Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left hemidiaphragm now appears well defined on the lateral view , suggesting resolution of the focal ___-___ opacity on the prior study . Mild cardiac enlargement is unchanged , and ICD remains in place with leads in right atrium and right ventricle . There are no pleural effusions . Moderate gastric distention is observed in the imaged portion of the upper abdomen .
    OUTPUT:
    
Rapid improvement of left lower lobe opacity favors either aspiration or atelectasis as the likely etiology .