Isabelle Simon

Comparison between ultrasound and magnetic resonance imaging in assessment of fetal cytomegalovirus infection

To evaluate whether fetal brain magnetic resonance imaging (MRI) adds useful information to the one obtained by ultrasound in fetuses with cytomegalovirus (CMV) infection.

Intracranial venous anomalies associated with atretic cephalocoeles

Background. Midline scalp lesions are frequent in children. They include soft-tissue masses and atretic meningocoeles. Their recognition is important as their treatment differs. Intracranial venous anomalies are known to be associated with atretic cephalocoeles.¶Materials and methods. A retrospective study was undertaken to assess the frequency of intracranial venous anomalies associated with atretic meningocoeles (AT). Thirty-one patients with AT were studied by MRI. There were 13 meningocoeles and 14 encephalocoeles; 4 have not yet received surgery.¶Results. Venous anomalies were found when the cephalocoeles lay above the torcular. They include absence of the straight sinus and duplication of the longitudinal sinus.¶Conclusion. Venous anomalies are frequent in atretic cephalocoeles and are part of the dysraphic state.

Neocortical neuronal arrangement in LIS1 and DCX lissencephaly may be different.

In type I or classical lissencephaly, two genetic causes, namely the LIS1 gene mapping at 17p13.3 and the DCX (doublecortin on X) gene mapping at Xq22.3 are involved. These are considered to act during corticogenesis on radial migratory pathways. The prevailing view is that heterozygous mutations in the LIS1 gene and hemizygous mutations in the DCX gene produce similar histological pattern. The present detailed neuropathological study in two unrelated fetuses with respectively a mutation in the LIS1 and the DCX genes do not confirm this view. In LIS1 mutation, the cortical ribbon displays a characteristic inverted organization, also called “four layered cortex” while in DCX mutation, the cortex displays a roughly ordered “six layered” lamination. Our hypothesis is that mutations of the LIS1 and DCX genes, may not affect the same neuronal arrangement in the neocortex. Because the pathology of proven XLIS is rarely documented, further detailed neuropathological analysis in other cases identified through molecular study would be of a great help in the recognition of neuronal population involved in these migrational disorders and their underlying molecular mechanism.

Prenatal Diagnosis of a Large Axillary Cystic Lymphangioma by Three-dimensional Ultrasonography and Magnetic Resonance Imaging

Cystic lymphangiomas are benign tumors of the lymphatic system, appearing as uniseptate or multiseptate cystic masses, often located in the area of the neck (75%) or the axilla (20%). l Postnatal outcome depends mainly on the size and location of the lesion.2 An increasing number of such congenital abnormalities are detected on routine conventional prenatal ultrasonography. 2-4 The absence of blood flow on color Doppler mapping is characteristic of lymphangiomas as opposed to hemangiomas. 5 So far, prenatal evaluation for the prognosis of fetal lymphangiomas has been based solely on two-dimensional ultrasonography (2DUS). 3,4 Magnetic resonance imaging (MRI) may help in assessing the extent of a lesion, as suggested in a recent case report of a fetal intra-abdominal lymphangioma. 6 We report a case of prenatal assessment of axillary lymphangioma by three-dimensional ultrasonography (3DUS), and we analyze the information provided by this technique in comparison with MRI and 2DUS.

OC169: Prediction of pulmonary hypoplasia with MRI

Prediction of pulmonary hypoplasia may be relevant in several conditions associated with impaired pulmonary growth, particularly in chronic severe oligohydramnios and congenital diaphragmatic hernia (CDH). Most experience has been gathered with CDH. The post-natal clinical evolution of fetuses with this condition is essentially associated with the degree of pulmonary hypoplasia, which will eventually determine the degree of pulmonary insufficiency and pulmonary hypertension. The development of strategies for in utero treatment of CDH prompted the search of prognostic signs predicting lethal pulmonary hypoplasia. The best predictor of pulmonary hypoplasia in CDH seems to be the size of the contralateral lung. Lung-to-head ratio (LHR) is the validated used parameter. LHR is calculated in a four chamber view, as the area of the right lung (anterior by transversal diameters) divided by the head circumference. The prognostic accuracy of LHR has been evaluated in left CDH cases. According to different authors, fetuses with LHR values below 1.0 have a high risk for severe pulmonary hypoplasia and neonatal death. LHR is still limited in predicting accurately the degree of pulmonary hypoplasia. Calculation of the right lung diameters may be subject to interobserver variability. It is expected that calculation of right lung volumetry, either by 3D ultrasound or MRI, could allow more precise estimations of the degree of pulmonary hypoplasia. While estimating the lung size or volume is probably the best predictor we have, it is likely that other factors, such as the time of onset in early pregnancy, may determine variable degrees of hypoplasia which may explain the variability in the survival of apparently similar cases. The use of Doppler indices in the fetal pulmonary artery has also been proposed to evaluate the degree of pulmonary hypoplasia. Results to date have showed a marked lack of accuracy both in oligohydramnios as in CDH, but according to recent studies it could constitute a valuable tool when used in combination with other clinical and/or biometrical parameters.

