Antenatal diagnosis of intestinal malrotation on fetal MRI

We report a case of intestinal malrotation without any associated GI tract complications diagnosed antenatally by fetal MRI. Antenatal US revealed a midline stomach. Subsequent fetal MRI confirmed the midline stomach and, in addition, revealed all loops of small bowel to the right of the midline and all large bowel to the left. All these features were consistent with intestinal malrotation. There was no abnormal bowel wall thickening, bowel dilatation, ascites or polyhydramnios. To our knowledge, this is a unique case of intestinal malrotation without associated GI tract complications diagnosed antenatally on fetal MRI.     

MRI of the fetal eyes: morphologic and biometric assessment for abnormal development with ultrasonographic and clinicopathologic correlation

BACKGROUND: Currently ocular biometric measurements are defined by US and are measured from the orbital walls. These bony landmarks cannot be seen by MRI, and therefore these measurements cannot be directly applied. OBJECTIVE: To define measurements of normal growth of the fetal eyes using MRI. MATERIALS AND METHODS: Transorbital views were analyzed in 198 fetal MR examinations. The ocular diameter (OD) and interocular and binocular distances (IOD and BOD) were measured and were plotted against gestational age. Fetuses with abnormalities affecting the eyes were evaluated separately. RESULTS: Of 198 scans, 146 had suitable images, 35 of which were abnormal. Normal growth of BOD, IOD and OD were determined, and compared with the respective already established US data. CONCLUSION: Normal growth charts were derived from a cohort of 111 normal fetuses. Because the margins of the vitreous are inside the bony orbit, at the same gestational age measurements of the BOD and OD are always less than the corresponding measurements by US, and those of the IOD are always more. Normal growth charts for MRI can now be used to support suspected diagnoses of orbital and ocular pathologies and the syndromes that give rise to them, and many examples are demonstrated.     

Diagnosis of Chiari III malformation by second trimester fetal MRI with postnatal MRI and CT correlation

We report a case of Chiari III malformation diagnosed by fetal MRI. Ultrasound (US) performed at a gestational age of 18 weeks demonstrated a posterior skull base cyst. Repeat US at 19 weeks demonstrated neural tissue in the cyst, consistent with an encephalocele. MR imaging at 23 weeks confirmed the presence of an occipital encephalocele, demonstrated additional bony defect in the upper cervical spine, and identified abnormal morphology and position of the brainstem consistent with the diagnosis of Chiari III. Postnatal MRI and CT confirmed the fetal MRI findings and demonstrate the utility of fetal MRI in the early evaluation of songraphically detected posterior fossa abnormalities.     

Value of fetal cerebral MRI in sonographically proven cardiac rhabdomyoma

Background Tuberous sclerosis complex (TSC) is an autosomal dominant phakomatosis associated with intracardiac rhabdomyomas. Objective The aim of our study was to examine the value of cerebral MRI in diagnosing TSC in fetuses with intracardiac rhabdomyomas, applying the TSC Consensus Conference (TSCCC) criteria. Materials and methods In a prospective manner six consecutive fetuses with cardiac rhabdomyomas (21–34 weeks’ gestation) underwent cerebral MRI. The MRI results were correlated with clinical follow-up at 10–34 months after birth, histology, and genetic data. Results In five of the six fetuses the diagnosis of TSC was established. In two of five fetuses MRI demonstrated cerebral manifestations of TSC that correlated well with severe epilepsy manifesting during the follow-up period. In another two of five fetuses MRI as well as clinical follow-up were normal. One of five pregnancies was terminated and histology demonstrated microscopically small subependymal nodules not demonstrated by MRI. Conclusion The results of our study agree with the available literature that fetal MRI is sufficient for the detection of cerebral lesions in TSC and should be better promoted. The TSCCC criteria can also be applied to fetal MRI.     

Congenital epulis: prenatal imaging with MRI and ultrasound

Congenital epulis is an uncommon benign tumor that originates from the alveolar ridge in newborns. It is also known as congenital gingival granular cell tumor. Although there have been around 200 reports of its postnatal diagnosis, this oral tumor has rarely been diagnosed prenatally. We present fetal MRI and Doppler prenatal imaging of an infant with two congenital epulides (simultaneous involvement of superior and inferior maxillas).     

