Setting up regional diagnostic reference levels for pediatric computed tomography in Latin America: preliminary results, challenges and the work ahead.

We established a framework for collecting radiation doses for head, chest and abdomen-pelvis computed tomography (CT) in children scanned at multiple imaging sites across Latin America with an aim towards establishing diagnostic reference levels (DRLs) and achievable doses (ADs) in pediatric CT in Latin America. Our study included 12 Latin American sites (in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Honduras and Panama) contributing data on the four most common pediatric CT examinations (non-contrast head, non-contrast chest, post-contrast chest and post-contrast abdomen-pelvis). Sites contributed data on patients' age, sex and weight, scan factors (tube current and potential), volume CT dose index (CTDIvol) and dose length product (DLP). Data were verified, leading to the exclusion of two sites with missing or incorrect data entries. We estimated overall and site-specific 50th (AD) and 75th (diagnostic reference level [DRL]) percentile CTDIvol and DLP for each CT protocol. Non-normal data were compared using the Kruskal-Wallis test. Sites contributed data from 3,934 children (1,834 females) for different CT exams (head CT 1,568/3,934, 40%; non-contrast chest CT 945/3,934, 24%; post-contrast chest CT 581/3,934, 15%; abdomen-pelvis CT 840/3,934, 21%). There were significant statistical differences in 50th and 75th percentile CTDIvol and DLP values across the participating sites (P<0.001). The 50th and 75th percentile doses for most CT protocols were substantially higher than the corresponding doses reported from the United States of America. Our study demonstrates substantial disparities and variations in pediatric CT examinations performed in multiple sites in Latin America. We will use the collected data to improve scan protocols and perform a follow-up CT study to establish DRLs and ADs based on clinical indications.

Reproducibility of a protocol for standardized reading of chest X-rays of children household contact of patients with tuberculosis.

BACKGROUND: The interpretation of the chest radiograph may vary because it depends on the reader and due to the non-specificity of findings in tuberculosis (TB). We aim to assess the reproducibility of a standardized chest radiograph reading protocol in contacts of patients with pulmonary TB under the 5 years of age. METHODS: Descriptive, cross-sectional study with children under the age of five, household contacts of patients with confirmed pulmonary TB from Medellín, Bello and Itagüí (Colombia) between Jan-01-2015 and May-31-2016. Standardized reading protocol: two radiologists, blinded independent reading, use of template (Dr. Andronikou design) in case of disagreement a third reading was performed. Kappa coefficient for intra and inter observer agreement, and prevalence ratio were estimated of sociodemographic characteristics, TB exposure and interpretation of chest X-ray. RESULTS: From 278 children, standardized reading found 255 (91.7%) normal X-rays, 10 (3.6%) consistent with TB, and 13 (4.7%) other alterations. Global agreement was 91.3% (Kappa = 0.51). Inter-observer agreement between readers 1-2 was 90.0% (Kappa = 0.59) and 1-3 93.2% (Kappa = 0.59). Intra-observer agreement for reader 1 was 95.5% (Kappa = 0.86), 2 84.0% (Kappa = 0.51), and 3 94.7% (Kappa = 0.68). Greater inter-observer disagreement was between readers 1-2 for soft tissue density suggestive of adenopathy (4.6%), airspace opacification (1.17%) and pleural effusion (0.58%); between readers 1-3 for soft tissue density suggestive of adenopathy (4.2%), opacification of airspace (2.5%) and cavities (0.8%). CONCLUSIONS: Chest radiographs are an affordable tool that contributes to the diagnosis of TB, so having a standardized reading protocol showed good agreement and improves the reproducibility of radiograph interpretation.

