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International audience; In France, the current recommendation is to perform a routine abdominopelvic ultrasound in any child under 2 years of age who is suspected to have been abused. We retrospectively studied the relevance of this practice in our center over the past fifteen years. This was a descriptive, retrospective study of all children under 2 years of age who had been subject to suspected abuse. Abdominal images and reports were reviewed and cross-referenced with possible clinical and biological signs. Four hundred and five children were included between 2006 and 2020, of whom 296 underwent abdominal imaging (2 initial abdominopelvic CT scans, 4 ultrasounds followed by CT scans, and 290 ultrasounds alone). Four examinations revealed traumatic abnormalities related to abuse. These four children all had clinical or biological anomalies. In the absence of clinical or biological signs, no imagery showed any abnormality related to abuse.

Background Diffusion-weighted imaging (DWI) has been described to correlate with tumoural necrosis in response to preoperative chemotherapy for osteosarcoma. Objective To assess the accuracy of DWI in evaluating the response to neoadjuvant chemotherapy at the mid-course treatment of long-bone osteosarcoma and in predicting survival. Materials and methods We conducted a prospective single-centre study over a continuous period of 11 years. Consecutive patients younger than 20 years treated with a neoadjuvant regimen for peripheral conventional osteosarcoma were eligible for inclusion. Magnetic resonance imaging (MRI) with DWI was performed at diagnosis, and mid- and end-course chemotherapy with mean apparent diffusion coefficients (ADC) calculated at each time point. A percentage less than or equal to 10% of the viable residual tissue at the histological analysis of the surgical specimen was defined as a good responder to chemotherapy. Survival comparisons were calculated using the Kaplan-Meier method. Uni- and multivariate analyses with ADC change were performed by Cox modelling. This is an expansion and update of our previous work. Results Twenty-six patients between the ages of 4.8 and 19.6 years were included, of whom 14 were good responders. At mid-course chemotherapy, good responders had significantly higher mean ADC values (P=0.046) and a higher increase in ADC (P=0.015) than poor responders. The ADC change from diagnosis to mid-course MRI did not appear to be a prognosticator of survival and did not impact survival rates of both groups. Conclusion DWI at mid-course preoperative chemotherapy for osteosarcoma should be considered to evaluate the degree of histological necrosis and to predict survival. The anticipation of a response to neoadjuvant treatment by DWI may have potential implications on preoperative management.

Contrast-enhanced MRI is often used for diagnosis and follow-up of children with inflammatory bowel disease. To compare the accuracy of diffusion-weighted MRI (DWI) to contrast-enhanced MRI in children with known or suspected inflammatory bowel disease. This retrospective, consecutive study included 55 children. We used ileo-colonoscopy and histology as the reference standard from the terminal ileum to the rectum, and contrast-enhanced MRI as the reference standard proximal to the terminal ileum. DWI and contrast-enhanced MRI sequences were independently reviewed and compared per patient and per segment to these reference standards and to the follow-up for each child. We obtained endoscopic data for 340/385 colonic and ileal segments (88%). The rate of agreement per segment between DWI and endoscopy was 64%, and the rate of agreement between contrast-enhanced MRI and endoscopy was 59%. Per patient, sensitivity and specificity of bowel wall abnormalities as compared to the endoscopy were 87% and 100% for DWI, and 70% and 100% for contrast-enhanced MRI, respectively. Positive and negative predictive values were, respectively, 100% and 57% for DWI, and 96% and 41% for contrast-enhanced MRI. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of DWI compare to contrast-enhanced MRI in the segments proximal to the terminal ileum were 90%, 98%, 90%, 98% and 96%, respectively. The diagnostic performance of DWI is competitive to that of contrast-enhanced MRI in children with known or suspected inflammatory bowel disease.

