Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a somewhat spiculated opacity identified at the left lung base laterally abutting the costophrenic angle on the frontal view . It is not clearly delineated on the lateral exam . Elsewhere , the lungs are clear . There is no effusion or pneumothorax . The cardiomediastinal silhouette is unremarkable . Median sternotomy wires are noted . Vascular stent projects over the region of the great vessels .
    OUTPUT:
    
Somewhat spiculated opacity identified at the left lung base laterally . While this may be due to atelectasis , repeat with attempted improved aeration for clearance could be attempted . If it persists , CT scan would be advised .