Pulmonary imaging in coronavirus disease 2019 (COVID-19): a series of 140 Latin American children.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which resulted in the worldwide coronavirus disease 2019 (COVID-19) pandemic of 2020, has particularly affected Latin America. OBJECTIVE: The purpose of the study was to analyze the imaging findings of pulmonary COVID-19 in a large pediatric series. MATERIALS AND METHODS: Children with SARS-CoV-2 infection confirmed by either quantitative reverse transcription-polymerase chain reaction from nasopharyngeal swabs or presence of circulating immunoglobulin M (IgM) antibodies and who underwent chest radiograph or CT or both were included in this retrospective multicenter study. Three pediatric radiologists independently reviewed radiographs and CTs to identify the presence, localization, distribution and extension of pulmonary lesions. RESULTS: We included 140 children (71 female; median age 6.3 years, interquartile range 1.6-12.1 years) in the study. Peribronchial thickening (93%), ground-glass opacities (79%) and vascular engorgement (63%) were the most frequent findings on 131 radiographs. Ground-glass opacities (91%), vascular engorgement (84%) and peribronchial thickening (72%) were the most frequent findings on 32 CTs. Peribronchial thickening (100%), ground-glass opacities (83%) and pulmonary vascular engorgement (79%) were common radiograph findings in asymptomatic children (n=25). Ground-glass opacity and consolidation were significantly higher in children who needed intensive care admission or died (92% and 48%), in contrast with children with a favorable outcome (71% and 24%, respectively; P<0.05). CONCLUSION: Asymptomatic children and those with mild symptoms of COVID-19 showed mainly peribronchial thickening, ground-glass opacities and pulmonary vascular engorgement on radiographs. Ground-glass opacity and consolidation were more common in children who required intensive care admission or died.

[Relationship between pattern of food consumption and body composition in university students: a cross-sectional study]. / Relación entre el patrón de consumo de alimentos y la composición corporal de estudiantes universitarios: estudio transversal.

INTRODUCTION: Introduction: young university students face a social dynamics that has generated complex lifestyles and, especially, an imbalance in the intake of macro and micronutrients, characterized by having a high caloric density intake, which results in significant excess of weight. It is unknown if these consumption patterns are related to body composition. This research aimed to determine the relationship between pattern of food consumption and body composition in university students. Method: an observational, descriptive, cross-sectional study with a sample of 189 students. Sociodemographic variables obtained by a survey, body composition variables obtained by bioimpedance, and food groups and their categories obtained via a 24-hour reminder method were included. A multinomial logistic regression model was performed to explain body composition according to consumption of food groups. Results: statistically significant associations were obtained between food consumption and body composition for visceral fat and consumption of eggs, meats, sausages and grains (p = 0.024), and consumption of sugars with bone mass (p = 0.029) and muscle mass (p = 0.013). The multiple regression model showed that sugar consumption increases the risk of having visceral fat (OR = 2.71), and increases the probability of being classified as an obese person (OR = 2.55). Consumption of eggs, meats, sausages, and grains favors an acceptable percentage of visceral fat (OR = 0.14). The consumption of fruits and vegetables increases the risk of having a high percentage of water (OR = 5.41), and low fat percentage (OR = 3.60). Conclusions: the consumption of sugars seems to have a close relationship with variables of body composition such as visceral fat, bone mass, and muscle mass. The consumption of fruits and vegetables was related to a low percentage of fat; however, their consumption is proportionally related to high levels of body water. Studies to establish associations between body composition and food consumption should be carried out taking into account specific intakes in order to establish a more accurate association.

INTRODUCCIÓN: Introducción: los jóvenes universitarios enfrentan diversas situaciones sociales que generan cambios en los estilos de vida. Estos están asociados a desequilibrios en la ingesta dietética, caracterizada por una gran densidad calórica, lo que produce sobrepeso. Al mismo tiempo, se conoce la relación entre los patrones de consumo y la composición corporal, pero existe un vacío en la población universitaria colombiana. Así pues, el objetivo de esta investigación fue determinar la relación del patrón de consumo de alimentos con la composición corporal en universitarios. Método: estudio observacional, descriptivo, de corte transversal con una muestra de 189 estudiantes. Se incluyeron variables sociodemográficas obtenidas por encuesta, variables de composición corporal derivadas de la bioimpedancia, y los grupos de alimentos y sus categorías por el método del recordatorio de 24 horas. Se realizó un modelo de regresión logística multinomial para explicar la composición corporal de acuerdo con el consumo de los grupos de alimentos. Resultados: se obtuvieron asociaciones estadísticamente significativas entre el consumo de alimentos y la composición corporal para la grasa visceral y el consumo de huevos, carnes, embutidos y granos (p = 0,024), y para el consumo de azúcares con respecto a la masa ósea (p = 0,029) y la masa muscular (p = 0,013). El modelo de regresión múltiple mostró que el consumo de azúcar incrementa la probabilidad de tener grasa visceral (OR = 2,71) y la probabilidad de clasificar a una persona como obesa (OR = 2,55). El consumo de huevos, carnes, embutidos y granos favorece la clasificación de la grasa visceral como aceptable (OR = 0,14). El consumo de frutas y verduras incrementa la probabilidad de presentar un alto porcentaje de agua (OR = 5,41) y la clasificación del porcentaje de grasa como bajo (OR = 3,60). Conclusiones: el consumo de frutas y verduras se corresponde con un porcentaje bajo de grasa; no obstante, su ingesta se vincula proporcionalmente con altos niveles de agua corporal. Se deben realizar estudios que establezcan asociaciones entre la composición corporal y el consumo de alimentos, teniendo en cuenta la ingesta específica que pueda establecer una correlación con mayor precisión.

