[Computed tomography in children with cystic fibrosis: The role of an expiratory protocol]. / Scanner thoracique chez l'enfant atteint de mucoviscidose : intérêt d'un protocole en expiration séquentielle pour réduire la dose d'irradiation.

INTRODUCTION: Chest computed tomography (CT) is essential to monitor lung disease in children with cystic fibrosis, but it involves recurrent exposure to ionizing radiation. The aim of this study was to compare the current complete CT protocol (volumetric end-inspiratory plus sequential expiratory acquisition) to a sequential expiratory acquisition protocol alone in terms of image analysis and ionizing radiation dose. METHODS: Seventy-eight CT scans from 57 children aged 5 to 18 years old were scored on the complete protocol images and on the expiratory sequential images only. Each CT protocol was scored independently, using the Brody scoring system, by two paediatric radiologists. RESULTS: Correlations between the Brody global scores of the two different CT protocols were very good (r=0.90 for both observers), for the bronchiectasis score (r=0.72 and 0.86), mucus plugging score (r=0.87 and 0.83), and expiratory trapped air (r=0.96 and 0.92). Total ionizing radiation dose was reduced, with the measured dose length product (DLP) reduced from 103.31mGy.cm (complete protocol) to 3.06mGy.cm (expiratory protocol) (P<0.001). CONCLUSION: An expiratory chest CT protocol was accurate in diagnosing early signs of CF disease and permitted significant reduction of radiation dose. This protocol would allow spacing out of complete CT scanning with its higher radiation dose and should be considered for the monitoring of lung disease severity in children with CF.

[Severe nutritional rickets in young children: Resurgence of an old disease]. / Rachitisme carentiel sévère du nourrisson : de nouveau d'actualité.

Nutritional rickets remains a significant public health issue for children worldwide. Although it has almost disappeared in industrialized countries following routine vitamin D supplementation, recent evidence suggests an increasing incidence, especially in young children. In addition to the classical clinical consequences on bone and the growth plate, rickets may also be associated with life-threatening neurological and cardiac complications in the most severe forms. Consequently, early screening and treatment are required. Here, we report the case of a 2-year-old child who presented with severe nutritional rickets associated with seizure and cardiomyopathy. Family screening revealed rickets in all the siblings. This case report emphasizes the importance of being aware of this disease, notably in population with sociocultural risk factors.

Relevance of MRI for management of non-displaced lateral humeral condyle fractures in children.

INTRODUCTION: The treatment for non-displaced (<2 mm displacement) fractures of the lateral humeral condyle in children is controversial. Most studies recommend non-surgical treatment. However, plain radiographs are not sufficient to evaluate extension of the fracture line through the articular cartilage. This explains the high frequency of secondary displacements and non-unions, despite well-conducted conservative treatment. We hypothesized that MRI could be used to analyse whether the fracture is complete or incomplete. This could help to determine whether surgical or conservative treatment is indicated. MATERIAL AND METHODS: This prospective study enrolled children being treated for a non-displaced (< 2 mm gap) fracture of the lateral humeral condyle. All patients were treated with a long-arm cast in the emergency room. An MRI was done later on without sedation. A specific protocol was used to reduce the duration of the examination. T2-weighted and proton density fat-saturated sequences were used. RESULTS: Twenty-seven patients were enrolled: 16 boys and 11 girls with a mean age of 5 years (2-10). The MRI was performed an average of 7 days (1-23) after the fracture. The MRI could not be interpreted in two cases because the child had moved during the examination. In the other 25 patients, the fracture was incomplete in 17 patients and complete in 8 patients. Two children had secondary displacement diagnosed 7 and 11 days after the fracture event. These two patients underwent open reduction and internal fixation. There was no correlation between patient age and the fracture being complete or incomplete. There were no cases of non-union. CONCLUSION: MRI appears to be a reliable method for determining whether the fracture line is complete or incomplete. It can be performed without sedation, even in children as young as 2 years of age. Use of an injury-specific MRI protocol reduces the length of the examination, thereby improving its performance. We recommend that it be used to analyse non-displaced fractures of the lateral humeral condyle in children. LEVEL OF EVIDENCE: 3 Prospective study.

[Thymoma in children: a rare and difficult diagnosis]. / Thymome de l'enfant : un diagnostic parfois difficile.

Thymoma is extremely rare within the pediatric age range, which could lead to delayed diagnosis. Based on the clinical case of a mediastinal tumor in an 8-year-old patient, we detail the key points in the management of this disease highlighted by our recent experience.

[Biliary peritonitis after traumatic rupture of a choledochal cyst]. / Péritonite biliaire par rupture traumatique d'un kyste du cholédoque.

Choledochal cysts are rare congenital malformations of the biliary tract. Traumatic rupture of a choledochal cyst can be misleading. An 11-year-old boy was admitted for peritonitis and intestinal occlusion after blunt abdominal trauma, evolving over 48 h. Laparotomy revealed bile ascites and a suspected duodenal perforation. After referral to our center, a CT scan showed a perforated choledochal cyst. Six months later, a complete excision of the cyst was successfully performed. This treatment is mandatory because of the risk of further complications such as lithiasis, pancreatitis, cholangitis, biliary cirrhosis, and malignant transformation (cholangiocarcinoma).

