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Congenital arhinia is a very rare condition especially when it is isolated. Most of arhinia are identified after birth and only five prenatal cases are described in the literature. Generally, arhinia is associated with other malformations mainly craniofacial anomalies. Genetics aberrations are uncommon. Our case was diagnosed in the second trimester of pregnancy and we found no associated anomaly except for a single umbilical artery. Autopsy confirmed the diagnosis and neuropathology analysis revealed the absence of olfactory bulbs and tracts.

The migration of three additives from polypropylene samples into a series of five liquid food simulants was investigated at 60 °C in a repeated migration regime. This regime was simulated by 20 migration periods each of 8 h and using initially additive free food simulants. Between these migration periods the bare samples were stored in an air conditioned room at around 23 °C for 16 h at working days and for 64 h during weekends. An asymptotic decrease of the additive level in the food simulants in the successive migration periods, from a maximum values towards zero, was observed when the additives easily solve in the food simulants. In contrast when the additives solve poorly in the food simulants this additive level decrease is almost linear and shows a slow decrease rate. In the first case the leaching/migration of the additives is controlled mainly by their diffusion in the matrix of the polymer. In the latter case this process is controlled mainly by the partitioning of the additives between the polymer and food simulants. Two approaches were used to model theoretically these results. In the first approach the mass transport equation was solved by using as input parameters overestimated diffusion and partitioning coefficients as estimated for polypropylene homopolymer, the used food simulants and the three additives according to the recommendations of a practical guidance document in support of migration modelling as stipulated in the Regulation (EU) 10/2011. As expected the results of these calculations overestimate the vast majority of the migration levels determined experimentally. However there are also situations in which this approach leads to underestimations of the real migration levels. In the second approach numerical fitting was applied with the same equation and using the diffusion and partition coefficients as adjustable parameters to obtain a best-fit between experimental and calculated results. It was found that the so obtained “realistic” diffusion coefficients are all lower than the overestimated ones mentioned above. Moreover these “realistic” coefficients depend not only on the nature of the additive but also on the nature of the food simulant in contact with the polymer. This suggests that interaction of food simulants with the polypropylene occurs, which changes the properties of the polymer and thus the mobility of the additive molecules in its matrix. For the “realistic” partition coefficients it was found that they all are higher than the conservative ones mentioned above. Using these “realistic” parameters a good fit between calculated and experimental migration results was found.

We report a case of a 32-week-old foetus affected by diastematomyelia. A third trimester echography suggested a spine abnormality. Further investigations by CT-scanner and MRI were performed to precise the anomaly and to better counsel the couple on the prognosis. We performed a review of the literature about embryological hypotheses, clinical presentations, antenatal investigations and prognosis of such a rare spinal malformation.

Current-voltage characteristics, critical current density and thermal conductivity measurements have been performed on YBaCuO/Ag composites. From current-voltage characteristics and critical current density measurements, it is shown that the YBaCuO/Ag composites can be viewed as superconducting link networks. Current-voltage characteristics and critical current density seem to obey a universal law. It has also been demonstrated that the thermal conductivity of the composites is dominated by the electronic contribution of silver.

The electrical resistivity, thermoelectric power and thermal conductivity have been measured between 4.2 and 300 K on three Bi1−xSbx alloys of different composition (x = 0.144, 0.165 and 0.181) prepared by the travelling heater method. The temperature dependences of these parameters follow the same general trends as those of semiconducting alloys having lower Sb contents. The antimony dependence of the figure of merit for semiconducting alloys has been determined for various temperatures. The dependence presents two maxima for Sb contents of x ≈ 0.09 and 0.16 around 80 K. These features have been qualitatively explained from the band structure and interband hole scattering mechanisms.

The preparation of YBa/sub 2/Cu/sub 3/O/sub 7-x/-Ag powders by a sol-gel method and the characterization of these powders and also pellets made from these powders is presented. Transmission electron microscopy (TEM) observations show that the silver is highly dispersed in the sample. However, the size of the silver particles in the YBa/sub 2/Cu/sub 3/O/sub 7-x/ matrix depends largely on the silver concentration in the sample. For low concentrations, the silver particles have sizes of area 10 nm and for higher concentrations the silver particle is larger. The TEM investigations of the powders shows fibre structures for the YBa/sub 2/Cu/sub 3/O/sub 7-x /-Ag composite. This structure is different from the structures usually observed in the YBa/sub 2/Cu/sub 3/O/sub 7-x/ system. The microanalysis of these fibres shows that they possess a composition of YBa/sub 2/Cu/sub 3/O/sub 7-x/, The oxygenation of the samples seems easier in YBa/sub 2/Cu/sub 3/O/sub 7-x/-Ag composites. The room temperature electrical resistivity of the pellets is decreased by the addition of silver but no enhancement of the superconducting critical temperature is observed.

