Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP chest film ___ at 20 :56 is submitted .
    OUTPUT:
    
Lung volumes remain low improved aeration but residual atelectasis at both lung bases . There has been interval development of a low attenuation 2 .8 cm elliptical opacity in the right mid lung which may reflect loculated fluid within the minor fissure or pleural space . Clinical correlation is advised . No evidence of pulmonary edema . No pneumothorax . Overall cardiac and mediastinal contours are stable .