Lower-limb lengths and angles in children older than six years: Reliability and reference values by EOS® stereoradiography.

BACKGROUND: Lower-limb alignment in children is classically assessed clinically or based on conventional radiography, which is associated with projection bias. Low-dose biplanar radiography was described recently as an alternative to conventional imaging. The primary objective of this study was to assess the reliability of length and angle values inferred from 3D reconstructions in children seen in everyday practice. The secondary objective was to obtain reference values for goniometry parameters in children. HYPOTHESIS: 3D reconstructions can be used to assess the lower limbs in children. MATERIAL AND METHODS: The paediatric reliability study was done in 18 volunteers who were divided into three groups based on whether they were typically developing (TD) children, had skeletal development abnormalities, or had cerebral palsy. The reference data were obtained in 129 TD children. Each study participant underwent biplanar radiography with 3D reconstruction performed by experts and radiology technicians. Goniometry parameters were computed automatically. Reproducibility was assessed based on the intra-class coefficient (ICC) and the ISO 5725 standard (standard deviation of reproducibility, SDR). RESULTS: For length parameters, the ICCs ranged from 0.94 to 1.00 and the SDR from 2.1 to 3.5mm. For angle parameters, the ICC and SDR ranges were 0.60-0.95 and 0.9°-4.6°, respectively. No significant differences were found across experts or radiology technicians. Age-specific reference data are reported. DISCUSSION: These findings confirm the reliability of low-dose biplanar radiography for assessing lower-limb parameters in children seen in clinical practice. In addition, the study provides reference data for commonly measured parameters. LEVEL OF EVIDENCE: IV.

Energy dependent chest wall thickness equations for male lung monitoring with germanium detectors.

The thickness and fat fraction of the chest wall are important parameters for in vivo lung monitoring. They have been measured from ultrasonic images on 374 male workers of the French nuclear industry using four measurement locations, as dictated by the size and position of the germanium detectors used for monitoring. The plastic muscle equivalent chest wall thickness (PMECWT) and the plastic 50% muscle-50% adipose equivalent chest wall thickness (X5050) have been calculated for each worker at 17, 59.5, and 185.7 keV, respectively. Multi-linear regression models have been tested to predict PMECWT and X5050 as a function of anthropometric measurements. Finally, it was considered whether the average chest wall thickness could be used instead of the material equivalent chest wall thickness. It was found that the mean chest wall thickness was (27 ± 5) mm and the mean fat fraction was (25 ± 8)%. The best and more convenient model for material equivalent chest wall thickness is a linear function of the body mass index. Depending on the energy, the standard errors of estimate for this model range between 3.2-3.4 mm for PMECWT and between 3.2-3.7 mm for X5050. At 59.5 and 185.7 keV, it was determined, to an excellent approximation, that the fat fraction and consideration of an equivalent material are unnecessary, contrary to the case at 17 keV.

[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.

[Fetal cerebral magnetic resonance imaging (MRI). Indications, normal and pathological patterns]. / Imagerie par résonance magnétique (IRM) foetale cérébrale : indications, aspects normaux et pathologiques.

Fetal MRI is a specific imaging modality, always performed after a reference ultrasound examination. The decision to perform an MRI-scan must take into account the anxiety constantly generated by the need for this unusual examination during pregnancy. To date, no side-effect associated with 1.5 tesla magnets has been described. Compared to ultrasonography, fetal brain MRI provides better contrast between grey and white matter, as well as better delineation of the brainstem (pontic curvature) and the cerebellum (lobules and fissures). However, it often remains difficult to inform parents about prognosis. Thereby, it is of utmost importance to be familiar with the definite criteria associated with a poor neurological prognosis such as lack of pontic curvature or as diffuse or bilateral cortical malformations. This has to be considered within the framework of French regulations which allow pregnancy termination with no time limit. The optimal timing to perform a fetal MRI-scan depends on the context. The period between 27 and 30 weeks of gestation is a good balance between gestational age and gyration or sulcation development. The main ultrasonographic findings requiring MRI are ventriculomegalies and posterior fossa abnormalities. MRI exploration can sometimes be performed despite a normal ultrasonography in case of genetic disorders such as tuberous sclerosis and lissencephalies. In addition to its diagnostic value towards decision to terminate pregnancy, fetal MRI can be used as "in vivo autopsy", in case of expected technical difficulties or refusal of post-abortion examinations by relatives. Technical advances (real time and specific sequences like diffusion tensor and spectroscopy) and prospective clinical studies will probably improve the efficiency of this method to assess neurological prognosis.

Interest of the steady state free precession (SSFP) sequence for 3D modeling of the whole fetus.