An enhancement of the in-plane thermal conductivity in the superconducting state is observed in most high-T-c superconductors. Here the observation of a similar enhancement of the thermal conductivity in copper-oxide compounds, which is not related to the superconducting transition, is reported. Since this anomaly is also accompanied by a significant variation of the electrical conductivity it indicates that a strong electron-phonon coupling exists and that thermal-conductivity enhancements in copper-oxide compounds should be attributed to an increase of its lattice component.

This study is focused on the investigation of the transport properties of Bi-Sb alloys. Electrical resistivity, thermoelectric power and thermal conductivity were measured in a direction perpendicular or parallel to the trigonal axis within the temperature range 4.2 - 300 K on various alloy compositions containing up to 18.2 at.% antimony. The temperature dependences of the three coefficients are described in detail. Low temperature behaviour depends strongly on the crystal purity, particularly in the semiconducting range. A qualitative explanation of these results is given in terms of an impurity band which merges with the conduction band. Thermoelectric properties are discussed and compared with previous studies.

The effect of fluorination on the transport properties of three classes of materials is presented. The intercalation of fluorine in graphitized carbon fibres drastically modifies their electrical behaviour. A wide range of conductivities is observed from sigma(300K) similar to 1.5 X 10(5) S cm(-1) for Csimilar to 14F to sigma(300K) similar to 10(2) S cm(-1) for C

This study describes for the first time the preparation of single crystal bismuth-antimony alloys by the traveling heater method, which requires a precise knowledge of the binary phase diagram of the alloys. Differential scanning calorimetry measurements were performed on homogeneous samples to determine both the liquidus and solidus lines on the Pi-rich side. The microhomogeneity and macrohomogeneity of an ingot with the specific composition Bi0.92Sb0.08 are discussed in detail. In addition, the figures of merit parallel and perpendicular to the trigonal axis were determined from 6 to 300 K and compared with literature values.

Endocrine disorders in the fetus are unusual. Still, several glands may be affected. Imaging may help in their visualization in normal and abnormal conditions, most often thanks to ultrasound but in selected cases through fetal MR imaging. For instances, thyroid goiter and its consequences are best demonstrated by ultrasound. Hypervascularisation on color Doppler suggests hyperthyroidism. Futhermore, resolution of the goiter under treatment can be monitored with sonography. Bilateral adrenal enlargement suggests congential adrenal hyperplasia and the fetal gender should be carefully examined as sexual differantiation disorders can be an association finding. Ovarian cysts are very common in the fetus and most often their course is benign. Still, torsion and bleeding may occur. The post evolution is often towards spontaneous resolution. Disorders of sexual differantiation encompass a wide number of anomalies. The role of imaging especially ultrasound, is to help understanding the anomalies by categorizing the phenotype. MR imaging is generally helpful in defining large and complex association malformations.

Bulk YBa2Cu3O7−x has been prepared by the sol-gel method using metal alkoxide and metal acetate as precursors and ammonia or ethylenediamine as complexing agent. The temperature of the transformation of the gel precursor to YBa2Cu3O7−x depended on the type of precursor and the agent used for adjusting the pH. The gel synthesized from precursor alkoxide gives YBa2Cu3O7−x at lower temperature (750‡C for 6 h) than with acetate. The gel synthesized by different metal acetates and ammonia produces YBa2Cu3O7−x at a lower temperature than the sample prepared from acetate and ethylenediamine. From X-ray diffraction studies it appears that a relationship exists between the reactivity of the gel and the orientation of the corresponding pellet. The preliminary results from a film prepared by painting the gel on alumina and yttria-stabilized zirconia are presented. A high sintering temperature (940‡C for 1 h) was found to be necessary for obtaining superconductor film. The reactions between YBa2Cu3O7−x and supports were reduced by using silver as buffer. The Ton of the film prepared on the modified alumina support was 91 K and Toff was 78 K.

