Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph obtained . Heart is mildly enlarged . There are scattered linear densities in the mid and right lower lung , likely representing atelectasis . An azygos fissure is noted . There is no definite sign of pneumonia or overt CHF . Mediastinal contour is normal . The imaged osseous structures are intact .
    OUTPUT:
    
Mild cardiomegaly with scattered linear subsegmental atelectasis . No overt edema or signs of pneumonia .