Fetal magnetic resonance imaging (MRI) has been gaining interest over the last two decades. Current fast MRI sequences provide imaging data of the whole uterus in less than 20 seconds, avoiding fetal motion related artifacts without any maternal or fetal sedation. MRI has proved to be a useful adjunct to echographic screening for prenatal diagnosis. However, MRI volumetric data is still mainly interpreted on 2D slices and 3D applications remain limited. In this paper, we discuss the qualities of the SSFP MRI sequences to provide adequate data for 3D segmentation and modeling of the fetus. Potential exploitations of 3D segmentation and derived anatomical models cover several domains: biometric and morphologic clinical studies, quantitative longitudinal studies of normal and abnormal fetus developments, direct visualization of the overall fetus body and simulations in different fields (surgery, radiation dosimetry,...).

[Subtle brain abnormalities in adrenomyeloneuropathy]. / Anomalies cérébrales subtiles de l'Adrénomyéloneuropathie.

PURPOSE: To describe subtle brain abnormalities detected on MRI in adult patients with adrenomyeloneuropathy (AMN). Materials and methods. Retrospective evaluation of data acquired prospectively as part of a clinical trial (Riluzole) in 66 adult patients with AMN without obvious brain lesion on MR. All patients underwent brain MR including T1W, T2W, FLAIR and spectroscopy. After a review had been validated by three different reviewers, review of MR images was performed by consensus using a semi-quantitative scale. RESULTS: Preliminary analysis of MR images confirmed the presence of signal abnormalities involving the corticospinal tracts in 36 patients (54.6%). Additional subtle abnormalities were also detected: white matter palor, mainly parieto-occipital in location, with patchy hyperintensity in 36 patients (54.6%), hyperintense pontocerebellar fibers on T2W and FLAIR in 25 patients (41.7%). The presence of elevated Cho/Cr and mI/Cr ratios, described in the literature, were confirmed. CONCLUSION: This retrospective study allows the description of an AMN pattern on MRI in patients without white matter or callosal abnormalities.

Prenatal demonstration of afferent vessels and progressive thrombosis in a torcular malformation.

OBJECTIVES: To elucidate a part of the prenatal natural history of dural sinus malformation of the posterior fossa. METHODS: Ultrasound and magnetic resonance imaging were performed from 31 to 32 weeks' gestation. RESULTS: We observed the progressive development of a thrombus that was visible as an expanding hyperechoic round area within a cystic mass of the posterior fossa. It was characterized, as expected for a vascular malformation, by the presence of blood flow into the aneurismal cavity. Color doppler identified superior sagittal and straight sinuses, and distinguished that their flow continued into the dilated torcular. Prenatal magnetic resonance imaging confirmed an arteriovenous malformation involving the dural sinus. CONCLUSION: The vascular malformation had a fixed volume and preceded the thrombosis, which formed within several days. The present case is the first report with all the prenatal sonographic features of this condition.

[Imaging of CNS manifestations of tuberous sclerosis in children]. / Imagerie cérébrale de la sclérose tubéreuse de Bourneville chez l'enfant.

Tuberous sclerosis (TS) is a frequent phakomatosis, with autosomal dominant transmission. The diagnosis relies on a list of criteria (2 major criteria or 1 major criterion and 2 minor criteria). Brain MRI is very important for diagnosis, already showing the major signs during fetal life: subependymal nodules, tubers and giant cell astrocytomas. In childhood, FLAIR sequences are the more interesting while in fetuses, neonates and infants T1 sequences are required because of the myelination process.

[Partial corpus callosum agenesis]. / Agénésie partielle du corps calleux de l'enfant.

PURPOSE: The diagnosis of corpus callosum agenesis (CCA) with prenatal MRI relies on indirect signs. However, they are known to be inconstant in case of incomplete CCA. The purpose of this study is to specify the frequency of indirect signs in partial CCA to approach the reliability of fetal MRI. MATERIALS AND METHODS: This retrospective study included 33 children with partial CCA. MRI were reviewed by two observers and a standardized radiological and clinical data collection was performed. Depending on the ratio CC length/anteroposterior brain diameter, two groups were statistically compared: subtotal partial CCA and mild partial CCA. RESULTS: 14% of patients had none indirect sign and 33% had only one sign. We found a significative difference of frequency for most of the indirect signs. 48% of patients had other cerebral anomalies. Clinical correlation showed no statistical difference between the two groups. CONCLUSION: This series shows that indirect signs are inconstant in partial CCA and related to the CC length. In contrast, mild and subtotal CCA have a similar neurological outcome. These data suggest that greatest care has to be taken in the interpretation of fetal MRI.

[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.

Neurological presentation in pediatric patients with congenital disorders of glycosylation type Ia.