We report measurements on the temperature and magnetic field dependences of the thermal conductivity, thermoelectric power, and specific heat of granular Co20Ag80 solids annealed at various temperatures. Giant magnetothermal conductivity and giant magnetothermopower are found to be correlated with the giant magnetoresistance. Thermal conductivity is dominated by its electronic contribution, and the Wiedemann-Franz law is found to be satisfied between 2 and 300 K, indicating that large-angle electron scattering processes dominate. The thermoelectric power is negative and its magnitude is considerably reduced by the annealing process. The contrasting relationship between electrical resistivity and thermoelectric power on annealing and in applied field is curved and discussed. No marked variation of specific heat with magnetic field in relation to the giant magnetoresistance has been observed. At very low temperatures, i.e. below T similar to 1 K, a nuclear contribution to the specific heat appears, whose temperature and magnetic field dependences have been explored.

The influence of a halogen-gas (Cl-2 or F-2) treatment on both structural and physical properties of La2CuO4 has been studied. In ail cases, the resulting product contains an excess of anionic species and shows superconducting properties below 32K and 40K respectively for the chlorine- or fluorine-treated sample. But these treatments have a different influence on the evolution of the: structural properties comparatively to those observed for the starting oxide : after chlorination a decrease of the orthorhombic distortion is detected, whereas an opposite trend is shown after fluorination. The Cl-2-gas treatment leads to an oxygen-excess phase La2CuO4.08, whereas the fluorination yields an oxyfluoride La2Cu(O,F)(4.17).

Measurements on the thermal conductivity and thermoelectric power of granular Co/sub 20/Ag/sub 80/ solids annealed at various temperatures are reported. Thermal conductivity is dominated by its electronic contribution, and the Wiedemann-Franz law to found to be satisfied between 2 K and 300 K, which is mainly ascribed to dominant large-angle elastic scattering processes. The thermoelectric power is negative, and is considerably reduced by the annealing process. Giant magnetothermal conductivity and giant magnetothermopower are found to be correlated with the giant magnetoresistance. >

The influence of fluorination on ceramic samples of La1.85-xNdxSr0.15CuO4 solid solutions has been studied. The presence of small amounts of fluorine species in the interior of the grains which has been evidenced by Auger electron spectroscopy significantly influences the structural and transport properties. It has been shown that the intercalation of fluorine into the structure reinforces the metallic-like behaviour and superconducting properties by hindering the tendency to the low-temperature structural transition and by increasing the charge carrier density.

The influence of Ba substitution for La and of the fluorination on the thermal conductivity, the electrical resistivity, the thermoelectric power and the specific heat of La2-xBaxCuO4 has been investigated. In the La2-xBaxCuO4 system, either the electron-phonon interactions or phonon-defect interactions may explain the temperature dependence of the thermal conductivity. The intercalation of the fluorine atom into the lattice leads to a superconducting transition with an onset higher than 30 K for all compositions investigated. The effect of fluorine intercalation in these oxides is similar to an increase in barium concentration. Indeed the presence of fluorine leads to an increase of the free carriers concentration and of the lattice disorder. For the particular composition x congruent-to 0.125, the fluorination seems to suppress the low-temperature structural transition (LTO-->LTT) and to eliminate all the anomalies usually observed in the transport properties.

The influence of fluorination on thermal conductivity, specific heat, magnetic susceptibility, electrical resistivity and thermoelectric power of La 1.85−y Sr 0.15 Nd y CuO 4 has been investigated. The temperature variation of the thermal conductivity of the untreated samples with Nd exhibits a change in slope just below the low-temperature structural transition (LTO--->LTT), which could be associated with strong phononelectron interactions. The specific heat of the y = 0.2 unfluorinated sample presents a jump near 50 K confirming the structural transition. Below 10 K, the specific heat of the two y = 0.8 samples (unfluorinated or fluorinated) shows an important increase with decreasing temperature, presumably associated with some type of magnetic ordering in the Nd 3+ ions. In addition to an increase of T c , the fluorination process suppress the anomalies observed in the thermal conductivity.

In the La1.85-xNdxSr0.15CuO4 system, phases deriving from the K2NiF4-type structure are found in the 0 less-than-or-equal-to x less-than-or-equal-to 0.98(5) composition range. Their superconducting properties are strongly influenced by the presence of chemical microinhomogeneities revealed by microprobe analysis and are dependent on the synthesis method, as discussed in more detail for x = 0.6. Electrical and magnetic measurements performed on samples of this system show that bulk superconductivity is observed only for x less-than-or-equal-to 0.4. The occurrence at low temperature of a structural transition explains the disappearance of the superconducting properties. This change induces a peculiar behaviour in the transport properties of these oxides.