Ultrasound elastography has been suggested for assessing organ fibrosis. To study the feasibility of shear-wave elastography in children with kidney disease and the correlation between elasticity and kidney fibrosis in order to reduce the indications for kidney biopsy and its complications. Four operators measured kidney elasticity in children with kidney diseases or transplants, all of whom also had a renal biopsy. We assessed the feasibility and the intraobserver variability of the elasticity measurements for each probe used and each kidney explored. Then we tested the correlation between elasticity measurements and the presence of fibrosis. Overall, we analyzed 95 children and adolescents, 31 of whom had renal transplant. Measurements with the convex probe were possible in 100% of cases. Linear probe analysis was only possible for 20% of native kidneys and 50% of transplants. Intraobserver variabilities ranged from moderate to high, depending on the probe and kidney studied. Elasticity was higher with the linear probe than with the convex probe (P

Resume Justification, radioprotection, sedation, resolutions (spatiale et de contraste), morphologie ou fonction, intervention et injection sont les differentes notions entrant en jeu dans le choix du meilleur examen d’imagerie cardiovasculaire en coupes pour les patients pediatriques. La TDM sera preferee pour toutes les pathologies des arteres coronaires, toute anomalie arterielle ou veineuse du nouveau-ne et nourrisson, ainsi que dans le bilan preoperatoire de la tetralogie de Fallot. L’IRM sera choisie pour tout bilan tumoral ou fonctionnel, de cardiomyopathie ou d’arythmie, ou des que la participation de l’enfant et/ou la taille des structures a analyser le permet.

Approximately, nine children per million age-related population start renal replacement therapy each year worldwide. All pediatric ages are interested. US-Doppler (USD) is the imaging modality of choice to explore renal graft. When additional information are needed, MR Imaging is preferred to CE-CT and scintigraphy as long as no sedation is needed. Vascular complications represent the most common cause of 1st-yearallograft lost and their reported incidence is up to 10%. Large amounts of fluid around the graft may lead to parenchymal and/or excretory system compression and hypoperfusion and may become infected. Pyelonephritis and post-transplant lympoproliferative disorders are frequent complications. Graft biopsies principaly carry risks of vascular damages.

Summary Purpose To assess the capabilities of a velocity ratio > 3 for the diagnosis of Budd-Chiari syndrome (BCS) in children after split liver transplantation using Doppler ultrasonography (DUS). Materials and methods A total of 28 children who underwent liver transplantation using a split procedure were included. There were 11 boys and 17 girls with a mean age of 3.8 years (range: 0.7–12 years). Velocity ratio between blood velocity upstream of the anastomosis and that at the level of the inferior vena cava anastomosis was calculated. Sensitivity, specificity and accuracy of DUS for the diagnosis of BCS were estimated using a velocity ratio > 3. Results Eight children (8/28; 29%) had BCS and 20 (20/28; 71%) did not have BCS using the standard of reference. A velocity ratio > 3 on DUS yielded 88% sensitivity (95% CI: 53–98%), 80% specificity (95% CI: 58–92%) and 82% accuracy (95% CI: 64–92%) for the diagnosis of BCS. Conclusion A velocity ratio > 3 on DUS is a reliable finding for the diagnosis of BCS in children after split liver transplantation.

Resume Objectif Etudier l’apport diagnostique complementaire et le role dans la prise en charge perinatale de l’imagerie par resonance magnetique (IRM) fœtale dans le diagnostic prenatal des anomalies de l’appareil urinaire. Materiels et methodes Etude retrospective monocentrique de novembre 2002 a juin 2011 des fœtus ayant beneficie d’une IRM apres diagnostic echographique d’uronephropathies malformatives. Les donnees echographiques et IRM ont ete comparees aux donnees radiologiques et/ou chirurgicales postnatales ou a la fœtopathologie. L’analyse des IRM a porte principalement sur la concordance diagnostique avec l’echographie, un apport diagnostique complementaire et/ou une modification de la prise en charge perinatale. Resultats Sur 154 IRM revues, le suivi a ete obtenu pour 108 dossiers. Les indications de l’IRM ont ete classees en six groupes : suspicion d’agenesie renale ( n = 20, 18,5 %), de valve de l’uretre posterieur ( n = 20, 18,5 %), de reflux ou de mega-uretere ( n = 14, 13 %), de syndrome de la jonction ( n = 24, 22,5 %), gros reins ( n = 7, 6,5 %) et divers ( n = 23, 21 %). Les informations fournies par l’echographie ont ete confirmees par l’IRM chez 72 patientes (67 %). L’IRM a apporte des donnees complementaires pour 36 patientes (33 %) et a modifie la prise en charge perinatale pour 16 patientes (15 %). Conclusion L’uro-IRM fœtale est un outil complementaire utile au bilan prenatal de certaines uropathies malformatives.