OBJECTIVE: Congenital disorders of glycosylation (CDG), formerly called carbohydrate-deficient glycoprotein syndromes, constitute a newly identified group of multisystem disorders characterized by defective glycosylation of N-glycosylated proteins. The objective of this work was to describe precisely neurological findings in patients with type Ia CDG (CDG-Ia) and to compare our results with the literature. STUDY DESIGN: We retrospectively reviewed neurological and neurodevelopmental, neuroimaging, and genetic features in ten patients with CDG-Ia who mainly presented with neurological abnormalities during childhood and therefore were referred to a neuropediatrician or a neurogeneticist. RESULTS: Neurological manifestations had a static clinical course, dominated by mental retardation and cerebellar dysfunction, and acute episodes: stroke-like episodes and seizures. However, microcephaly, retinopathy, and polyneuropathy were progressive. All patients had severe global neurodevelopmental delay: only one was able to walk alone at ten years of age and only one could read. Marked heterogeneity in manifestations and delay of diagnosis was noted across the patients. Cerebellar hypoplasia was found by magnetic resonance imaging in all ten patients and olivopontocerebellar hypoplasia in four patients. As in the literature, there was no clear phenotype-mutation correlation. CONCLUSION: Our findings confirm the importance of a precise and complete description of the neurological and neuroradiological phenotype delineating the phenotype of CDG-Ia to increase the likelihood of diagnosing the disease.

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.

[Prenatal diagnosis of isolated posterior fossa anomalies: attempt at a simplified approach]. / Diagnostic anténatal des anomalies isolées de la fosse postérieure: tentative d'approche simplifiée.

The authors suggest, after some embryological, anatomical and nosological reviews, a simplified approach mainly based on the appearance of the pons, cerebellar hemispheres and vermis, independently from an associated cystic dilatation of the posterior fossa. Pontocerebellar hypoplasias and partial or total vermian agenesis are detailed because they can be diagnosed with a prenatal MRI. This classification based on our experience and on the literature data should be of value to evaluate the neurological prognosis.

[Techniques to improve the accuracy of CT-guided abdominal biopsy]. / Techniques permettant d'améliorer la rentabilité des ponctions abdominales sous scanner.

STUDY AIM: The aim of this paper is to present an overview of the various technical progresses made in the field of CT-guided abdominal biopsies. Recent improvements allowed to markedly increase the efficiency of biopsies and to decrease the number of complications. The main innovations concern the guidance technique itself with the availability of ultra-fast CT systems, the development of automated biopsy systems, which allow to improve the size and quality of tissue samples and numerous technical tricks, allowing an easier access to target lesions, either in patient positioning or in displacement of anatomical structures. A better management of tissue samples favored by a close collaboration with pathologists is also mandatory. The last section of the paper is an overview of the rare complications of CT-guided biopsies.

[Role of MRI in the diagnosis of breast diseases]. / Place de l'IRM dans le diagnostic des affections mammaires.

UNLABELLED: ADVANTAGES AND LIMITATIONS: Magnetic resonance imaging of the breast is probably the most sensitive method for detecting or ruling out breast disease. It is however not as specific as expected. TECHNIQUE: All examinations are performed with and without gadolinium intravenous administration, excepted in the case of silicone implant reconstruction mammoplasty. Dynamic contrast-enhanced MRI sequences are necessary with a permanent balance between temporal resolution, spatial resolution, and signal. MRI of the breast is not indicated as a routine examination in a screening program, neither to improve the specificity of infra-clinic lesions, nor in simply dense breasts without any known risk factor or in circumscribed masses. INDICATIONS: MRI is best used to improved the sensitivity of mammography and sonography in selected patients. The selected indications are: evaluation of the volume and extension of breast lesions evaluation of the therapeutic response after chemotherapy, and detection or exclusion of the local recurrence in patients with breast conservation therapy. PERSPECTIVES: The future indications and perspectives of MRI include interventional breast radiology (MRI-guided core biopsy), and thermocoagulation therapy. It may be interesting for the evaluation of patients with contrast enhanced MRI lesions with normal mammography and sonography, and also in woman with a genetically defined high breast cancer risk.

[Radiologic anomalies of pseudohypoparathyroidism: diagnostic importance]. / Les anomalies radiologiques de la pseudohypoparathyroïdie: importance diagnostique.

Pseudohypoparathyroidism is a congenital metabolic disorder which is often revealed by growth retardation. The diagnosis may be suggested by plain radiological findings such as short metacarpals, mainly the fourth, epiphyseal anomalies or subcutaneous calcifications. The following biological tests are mandatory to confirm this diagnosis: CaP workup and plasma level of PTH; urine cAMP measurement after PTH challenge; Evaluation of protein Gs activity In this study of 20 cases displays will be reviewed the different radiological findings seen in patients with PsHP and the relative value discussed, such as narrowing of the spinal canal and presence of bony findings of hyperparathyroidism.