Fetal pyelectasis is the most frequently encountered anomaly on prenatal ultrasound. The ultrasound diagnostic criteria are well established: nature of dilated structures, degree of dilatation, ultrasound appearance of the kidneys, volume of amniotic fluid. Ultrasound can also determine if the anomaly is isolated or not, which is important for the management and prognosis of the pregnancy. Ultrasound is the initial postnatal study to evaluate the urinary tract. Further management will be based on suspected diagnosis. In cases of suspected vesico-ureteral reflux, VCUG is performed. In cases of obstructive uropathy or complex malformation (duplications), MRI is performed at 6 months of age to further define the anatomy of the urinary tract. Radionuclide renogram, performed in most cases, allows evaluation of split renal function. Follow-up ultrasound is important to monitor renal development, urinary tract dilatation and appearance of the renal parenchyma. Functional follow-up is assured by radionucline renography. This comprehensive follow-up is recommended to prevent complications and progressive loss of renal function.

Urinary tract infection is very common in children. Its diagnosis, management and treatment have led to abundant literature and many controversies. The main challenges are to identify patients at risk of infection and those at risk of complicated infections. Long-term complications include reflux nephropathy, renal hypertension and stage renal disease. Imaging has a triple role: to confirm the diagnosis in patients with equivocal clinical symptoms; to determine patients at risk of recurrence; prevention of infection by detecting already in utero patients with congenital malformation. During the acute phase, Ultrasound has an important role in detecting favouring conditions such as urinary tract dilatation. The use of color Doppler increases the sensibility and specificity of ultrasound. To date, DMSA scan is the key examination for demonstrating the parenchymal lesions. CT-scan and MRI are rarely used in this acute phase. Retrograde voiding cystography (RVC) will be used whenever vesico-ureteric reflux is suspected. A decision algorithm can be proposed bases on US and DMSA; RVC will be performed whenever one of them is positive. CT or MRI will be used to look for abscesses complicating the UTI. DMSA scan is the gold standard for detecting renal scanning, sequellae of the infection. In the future, the role of MRI will surely increase for the demonstration of uropathy acute and sequelae of the renal involvement.

In the La1.85-xNdxSr0.15CuO4 system, phases deriving from the K2NiF4-type structure are found in the 0 less-than-or-equal-to x less-than-or-equal-to 0.98(5) composition range. Their superconducting properties are strongly influenced by the presence of chemical microinhomogeneities revealed by microprobe analysis and are dependent on the synthesis method, as discussed in more detail for x = 0.6. Electrical and magnetic measurements performed on samples of this system show that bulk superconductivity is observed only for x less-than-or-equal-to 0.4. The occurrence at low temperature of a structural transition explains the disappearance of the superconducting properties. This change induces a peculiar behaviour in the transport properties of these oxides.

The influence of fluorination on the thermal conductivity, the electrical resistivity and the thermoelectric power of YBa2Cu3O7-delta has been investigated. It was found that the presence of fluorine does not drastically modify the thermal conductivity of the YBa2Cu3O7-delta compounds. The sip of the thermoelectric power was found to be negative between 92 and approximately 200 K for the sample without fluorine and positive above 92 K for the YBa2Cu3O7-delta compound treated in fluorine atmosphere. Also, a small increase of the electrical resistivity was found after treatment with fluorine. These results are consistent with the fact that the fluorine treatment generates passivation layers around the ceramic grains without affecting the inner structure of the grains.

The influence of a low temperature fluorine gas treatment on structural, superconducting and transport properties of oxides with the K2NiF4 structure has been studied. When materials with the composition La2-xBaxCuO4 where 0 less-than-or-equal-to x less-than-or-equal-to 0.04 are treated under 1 bar of F2 gas at 200-degrees-C, an increase in the orthorhombic distortion (b - a) is observed and the materials become superconductors. The insertion of anionic species in the lattice is confirmed by the observation of an increase in weight and in the c-parameter and by the elemental analysis. After annealing at 200-250-degrees-C under vacuum or argon atmosphere, La2-xBaxCu(O,F)4+delta oxyfluorides lose their superconducting properties. This change is accompanied by a structural orthorhombic-to-orthorhombic transition for values of x up to 0.02 and by an orthorhombic-tetragonal-orthorhombic sequence where x = 0.04. Similar behaviour is also observed in the T/O solid solution in the La2-xNdxCuO4 SYStem (0 less-than-or-equal-to x less-than-or-equal-to 0. 3).

