Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild to moderate cardiomegaly is again noted . The mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . Streaky left lower lobe opacity may reflect atelectasis but infection can not be excluded in the correct clinical setting . No pleural effusion or pneumothorax is demonstrated . There are no acute osseous abnormalities . Oral contrast material seen within the colon .
    OUTPUT:
    
Streaky left lower lobe opacity , likely atelectasis , but infection is not excluded in the correct clinical setting .