Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is minimal patchy opacity in the retrocardiac region medially , probably slightly worse compared with ___ . There is minimal atelectasis at the right base , also more pronounced . There is upper zone redistribution , without overt CHF . No gross effusion . Small left upper lobe nodule and left upper lobe opacities as well as small pericardial effusion and bronchial wall thickening seen on the CT scan performed 1 day earlier are not well depicted radiographically .
    OUTPUT:
    
Minimal patchy opacity in the retrocardiac region medially and minimal atelectasis at the right lung base , both slightly worse compared with ___ . While this could represent atelectasis , an early pneumonic infiltrative or changes related to aspiration could also account for the retrocardiac opacity . Upper zone redistribution , similar to the prior film . No overt CHF .