Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is interval elevation of the right hemidiaphragm with associated right basilar and perihilar opacities , likely representing atelectasis ; however , pneumonia can not be completely excluded . Lung volumes are low with secondary widening of the cardiomediastinal silhouette . There is no pleural effusion and no pneumothorax .
    OUTPUT:
    
Elevation of the right hemidiaphragm with associated right basilar opacity , likely representing atelectasis , less likely pneumonia .