder dysfunction.

CONCLUSIONS

The survival in MMIHS in recent years has improved. The majority of survivors are either maintained by TPN or have undergone multiorgan transplantations.

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.

Gastrointestinal pathology in neonates: new imaging strategies

The mainstay of imaging of gastrointestinal (GI) pathology in infants has always been and still is the plain radiograph of the abdomen and conventional contrast studies. In this review emphasis is placed on the situations where there are new imaging strategies and alternative modalities of imaging, including US, CT, MRI and radionuclide studies. This review will deal with GI pathology in the newborn and in the older neonate. It will also refer to any new approaches to imaging GI pathology in the premature infant. Finally the review will address how antenatal diagnosis of gastrointestinal tract abnormalities has changed the imaging strategy and management of the neonate.

Megacystis-microcolon-intestinal hypoperistalsis syndrome: a case report

Megacystis Microcolon Intestinal Hypoperistalsis Syndrom (MMIHS) is a quite rare congenital and fatal disease which was firstly defined by Berdon and his colleagues. It appears through a widely enlarged bladder and microcolon and its cause is unknown (Berdon et al., 1976; Carmelo et al., 2005; Makhija et al., 1999; Loening-Baucke and Kimura 1999; Redman et al., 1984; Hsu et al., 2003; Yigit et al., 1996; Srikanth et al., 1993). The disease is found in females three or four times more than in males (Srikanth et al., 1993; Sen et al., 1993; Hirato et al., 2003). Most of the cases die within the early months of their lives (Yigit et al., 1996; Srikanth et al., 1993; Sen et al., 1993; Hirato et al., 2003). We present the case of a female newborn with antenatal ultrasound revealing intestinal mass and bilateral hydroureteronephrosis. The case was admitted for intestinal obstruction after birth.

Prenatal ultrasound and fetal MRI: the comparative value of each modality in prenatal diagnosis

Fetal MRI is used with increasing frequency as an adjunct to ultrasound (US) in prenatal diagnosis. In this review, we discuss the relative value of both prenatal US and MRI in evaluating fetal and extra-fetal structures for a variety of clinical indications. Advantages and disadvantages of each imaging modality are addressed. In summary, MRI has advantages in demonstrating pathology of the brain, lungs, complex syndromes, and conditions associated with reduction of amniotic fluid. At present, US is the imaging method of choice during the first trimester, and in the diagnosis of cardiovascular abnormalities, as well as for screening. In some conditions, such as late gestational age, increased maternal body mass index, skeletal dysplasia, and metabolic disease, neither imaging method may provide sufficient diagnostic information.

IRM fœtale : indications, limites et dangers

Although prenatal sonography remains the primary imaging method for screening fetal anomalies, fetal MRI with ultrafast imaging technique is a complementary imaging method as soon as the second trimester. It allows better tissue contrast images than does US, a large field of view of the foetus and is not limited by large maternal body habitus and oligohydramnios, without any risk for the foetus. In the future, the development of new techniques (diffusion-weighted imaging, proton MR spectroscopy) and faster sequences will make it possible to widen the indications i.e. cardiac, functional renal and cerebral imaging.

Fetal Magnetic Resonance Imaging as a Complement to Fetal Ultrasonography

Ultrasonography is the screening method of choice for the evaluation of the fetus. It is safe, inexpensive, and easily performed. However, it is operator dependent, and evaluation may be limited because of fetal position, maternal obesity, overlying bone, and/or oligohydramnios. Magnetic resonance imaging is an alternative modality that uses no ionizing radiation, has excellent tissue contrast and a large field of view, is not limited by obesity or overlying bone, and can image the fetus in multiple planes, no matter the fetal lie. Faster scanning techniques allow studies to be performed without sedation in the second and third trimester with minimal motion artifact.