Lymphangiomatosis in a 14-year-old female presenting with chylothorax and multiple cystic lesions.

Lymphangiomatosis is a rare congenital disease; diagnosis is made in the first 2 decades and affects almost all body parts. Imaging findings play an important role in the diagnosis. We present a case of a patient with lymphangiomatosis whose diagnosis was made solely with imaging findings; we also include a small review of the topic.

Primary osseous Burkitt lymphoma with nodal and intracardiac metastases in a child.

Burkitt lymphoma (BL) is the most frequent non-Hodgkin lymphoma in pediatric patients, accounting for approximately 34% of the cases of lymphoma in children. This subtype of non-Hodgkin lymphoma was first described in 1958 as a monoclonal proliferation of B cell lymphocytes. Cardiac involvement of BL in association with osseous compromise and lymphadenopathy is rare and poorly documented. We report a case of femur primary BL in an 8-year-old boy with metastatic cardiac involvement, retroperitoneal and iliofemoral lymphadenopathy, and hepatosplenomegaly. We highlight the diagnostic challenge in a patient with clinical nonspecific findings and systemic disease.

Tracheobronchomegaly following intrauterine tracheal occlusion for congenital diaphragmatic hernia.

BACKGROUND: Fetuses with severe congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia may benefit from fetal endoluminal tracheal occlusion (FETO). Enlargement of the main bronchi and trachea appears to be a common complication of FETO. OBJECTIVE: To retrospectively evaluate the trachea and main bronchi of infants who underwent FETO for CDH and compare diameters with age-matched references. MATERIAL AND METHODS: Postnatal and follow-up chest radiographs were performed in seven children with unilateral CDH treated by FETO. Additional CT was performed in six of these (one neonate died before CT could be performed). Images were acquired from 3 days to 23 months of age. For each child, radiographs and CT images with optimal visualisation of the airways were selected for retrospective analysis. Tracheal and bronchial morphology was assessed by two experienced paediatric radiologists, and the diameters of these structures measured and compared with age-matched references. RESULTS: Mean diameters of the trachea and main bronchi were above the age-matched normal range in all patients, regardless of the side of the hernia or the degree of lung hypoplasia. CONCLUSION: Enlargement of the trachea and main bronchi appears following FETO and persists at least to the age of 5 years.

Cardiovascular magnetic resonance findings in a pediatric population with isolated left ventricular non-compaction.

BACKGROUND: Isolated left ventricular non-compaction (LVNC) is an uncommon disorder characterized by the presence of increased trabeculations and deep intertrabecular recesses. In adults, it has been found that ejection fraction (EF) decreases significantly as non-compaction severity increases. In children however, there are a few data describing the relation between anatomical characteristics of LVNC and ventricular function. We aimed to find correlations between morphological features and ventricular performance in children and young adolescents with LVNC using cardiovascular magnetic resonance (CMR). METHODS: 15 children with LVNC (10 males, mean age 9.7 y.o., range 0.6-17 y.o.), underwent a CMR scan. Different morphological measures such as the compacted myocardial mass (CMM), non-compaction (NC) to the compaction (C) distance ratio, compacted myocardial area (CMA) and non-compacted myocardial area (NCMA), distribution of NC, and the assessment of ventricular wall motion abnormalities were performed to investigate correlations with ventricular performance. EF was considered normal over 53%. RESULTS: The distribution of non-compaction in children was similar to published adult data with a predilection for apical, mid-inferior and mid-lateral segments. Five patients had systolic dysfunction with decreased EF. The number of affected segments was the strongest predictor of systolic dysfunction, all five patients had greater than 9 affected segments. Basal segments were less commonly affected but they were affected only in these five severe cases. CONCLUSION: The segmental pattern of involvement of non-compaction in children is similar to that seen in adults. Systolic dysfunction in children is closely related to the number of affected segments.

Correlation between US and MRI for prenatal lung volumetry in diaphragmatic hernia, and use of Doppler to identify the ipsilateral lung cap.