Fetal MRI: techniques and protocols

The development of ultrafast sequences has led to a significant improvement in fetal MRI. Imaging protocols have to be adjusted to the rapidly developing fetal central nervous system (CNS) and to the clinical question. Sequence parameters must be changed to cope with the respective developmental stage, to produce images free from motion artefacts and to provide optimum visualization of the region and focus of interest. In contrast to postnatal studies, every suspect fetal CNS abnormality requires examination of the whole fetus and the extrafetal intrauterine structures including the uterus. This approach covers both aspects of fetal CNS disorders: isolated and complex malformations and cerebral lesions arising from the impaired integrity of the feto-placental unit.     

Fetal and neonatal origins of altered brain development

Abnormal development of the brain during fetal life is now thought to contribute to the aetiology of many neurological disorders that manifest throughout life. Many factors are likely to underlie such abnormal development including genetic makeup and an adverse intrauterine environment. This review will focus on prenatal hypoxic/ischaemic injury, inflammatory/infective insults and preterm birth. A range of experimental models have been used to characterize lesions formed in response to these insults and to determine mechanisms of damage resulting from such events. Relatively brief periods of fetal hypoxia result in neuronal death (cerebellum, hippocampus, and cerebral cortex), white matter damage and reduced growth of neural processes. These effects are more profound at mid than late gestation. Chronic mild placental insufficiency can result in fetal growth restriction and deficits in neural connectivity and myelination. Exposure of the preterm fetus to inflammatory agents causes brain damage particularly in the white matter and this is exacerbated by hypoxia. Premature birth without potentiating factors can result in subtle neuropathologies including cerebral white matter gliosis, hippocampal sclerosis and subarachnoid haemorrhage; the extent of the damage appears to be related to the regimen of ventilatory support. These studies show that the timing, severity and nature of specific insults are critical in determining the pattern of injury and thus the extent to which neurological function will be affected postnatally. Defining the causes, patterns and mechanisms of brain injury is crucial if we are to develop rational neuroprotective strategies to reduce the burden of altered brain growth and poor functional and behavioural outcomes.     

MRI技术在胎儿先天性心脏病诊断中的应用

先天性心脏病是造成新生儿死亡的主要原因之一.在产前对胎儿先天性心脏病进行诊断、评估预后是目前围生医学发展的重要内容.胎儿心脏彩超对于孕中期胎儿先天性心脏病的诊断具有相对较高的灵敏度,是胎儿先天性心脏畸形诊断的金标准.胎儿心脏核磁共振技术在过去十年内发展迅速,其视野大、可重复性好等优点在某些情况下可以弥补胎儿心脏超声的不足,但其技术上的问题也局限了其在临床上的应用,目前被认为是胎儿先天性心脏病的二线诊断方法.该文就胎儿心脏核磁共振技术在胎儿先天性心脏病诊断中应用的方法、优势以及局限性进行综述.     

MRI在诊断胎儿畸形中的应用

MRI没有电离辐射,具有良好的软组织对比,高空间分辨率,多维成像技术,能清楚直观地观察到病变的病理变化,并能一定程度上判断疾病的预后.随着MRI的发展,其已越来越广泛地应用于胎儿畸形的诊断.该文从胎儿的各个系统,包括中枢神经系统、循环系统、呼吸系统、消化系统、泌尿生殖系统、肌肉骨骼系统、内分泌系统等,阐述了MRI在诊断胎儿畸形中的应用及对胎儿畸形处理与预后的判定价值.     

MRI of the fetal spine

Magnetic resonance imaging of the fetal spine is a vital complement to fetal sonographic examination. Assessing the wide spectrum of spinal dysraphism, as well as spinal neoplasia, allows for more correct prenatal diagnoses, patient care planning, and patient counselling. Proper appraisal of the value of experimental procedures, such as fetal myelomeningocoele repair, requires a high level of diagnostic accuracy for the selection and follow-up of appropriate candidates.     