Purpose To study the complementary diagnostic value and role in the perinatal management of foetal MRI in the prenatal diagnosis of abnormalities of the urinary tract. Patients and methods Retrospective monocentric study from November 2002 to June 2011 of foetuses benefiting from an MRI after ultrasound diagnosis of uronephropathy abnormalities. Ultrasound and MRI data were compared with postnatal radiological and/or surgical data or with the foetopathology. The MRI analysis focused on the diagnostic concordance with the ultrasound, the complementary diagnostic contribution and/or a change in perinatal care. Results Of the 154 MRI examined, a follow-up was obtained for 108 cases. The indications for MRI were classified into six groups: suspected renal agenesis ( n = 20, 18.5%), posterior urethral valve ( n = 20, 18.5%), reflux or megaureter ( n = 14, 13%), uretropelvic junction syndrome ( n = 24, 22.5%), enlarged kidneys ( n = 7, 6.5%) and others ( n = 23, 21%). The information supplied by ultrasound was confirmed by MRI in 72 patients (67%). MRI provided additional data for 36 patients (33%) and changed the perinatal care for 16 patients (15%). Conclusion Foetal uro-MRI is a useful complementary tool in the prenatal diagnosis of some uropathy abnormalities.

International audience; The different factors involved in the choice of the best cardiovascular ă imaging examination for pediatric patients are justification, radiation ă protection, sedation, resolutions (spatial and contrast), morphology or ă function, intervention and contrast enhancement. Computed tomography is ă preferable for all coronary artery conditions, any arterial or venous ă abnormalities in newborns and infants and in the preoperative assessment ă for tetralogy of Fallot. Magnetic resonance imaging is used for any ă tumoral or functional assessment, cardiomyopathy or arrhythmia or if the ă child's participation and/or size of the structures being examined ă allows using this technique. (C) 2016 Editions francaises de radiologie. ă Published by Elsevier Masson SAS. All rights reserved.

Objectifs Comparer la qualite des radiographies thoraciques pediatriques numeriques realisees avec un detecteur a structure granulaire a celles d’un detecteur a aiguilles sur lequel une reduction de 40 % de charge est appliquee. Materiels et methodes Il s’agit d’une etude prospective randomisee comparative de 296 patients, repartis en deux groupes de cinq categories de poids de 4 a 60 Kg. Des constantes standard sont appliquees au groupe « detecteur a structure granulaire ». Les constantes sont reduites de 40 % dans le groupe« detecteur a aiguilles », d’apres les conclusions d’une etude prealable sur fantome. La qualite des cliches estimee par la visualisation de huit structures anatomiques est evaluee en aveugle sur le detecteur utilise par six radiologues. La dose est exprimee en produit dose surface. Les resultats ont fait l’objet d’une analyse statistique. Resultats Sur l’ensemble de la population, une qualite d’image superieure est obtenue avec un gain radique variant de 33 % a 46 % selon la categorie de poids avec le detecteur a aiguilles. Pour les quatre categories de poids les plus faibles, cette qualite est identique. Conclusion A qualite d’image au moins egale, le nouveau detecteur a aiguilles permet une reduction de dose d’environ 40 %.

Objective Compare the irradiation delivered in conventional radiography and digital radiography by image intensifier during a scoliosis workup. Patients and methods Our prospective randomized study included 105 patients, all of whom were identified according to sociodemographic parameters as well as criteria evaluating the quality of the full front spinal x-ray at PA incidence. The entry dose at the scapula and the exit dose in interorbital, thyroid, mammary, and hypogastric projection was measured by thermoluminescent dosimeters. Results The results of 71 girls and 28 boys, aged a mean 13.8 years with a mean weight of 47 kg were analyzed. At equal image quality, the entry dose was not significantly different between the two techniques; the mean exit dose reduction was 64% during digital acquisition. This reduction involved the interorbital (162%), mammary (43%), and thyroid (309%) regions. However, this system is more irradiating in the hypogastric region (34%). Conclusion The dosimetric evaluation of the different imaging techniques used to explore the entirety of the spine should be part of radiologists' quality standard used to document their work and their choices.

