A. Aschero

Contribution of the foetal uro-MRI in the prenatal diagnosis of uronephropathies.

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.

Radiographie des scolioses : dosimétrie comparée entre la technique conventionnelle et la fluorographie numérique

Resume Objectif Comparer l’irradiation delivree en radiographie conventionnelle et en radiographie numerique par amplificateur de brillance lors du bilan d’une scoliose. Patients et Methodes Notre etude prospective randomisee comporte 105 patients. Des parametres socio-demographiques ainsi que des criteres permettant de juger de la qualite du cliche du rachis en totalite de face en incidence postero-anterieure ont ete consignes pour tous ces patients. La mesure de la dose d’entree a l’omoplate et de la dose de sortie en projection inter-orbitaire, thyroidien, mammaire et hypogastrique a ete effectuee par dosimetres thermoluminescents. Resultats Les resultats de 71 filles et 28 garcons âges en moyenne de 13,8 ans et de poids moyen 47 kg ont pu etre analyses. A qualite egale d’image, la dose d’entree est non significativement differente entre les deux techniques; la reduction de dose moyenne en sortie est de 64 % lors de l’acquisition numerique. Cette reduction interesse les regions, interorbitaire (162 %), mammaires (43 %) et thyroidienne (309 %). Par contre ce systeme est plus irradiant au niveau hypogastrique (34 %). Conclusion L’evaluation dosimetrique des differentes techniques d’imagerie permettant l’exploration du rachis en totalite doit faire partie du contrat qualite du radiologue pour justifier de leurs realisations et de leur choix.

Cardiac CT or MRI in pediatric practice: Which one to choose?

The different factors involved in the choice of the best cardiovascular imaging examination for pediatric patients are justification, radiation protection, sedation, resolutions (spatial and contrast), morphology or function, intervention and contrast enhancement. Computed tomography is preferable for all coronary artery conditions, any arterial or venous abnormalities in newborns and infants and in the preoperative assessment for tetralogy of Fallot. Magnetic resonance imaging is used for any tumoral or functional assessment, cardiomyopathy or arrhythmia or if the childs participation and/or size of the structures being examined allows using this technique.

Sonographic diagnosis of a common pancreaticobiliary channel in children.

BackgroundA 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.ObjectiveTo illustrate the sonographic diagnosis of a common pancreaticobiliary channel in children referred for abdominal pain or jaundice.Materials and methodsFour children were diagnosed by ultrasonography and the diagnosis was subsequently confirmed by MRI.ResultsSonography 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.ConclusionA 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.

Chronic inflammatory diseases of the bowel: diagnosis and follow-up

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.

Can diffusion weighting replace gadolinium enhancement in magnetic resonance enterography for inflammatory bowel disease in children

BackgroundContrast-enhanced MRI is often used for diagnosis and follow-up of children with inflammatory bowel disease.ObjectiveTo compare the accuracy of diffusion-weighted MRI (DWI) to contrast-enhanced MRI in children with known or suspected inflammatory bowel disease.Materials and methodsThis 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.ResultsWe 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.ConclusionThe diagnostic performance of DWI is competitive to that of contrast-enhanced MRI in children with known or suspected inflammatory bowel disease.

Complications of Renal Graft

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.

Doppler ultrasound in the diagnosis of Budd-Chiari syndrome in children after split liver transplantation

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 11boys and 17girls with a mean age of 3.8years (range: 0.7-12years). 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.

SFIPP CO-02 - IRM de la torsion d’annexe en pédiatrie.

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.

Lesions vasculaires des parties molles de l’enfant

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.