Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A portable frontal chest radiograph demonstrates a normal cardiomediastinal silhouette . There is retrocardiac opacity with obscuration of the left hemidaphragm , which could reflect a combination of left lower lobe volume loss and sequela of aspiration , including aspiration pneumonia . There may be a trace left pleural effusion . No pneumothorax is appreciated .
    OUTPUT:
    
1 . New retrocardiac opacity , which could represent a combination of left lower lobe volume loss and sequela of aspiration , including aspiration pneumonia . 2 . Probable trace left pleural effusion .