Resume La prise en charge optimale d'une malformation lymphatique (ML) doit se faire au sein d'une consultation multidisciplinaire comportant des dermatologues, des radiologues et des chirurgiens plasticiens et vasculaires. Toute decision therapeutique doit etre prise a la lumiere d'une exploration echographique et IRM de qualite. En fonction de la taille, du siege et du retentissement sur les structures vitales de cette tumeur benigne, un acte therapeutique peut etre necessaire. La sclerose percutanee represente un traitement de choix, efficace, peu risque et devant etre propose en premiere intention quand une indication therapeutique est retenue.

Magnetic resonance cholangiopancreatography (MRCP) could aid in the diagnosis of biliary atresia, a hepatic pathology with thin, irregular or interrupted biliary ducts. There is little published evidence of MRCP appearances in normal neonates and young infants. To assess the use of MR cholangiopancreatography in visualizing the biliary tree in neonates and infants younger than 3 months with no hepatobiliary disorder, and to assess this visibility in relationship to the child’s age, weight, and sedation and fasting states. Between December 2008 and October 2010 our department performed MRI of the brain, orbits and face on 16 full-term neonates and infants. Each child was younger than 3 months (90 days) and without any hepatobiliary disorders. The children were scanned with a respiratory-gated 0.54 × 0.51 × 0.4-mm3 3-D MRCP sequence. We used a reading grid to assess subjectively the visibility of the extrahepatic bile ducts along with extrahepatic bile duct confluence. The visibility of the extrahepatic bile duct confluence was assessed against age, weight, and sedation and fasting states. The extrahepatic bile duct confluence was seen in 10 children out of 16 (62.5%). In the neonate sub-group (corrected age younger than 30 days), the MRCP was technically workable and the extrahepatic bile duct confluence was seen in four cases out of eight (50%). This visualization was up to 75% in the subgroup older than 30 days. However, statistically there was no significant difference in visibility of the extrahepatic bile duct confluence in relationship to age, weight or MRCP performance conditions (feeding, fasting or sedation). The complete normal biliary system (extrahepatic bile duct confluence included) is not consistently visualized in infants younger than 3 months old on non-enhanced MRCP. Thus the use of MRCP to exclude a diagnosis of biliary atresia is compromised at optimal time of surgery.

Preoperative diffusion-weighted MRI (DW-MRI) has been described as an efficient method to differentiate good and poor responders to chemotherapy in osteosarcoma patients. A DW-MRI performed earlier during treatment could be helpful in monitoring chemotherapy. To assess the accuracy of DW-MRI in evaluating response to chemotherapy in the treatment of osteosarcoma, more specifically at mid-course of treatment. This study was carried out on a prospective series of adolescents treated for long-bone osteosarcoma. MR examinations were performed at diagnosis (MRI-1), at mid-course of chemotherapy (MRI-2), and immediately before surgery (MRI-3). A DW sequence was performed using diffusion gradients of b0 and b900. The apparent diffusion coefficients (ADC1, ADC2, ADC3, respectively), their differentials (ADC2 − ADC1 and ADC3 − ADC1), and their variation (ADC2 − ADC1/ADC1 and ADC3 − ADC1/ADC1) were calculated for each of these three time points. Fifteen patients were included. Patients with no increase in ADC showed a poor response to chemotherapy on their histology results. At mid-course, the three calculated values were significantly different between good and poor responders. ADC2 − ADC1 enabled us to detect, with 100% specificity, four out of seven of the poor responders. There was no significant difference in the values at MRI-3 between the two groups. DW-MRI performed both at baseline and mid-course of neoadjuvant chemotherapy is an efficient method to predict further histological response of osteosarcoma. This method could be used as an early prognostic factor to monitor preoperative chemotherapy.

