Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single AP chest radiograph was obtained . Left lower opacity silhouettes the left hemidiaphragm , corresponding to atelectasis and effusion on the recent chest radiograph . The hila are mildly indistinct , unchanged from prior exams . There is no new consolidation or pneumothorax . Moderate cardiomegaly is unchanged .
    OUTPUT:
    
Left basilar opacity , likely effusion and atelectasis .