Obstetrical ultrasound has induced a marked increase in the perinatal diagnosis of broncho-pulmonary and mediastinal malformations. The spectrum of malformations amenable to antenatal diagnosis is wide (Table 1). The numerous classifications and terminologies attempt to incorporate a common origin and association of many lesions, including variable foregut airway, lung, and vascular components. Aside from the classical anomalies, such as congenital cystic adenomatoid malformations (CCAM), and sequestration, other, less common ones can also be considered as part of the spectrum (pulmonary hypoplasia, pulmonary aplasia, tracheal bronchus, etc.).

Thanks to improving technology and experience, sonographic surveying of fetal development is now more accurate and precise. Further, more anomalies are detected, allowing the adaptation of postnatal management, if necessary.

To investigate the correlation between fetal lung volume (FLV), measured with magnetic resonance imaging (MRI), and postnatal mortality in newborns with prenatally diagnosed isolated congenital diaphragmatic hernia (CDH).In a 4-year prospective multicenter study, 77 fetuses with isolated CDH diagnosed between 20 and 33 weeks' gestation underwent fast spin-echo T2-weighted lung MRI. These MRI-FLV measurements were compared with a previously published normative curve obtained in 215 fetuses without thoracoabdominal malformations and with normal ultrasound biometric findings. FLV measurements were correlated with postnatal survival. The mean gestational age at MRI was 31.3 weeks.The measured/expected FLV ratio was significantly lower in the newborns with CDH who died compared with those who survived (23.6 +/- 12.2 vs. 36.1 +/- 13.0, P0.001). When the ratio was below 25%, there was a significant decrease in postnatal survival (19% vs. 40.3%, P = 0.008). Survival was significantly lower for neonates when one lung could not be seen by fetal MRI compared with those fetuses with two visible lungs on MRI (17.9% vs. 62.1%, P0.001).In isolated CDH, FLV measurement by MRI is a good predictor of postnatal mortality due to pulmonary hypoplasia.

To describe an antenatal sonographic renal pattern encountered in Bardet-Biedl syndrome, a rare autosomal recessive disorder whose definitive diagnosis is often delayed, and to describe the evolution of the sonographic appearance of the kidneys after birth.Among a large group of fetuses with hyperechoic kidneys, we retrospectively analyzed the prenatal sonographic findings and clinical and postnatal renal sonographic evolution of 11 patients who were found to be affected by Bardet-Biedl syndrome.All 11 fetuses presented enlarged homogeneously hyperechoic kidneys without corticomedullary differentiation. The diagnosis was established before birth in three fetuses thanks to their familial history. It was confirmed during childhood in the remaining eight based on the development of the classic features of the syndrome. In the postnatal period, the prenatal pattern persisted for a few months in all 11 cases. The sonographic aspects of the kidneys normalized in most cases between 1 and 2 years after birth.In affected families, the prenatal appearance of enlarged hyperechoic kidneys without corticomedullary differentiation should prompt a diagnosis of recurrence in the family of Bardet-Biedl syndrome, especially when polydactyly is present. In non-affected families, Bardet-Biedl syndrome should be included in the differential diagnosis whenever such an appearance is discovered in utero. The postnatal evolution of the renal sonographic findings is variable and normalization generally occurs by the age of 2 years.

The temperature dependence of the electrical conductivity of a conducting polymer composite is reported from 77 to 450 K. The relationship between the temperature dependence of the conductivity and the structure of the composite is discussed. The low-temperature electrical resistivity of low-density polyethylene/polypyrrole composite was also investigated and a linear relationship between the resistivity and T--1/4 was found in the liquid-nitrogen temperature range.

Measurements on the temperature dependence of the specific heat of pure C60 in the range 4 < T < 300 K are reported. A large hysteresis is observed between 165 and 270 K. On cooling, two peaks are observed, respectively, around 255 and 165 K. On heating, only one large peak is observed at 255 K. These results are tentatively discussed in terms of the dynamics of the C60 molecules in the crystal.

The specific heat of fullerenes extract (C60/C70) has been measured in the temperature range 4 < T < 560 K. The temperature variation of the specific heat exhibits an anomalous behaviour. Below 80 K, it presents a classical temperature variation with a dependence close to a T3 below 10 K. The measurements bring two transitions to the fore : one around 250 K corresponding to the well known orientational phase transition, and the other around 90 K which is attributed to the freezing of the rotational motion of the molecules.

