Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior exam , there appears to be increased opacification at the left base . When compared to the subsquent CT , this is likely due to increasing atelectasis , predominantly in the lingula . There is a moderate left pleural effusion which is stable . There is a small right effusion . The left apex and right lung are clear . There is no pulmonary edema . There is no pneumothorax . The mediastinal contours are normal . The heart size is difficult to evaluate given the surrounding opacification .
    OUTPUT:
    
Increasing opacification of the left base , likely due to a combination of a stable pleural effusion and increasing atelectasis . These abnormalities are better characterized on the subsequent CT .