Prenatal echocardiographic assessment of right aortic arch.

OBJECTIVES: To report our experience with fetal diagnosis of right aortic arch (RAA) variants based on the ductus arteriosus (DA) anatomy and brachiocephalic vessel branching pattern in relation to the trachea, and to establish whether the echocardiographic 'V-shaped' or 'U-shaped' appearance of the junction between the DA and aortic arch (AA) in the fetal upper mediastinal view is sufficiently accurate for assessment of fetal AA anatomy. METHODS: This was a retrospective study of pregnancies with a prenatal diagnosis of fetal RAA that had postnatal confirmation of AA anatomy, referred to our tertiary center during 2011-2017. Prenatal and postnatal medical records, including echocardiographic and computed tomography (CT)/magnetic resonance imaging (MRI) scan reports, were reviewed, and cardiac and extracardiac abnormalities and the results of genetic testing were recorded. RESULTS: Of 55 consecutive pregnancies with a prenatal diagnosis of fetal RAA, six were lost to follow-up, one was terminated and three were excluded due to lack of postnatal confirmation of AA anatomy. Of the remaining 45 pregnancies, AA anatomy was assessed postnatally by CT in 39, by MRI in one and by direct examination at cardiac surgery in five. A U-shaped appearance was found in 37/45 (82.2%) patients, all of which had a complete vascular ring (CVR). Of these 37 patients, on postnatal confirmation, 21 (56.8%) had RAA with Kommerell's diverticulum, left posterior ductus arteriosus (LPDA) and aberrant left subclavian artery (ALSA) (RAA/LPDA/ALSA), 11 (29.7%) had a double AA (DAA), four (10.8%) had RAA with Kommerell's diverticulum, LPDA and mirror-image (MI) branching (RAA/LPDA/MI), and one (2.7%) had RAA with Kommerell's diverticulum, LPDA and aberrant left innominate artery (ALIA) (RAA/LPDA/ALIA). A V-shaped appearance was found in 3/45 (6.7%) patients, all of which had RAA with right DA not forming a CVR and MI branching. In the 5/45 (11.1%) fetuses with neither U- nor V-shaped appearance, RAA with left anterior DA arising from the left innominate artery and MI branching, not forming a CVR, was found. Twelve (26.7%) fetuses had a congenital heart defect (CHD). RAA forming a CVR (U-shaped appearance) was associated with a septal defect in 6/37 (16.2%) fetuses, while RAA not forming a CVR (V-shaped appearance or no U- or V-shaped appearance) was associated with major CHD in 6/8 (75.0%) fetuses. CONCLUSIONS: In fetuses with RAA, V-shaped appearance of the junction between the DA and AA indicates only that the transverse AA and DA run together on the same side of the thorax (trachea) while a U-shaped appearance is always a sign of a CVR. Among fetuses with a CVR, RAA/LPDA/MI is more frequent than described previously. Finally, RAA forming a CVR is not usually associated with complex CHD, as opposed to RAA not forming a CVR. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

[Lung is also involved in juvenile dermatomyositis]. / Le poumon est une cible de la dermatomyosite de l'enfant.

Juvenile dermatomyositis is the leading cause of chronic idiopathic inflammatory myopathy of auto-immune origin in children. Lung involvement in inflammatory myopathies is well described in adults, involving mostly interstitial lung disease, aspiration pneumonia and alveolar hypoventilation. We propose to describe its specificities in children. Pulmonary involvement may be asymptomatic and therefore must be systematically screened for. In case of clinical or functional respiratory abnormality, a chest computed tomographic (CT) scan is necessary. In children, a decrease of respiratory muscle strength seems common and should be systematically and specifically searched for by non-invasive and reproducible tests (sniff test). Interstitial lung disease usually associates restrictive functional defect, impairment of carbon monoxide diffusion and interstitial lung disease on CT scan. As in adults, the first-line treatment of juvenile dermatomyositis is based on corticosteroids. Corticosteroid resistant forms require corticosteroid bolus or adjuvant immunosuppressive drugs (methotrexate or cyclosporine). There is no consensus in pediatrics for the treatment of diffuse interstitial lung disease. Complications of treatment, including prolonged steroid therapy, are frequent and therefore a careful assessment of the treatments risk-benefit ratio is necessary, especially in growing children.

[Chest computed tomography in children: indications, efficiency and effective dose]. / Tomodensitométrie thoracique chez l'enfant : un examen utile mais irradiant.