Besides increasing the work of ventilation, emphysema increases lung volume which in itself has a deleterious effect on the inspiratory muscles. We review here the effects of an acute change in lung volume on the configuration of the rib cage and muscle function. We also discuss the effects of the chronic distension associated with emphysema. The effects produced by changes in muscle length and configuration on the mechanical force and action of inspiratory muscles is detailed with particular focus on the diaphragm and its structural adaptations to experimental emphysema. We also analyze the activation pattern of inspiratory and expiratory muscles during the breathing process in patients with emphysema. Finally, we discuss the effects of single-lung transplantation and reduction surgery on chest distension and improved inspiratory muscle function.

Objectifs pedagogiques IRM fœtale neurologique Presenter les differents types de sequence et leurs applications en neuro IRM fœtale Presenter les avancees techniques : diffusion, spectroscopie de protons et leurs applications Decrire les regles generales du developpement cerebral Presenter les limites techniques des explorations comparees a la periode postnatale IRM fœtale thoraco-abdominale Definir dans quelles indications de pathologie abdominale, l’IRM fœtale est un bon complement a l’echographie. Expliquer la technique IRM (adaptee a chaque indication) utilisee pour la realisation des examens. Demontrer dans quelle mesure cette technique peut modifier le suivi des grossesses et la prise en charge neonatale des fœtus atteints.

Samples of Bi1−xSbx alloys have been grown by the Traveling Heater Method. Measurements of the electrical and thermal transport properties have been conducted in the 4.2–300 K temperature range on Bi0.93Sb0.07 and Bi0.91Sb0.09 single crystals cut in a parallel or a perpendicular direction to the trigonal axis. An analysis of the temperature dependence of transport parameters and of anisotropy is then presented and discussed.

Low-temperature specific heat and differential-scanning-calorimetry (DSC) measurements have been performed on polycrystalline C70. At high temperature, the DSC measurements reveal two phase transitions at 280 and 337 K, respectively. At low-temperatures, the measurements reveal an excess of specific heat with respect to that of graphite, with a classical behavior and a Debye temperature of 145 K. At 50 K a second-order transition is observed.

The authors report the fortuitous demonstration of an asymptomatic gossypiboma during the preoperative staging of a rectal carcinoma 13 years after abdominal surgery for perforated gastric ulcer. Ultrasonography disclosed a well-defined hypoechoic mass containing highly echogenic foci with a strong posterior shadow. The CT findings are reported, as well as the complementary aspects of sonography. Differential diagnosis from tumors of the lesser omentum is also presented.

Objectifs Connaitre les diagnostics differentiels des lesions kystiques abdominales fœtales. Connaitre la semiologie echographique qui permet de les caracteriser. Connaitre les indications et apports de l’IRM dans ce contexte. Messages a retenir Les lesions kystiques abdominales sont frequentes chez le fœtus. L’echographie les identifie et le plus souvent en etablit l’etiologie. L’IRM est un bon outil complementaire pour caracteriser les lesions atypiques, preciser leurs rapports et leur impact sur les autres structures abdominales. Resume Les lesions kystiques abdominales sont frequentes chez le fœtus. Elles peuvent se developper aux depens de nombreux organes. Il peut s’agir de lesions d’origine digestive (duplication, dilatation), de kystes mesenteriques, biliaires, ovariens, surrenaliens ou renaux. Certaines tumeurs peuvent aussi presenter un aspect essentiellement kystique (lymphangiome, teratome). Le role de l’echographie est d’identifier ces lesions et de tenter d’en preciser l’origine en fonction de leur topographie et de leur aspect (parois, contenu). L’IRM est utilisee en seconde intention pour preciser un diagnostic incertain, mieux definir les rapports de la lesion et mieux la caracteriser en en precisant le contenu (sang, meconium).

Objectifs pedagogiques Decrire succinctement les principales etapes du developpement anatomique des regions pelvienne et perineale. Decrire les principales etapes du developpement genital. Illustrer ces developpements par des correlations echo-embryologiques. Decrire les variantes morphologiques. Messages a retenir Le developpement du pole caudal de l’embryon est un phenomene complique et est regi par de nombreuses interactions. L’echographie obstetricale permet de suivre le developpement perineo- pelvien et de situer les principales structures anatomiques. Les organes genitaux internes du fœtus fille ne sont visualises que relativement tard dans la grossesse.