<s>[INST] context: Air bronchogram in chest X- Ray Age of onset of infant Respiratory distress syndrome Infant respiratory distress syndrome presents immediately or soon after bih. Incidence and severity of RDS is inversely related to gestational age Approximately 50% of the neonates born at 26 - 28 weeks gestation develops respiratory distress syndrome where as less than 30% of premature neonates born at 30-31 weeks gestation develop respiratory distress syndrome. Administration of antenatal coicosteroid reduces the incidence of respiratory distress syndrome Administration of single dose of corctisteroid reduces the incidence and severity of respiratory distress syndrome if delivery occurs within one week of administration of coicosteroid. Administration of coicosteroid cause 50% reduction in the incidence of respiratory distress syndrome. Air bronchogram is a characteristic X- Ray feature of Hyaline membrane disease X-Ray features of Hyaline membrane disease -Pronounced hypoaeration - B/L diffuse reticulogranular opacities in the pulmonary parenchyma. - "Prominent air bronchograms" (aerated bronchioles super- imposed on a background of collapsed alveole) Air bronchogram Air bronchogram refers to the visualization of air filled bronchus when the surrounding alveoli are opacified, Normally, the lung ,fields are radioluscent and the bronchi are not separately visualized. But in ceain conditions there is opaification of the alveoli due to various reasons. Due to this reason, the bronchus stands out as "radioluscent" in contrast to the adjacent alveoli, that are" radioopaque" These changes can be due to pneumonic consolidation, collapse of a pa of the lung, or inflammatory edema in the lung tissue. Conditions associated with Air bronchogram - ARDS - Hyaline membrane disease - Alveolar cell carcinoma - Pulmonary consolidation - Pulmonary edema Alveolar proteinosis Sarcoidosis Lymphoma [/INST] question: Which of the following will our the diagnosis of RDS in new born aEUR' | options: A: Receipt of antenatal steroids B: Air bronchogram in chest X-ray C: Manifests after 6 hrs D: Occurs after term gestation | answer: B </s>