Determination of the anatomical location of an antenatal intestinal occlusion by magnetic resonance imaging

Congenital malformations of the gastrointestinal tract in neonates at aristide le dantec university hospital in Dakar: Concerning 126 cases

OBJECTIVE

Congenital malformations of the gastrointestinal tract are one of the major causes of neonatal mortality, especially in developing countries. The aim of this study is to assess the overall management of gastrointestinal malformations.

PATIENTS AND METHODS

The study design is monocentric and retrospective. It includes all newborns aged 1-28 days with malformations of the gastrointestinal tract between 1^st January 2014 and 31^st December2018, at the Paediatric Surgery Department of Aristide Le Dantec University Hospital in Dakar. Data were collected by studying patient's records and surgical procedures.

RESULTS

During the five-year study, 405 newborns with congenital anomalies were admitted to our hospital. A total of 126 newborns were diagnosed with gastrointestinal tract malformations. The incidence was 25.2 cases a year. The sex distribution was 74 boys (58.7%) and 52 girls (41.2%). The mean age at diagnosis was 7.4 ± 3.2 days. Two cases were diagnosed antenatal (1.59%). The mean time to post-natal diagnosis was 6.5 ± 2.1 days. The most common malformation was oesophageal atresia with 43 cases (34.1%). The average time between diagnosis and surgery was 48 h. Out of the 126 cases, 77 (61.1%) received surgery and 49 (38.9%) died before surgery. The main causes of pre-operative death were intricate and dominated by lung infections (42.9%). Among the 77 newborns, who received surgery, 38 (%) had a simple post-operative course, 39 (50.6 %) died. Post-operative deaths were dominated by anaesthetic complications (30.8%), lung infections (46.1%). The overall mortality was 69.8% (n = 88).

CONCLUSION

The low socio-economic status, poor pre-natal diagnosis, prematurity, post-natal diagnostic delay, obsolete medical equipment and the lack of neonatal intensive care units were identified as the major factors for high mortality in neonates with gastrointestinal tract malformations in a developing country.

Ultrasound and Fetal MRI Complementary Contributions to Appropriate Counseling in Small Bowel Obstruction

OBJECTIVE

Bowel obstructions beyond the duodenum represent a heterogeneous group of congenital anomalies with a highly variable prognosis, the main issue being postnatal short bowel syndrome (SBS). The objective of our study was to evaluate the contributions of fetal MRI in cases of bowel obstruction.

MATERIALS AND METHODS

A retrospective analysis of all newborns, for whom both ante-natal ultrasound and fetal MRI were available, referred to our center for suspected bowel obstruction was performed. Examinations were reviewed blinded to the postnatal outcome. Key outcome measures included exact diagnosis and the existence of postoperative SBS. We evaluated the contribution of MRI in determining precise location and etiology of the bowel obstruction, dilatation of the proximal bowel loops, and assessment of the quality of the remaining distal bowel loops.

RESULTS

Twenty-five newborns were included. There were 19 single obstructions and 6 complex forms (4 apple peel syndromes and 2 multiple atresias). MRI correctly identified the affected segment of the small bowel in 59.1% of the cases. MRI identified the mechanism of obstruction in 72% of cases. MRI reliably predicted an abnormal appearance of the bowel distal to the obstruction in 100% of the severe cases (3/3) and in 66.7% of complex forms (4/6).

CONCLUSION

Our study suggests that fetal MRI, when done in addition to prenatal ultrasound, is contributory in the management of fetuses with suspected bowel obstruction. MRI may be particularly useful in determining the location and origin of the bowel obstruction and in assessing the quality of the bowel distal to the obstruction, which might assist in the prediction of SBS and more detailed prenatal counseling.

Fetal body MRI for fetal and perinatal management

Fetal magnetic resonance imaging (MRI) has become a valuable adjunct to ultrasound (US) in diagnosing fetal abnormalities. This review is intended to highlight the contribution of MRI in parental counselling and perinatal treatment. A state-of-the-art fetal MRI protocol with experts of maternal-fetal medicine present in the MRI suite allows emphasis on patient-centred care and maximises therapeutic options.

