Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Linear bilateral lower lobe opacities are most consistent with atelectasis . Otherwise , the lungs are clear without focal opacity , pulmonary edema , pleural effusion or pneumothorax . Mild cardiomegaly is stable . The thoracic aorta is ectatic and contains dense calcifications . No acute osseous abnormality .
    OUTPUT:
    
No acute cardiothoracic process .