Approximately one fourth of cases of inflammatory bowel disease (IBD) occur during childhood and children are more prone than their adult counterparts to have severe disease at presentation. To investigate these diseases MR imaging is no longer an emerging tool. Numerous reviews and articles have been published on this topic underlying the advances of imaging but also the complexity and the financial impact on management of such diseases. In children it seems reasonable to consider US as the first imaging examination to perform, especially when the diagnosis of IBD is unknown. However, we believe that recent and future technical progress, especially the ability of MR to display reproducible data, and the need for gold standard evaluation of new medical therapies will increase the role of MR enterography.

A common pancreaticobiliary channel is a very rare condition, but its diagnosis is of paramount importance since it can lead to complications that can be prevented. To illustrate the sonographic diagnosis of a common pancreaticobiliary channel in children referred for abdominal pain or jaundice. Four children were diagnosed by ultrasonography and the diagnosis was subsequently confirmed by MRI. Sonography demonstrated a pancreaticobiliary junction located in the pancreatic head above the sphincter of Oddi. This rare congenital anomaly was confirmed in all patients by MRI. A common pancreaticobiliary channel can be diagnosed by sonography. Nevertheless, our experience is limited, and although sonography can provide an alert and can assist management, it cannot yet replace MRI.

Objectif discuter et illustrer les signes de torsion d’annexe en IRM dans la population pediatrique. Evaluer son interet. Materiels et methodes etude retrospective de 19 cas, d’âge moyen 13 ans, operes apres diagnostic de torsion d’annexe a l’IRM. Relecture des donnees cliniques, echographiques, des IRM, des comptes-rendus operatoires, histologiques et comparaison des deux groupes. Resultats le diagnostic de torsion a l’IRM a ete confirme en chirurgie dans 13 cas, dont 2 etaient des torsions tubaires isolees. 6 cas etaient des faux positifs de torsion en IRM dont 4 kystes hemorragiques de l’ovaire, une peritonite appendiculaire associee a un kyste ovarien, et un ovaire normal. L’IRM a redresse le diagnostic de torsion, non vu en echographie dans 8 cas dont 3 ovaires ont pu etre sauves par detorsion. Les signes IRM les plus frequents en cas de torsion etaient les signes tubaires (oedeme, tour de spire) et les signes d’ischemie. L’hemorragie intraovarienne en cas de torsion etait correlee en anatomopathologie a de l’infarcissement hemorragique. 38% des torsions etaient associees a une masse ovarienne. Conclusion l’IRM realisee en urgence presente un interet diagnostic et pronostic dans les suspicions de torsion d’annexe en pratique pediatrique.

Objectifs Evaluer l’IRM de diffusion dans la prise en charge des osteosarcomes de l’enfant et de l’adolescent. Materiels et methodes Etude retrospective chez 10 enfants et adolescents (âge moyen 13,5 ans) presentant un osteosarcome des os longs. Trois examens IRM ont ete realises : au diagnostic (IRM1), en cours de chimiotherapie (IRM2), en pre-operatoire (IRM3). Une sequence de diffusion a ete obtenue avec des gradients de diffusion (b) variables en b300, b600 et b900. Le coefficient de diffusion apparent tumoral (ADC) a ete calcule aux 3 valeurs de b. Les resultats ont ete confrontes aux resultats histologiques de la piece operatoire, facteur pronostique essentiel des osteosarcomes. Resultats Une augmentation de l’ADC entre l’IRM 1 et l’IRM 3 temoigne d’une reponse au traitement sous forme d’une necrose intra-tumorale. Cette augmentation, correlee au resultat histologique final confirme la valeur pronostique de l’IRM de diffusion. Les resultats de l’IRM 2 temoignent de la dynamique de la reponse au traitement et verifient que l’IRM de diffusion est un moyen precoce d’estimer le pronostic. La comparaison des ADC calcules en fonction des differents b, precise le niveau de b necessaire lors de l’exploration des osteosarcomes. Conclusion L’IRM de diffusion est capable de surveiller la reponse des osteosarcomes a la chimiotherapie pre-operatoire. Son potentiel a definir precocement un pronostic reste a preciser.