Radiological aspects of the fetal alcohol syndrome

The fetal alcohol syndrome has recently been clinically recognised and has a characteristic facial phenotype. The condition is the result of chronic maternal alcohol ingestion affecting the first trimester. A survey of our cases has shown that skeletal maldevelopment is a part of the syndrome and can help in its early recognition.This paper was given at the 18th E.S.P.R. meeting in Oslo on 22nd May 1981     

适于胎龄儿和小于胎龄儿小脑发育的对比研究

目的 探讨适于胎龄儿（AGA）和小于胎龄儿（SGA）的小脑发育是否存在差异。方法 选取165例胎龄25~40⁺⁶周的AGA和105例相应胎龄的SGA纳入研究。于新生儿出生24~48 h内采用超声测量小脑横径、小脑蚓部高度、小脑蚓部面积、小脑蚓部周长、小脑横径切面小脑面积、小脑横径切面小脑周长。采用Pearson相关分析法进行各测量值与胎龄关系的分析。结果 不论AGA还是SGA,小脑各测量值和胎龄均呈正相关（r=0.50~0.81,P < 0.05）。AGA和SGA各测量值在胎龄25~27⁺⁶周、28~30⁺⁶周、31~33⁺⁶周亚组中的比较差异无统计学意义（P > 0.05）,但在胎龄34~36⁺⁶周、37~40⁺⁶周亚组中,SGA的各测量值均明显低于AGA（P < 0.05）。结论 胎龄 < 34周SGA的宫内小脑发育与同胎龄的AGA类似,而≥34周SGA的宫内小脑发育落后于AGA。     

Pontomedullary disconnection: fetal and neonatal considerations

The cerebellar and pontocerebellar hypoplasias present a unique challenge when detected in the developing fetus. A diverse aetiology and prognosis make counselling of these families difficult. Advances in fetal imaging allow for more accurate diagnosis and counselling, but postnatal MRI is still required. A case is presented in which cerebellar hypoplasia was detected at 20 weeks gestation. Later fetal imaging provided further information, but a diagnosis of pontomedullary disconnection was not made until the postnatal MRI scan. The clinical findings and possible causes of such pontocerebellar abnormalities are discussed.     

Morphological spectrum of prenatal cerebellar disruptions

There is increasing evidence that the cerebellum is susceptible to both prenatal infections and haemorrhages as well as being vulnerable in extremely preterm babies, but not to perinatal and postnatal hypoxic-ischaemic injuries. Starting with the imaging appearance we describe and illustrate a spectrum of prenatal cerebellar disruptions: cerebellar agenesis; unilateral cerebellar hypoplasia; unilateral cerebellar cleft; global cerebellar hypoplasia; vanishing cerebellum in myelomeningocele; and disruption of cerebellar development in preterm infants. We discuss neuroradiological characteristics, possible disruptive events, and clinical findings in the different morphological patterns. Remarkably, the same disruptive agent can cause different neuroradiological patterns, which appear likely to represent a morphological spectrum. The analysis of imaging patterns is crucial in recognising cerebellar disruptions. Recognition of cerebellar disruptions and their differentiation from cerebellar malformations is important in terms of diagnosis, prognosis, and genetic counselling.     