OP06.09: Subependymal pseudocyst in the fetal brain: prenatal diagnosis and outcomes: Short oral presentation abstracts

The mean gestational age at diagnosis was 30 weeks. The cases were divided into apparently isolated SEPC (group A, n=16), and those with additional findings on US, MRI or amniocentesis (group B, n=4) (Table 1). Amniocentesis was performed in 65% of cases. Fetal brain MRI was performed in 90%. The inferior wall of the frontal horns was the main location in both groups. There was no difference in size, number or laterality between the two groups. All cases in group A had a normal neonatal outcome including a case of congenital CMV infection. In group B, 3 infants had metabolic diseases and poor neonatal outcomes, 2 cases of pyruvate carboxylase deficiency and 1 case of pyruvate dehydrogenase deficiency (Figure 3). Family history of metabolic disease (p=0,04), consanguinity (p=0,04), MRI results (polymicrogyria p=0,04) are significantly associated in this study with a poor outcome. Table 1. Characteristics comparison

Prenatal sonographic description of fetuses affected by pyruvate dehydrogenase or pyruvate carboxylase deficiency

Pyruvate dehydrogenase deficiency (PDHD) and pyruvate carboxylase deficiency (PCD) are diseases with severe neonatal forms, and their low prevalence makes them difficult to diagnose during pregnancy. Our objective was to describe prenatal ultrasound features that may be suggestive of these diagnoses.

OC097: Fetal MRI and CMV infection

of severe brain tumors were terminated upon diagnosis. 3. Tumors associated with good prognosis were seldom associated with TOP. In some of them, an early decision for TOP was reversed after counseling. 4. In several cases, TOP was carried out opposing the teams counseling to continue the pregnancy. 5. Late TOP (beyond 24 week’s gestation) was carried out in most cases of fetal tumors. Conclusions: The natural history of and prognosis of most fetal tumors is well established. Ultrasound has made it possible to detect them early and to perform an accurate follow-up, thus allowing a right decision making process regarding TOP. Apart from intracranial tumors where the chances for the fetus are poor, other tumor location do not give a bad prognosis in advance.

P099: Value of MR imaging in the prenatal diagnosis of clastic cerebellar lesions

Objective: To evaluate the contribution of prenatal MRI for the analysis of vascular cerebellar lesions. Methods: Retrospective study in the last ten years of 9 MRI cases. MRI results were compared with ultra-sound and pathology in five cases. Results and conclusion: MRI morphological abnormalities, which were favouring cerebellar vascular lesions were: unilateral hemispheric hypoplasia, unilateral hemispheric cleft, signal heterogeneity, irregular margins. Pathology confirmed vascular etiology whenever it was done. These morphological abnormalities of the cerebellum on the MRI should suggest a vascular mechanism. In those cases, underlying conditions must be looked for (placental anomalies, fetal distress, thrombophilia).

P168: Prenatal diagnosis of a large axillary cystic lymphangioma by three‐dimensional ultrasound and magnetic resonance imaging

A 22-year-old woman, G1, P0, started prenatal care at 7 weeks of gestation. Ultrasound evaluation at 17 weeks revealed bilateral large, bright, hyperechogenic kidneys. Fetal bladder and the amniotic fluid volume were within normal limits then. Detailed ultrasonographic examination of the fetus did not show any additional abnormalities and amniocentesis performed for fetal karyotype resulted as 46, XY. Patient’s family history revealed an adult type polycystic kidney disease (ADPKD) in her spouse and mother in law. After paediatric nephrology, paediatric surgery, and genetic counseling, this condition was thought as ADPKD clinically. Patient elected to continue to pregnancy understanding the implications and the long-term outcome of the fetus. Serial ultrasound examinations demonstrated further renal enlargement. Fetal renal artery doppler assessment revealed an early diastolic notch (renal artery doppler; S/D: 5.73, RI: 0.8) at 27 weeks of gestation; with the presence of oligohydramnios. At 37 weeks of gestation, C/S was performed for breech presentation. A 3610 g, male fetus with 1 and 10-minute Apgar scores of 10 was delivered. Neonatal abdominal ultrasound showed hyperechogenic and enlarged kidneys with multiple cysts < 6.5 mm. DTPA revealed a reduction in renal perfusion with a delay in reaching the maximum concentration of the urine; no reflux was present at VCUG. Right and left kidney had a GFR of 45 ml/min and 39 ml/min respectively. Urine analysis and culture have no pathologic findings. At postpartum day 1, hypertension developed, which then responded to multiple antihypertensive drug therapy. This is the first case in the literature in which an abnormal fetal renal artery doppler measurement has been detected in a fetus with ADPKD, which presented with early hypertension after delivery.