Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is mildly enlarged . Upper mediastinal contours are unremarkable . Sternotomy wires and mediastinal clips are intact . Low lung volumes . Streaky left base opacity is consistent with atelectasis though infection can not be entirely excluded . No substantial pleural effusion or pneumothorax . Chronic right rib fractures .
    OUTPUT:
    
Mild cardiomegaly with streaky left base opacity most consistent with atelectasis , though infection can not be excluded .