Objectif Etudier la capacite de l’IRM fœtale de detecter une malrotation intestinale. Materiel et Methodes Etude retrospective sur 5 ans de notre base de donnees d’IRM fœtales non cerebrales. Resultats Quatre cent une IRM fœtales furent analysees. Dans 34 cas (8,5%), le jejunum proximal etait considere en position anormale, cad ailleurs que dans le flanc gauche sous l’estomac sur les sequences ponderees en T 2 . Dans 22 cas (65%), le jejunum etait situe dans l’hemi-thorax gauche dans le cadre d’une hernie diaphragmatique gauche (groupe A). Dans 7 cas (20%) il etait en position extra-abdominale dans le cadre d’un laparoschisis (group B). Dans 5 cas (15%) il etait anormalement situe dans l’abdomen, en position mediane ou dans le flanc droit, avec un estomac en position normale (group C). Tous les cas des groupes A et B ont ete confirmees en periode post-natale ou a l’autopsie. Dans 4 cas du groupe C (syndrome de Prune-Belly, poche colonique, atresie digestive, cardiopathie) la malrotation n’etait pas suspectee en echographie et etait confirmee apres la naissance. Dans le dernier cas, l’intestin etait refoule a droite par une duplication digestive geante, et le TOGD post-natal etait normal. Conclusion Grâce a son excellente resolution en contraste en ponderation T 2 , l’IRM fœtale identifie avec precision une position anormale du jejunum, en dehors de toute suspicion echographique, avec une excellente correlation postnatale.

Objectifs Connaitre les principales lesions vasculaires de l’enfant. Connaitre leur semeiologie clinique. Connaitre leur semeiologie echographique et IRM. Discuter de la strategie d’exploration devant la decouverte d’une lesion vasculaire. Messages a retenir L’âge de l’enfant est un element important d’orientation. Le caractere congenital ou acquis des lesions reduit la gamme diagnostique. L’echographie de premiere intention fait la majorite de ces diagnostics. Elle determine l’indication de l’IRM et le type de sequences a effectuer. La radiographie est systematique quand la nature ou les limites de la lesion ne sont pas identifiees en echographie. Resume Les lesions les plus frequentes sont pour les tumeurs, les hemangiomes immatures (HI) et pour les malformations les lymphangiomes kystiques et les malformations veineuses. L’analyse echodoppler permet de separer les lesions a haut debit (hemangiome et malformation arterio-veineuse) des lesions sans ou a bas debit (lym-phangiome et malformation veineuse). L’IRM est indiquee en cas de doute pour la caracterisation ou pour le bilan d’extension pre-therapeutique. La reconnaissance echographique de ce type de lesions determine le type de sequences IRM multiplanaires principales, ponderees T2 pour les malformations a flux lent et angiographiques en cas de malformation arterio-veineuse. La biopsie en l’absence d’identification formelle est a discuter en consultation multidisciplinaire.

Objectifs pedagogiques Connaitre la physiopathologie. Decrire les germes impliques. Connaitre le role et l’apport des differentes techniques d’imagerie dans le diagnostic et le pronostic. Definir les grandes lignes de la prise en charge. Messages a retenir Les infections osteo-articulaires de l’enfant en croissance sont des urgences medico-chirurgicales, le plus souvent hematogenes. L’arthrite et l’osteomyelite sont frequentes chez l’enfant car les zones de croissance (qui sont juxta-articulaires) sont richement vascularisees. Toute douleur osseuse ou articulaire febrile chez l’enfant est une infection osteo-articulaire jusqu’a preuve du contraire. Les prelevements bacteriologiques sont d’autant plus urgents a realiser qu’ils doivent preceder l’antibiotherapie. Le pronostic fonctionnel est constamment mis en jeu. Le pronostic vital rarement.

