Imaging features of atypical bleeds in young patients with hemophilia.

Hemarthroses and muscle bleeds are well-known and well-documented complications in pediatric and young adult hemophilia patients. In contrast, deep bleeds in atypical locations can be a diagnostic challenge, since clinicians and radiologists are often unfamiliar with their clinical and radiological features. Some atypical bleeds, however, can be life-threatening or severely disabling, highlighting the need for prompt, accurate diagnosis. Rare bleeds include central nervous system bleeds (including intracranial and spinal hematomas), urogenital bleeds, intra-abdominal bleeds (mesenteric and gastrointestinal wall hematomas) and pseudo tumors in unusual locations like the sinonasal cavities. Because clinical assessment can be difficult, clinicians and radiologists should be aware of the possibility of these rare complications in their hemophilia patients, so that they can avoid unnecessary invasive diagnostic and surgical procedures and institute prompt, appropriate treatment. The purpose of this review is to illustrate the imaging features of bleeds that occur in rare locations in young (i.e., children and young adults) patients with hemophilia to make the reader more familiar with these conditions.

[Value of whole-body MRI in vertebral fractures]. / Intérêt de l'IRM corps entier dans les fractures vertébrales.

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare autoinflammatory disease in children. Pathological vertebral fracture may be the first symptom revealing this disease. We describe the case of a 14-year-old boy, with no significant past medical history, who had a sudden dorsal pain after carrying a friend on his back. Plain radiographs and MRI showed fractures of the superior endplate of T5 and T6 associated with a mild degree of kyphosis. MRI allowed ruling out discitis. The diagnostic hypotheses raised were cancer (lymphoma, leukemia), Langerhans cell histiocytosis, osteogenesis imperfecta, and CRMO. A whole-body MRI (wbMRI) was performed and disclosed several clinically silent signal abnormalities in key sites of CRMO (pelvic bone and tibial metaphyses). We point out that CRMO should be systematically added to the list of possible diseases in case of vertebral fracture. In this perspective, wbMRI is a major noninvasive tool to assess the diagnosis of CRMO, and allows avoiding a bone biopsy in most cases.

Ovarian tumors in children and adolescents: a series of 41 cases.

OBJECTIVE: Pictorial review with a detailed semiological analysis of ovarian tumors in children and adolescents to provide a relevant diagnostic approach. PATIENTS AND METHODS: Retrospective study (2001-2011) of 41 patients under the age of 15 who underwent surgery for an ovarian mass with a definite pathological diagnosis. RESULTS: Sixty-two percent of the lesions were benign, 33% were malignant and 5% were borderline. Germ cell tumors were most frequent (77.5%), followed by sex cord stromal tumors (12.5%) and epithelial tumors (7.5%). Malignant tumors were more frequent in children between 0 and 2 years old. On imaging, calcifications and fat were specific for germ cell tumors; the presence of a mural nodule was predictive of a mature teratoma (P<0.001). Predictive factors for malignancy were clinical, including abdominal distension (P<0.01) or a palpable mass (P=0.05), biological, including increased hCG and/or AFP levels (P<0.001) and radiological, including tumors larger than 12 cm (P<0.05), tumoral hypervascularity (P<0.01) and voluminous ascites (P<0.01). CONCLUSION: This semiological analysis confirms the role of imaging in diagnosing the etiology of ovarian lesions in children and adolescents and emphasizes the importance identifying tumoral hypervascularity, which, in addition to classic criteria, is highly predictive of malignancy.

Flatfoot in children and adolescents. Analysis of imaging findings and therapeutic implications.