BACKGROUND: Pulmonary hypoplasia is a common cause of neonatal death. OBJECTIVE: To describe the correlation between relative fetal lung volume (RFLV) and lung-to-head ratio (LHR) in fetuses with unilateral diaphragmatic hernia. Additionally, to describe identification of the ipsilateral lung cap by power Doppler. MATERIALS AND METHODS: Single-institution study of consecutive fetuses with diaphragmatic hernia. LHR (by US) and RFLV (by MRI) were correlated in fetuses with and without an ipsilateral lung cap seen at MRI. In four, color/power Doppler was used to follow the pulmonary artery of the ipsilateral lung to identify the compressed cap. RESULTS: The study included 48 fetuses of 20-38 weeks' gestational age (mean, 26 weeks). Mean LHR was 1.52 (range, 0.6-3) in fetuses with a lung cap and 1.15 (range, 0.6-2.58) in fetuses without (P = 0.043). Mean RFLV was 47.4% (range, 18-80%) in fetuses with and 32.9% (range, 14-57%) in fetuses without a lung cap (P = 0.005). RFLV and LHR correlated (r = 0.41, P = 0.01 in those with a cap; r = 0.50, P = 0.05 in those without). Power Doppler identified the ipsilateral lung cap and pulsed Doppler confirmed pulmonary vascularization in four of four fetuses. CONCLUSION: LHR underestimates lung volume in fetuses with an ipsilateral lung cap. Power Doppler may be useful for identifying the cap.

Estandarización del aislamiento y caracterizaciónde células estromales de decidua y útero murinos / Estandardização do isolamento e caracterização de células estromales de decídua eútero murinos / Standardization of isolation and characterization of decidual stromal cells and murine uterus

Las células estromales son las células más abundantes presentes en la decidua y juegan un papelmuy importante durante la implantación, la nutrición fetal y el mantenimiento del embarazo. Losprocedimientos que se han descrito para el aislamiento de células estromales requieren el uso de muchosanticuerpos monoclonales ya que hay contaminación con otros tipos celulares en la decidua y ademásalgunos marcadores características de células estromales, muestran variabilidad en los diferentes díasde la gestación. En este estudio se estandarizó un procedimiento de aislamiento por digestión enzimática,gradiente de densidad y adherencia al plástico y se caracterizaron las células estromales murinas porexclusión de marcadores que se expresan en macrófagos (F4-80), células epiteliales y trofoblasto(citoqueratina-7), obteniéndose un 98% de células negativas para estos marcadores que correspondería alas células estromales. Esta técnica de aislamiento permite obtener células estromales con métodos menoscostosos y altamente eficientes que facilita el acceso a un modelo celular de gran utilidad en el estudio dela fisiología de la gestación en diferentes especies.

Stromal cells are the most abundant cell population present in decidual tissue; they are involved inkey processes during embryo implantation, fetal nutrition and the pregnancy maintenance. Described procedures for stromal cells isolation require the use of many monoclonal antibodies due to contaminationwith another cell types in the decidua; besides, some markers of stromal cells show variability during thedays of gestation. In this study, we standardized a procedure for isolation by enzymatic digestion, densitygradient and adherence to plastic. Murine stromal cells were characterized by exclusion of markers thatare expressed in macrophages (F4-80), epithelial cells and trophoblast (cytokeratin-7), yielding a 98% ofnegative cells for these markers that correspond to stromal cells. This isolation procedure permits to obtainstromal cells with less expensive and high efficiency methods that provide a useful cellular model to studythe physiology of gestation in different species.

As células estromales são as células mais abundantes presentes na decídua e tem um papel muitoimportante durante a implementação, a nutrição fetal e a manutenção da gravidez. Os procedimentosdescritos para o isolamento das células estromales necessitam o uso de muitos anticorpos monoclonais jáque há contaminação com outros tipos celulares na decídua e demais alguns marcadores característicosdas células estromales que tem variabilidade nos diferentes dias de gestação. No presente trabalho foiestandardizado um procedimento de isolamento por digestão enzimática, gradiente de densidade eaderência ao plástico e foram caracterizados as células estromales murinas por exclusão de marcadoresque expressão em macrófagos (F4-80), células epiteliais e trofoblasto (citoqueratina-7), obtendo-se um98% de células negativas para estes marcadores que corresponderia às células estromales. Esta técnicade isolamento permite obter células estromales com métodos menos custosos e altamente eficientes quefacilita o aceso a um modelo celular de grande utilidade no estudo da fisiologia da gestação em diferentesespécies.