Objectifs Evaluer en IRM, dans une population d’enfants et d’adolescents presentant un traumatisme isole de la cheville, la realite et la frequence des lesions ligamentaires. Materiels et methodes Etude prospective chez 117 enfants admis aux urgences pour traumatisme de la cheville et ne presentant pas de fracture sur les cliches standard face et profil. Realisation d’une IRM en antenne de surface comprenant 5 sequences : T1 et DP-T2 saturation de graisse dans le plan coronal et DP-T2 dans le plan axial transverse en coupes de 3 mm jointives. Resultats Cinquante garcons (43,1 %) et 66 filles (56,9 %) d’âge moyen 11,6 ans (minimum 8 ans, maximum 15 ans) ont ete inclus. Quatre vingt sept pour cent (102 /117) des IRM etaient analysables. Chez vingt cinq patients une lesion interessant au moins le faisceau talo-fibulaire anterieur etait presente ; il s’agissait de lesions mineures avec epaississement et modification de signal du ligament dans 20 cas et de lesions majeures avec interruption de la continuite de ce ligament dans 5 cas. Pour ces 5 derniers patients, la physe tibiale etait ouverte dans 2 cas (2 %) et fermee dans 3. Conclusion L’entorse grave de la cheville sans fracture osteo-chondrale associee existe mais reste exceptionnelle chez les patients a physe ouverte.

Objectifs pedagogiques Proposer un kit d’auto-enseignement sur l’approche diagnostique des masses mediastinales chez l’enfant. Connaitre l’anatomie compartimentale du mediastin. Connaitre les principales etiologies (par frequence et par gravite) pour chaque compartiment du mediastin. Au sein de chaque compartiment, savoir identifier les elements semiologiques permettant de s’orienter. Messages a retenir Le thymus, normal ou pathologique, est le principal element du mediastin anterieur. Les adenopathies et malformations bronchopulmonaires sont les 2 causes principales d’opacites du mediastin moyen. Le neuroblastome doit toujours etre elimine en cas de masse mediastinale posterieure.

Objectifs Proposer un kit d’auto-enseignement sur la prise en charge diagnostique en imagerie des traumatismes abdominaux de l’enfant. Materiels et methodes Notre travail est base sur l’experience collegiale de notre CHU et de la revue de la litterature. Devant la demande d’un clinicien sur les consequences locales, regionales et generales d’un traumatisme abdominal chez un enfant, le radiologue lui proposera l’(les) examen (s) le (s) plus performant (s), en fonction de son plateau technique et des difficultes d’exploration liees a l’etat clinique du patient. Resultats Pour etayer son choix d’imagerie, il faut connaitre les specificites anatomiques, la frequence et la variete des lesions viscerales secondaires a un traumatisme abdominal en pratique pediatrique ainsi que le contexte de survenue et les signes cliniques qui l’accompagnent. Un algorithme decisionnel est donc propose, en fonction de ces donnees. L’aspect et le mode d’exploration (echographie, scanner) des principales lesions seront presentes. Conclusion Ce kit d’auto-enseignement s’adresse principalement aux differents intervenants susceptibles d’avoir a gerer un traumatisme abdominal en pratique pediatrique.

Objectifs Nous rapportons notre experience dans le traitement percutane des osteomes osteoides par thermocoagulation au laser sous guidage tomodensitometrique au sein d’une population pediatrique. Materiels et methodes Parmi les 27 patients traites par voie percutanee dans le service, 15 l’ont ete depuis 2002 par thermocoagulation au laser. Il s’agissait de 15 enfants et adolescents (âges de 4 a 17 ans), presentant des osteomes osteoides localises au bassin (n = 3), au femur (n = 6) et au tibia (n = 6). Toutes les procedures ont ete realisees sous anesthesie generale et 6 d’entre elles ont necessite la collaboration d’un radiologue et d’un chirurgien orthopediste (abord du foyer par forage). Resultats Une seule complication technique, sans consequence, est survenue en per-procedure (fragment metallique a proximite du nidus). Disparition de la symptomatologie douloureuse le lendemain du geste pour tous les patients, confirmee a distance, par un recul moyen de 19,7 mois (intervalle de 15 jours a 38 mois). Une seule patiente a presente une recidive ayant necessite un second traitement per-cutane (premiere patiente traitee par laser). Conclusion La thermocoagulation au laser sous guidage tomodensitometrique est un traitement simple, peu invasif et efficace des osteomes osteoides de l’enfant.