INTRODUCTION: New multidetector row computed tomography (CT) has made the imaging of younger children more feasible and extending CT indications to a wide range of pediatric respiratory diseases in the last few years. However, CT is a source of radiation exposure. The aim of this study was to evaluate the main indications and the contribution of chest CT in pediatric pulmonology as well as induced radiation. METHODS: This was an observational, prospective study. Children whose chest CTs were analyzed during multidisciplinary meetings (radiologist, pulmonary pediatrician) were included from November 2009 to April 2010. We collected demographic data, CT results, contribution of CT to diagnosis and management, and radiation doses (dose-length product [DLP] and effective dose). Radiation doses were compared according to the CT scans (Lille University Hospital with 128-slice dual-source CT or Lille University Hospital single-source 64-slice CT, or CT performed outside the university hospital). RESULTS: One hundred thirty-five patients were included. The mean age was 6.4 years old. The main indications were analysis of bronchial disease (44%), infectious disease (16%), interstitial disease (14%), or a malformation (9%). The aim of CT was diagnosis (61%) or follow-up of previous lung diseases (39%). Diagnosis chest-CT directly contributed to diagnosis in 48% of cases and to treatment in 24%. Follow-up CT contributed to diagnosis in 38% and treatment in 19% of cases. DLP and effective doses were significantly lower for CT performed in the university hospital, especially with the 128-slice CT compared to the others (P<0.001). The effective doses were: 128-slice CT, 0.61 mSv ± 0.32; 64-slice CT, 1.24 mSv ± 0.97; outside university hospital, 2.56 mSv ± 1.98. CONCLUSION: This study confirms the role played by chest CT in children, which contributes to diagnosis and management of lung diseases. The main concern of CT application, especially in children, is the radiation burden. Children are more susceptible to the effects of radiation than adults and have a longer life expectancy to develop complications. Both radiologists and pediatricians should be aware of a potential risk and have to conjugate their efforts in reducing this risk. The wide range of radiation doses in this study for the same CT procedures underlines the extensive efforts still needed to limit radiation exposure in children.

Single- and dual-source chest CT protocols: Levels of radiation dose in routine clinical practice.

PURPOSE: To establish the radiation dose level for single- and dual-source thoracic CT scans in daily practice. MATERIALS AND METHODS: The dose levels delivered during 634 consecutive examinations over a period of 2 months were recorded. The CT scans were performed using: (a) a standard protocol (single source, single energy [group 1]: n=266; dual source, single energy [group 2]: n=276; (b) with prospective ECG synchronisation [group 3]: n=13; or (c) with dual energy [group 4]: n=79. All the acquisitions included kilovoltage selection depending on the weight and automatic milliamperage modulation. RESULTS: The mean DLP of the standard protocols was 97.12 mGycm (group 2; BMI=23.1kg/m(2)) and 211.1 mGycm (group 1; BMI=27.3kg/m(2)), the choice of protocol depending on the diameter of the thorax relative to the diameter of the field of the second source, and therefore on the patient's morphotype. When imaging included examination of the proximal and middle coronary arteries (group 3), the mean DLP was 105.5 mGycm. Morphological and functional imaging (group 4) was obtained with a mean DLP of 404.3 mGycm. CONCLUSION: Depending on the objective of the protocol, the mean DLP varied from 97.12 to 404.3 mGycm.

[Pulmonary embolism diagnosed during an endobronchial ultrasound procedure]. / Embolie pulmonaire diagnostiquée au cours d'une échoendoscopie bronchique.

INTRODUCTION: Pulmonary embolism occurs frequently in lung cancer. The clinical features are non-specific and the diagnosis is often missed. CASE REPORT: A 60-year old man presented with a right upper lobe mass associated with right hilar adenopathy. Both had activity on positron emission tomography. As bronchoscopy was normal, an endobronchial, ultrasound guided, transbronchial needle aspiration (EBUS-TBNA) was performed to obtain a diagnosis. During the procedure, a hypoechogenic image was seen in the right pulmonary artery. A CT pulmonary angiogram confirmed the diagnosis of right pulmonary embolism. The transbronchial needle aspiration confirmed the neoplastic nature of the adenopathy. To our knowledge, this is the first description of a pulmonary embolism diagnosed by EBUS. This observation confirms the results of a recently published study showing that known pulmonary embolism can be detected by EBUS. CONCLUSION: Although EBUS is not the classic tool for the diagnosis of pulmonary embolism, it seems advisable to undertake a careful examination of the proximal pulmonary artery during an EBUS procedure.

Study of complement-mediated anaphylaxis in humans. The role of IgG subclasses (IgG1 and/or IgG4) in the complement-activating capacity of immune complexes.

The role of Ig classes and subclasses in complement activation has been investigated both in vitro and in experimental animals, but not in humans. This study was conducted to determine the immunologic events of post-transfusion anaphylaxis in humans, and the effects of immune complexes of different IgG subclass compositions on complement activation. The ability of immune complexes containing mixed IgG1 and IgG4 or IgG4 Ab only to activate complement was investigated in two patients with von Willebrand's disease (a congenital bleeding disorder). This disease was complicated by precipitating IgG alloantibodies to von Willebrand factor (vWF), which triggered complement-mediated anaphylaxis after infusion of vWF-containing preparations. Complement activation was greater in the presence of mixed IgG1- and IgG4-vWF complexes than with IgG4-vWF alone. In one patient, the generation of large amounts of C4a, C3a, and terminal complement complexes following the formation of mixed IgG1- and IgG4-vWF was associated with life-threatening anaphylaxis. In this patient, IgG4 appeared to have no inhibitory effect on antigen-bound IgG1-mediated complement activation. In the other patient, formation of IgG4-vWF led to a lesser degree of complement activation and was associated with moderately severe anaphylaxis. Since neither patient showed any biochemical alterations indicating the involvement of mast cells or the contact phase of coagulation at any time, it is probable that the pathogenetic mechanism of the clinical syndrome was a direct effect of complement anaphylatoxins on vascular permeability and smooth muscle contraction. In both patients, IgG-vWF bound C4 and C3 (IgG4-vWF to a lesser extent than mixed IgG1- and IgG4-vWF), and this probably prevented serum sickness as a complication.