Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperexpanded consistent with chronic pulmonary disease . Compared to the prior chest radiograph of ___ , there is a new left lower lobe opacity . Mild cardiomegaly and aortic calcifications persist . The right lung is clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
New left lower lobe opacity could represent atelectasis , however , in the correct clinical setting this could represent pneumonia .