INTRODUCTION: Pes planovalgus (PPV) is a complex three-dimensional deformity of which routine radiographs provide only a two-dimensional analysis. HYPOTHESIS: Angles and other radiographic parameters of the foot in children and adolescents, when studied on both the dorsoplantar and the lateral view, can be used to establish a radiographic classification system for PPV that provides useful therapeutic guidance in clinical practice. MATERIALS AND METHODS: A retrospective single-centre study was conducted on 65 feet in 35 patients aged 7 to 18 years and having adequate ossification. All patients had a clinical diagnosis of idiopathic or neurologic PPV and available weight-bearing dorsoplantar and strict lateral radiographs. We excluded pes planus due to tarsal coalition, congenital bone deformities, or overcorrection of talipes equinovarus (n=25). All possible axes were drawn and angles measured after an evaluation of interindividual agreement. RESULTS: We identified four patterns of PPV: subtalar pes planus (n=16) with marked subtalar valgus and longitudinal sag predominating at the talonavicular joint, midtarsal pes planus (n=12) without subtalar valgus but with marked midtarsal abduction and sag predominating at the cuneonavicular joint, mixed pes planus (n=28) with subtalar valgus, midtarsal abduction, and sag at both the talonavicular and cuneonavicular joints, and pes planocavus (n=9) with sag of the medial arch and cavus deformity of the lateral arch. CONCLUSION: This original classification system provides therapeutic guidance by helping to match the surgical procedure to the nature and location of the deformities. LEVEL OF EVIDENCE: Level IV.

Fetal tumors of the choroid plexus: is differential diagnosis between papilloma and carcinoma possible?

Fetal choroid plexus tumors are uncommon. The prognosis is widely variable and depends on the histological findings: papilloma or carcinoma. We report a case of prenatal diagnosis of choroid plexus mass detected by ultrasound at 33 weeks of gestation. Prenatal (T1, T2, T2* and diffusion weighted sequences) magnetic resonance imaging (MRI) was used to rule out a hematoma. Follow-up examination by ultrasound and MRI revealed a significant increase in the volume of the mass, suggesting a diagnosis of malignant tumor. A healthy neonate was delivered by Cesarean section at 38 weeks of gestation. Full surgical excision of the tumor was performed at 20 days after delivery and histological analysis revealed a papilloma.

Pineal cysts in children.

OBJECTIVE: To describe the prevalence and characteristics of pineal cysts found on MRI in children. METHODS: This is a retrospective monocentric study of all brain magnetic resonance imaging (MRI) examinations performed under the same technical conditions for checking the idiopathic nature of short stature (ISS group, n = 116) and for the investigation of central precocious puberty (CPP) over a 3-year period (n = 56). Dimensions, wall and septal thickness, number of locules, signal intensity, and the presence of a solid component were analysed. Ten of 19 cysts were re-evaluated (follow-up interval 4-28 months). The prevalence of the pineal cysts was compared between the two groups using χ2 and Fisher's exact tests, and a significance threshold of p < 0.05. RESULTS: The prevalence of cysts was comparable in the two groups, CPP (10.7%) and ISS (11.2%). Cyst characteristics were similar in the two groups and 74% had thin septations. None of the cysts changed on follow-up. None of the children with pineal cysts exhibited neurological signs. CONCLUSION: Benign pineal cysts are a common finding in young children. High-resolution MRI demonstrates that these cysts are often septated. This pattern is a normal variant and does not require follow-up MR imaging or IV contrast media.

Pediatric outcome of children with the prenatal diagnosis of isolated septal agenesis.

BACKGROUND: Isolated Septal Agenesis (SA) is a rare disease with clinical outcomes (especially neurological outcomes) that are unknown. The purpose of this study was to evaluate the clinical outcome of these children. METHODS: We conducted a retrospective multicenter study of 17 children with an isolated SA or SA combined with a moderate ventricular dilatation (VD) that was diagnosed antenatally and confirmed by a magnetic resonance imaging (MRI) performed in the antenatal period. RESULTS: Of the 17 children, 14 had normal neurological examinations, 2 had language development delay and visuo-spatial dyspraxia, and 3 of the 17 children had behavioral problems. Eight children had neuropsychological evaluations, and the results were normal in six cases. There were 3 cases of septo-optic dysplasia (SOD) diagnosed postnatally, which highlighted the difficulties in assessing the optic tract and hypothalamic-pituitary region in antenatal imaging. Language delay and behavioral disorders were the main abnormalities at follow-up. CONCLUSION: The discovery of an isolated SA reveals the difficulties of prenatal diagnosis to correlate the neurological and functional prognosis to morphological findings. The prognosis seemed to be good. It appears necessary to improve the diagnostic performance of fetal brain imaging and to follow-up these children prospectively to assess their long-term cognitive-behavioral outcomes.

