Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal upright view of the chest was obtained . The heart is mildly enlarged , similar to prior . Aeration is improved compared with the prior exam . Small linear opacity is present at the left lung base and the left costophrenic angle is indistinct . No focal consolidation or pneumothorax . Right humeral head screw is similar to prior .
    OUTPUT:
    
Stable mild cardiomegaly , small left base atelectasis , and possible small left pleural effusion . No focal consolidation .