Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral radiographs of the chest were acquired . Heterogeneous opacities at the left lung base could be atelectasis , although an infectious process in the left lower lobe can not be excluded . The lungs are otherwise clear . There is a small - to - moderate left pleural effusion , new compared to CT from ___ . The heart size is normal . The mediastinal contours are normal . There is no pneumothorax . Surgical clips are seen overlying the abdomen .
    OUTPUT:
    
1 . Left base opacity , may be due to pleural effusion and atelectasis , but underlying consolidation is note excluded .