[Venous infarction of the neonate]. / L'infarctus veineux hémorragique du nouveau-né

PURPOSE: To determine the imaging features of hemorrhagic infarction in neonates. PATIENTS AND METHODS: Retrospective study (1998-2008) of 19 children (17 premature and 2 term deliveries) with early lobar hyperechogenicity on transfontanel US (TFUS). Group I: 11 born infants with clinical as well as TFUS and MRI follow-up. Group II: 8 premature infants deceased within a week from multisystem pathology, with neuropathological study available in 3 cases. RESULTS: Group I (n=11): periventricular hyperechogenicity in a frontal (7), frontoparietal (2), parietooccipital (1) and temporoparietal (1) distribution with developing cavitary change (n=6). MRI showed a cortex sparing intraparenchymal hematoma. Group II (n=8): periventricular hyperechogenicity in a frontal (4), frontoparietal or parietal (3) and occipital (1) with developing cavitary change (3). Neuropathological examination showed characteristic lesions of venous hemorrhagic infarction. Clinical outcome was generally favorable for the surviving infants with contralateral motor deficit (n=5) non-correlated to the extent of the initial lesions. CONCLUSION: Venous hemorrhagic infarction mainly affetcs premature infants and typically involves the periventricular frontal white matter. Prognosis is generally favorable. It is thus important to differentiate this entity from asymmetrical cystic periventricular leukomalacia with much different prognosis.

[Current events in fetal magnetic resonance]. / Actualité sur l'imagerie par résonance magnétique (IRM) foetale.

The challenge of fetal imaging is crucial in France because of the law allowing termination of pregnancy (TOP) until the end of pregnancy. Fetal MRI is an imaging tool always used after ultrasonography (US). Its indications are pertinent only in relation with a prenatal center. Fetal MRI raises parental anxiety to take into account before and during the examination. To date, cerebral indications are predominant. Fetal brain maturation can be followed with MRI (gyration and myelination) but the optimal moment of a fetal MRI depends on the suspected pathology: the analysis of gyration is possible only by 28 WG, as before this time, the brain surface is smooth; in contrast, the posterior fossa demonstrates a definitive morphology since 20 WG. The ventriculomegaly is the most frequent call sign and includes various entities. MRI can disclose associated abnormalities (heterotopia, gyration, white matter, median line), which can suggest diagnosis and pronosis. A cystic pouch of the posterior fossa must lead to a careful analysis of cerebellum and brainstem to approach the diagnosis. Extracerebral indications become progressively larger and fetal MRI is a useful complementary tool after US to study tumors, particularly cervicothoracic masses. MRI can help to assess the level of bowel obstruction but multiple stenosis and post-stenotic bowel is difficult to evaluate. Fetal MRI can help to evaluate bilateral important pyelocalicial dilatation.

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,...).

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 childhood brain tumors]. / Imagerie des tumeurs cérébrales de l'enfant.

Brain tumors represent around a quarter of all solid tumors observed in the pediatric population. Infratentorial tumors are the most frequent, mostly encountered between 4 and 11 years of age. Early imaging is important because initial symptoms can be misinterpreted as statural and pubertal disorders or pseudoabdominal symptoms with apathy and vomiting in infants. Because signal abnormalities on MRI are most often not specific, it is essential to take into account the clinical and topographic characteristics of the lesion to establish an appropriate differential diagnosis. The main patterns of brain tumors observed in pediatrics are presented. Brain metastases are very unusual in children, in contrast to lepto-meningeal metastasis.

[Diffusion-weighted imaging of the brain: normal patterns, traps and artifacts]. / IRM de diffusion de l'encéphale: aspect normal, images pièges et artefacts.

Owing to its rapid acquisition time and high sensitivity, diffusion-weighted imaging has turned into a routine sequence for brain imaging. This is the case not only for stroke, but also for various diseases such as abscesses or tumors. Being aware of the artifacts is important for optimal interpretation. After a brief review of the normal patterns, the most frequent artifacts, inherent to the echoplanar imaging technique, are described and we provide suggestions to avoid them. Most current traps are caused by T2-weighting of the diffusion images; the key for avoiding erroneous interpretation relies on the ADC map.

[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.