Fetal Body Imaging: When is MRI Indicated?

Recent improvements in fetal therapies and perinatal care and the multidisciplinary involvement in fetal medicine have increased the demand for more accurate prenatal diagnosis. Fetal Magnetic Resonance Imaging (MRI) is a complementary imaging technique for the assessment of thoraco-abdominal anomalies for which Ultrasonography (US) is not conclusive. It is indicated in selected situations to precise the prognosis in diaphragmatic hernia, to characterise the nature and extension of a pulmonary malformation, to locate a bowel atresia or to better depict an abdominal cystic lesion or tumoural extension. It has become a mandatory complementary diagnostic tool and improves the management of the fetuses and newborns.

[Fetal MRI practices in a university prenatal center]

OBJECTIVES

Fetal MRI is a third intention examination to prenatal diagnosis. If its diagnostic value is well known in many pathologies, its place in the management of pregnancies remains unclear.

METHODS

We collected retrospectively demographical, radiological (fetal MRI indications, fetal anatomical region and diagnostic information provided by fetal MRI) and obstetrical data of pregnant patients in university prenatal center during a 5 years' period.

RESULTS

Among 2439 patients of the prenatal center, 196 (8%) patients with fetal MRI were included. The main anatomical regions studied were the brain (n=132, 67%), the thorax (n=31, 16%) and the abdomen (n=25, 13%). No cardiac fetal MRI was performed. Ninety-five percent of fetal MRI was consecutively of an ultrasound sign. Fetal brain MRI was abnormal in 65% of cases, the thoracic and abdominopelvic MRI in 81.5%. The ultrasound diagnosis was unchanged in 42%, completed in 50% and redirected in 8% of cases. A termination of pregnancy was deemed admissible in 31% of patients with MRI versus 21% in patients without MRI (P=0.001).

CONCLUSION

Fetal MRI requires selective indications and provides additional diagnostic information with important implications for the future of the pregnancy, particularly in case of severe and incurable pathologies. Our results could be useful as a reference basis for the comparison with others prenatal center practices.

Prenatal Imaging of the Gastrointestinal Tract with Postnatal Imaging Correlation

Prenatal detection of a wide variety of anomalies and masses of the gastrointestinal tract is now possible. Prenatal imaging with ultrasonography and in selected cases magnetic resonance imaging provides invaluable information to the referring obstetrician, the maternal fetal medicine specialist, the neonatologist and pediatrician who will care for the child after birth, the surgeons and pediatric specialists who will repair or manage a prenatally detected anomaly, and of course to the parents, allowing them to prepare psychologically and financially for the specific interventions that may be needed for their child. Additional screening for associated anomalies can take place, route of delivery can be decided, and arrangements for delivery in an appropriate setting can be made. Prenatal detection also allows for consideration for pregnancy termination. This article will give a broad overview of anomalies of the gastrointestinal tract that can be detected prenatally and their imaging appearance postnatally.

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.

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.

Avaliação crítica dos benefícios e limitações da ressonância magnética como método complementar no diagnóstico das malformações fetais