MRI of the fetal posterior fossa

MRI is a useful tool to complement US for imaging of the fetal posterior fossa (PF). In France, the discovery of a PF malformation in the fetus frequently leads to termination of pregnancy (80% in a personal series). However, despite improved accuracy in the diagnosis of PF abnormalities, prognosis remains uncertain. The first objective of this review is to document the normal MRI landmarks of the developing fetal PF. Because of their thinness, the visibility of the cerebellar fissures is dramatically delayed on MRI compared to macroscopic data. An important landmark is identification of the primary fissure of the vermis, normally seen at around 25–26 weeks gestation (WG) on the sagittal slice, separating the larger posterior lobe from the anterior lobe (volume ratio around 2:1). The prepyramidal and secondary fissures are usually only identifiable after 32 WG and the hemispheric fissures are difficult to see until the end of pregnancy. Considering the signal changes, high signal on T2-weighted (T2-W) sequences is seen from 25 WG in the posterior part of the brain stem (tegmentum and ascending sensory tracts) related to myelination. The low signal intensities seen within the cerebellum on T2-W images correspond to high cellularity of grey matter (deep nuclei), as there is no myelination within the white matter before 38 WG. The second objective is to highlight the signs highly predictive of a poor neurological prognosis. Lack of pontine curvature or vermian agenesis without a PF cyst (small volume of PF) is greatly associated with poor neurological status. The third objective is to propose a diagnostic strategy in difficult cases where prognosis is important, e.g. the Dandy Walker continuum. Analysis of the cerebellum is often impossible if a PF cyst is present (whatever its nature) as the mass effect usually blurs the foliation and even impairs evaluation of the normal ratio between the posterior and anterior lobes of the vermis. Isolated cerebellar hypoplasias raise the question of prognosis and genetic counselling. Such uncertainties require an amniocentesis and a careful search for other anomalies (cerebral and extracerebral). Unilateral abnormalities of a cerebellar hemisphere can be associated with good neurological status if they are isolated. The final objective is to discuss other rare PF fetal abnormalities, such as vascular malformations and tumours.     

Intrauterine fetal transfusions in the management of fetal anemia and fetal thrombocytopenia

During the past 40 years, rhesus alloimmunization has gone from being one of the major causes of perinatal mortality to an almost eradicated disease. The unraveling of the pathophysiology, the development of reliable diagnostic tools, a very effective prophylaxis program, and for those (nowadays rare) cases slipping through the prevention system the availability of treatment by intrauterine blood transfusions, together constitute one of the great triumphs in modern medicine. Although Rh-D alloimmunization remains the most common indication for fetal blood transfusion therapy, an increasing percentage of these procedures is used to treat other causes of fetal anemia such as Kell alloimmunization and parvovirus B19 infection. Apart from transfusing blood, the same technique can be used to transfuse platelets to thrombocytopenic fetuses. This chapter describes the technique of fetal transfusion, and reviews the current management of fetal anemia and fetal thrombocytopenia.     

MRI reveals fetus in fetu in the mediastinum

Fetus in fetu is an extremely rare condition in which a fetiform calcified mass is contained within the newborn or infant, often in the retroperitoneal cavity. We report a case of a fetus in fetu in the posterior mediastinum of a newborn. The prospective diagnosis was made by fetal US and MRI and confirmed by postnatal plain radiograph, CT and MRI.     

Indices of fetal development derived from heart rate patterns

Background

The fetal precursors of mental and cardiovascular disease caused by adverse prenatal environmental influences and manifesting in later age are an important issue of developmental medicine. However the number of measurable functional parameters of a fetus is limited. Evaluation of key parameters involving fetal autonomic control could permit an earlier detection of developmental problems and improved therapeutic strategies. Thus far, however, even the maturation of normal autonomic control has not been sufficiently assessed.

Aim

The objective of the present work is to describe normal fetal maturation based on indices of autonomic heart rate modulation.

Study design

Heart beat interval series were magnetocardiographically recorded with 1 kHz sampling rate over 30 min in 78 normal fetuses, gestational age (GA) 23-40 weeks. Indices considered were: number of accelerations (AC) and decelerations (DC), RMSSD, SDNN, and short-term/long-term autonomic information flows (AIF_NN, AIF_fVLF). These were measured from the entire 30 min data sets and from activity-specific subsets (10 min).

Results

In the 30 min recordings: the number of AC increased, number of DC decreased, rMSSD and SDNN increased and AIF_fVLF increased with GA, but AIF_NN remained constant. In the 10 min subsets: SDNN increased in the active state but remained constant in the quiet state and AIF_NN decreased with GA in the quiet state.

Conclusion

Heart rate patterns from 30 min biomagnetic recordings may provide new indices with which to assess the normal and abnormal maturation of fetal autonomic control and to identify risk of possible disorders in later life.