Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph demonstrate clear lungs bilaterally . Cardiac silhouette is mildly enlarged . Upper lobe pulmonary vasculature is equivalent in caliber to lower lobe vessels . There is no pulmonary edema . There is no pleural effusion or pneumothorax . No air under the right hemidiaphragm is identified .
    OUTPUT:
    
Mild cardiomegaly and / or pericardial effusion . No focal opacity convincing for pneumonia .