Prognosis value of early diffusion MRI in Legg Perthes Calvé disease.

PURPOSE: To evaluate diffusion MRI of the proximal femoral epiphysis and metaphysis as a prognosis factor in Legg Calvé Perthes (LCP) disease. METHODS: Thirty-one children (mean age 5.5 years, range 2.5-10.5) with unilateral LCP were included in a prospective, consecutive series. Radiographs were analysed and classified as per Herring criteriae. Mean follow-up was 19 months (range 6-30). Forty-nine MRI scans were performed at either the condensation or fragmentation stage. Apparent Diffusion Coefficient (ADC) of both the femoral epiphysis and metaphysis were measured bilaterally and ADC ratio were calculated, then compared to the Herring group. RESULTS: Sixteen hips were rated Herring A or B, 3 Herring B-C and 12 Herring C. ADC was increased in affected hips compared to unaffected sides, both at the femoral epiphysis (P<0.001) and metaphysis (P<0.0001). ADC ratio of the femoral metaphysis was positively correlated to Herring classification: if superior to 1.63, it was associated with a bad prognosis (Herring B-C or C) (P=0.0017, sensitivity=89%, specificity=58%). Interobserver reliability of ADC measurement was excellent. The 1.63 threshold could be determined as early as the condensation stage. CONCLUSIONS: Diffusion presents several advantages including being non radiating and non invasive. It does not need contrast medium administration and it can be performed without anaesthesia. The origin of the increased ADC remains unknown. Basically, it reflects molecular changes (true diffusion) but it is also influenced by the vascular supply (pseudo-diffusion). ADC ratio could provide an early prognosis before Herring classification is applicable. LEVEL OF EVIDENCE: Level III. Prospective uncontrolled study.

[Unusual fetal teratoma presenting as a posterior mediastinal cyst]. / Présentation atypique d'un tératome fœtal du médiastin postérieur.

Mediastinal cysts are uncommon prenatal findings. As isolated and non-compressing entities, they don't compromise the course of gestation. Massive lesions can compress vital structures, resulting in fetal demise. Thus, close follow-up with sonographic monitoring is recommended until birth. Non-hydroptic fetuses can be managed expectantly. Definitive etiology is known after surgical resection only. We present the first case of posterior mediastinal teratoma associated with severe vertebral abnormalities. After CT scan and fetal MRI, medical termination of pregnancy was decided. Histological examination revealed an immature teratoma. With this unique case report, we discuss the optimal prenatal management of mediastinal cysts.

Diffusion MRI of the neck of the femur in Legg-Calve-Perthes disease: a preliminary study.

PURPOSE: To evaluate diffusion MR imaging of the neck of the femur in Legg-Calve-Perthes disease (LCPD). MATERIAL AND METHODS: This is a prospective study in 27 children followed for unilateral LCPD. Forty-six MRIs were carried out with bilateral quantification of the apparent diffusion coefficient (ADC) of the neck of the femur. The intra- and inter-observer variability of the ADC measurements was evaluated. The association between the ADC and age as well as the healthy or pathological status of the neck of the femur and the Catterall classification were looked for. RESULTS: Intra- and inter-observer reproducibility of the ADC measurements was excellent. A statistically significant negative correlation between the ADC of the healthy neck of the femur and age was found. There was a significant increase in the ADC of the pathological neck of the femur compared to the healthy neck. The ratio of the pathological neck ADC and the healthy neck ADC was significantly associated with the Catterall classification. CONCLUSION: The quantification of the ADC of the neck of the femur is reproducible. This could be useful in the treatment of LCPD, where there is an early and significant increase in the ADC on the pathological side. This increase could have a prognostic value, as it is correlated with the Catterall classification.

Ovarian masses in adolescent girls.

Ovarian masses are the most frequent gynecological pathology seen in adolescent girls. Functional or organic tumors of the ovary are usually benign and the incidence rises with age. Most cysts are functional and adnexal torsion is the main complication, but a malignant etiology must nevertheless always be eliminated. The clinical presentation is quite variable. Ultrasonography is the investigation of choice: the sonogram will reveal a strictly fluid, benign functional cyst, suggest an adnexal torsion, and provide evidence of a heterogeneous mass. Emergency surgery is indicated only in the case of suspected ovarian torsion, in order to perform detorsion. In all other cases, serum tumor marker measurements will orient the diagnosis and MRI is an essential complement to imaging of tumors with heterogeneous solid components. Surgery and histopathological examination then determine the stage and the benign or malignant nature of the mass. Ovarian tumors are classified by the World Health Organization based on the cell of origin into epithelial tumors, germ cell tumors and sex cord-stromal tumors. Surgery should always follow oncological standards and be as conservative as possible to preserve future fertility.

