Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Semi-upright portable chest radiograph was obtained . Low lung volumes crowd the pulmonary vasculatory . The right hilus is enlarged . A vague retrocardiac opacity is identified . Cardiomegaly is mild .
    OUTPUT:
    
1 . Retrocardiac opacity compatible with pneumonia or atelectasis 2 . Prominence of the right hilus may be secondary to low lung volumes or hilar opacity . Suggest follow up radiographs , ideally with better inspiration .