OBJETIVO: Avaliar, por meio da ressonância magnética, uma série de fetos com diagnóstico ultra-sonográfico de malformação, a fim de estabelecer os benefícios e limites diagnósticos proporcionados pela técnica de ressonância magnética fetal, em comparação com a ultra-sonografia. MATERIAIS E MÉTODOS: Foram estudadas 40 mulheres entre 15-35 semanas de gestação com diagnóstico de anomalia fetal durante o exame de ultra-sonografia. As pacientes foram encaminhadas para o estudo complementar com ressonância magnética. As indicações para o estudo da ressonância magnética fetal foram: anomalias do sistema nervoso central, do tórax, do abdome, renais, esqueléticas e tumores. A avaliação pós-natal incluiu a revisão das imagens de ultra-sonografia e ressonância magnética, o acompanhamento do nascimento, exames laboratoriais, radiológicos e necropsia. RESULTADOS: Os resultados mostraram que os estudos complementares com ressonância magnética fetal trouxeram informações adicionais em 60% dos casos estudados. Os benefícios da ressonância magnética fetal foram: ampliação da avaliação global, aumento do campo de avaliação, maior resolução tecidual pelo uso de seqüências, e avaliação em pacientes obesas e com oligoidrâmnio. Os limites da ressonância magnética fetal foram: evitar exame no primeiro trimestre, avaliação do fluxo sanguíneo, movimentação fetal, claustrofobia materna, estudo do coração fetal e esqueleto. CONCLUSÃO: A ressonância magnética fetal pode ser utilizada como método complementar para a avaliação das malformações fetais.

The usefulness of fetal MRI for prenatal diagnosis

PURPOSE

Fast MRI has provided detailed and reproducible fetal anatomy. This study was performed to evaluate the usefulness of fetal MRI for prenatal diagnosis.

MATERIALS AND METHODS

Fifty-six fetuses with congenital abnormalities on ultrasonography were evaluated by fetal MRI from 2001 to 2004 in Severance Hospital. Final diagnosis was made by postnatal pathology, postnatal MRI, and other modalities (such as ultrasound, retrograde pyelogram). A 1.5-Tesla superconductive MR imaging unit was used to obtain half-Fourier acquisition single-shot turbo spin images.

RESULTS

Of the 56 fetuses, intracranial abnormalities were found in 26 fetuses, intraabdominal abnormalities in 17 fetuses, intrathoracic in 6 fetuses, head and neck in 5 fetuses, and other sites in 2 fetuses. There were six cases in which the diagnoses of fetal MRI and ultrasonography differed. In such cases, fetal MRI provided more exact diagnosis than ultrasonography (5 vs. 0). Three fetuses with intracranial abnormalities on ultrasonography were diagnosed as normal by fetal MRI and in postnatal diagnosis.

CONCLUSION

Although ultrasonography is known as a screening modality of choice in the evaluation of fetus because of the cost-effectiveness and safety, the sonographic findings are occasionally inconclusive or insufficient for choosing the proper management. Thus, in this study, we suggest that fetal MRI is more useful than ultrasonography for the evaluation of intracranial abnormalities in some instances. For prenatal counseling and postnatal treatment planning, fetal MRI can be informative when prenatal ultrasonography is inadequate and doubtful.

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.

Foetal magnetic resonance imaging and echogenic bowel

OBJECTIVES

To evaluate how foetal magnetic resonance imaging (MRI) may change the diagnosis in cases of ultrasound (U/S) findings of echogenic bowel (EB).

METHODS

Seventeen foetuses with EB underwent serial U/S examinations, foetal MRI, cystic fibrosis screening and maternal viral serologic tests. MRI protocol included T2-weighted half-Fourier acquired single-shot turbo spin-echo (HASTE) sequence and gradient echo (GE) T1-weighted images. Foetal abdominal MRI analyzed patterns were size and signal of small bowel, colon and rectum, ascites and abdominal mass. All neonates had complete clinical examination, abdominal sonography, and a 6 months clinical follow-up.

RESULTS

Eleven foetuses with isolated EB had normal MRI and normal outcome. In comparison, all the 6 foetuses whose U/S patterns showed associated signs had abnormal MRI (p < 0.001). Five had proven pathology (83.3%: 5/6) and only 1 (16.7%: 1/6) had no proven pathology and normal postnatal outcome (p = 0.001). For those five, foetal MRI showed bowel abnormalities with one case of bowel duplication and four cases of bowel obstruction. Two out of the four cases of bowel obstruction were genetically diagnosed as cystic fibrosis. The two remaining cases were diagnosed as ileal atresia.

