Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable upright view of the chest demonstrates tracheostomy tube unchanged in position . Patient 's body habitus limits evaluation . Within this limitation , right lower lobe opacity is new since prior exam . Hilar and mediastinal silhouettes are unchanged . Heart is moderately enlarged . Left costophrenic angle is slightly obscured , suggestive of possible pleural effusion . No appreciable pneumothorax . No right pleural effusion .
    OUTPUT:
    
Slightly limited evaluation due to patient 's body habitus . Right lower lobe opacity is new since prior exam , and may represent atelectasis or aspiration in appropriate clinical setting .