[The acutely limping child]. / La boiterie aiguë de l'enfant.

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.

[Pediatric osteo-articular infections with negative culture results: what about Kingella kingae?]. / Infections ostéo-articulaires septiques à culture négative chez l'enfant: avez-vous pensé à Kingella kingae?

Kingella kingae is an emerging pathogen that is recognized as a causative agent of septic arthritis and osteomyelitis, primarily in infants and children. The bacterium is best detected by rapid inoculation in blood culture systems or by real-time PCR assays. Pathogenesis of the agent was linked recently to the production of a potent cytotoxin, known as RTX, which is toxic to a variety of human cell types. The locus encoding the RTX toxin is thought to be a putative virulence factor, and is, apparently, essential for inducing cytotoxic effects on respiratory epithelial, synovial and macrophage-like cells. Herein, we describe a novel real-time PCR assay that targets the RTX toxin gene. The assay exhibited a sensitivity of 30 c.f.u., which is 10-fold more sensitive than a previously published semi-nested broad-range 16S rRNA gene PCR, and showed no crossreactivity with several related species and common osteoarticular pathogens. Its clinical impact is illustrated by three pediatric cases.

[Imaging of pediatric spine injury]. / Traumatismes du rachis chez l'enfant.

Spine injuries in the pediatric population can lead to instability and subsequent neurological damage. Initial work up includes frontal and lateral cross-table spine radiographs, completed by CT and MRI when any doubt exists about possible injury. At the cervical level, injuries frequently involve the first three segments.

[Brain MRI: ante and postnatal correlations]. / IRM cérébrale: corrélations pré et post-natales.

Fetal brain MRI provides complementary information to ultrasonography exploration, the gold standard for antenatal evaluation. Certain specific correlations between the antenatal and postnatal findings merit discussion: cysts after increase in volume during the perinatal period; certain anomalies are at the limit of resolution (tuber of tuberous sclerosis, heterotopy); anatomic visibility of certain structures does not exclude function deficiency (optical chiasma in septo-optic dysplasia; ventricular dilatation is a frequent sign but can occur in very different entities.

[Imaging of the pediatric cerebellum]. / Imagerie du cervelet de l'enfant.

After a brief overview of embryology, histogenesis, anatomy, as well as terminology, the authors will review the main acquired (neoplastic and non-neoplastic) and congenital (malformative and non-malformative) cerebellar pathologies through a pictorial essay. Even though there is some overlap, malformations are classified into agenesis, hypoplasia, and dysplasia, either cystic or non-cystic. Their embryological origin will be discussed. The main known syndromes associated with vermian agenesis will be reviewed. Non-neoplastic acquired cerebellar lesions, including atrophy and isolated signal anomalies, will be briefly reviewed. A classification of the main cerebellar malformations will be proposed.

[A peculiar form of neonatal adrenal insufficiency: the IMAGe association. Two new cases]. / Une forme particulière d'insuffisance surrénalienne du nouveau né: l'association IMAGe. A propos de deux nouveaux cas.

We report two siblings with an IMAGe syndrome. IMAGe is a newly reported syndrome characterized by the association of intra-uterine growth retardation, metaphyseal dysplasia, congenital adrenal hypoplasia and genital anomalies. This clinical association has only been described in five unrelated males. These two additional patients (one brother and one sister) suggest an autosomal recessive inheritance although identification of new cases will give further insight into the pathogenesis. The radiologic signs of osteopenia and metaphyseal dysplasia can suggest this diagnosis in affected individuals.

Magnetic resonance imaging of the fetal brain.

US remains the key imaging technique for prenatal screening of CNS pathology. However, MR imaging of the fetal brain is a powerful tool to further characterize CNS anomalies, especially during the third trimester. The prognosis of CNS anomalies detected at fetal MR imaging is not always known. As such, management may be problematic with regards to medical interruption of pregnancy. A multidisciplinary approach is essential in order to insure comprehensive evaluation and management of the pregnancy.

[Diagnosis and follow-up of pseudo-meningiomatous metastasis of prostatic cancer: value of MRI]. / Diagnostic et suivi d'une métastase pseudo-méningiomateuse de cancer prostatique: intérêt de l'IRM.

We present the case of a patient with neurological signs, who underwent a CT scan then a MRI which displayed a meningiomatous lesion. The general and biological examination revealed a metastatic prostatic carcinoma, and the meningeal lesion was considered a secondary lesion. Follow-up during hormonal therapy showed the regression of the meningeal lesion and thus confirmed our hypothesis, which avoided surgical biopsy.