CONCLUSION

MRI could provide additive information in cases of EB associated with bowel dilatation.

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

OBJECTIVE

To analyze the contribution of fetal magnetic resonance imaging (MRI) and amniotic fluid digestive enzyme (AFDE) assays to the evaluation of gastrointestinal tract abnormalities.

METHODS

This was a prospective study involving 24 fetuses suspected of having gastrointestinal tract abnormalities on ultrasound examination. MRI was used to analyze the location of the obstruction, the visibility of the small bowel not involved in the obstruction, and the visibility and size of the colon and rectum. Abnormalities were further evaluated by AFDE assays. The final diagnosis was based on postnatal or fetopathological examination.

RESULTS

In duodenojejunal obstructions, MRI (6/6) and AFDE assays (4/4) correctly identified the level of obstruction, but were less accurate for small bowel obstructions (MRI, 10/11; AFDE assays, 7/11). The small bowel not involved in the obstruction was correctly evaluated by MRI as being viable in six cases and as abnormal in eight cases (multiple obstructions or necrosis). However, it was thought antenatally to be abnormal by MRI in four cases in which it was found to be normal on postnatal findings. Three cases in which the colon was found to have abnormal echogenicity were considered normal both by MRI and AFDE assay, in agreement with postnatal findings. Two cases of microcolon-megacystis-intestinal hypoperistalsis syndrome (MMIHS) were diagnosed both by MRI and AFDE assay. Of the three anorectal malformations, two were overlooked by ultrasonography and one by MRI. MRI also overlooked 2/3 associated rectourethral fistulas.

CONCLUSION

MRI and enzyme analysis are good complementary tools to ultrasonography for identifying the level of gastrointestinal obstruction and diagnosing MMIHS. MRI can assess the normality of the intestinal tract not involved in the obstruction, but not multiple obstructions, necrosis and small urodigestive fistulas.

Fetal abdominal magnetic resonance imaging

This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages.

Fast Fetal Magnetic Resonance Imaging

Fetal magnetic resonance imaging (MRI) can be used as a problem-solving tool when ultrasonic findings are equivocal. The role of fetal MRI has increased as obstetricians become aware of its potential and in utero therapy for anomalies becomes increasingly sophisticated. In this pictorial essay, we present a wide range of anomalies diagnosed or confirmed using MRI and discuss findings that help in the differential diagnosis.

Ultrafast fetal MRI and prenatal diagnosis

Improvements in magnetic resonance imaging (MRI) technology continue to provide faster scan times and higher resolution increasing the applications for fetal imaging. MRI is an adjunct to good prenatal ultrasound scan (US). It provides significant additional information that improves diagnostic accuracy in evaluation of the fetal brain, spine, neck, chest, abdomen, and urinary tract. MRI provides important anatomic information that helps in planning delivery and surgical procedures.

Prenatal evaluation for fetal surgery

The selection of fetuses that may benefit with in utero surgery is being developed. Noninvasive and invasive prenatal diagnosis techniques are utilized to try and gain as much knowledge about the fetus so that the appropriate counseling of parents can be undertaken. The most common invasive techniques are amniocentesis and chorionic villus sampling for fetal karyotyping and genetic diagnosis. Noninvasive techniques include ultrasound (2D and 3D), fetal echocardiography and magnetic resonance imaging. Additional techniques such as specific Doppler evaluation of vascular components, new techniques to look at fetal electrocardiograms and the use of computer tomography are also considered. The most common conditions for which in utero fetal surgery is also being considered are twin to twin transfusion syndrome, myelomeningocele, sacrococcygeal teratoma, cystic adenomatoid malformation of the lung with fetal hydrops and other monochorionic twin abnormalities (severe discordant birth defects or twin reversal arterial perfusion sequences). Ongoing evaluation of the sensitivity, specificity, positive and negative predicted values of these evaluation tools is required so that appropriate selection of fetuses for the surgery can be made.