Value of diffusion-weighted images in differentiating mid-course responders to chemotherapy for osteosarcoma compared to the histological response: preliminary results.

BACKGROUND: 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. OBJECTIVE: To assess the accuracy of DW-MRI in evaluating response to chemotherapy in the treatment of osteosarcoma, more specifically at mid-course of treatment. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Pulmonary sequestration and enteric cyst, 2 expressions of the same abnormality]. / Séquestration pulmonaire et kyste entérique, 2 expressions d'une même anomalie. Illustration par un cas.

We report the case of an 18-month-old boy operated on for a right lower lobe bronchopulmonary sequestration. At the immediate postoperative check-up, a septic right thoracic effusion appeared, connected to a cystic mediastinal retrocrural formation on CT. After a drainage attempt and medical therapy, the abdominal lesion was resected. Histological examination showed that the cyst cavity was lined with pseudostratified non-ciliated epithelium, without cartilage, consistent with an enteric cyst. Regardless of the embryological theory, a literature review confirmed that in presence of one of these two lesions, one should systematically look for the other.

[The chronically limping child]. / Boiterie chronique de l'enfant.

Chronic limping in children usually indicates the presence of an underlying organic lesion. Clinical evaluation establishes the site and type of limping. It may suggest a neurological or mechanical lesion or locoregional etiology at the level of the hip or pelvis. Plain radiographs and ultrasound are firstline imaging techniques. The diagnosis may be delayed either due to ignorance of age-specific entities or false positive or negative results on plain films and ultrasound. MRI now plays a major role for diagnosis. Multiple potential underlying etiologies including trauma, infections, arthritides or tumors are best evaluated with MRI. The MRI examination should not be limited only to the hip joint.

[Evolution of the pelvis and hip throughout history: from primates to modern man]. / Évolution du bassin et de la hanche « à travers les âges ¼: des primates à l'homme moderne.

The evolution to a bipedal mode of locomotion was accompanied by a verticalization of the spine and a modification in the shape of the pelvis: horizontal curvature and sagittal rotation. Phylogenesis meets ontogenesis: flat bones in fetuses similar to the monkey, australopithecus features at birth and "human-like" features by 7 or 8years of age. These anatomical modifications explain the characteristics of human bipedalism: stable, economical, with hip and knee extension in the standing position with little lateral motion. Some pathologies induce a regression to a more archaic mode of bipedal locomotion.

[Unusual association of chylopericardium and aortic hypoplasia in a neonate]. / Association inhabituelle chez un nouveau-né d'un chylopéricarde et d'une hypoplasie aortique.

We report the case of a neonate with two very rare anomalies: primary chylopericardium and diffuse hypoplasia of the thoraco-abdominal aorta. The presentation on the 16th post-natal day was with dyspnoea and refusal to feed. The initial clinical examination revealed hepatomegaly and weak femoral pulses. 2D ultrasound gave a diagnosis of a large compressive pericardial effusion combined with moderate hypoplasia of the aortic isthmus. Emergency pericardial drainage removed 80ml of chylous liquid. Following prolonged parenteral nutrition, the pericardial effusion stabilised. A mechanism of diffuse vascular disease affecting the aorta and the lymphatic system is suggested.

Long-term effects on tibial growth after intraosseous infusion: a prospective, radiographic analysis.

BACKGROUND: Evaluate, by radiographic analysis, tibial growth after an intraosseous infusion (IOI) in a pediatric population. METHODS: We performed a prospective simple blind study, between January 1, 1994, and July 1, 2001, which included pediatric patients who needed an intraosseous trocar in emergency situations. During the follow-up, roentgenographs were performed. On each radiologic view, different measurements were carried out: anterior and lateral tibial length, anterior and lateral width at 2 diaphyseal levels. We compared the anterior length values to those published in the Anderson et al tables. When only one tibia was punctured, the mean measurements were compared with the control leg measurements using a paired t test. RESULTS: The initial population included 78 patients. Of these 78 subjects, 42 died, 10 families could not be contacted, and one refused to participate. Two children were excluded because they had other conditions that could influence tibial growth. The study included 23 children. The puncture site was the proximal tibia. The mean age was 18.6 months at the time of IOI, the mean time of infusion was 5 hours, and the mean perfused volume was 225 mL. The mean radiologic follow-up time was 29.2 months. When compared with the Anderson et al tables, all the anterior length values were within the 95% confidence interval. For the other measurements, the statistical analysis showed no significant difference between punctured and control legs. CONCLUSION: There is no long-term effect on tibial growth after an IOI when the IO trocar is properly placed.

[Value of MR imaging of the fetal kidney]. / Apport de l'IRM dans l'étude du rein foetal.

Sonography is the imaging modality of choice for initial evaluation of the fetus. However, the role of MR imaging for fetal evaluation is expanding. Based on a review of seven cases, the role of MRI to further characterize renal abnormalities detected at US, especially hyperechoic kidneys, is demonstrated.