Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Previously seen ET tube has been removed and replaced with a mask which overlies portions of the left neck , at the site of previously seen subcutaneous emphysema . Technical factors limit re-evaluation of areas where subcutaneous emphysema and possible paratracheal emphysema was seen on the prior study . Relative lucency along the right mediastinal contour could reset represent either ___ ___ artifact or small amount of pneumomediastinum . The cardiomediastinal silhouette is grossly unchanged , with probable mild cardiomegaly . Of note , there are faint alveolar opacities at both lung bases , that appear to have progressed compared with 1 day earlier . There is minimal , if any , upper zone redistribution , making CHF unlikely . No gross effusion .
    OUTPUT:
    
Alveolar opacities at both bases , new or considerably progressed compared with 1 day earlier . No upper zone redistribution to suggest CHF . Clinical correlation is requested . These could reflect bibasilar pneumonic infectious infiltrates or areas of aspiration pneumonitis . Other etiologies for alveolar opacities remain in the differential . Mild cardiomegaly , similar to prior . No gross pneumomediastinum , though linear lucency along the right mediastinum could reflect either trace mediastinal air or more likely ___ artifact . Areas where gas was previously seen about the neck pain and question upper trachea are not well visualized on the current study , in part due to overlying O2 mask .